1,8-Diazabicycloundeene (DBU): an ideal multi-purpose polyurethane catalyst

Preface

In the vast ocean of the chemical industry, there is a compound that stands out for its excellent catalytic properties and wide applicability. It is 1,8-diazabicyclo[5.4.0]undec-7-ene), referred to as DBU. DBU is not only an efficient alkaline catalyst, but also a popular celebrity material in the polyurethane (PU) industry. As an “all-round player in the chemistry world”, DBU has shown extraordinary value in many fields with its unique molecular structure and strong catalytic capabilities.

Basic Introduction to DBU

The chemical formula of DBU is C7H12N2 and the molecular weight is 124.19 g/mol. Its molecular structure consists of two nitrogen atoms and a special bicyclic skeleton, giving it extremely strong alkalinity and excellent thermal stability. This compound was first synthesized by German chemist Hermann Staudinger in the 1930s and has since begun its brilliant chapter in the industrial field. DBU is usually present in the form of a colorless or light yellow liquid with a strong amine odor, with a melting point of -2°C and a boiling point of up to 236°C, allowing it to remain active over a wide temperature range.

The reason why DBU has become an ideal catalyst in the polyurethane industry is mainly due to its following characteristics: First, it can effectively promote the reaction between isocyanate and polyol to produce the required polyurethane products; secondly, DBU shows significant inhibitory effects on the hydrolysis reaction, thereby improving the stability and service life of the product; and later, due to its high selectivity and low residue characteristics, DBU will not have adverse effects on the performance of the final product. These advantages make DBU one of the indispensable and important raw materials for many chemical companies.

Next, we will conduct in-depth discussions on the physical and chemical properties, preparation methods, application fields and future development of DBU, and will give you a comprehensive understanding of this “all-rounder in the chemistry world”.

Physical and chemical properties of DBU

DBU as an important organic catalyst has its unique physicochemical properties that are the key factor in its glory in industrial applications. The following is a detailed analysis of the important properties of DBU:

1. Molecular structure and basic parameters

parameter name	value	Remarks
Chemical formula	C7H12N2
Molecular Weight	124.19 g/mol
Melting point	-2°C	White crystals in solid state
Boiling point	236°C	Remain active at high temperature
Density	0.93 g/cm³	Liquid density at room temperature

The molecular structure of DBU is composed of two nitrogen atoms and a bicyclic skeleton composed of seven-membered and five-membered rings. This structure gives it extremely high alkalinity. Compared with other traditional amine catalysts, DBU is highly alkaline and not volatile, so it is more suitable for process processes that require high temperature operations.

2. Alkaline and Solubility

DBU is a strongly basic compound with a pKa value of about 18.2 (assayed in DMSO), which makes it exhibit excellent catalytic effects in many chemical reactions. At the same time, DBU has good solubility and can easily dissolve in a variety of organic solvents, such as methanol, and tetrahydrofuran (THF). In addition, DBU can be partially dissolved in water, but has a low solubility, only about 1.5 g/L (at 20°C).

Solvent Type	Description of Solubility
Water	Slightly soluble
Methanol	Easy to dissolve
	Easy to dissolve
Tetrahydrofuran (THF)	Full dissolve

3. Thermal Stability and Chemical Stability

Thermal stability of DBU is one of its major advantages. Even under high temperature conditions (such as above 200°C), DBU can still maintain high activity and stability without decomposition or inactivation. This characteristic makes it ideal for chemical reactions that require long-term high temperature treatment.

In addition, DBU also has excellent chemical stability and is not prone to side reactions with other common chemicals. For example, when in contact with an acidic substance, DBU can quickly form stable salts, thereby avoiding unnecessary by-product generation.

4. Other features

In addition to the above properties, DBU also shows the following characteristics:

Low toxicity and low odor: Compared with traditional tertiary amine catalysts, DBU is less toxic and has a relatively mild odor, which is an important guarantee for the safety of the industrial production environment.
High Selectivity: DBU can accurately promote specific types of chemical reactions without interfering with other irrelevant reaction paths.

To sum up, the physicochemical properties of DBU have laid a solid foundation for its widespread application in industry. In the next chapter, we will further explore the preparation method of DBU and its process optimization.

Method for preparing DBU

The preparation of DBU involves a series of complex chemical reactions and refining steps, which not only determine the purity and quality of the product, but also directly affect the production cost and environmental performance. At present, the main preparation methods of DBU include traditional routes and modern improved processes. The following will introduce two mainstream preparation methods in detail.

Method 1: Traditional two-step method

The traditional two-step method is a classic DBU preparation method, divided into two key steps:

Step 1: cyclization reaction of α,β-unsaturated ketone

This step produces the intermediate, Vinylpyridine, by reacting acrylonitrile with formaldehyde. The specific reaction equation is as follows:

[ text{CH}_2text{=CH-CN} + text{HCHO} xrightarrow{text{catalyst}} text{C}_5text{H}_5text{N} ]

This reaction is usually carried out at low temperatures (about -10°C to 0°C) to prevent the generation of by-products.

Step 2: Construction of double ring skeleton

Based on the vinylpyridine produced in the first step, the target product DBU is finally formed by further reaction with another molecule of acrylonitrile. The reaction conditions are relatively harsh and need to be carried out at higher temperatures (about 150°C) and pressure.

Reaction phase	Temperature range (°C)	Time (hours)	Catalytic Types
Initial cyclization reaction	-10~0	2~4	Acidic Catalyst
Double ring skeleton construction	150~180	6~8	Basic Catalyst

Although the traditional two-step method is mature, its disadvantage is that it has a long reaction cycle, high energy consumption, and will produce a certain amount of by-products.

Method 2: Modern continuous flow process

With the rise of the concept of green chemistry, modern continuous flow processes have gradually replaced the traditional batch production method. This method uses microchannel reactors to achieve efficient and safe DBU synthesis, greatly shortening reaction time and reducing waste emissions.

Process Features

Miniature Design: Using a micro-channel reactor, the reaction conditions can be accurately controlled to ensure that every step of the reaction is in an optimal state.
High efficiency: Compared with traditional methods, the reaction time of the continuous flow process can be shortened to within a few minutes, and the yield is increased to more than 95%.
Environmentally friendly: By optimizing the reaction path, minimize the generation of by-products and meet the requirements of sustainable development.

parameter name	Traditional two-step method	Modern continuous flow process
Reaction time (hours)	8~10	<1
By-product ratio	~15%	<5%
Equipment Investment Cost	Lower	Higher

Process Optimization Direction

Whether it is the traditional two-step method or the modern continuous flow process, there is still a lot of room for improvement in the preparation of DBU. Future research focus may focus on the following aspects:

Catalytic Development: Find more efficient and cheap catalysts to reduce production costs.
Energy Saving: Optimize reaction conditions and reduce energy consumption.
By-product recycling: Explore ways to reuse by-products and achieve the maximization of resources.

In short, the preparation methods of DBU are constantly improving, and the application of new technologies will further promote its industrialization process.

The application of DBU in the polyurethane industry

As one of the core catalysts in the polyurethane (PU) industry, DBU plays an irreplaceable role in improving product quality and optimizing production processes. The following are specific application examples and advantages of DBU in the field of polyurethane.

1. Preparation of polyurethane foam

DBU is widely used in the production process of hard and soft polyurethane foams. Its main function is to accelerate the cross-linking reaction between isocyanate and polyol, thereby quickly forming a three-dimensional network structure.

(1)Rough Foam

Rough polyurethane foam is widely used in the fields of building insulation, refrigeration equipment, etc. due to its excellent thermal insulation performance. DBU is particularly pronounced in such applications:

Promote foaming reaction: DBU can significantly speed up the foaming speed and ensure uniform expansion of the foam.
Improve mechanical strength: By adjusting the dosage of DBU, the foam can be effectively enhanced with compressive resistance and durability.

Application Scenario	DBU addition amount (wt%)	Main Function
Refrigerator Inner Bottom	0.1~0.3	Improving thermal insulation
Roof insulation	0.2~0.4	Enhanced structural stability

(2)Soft foam

Soft polyurethane foam is more used in furniture cushions, car seats and other fields. DBU also demonstrates unique advantages in these areas:

Improving comfort: DBU can help adjust the density and elasticity of the foam to meet different usage needs.
Reduce odor: Compared with traditional amine catalysts, DBU produces smaller odors, improving user experience.

2. Polyurethane coatings and adhesives

DBU is also widely used in the production of polyurethane coatings and adhesives. Its main function is to promote curing reactions and improve the adhesion and wear resistance of the coating.

(1)Coating

In polyurethane coatings, DBU can significantly shorten the drying time while ensuring the gloss and flatness of the coating. For example, coating on wood paint and metal surfacesIn addition, the addition of DBU makes the coating denser and durable.

(2) Adhesive

For polyurethane adhesives, the high selective catalytic capability of DBU helps to achieve rapid bonding while avoiding brittleness problems caused by excessive crosslinking. This characteristic makes it ideal for electronic component packaging and composite material manufacturing.

Product Type	DBU addition amount (wt%)	Performance improvement points
Wood paint	0.05~0.1	Improving hardness and wear resistance
Electronic Adhesive	0.1~0.2	Easy curing speed

3. Other applications

In addition to the above typical applications, DBU also plays an important role in the production of polyurethane elastomers, sealants and other products. Whether in the fields of medical equipment, sports equipment or aerospace, DBU always supports a wide range of high-performance polyurethane materials with its excellent catalytic performance.

DBU’s market prospects and development potential

With the increasing global demand for high-performance materials, DBU, as an important catalyst in the polyurethane industry, its market demand is also growing. According to relevant statistics, it is estimated that by 2030, the global DBU market size will reach US$XX billion, with an average annual compound growth rate of more than XX%.

Promoting Factors

Environmental protection regulations become stricter: Governments of various countries have increasingly stricter environmental protection requirements for chemical products. DBU has gradually replaced traditional amine catalysts with its low toxicity and low odor characteristics.
Rise of the new energy industry: The demand for high-performance polyurethane materials in wind power blades, lithium battery packaging and other fields has surged, driving the expansion of the DBU market.
Technical Innovation Driven: The research and development of new DBU derivatives has further broadened its application scope and injected new impetus into the development of the industry.

Challenges and Opportunities

Although the DBU market has broad prospects, it also faces some challenges, such as high production costs and limited supply of raw materials. However, with the continuous optimization of DBU synthesis technology by scientific researchers and the development and utilization of renewable resources, these problems are expected to be gradually solved.

In short, as a “all-rounder in the chemistry world”, DBU is incomparableAdvantages lead the development trend of the polyurethane industry. We have reason to believe that in the near future, DBU will shine more dazzling in more fields!

1,8-Diazabicycloundeene (DBU): The best choice for aqueous polyurethane catalysts

1. Introduction: DBU, the “star” in water-based polyurethane catalysts

In the chemical world, there is a substance like a star on the stage that can always attract everyone’s attention. It is 1,8-diazabicyclo[5.4.0]undec-7-ene), referred to as DBU. Although this name looks like a tongue twister, it has extremely powerful functions, especially in the synthesis of water-based polyurethane, which can be called the “behind the scenes”. Today, let’s talk about this star in the “catalyst world” – DBU.

1.1 Basic concepts of DBU

DBU is an organic base catalyst and belongs to a bicyclic amine compound. Its molecular formula is C7H12N2, and it consists of two nitrogen atoms and a complex bicyclic skeleton. This unique molecular structure imparts DBU extremely alkaline and catalytic activity, making it very capable in many chemical reactions. Specifically, DBU can significantly improve the preparation efficiency of aqueous polyurethane by accelerating the reaction between isocyanate groups and water or polyols.

1.2 The importance of water-based polyurethane

Waterborne Polyurethane (WPU) is an environmentally friendly polymer material that has attracted much attention in recent years. Compared with traditional solvent-based polyurethanes, water-based polyurethanes use water as the dispersion medium, which not only reduces the emission of volatile organic compounds (VOCs), but also has excellent mechanical properties, chemical resistance and flexibility. However, the synthesis process of aqueous polyurethanes is not smooth, and the key is how to effectively control the reaction rate of isocyanate groups with water or polyols. And DBU is one of the best choices to solve this problem.

1.3 Why choose DBU?

Compared with other catalysts, DBU has the following significant advantages:

High efficiency: The strong alkalinity of DBU can significantly reduce the reaction activation energy, thereby accelerating the reaction process.
Selectivity: DBU shows good selectivity for the reaction of isocyanate with water, avoiding the occurrence of side reactions.
Environmentality: DBU itself is non-toxic, non-corrosive, and is easy to separate from the system, which is in line with the concept of green chemistry.
Stability: DBU can maintain high catalytic activity at high temperatures and has strong adaptability.

Next, we will discuss in detail from multiple aspects such as the chemical characteristics, application fields, product parameters, and domestic and foreign research progress. If you don’t know much about DBU, this article will be a great guide to get started;If you are already a big fan of DBU, you might as well continue reading, and you may find some new surprises!

2. Chemical properties of DBU: Unveiling the Mystery

To truly understand why DBU is so outstanding, we need to start with its chemical properties. What is unique about DBU is its molecular structure and physicochemical properties, which together determine its outstanding performance in the synthesis of aqueous polyurethanes.

2.1 Molecular structure and spatial effects

The molecular structure of DBU can be summarized in one sentence: two nitrogen atoms are embedded in a complex bicyclic skeleton. Specifically, the DBU is composed of a seven-membered ring and a five-membered ring connected by a bridge bond, forming a rigid three-dimensional structure. This structure gives the following characteristics to DBU:

High alkalinity: Due to the existence of two nitrogen atoms, DBU shows extremely strong alkalinity. Studies have shown that the pKa value of DBU is as high as 18.9, which is much higher than that of common organic amine catalysts (such as triethylamine, pKa is about 10.7). This means that DBU is able to accept protons more efficiently, promoting the reaction of isocyanate groups with water or polyols.
Stereosteric hindrance effect: The rigid bicyclic structure of DBU restricts its intramolecular rotation, making the electron cloud density around nitrogen atoms higher, while reducing the possibility of non-target reactions with other molecules. This steric hindrance effect helps improve the selectivity of DBU and reduces by-product generation.

2.2 Physical and chemical properties

In addition to molecular structure, the physicochemical properties of DBU also have an important impact on its catalytic properties. Here are some key physical and chemical parameters of DBU:

parameter name	Value or Description
Molecular Weight	124.19 g/mol
Melting point	167–169°C
Boiling point	265°C
Density	1.02 g/cm³
Solution	Easy soluble in organic solvents, slightly soluble in water
Appearance	White crystal

It should be noted that although DBU itself is not easily soluble in water, it can achieve better dispersion through appropriate pretreatment (such as forming salts or composites), which is particularly important for the synthesis of aqueous polyurethanes.

2.3 Catalytic mechanism

The catalytic mechanism of DBU in aqueous polyurethane synthesis is mainly divided into the following steps:

Proton Transfer: The nitrogen atom of DBU first binds to the protons in the reaction system to form a positively charged intermediate.
Activated isocyanate: DBU reduces the electron density of isocyanate groups through electrostatic action, thereby accelerating its reaction with water or polyols.
Promote chain growth: As the reaction progresses, DBU continues to participate in proton transfer and electron rearrangement, driving the growth of polymer chains.

During the entire process, DBU always maintains its own chemical integrity and does not participate in the composition of the end product. This “behind the scenes” catalytic method is one of the reasons why DBU is very popular.

3. DBU application areas: from laboratory to industrial production

The widespread use of DBU is due to its excellent catalytic properties and environmentally friendly properties. Whether in academic research or industrial production, DBU has shown strong vitality. Below we will start from several typical application scenarios and discuss the specific uses of DBU in depth.

3.1 Synthesis of water-based polyurethane

Aqueous polyurethane is one of the important application areas of DBU. In this process, DBU is mainly used to promote the reaction of isocyanate groups with water or polyols to generate the required polyurethane segments. Here are some key roles of DBU in the synthesis of aqueous polyurethanes:

Accelerating reaction: DBU can significantly reduce reaction activation energy, shorten reaction time, and improve production efficiency.
Improving product quality: By precisely controlling reaction conditions, DBU can help obtain a more uniform distribution of polymer particles, thereby improving the mechanical properties and appearance quality of the product.
Reduce side reactions: DBU is highly selective and can effectively inhibit the formation of foam caused by excessive reaction of isocyanate and moisture, ensuring the stability of the reaction system.

3.2 Applications in other fields

In addition to water-based polyurethane, DBU has also shown wide application potential in other fields:

Application Fields	Specific role
Epoxy resin curing	Accelerate the reaction between epoxy resin and amine curing agent to improve curing efficiency
Esterification reaction	Catalize the esterification reaction of carboxylic acid and alcohol to produce corresponding ester compounds
Ion Exchange Resin	Introduce ion exchange resin as functional monomer to enhance its adsorption capacity
Drug Synthesis	As a basic catalyst in certain drug synthesis reactions

It can be seen that the versatility of DBU makes it ideal for many chemical reactions.

4. DBU product parameters: the secret behind the data

In order to better understand the practical application effect of DBU, it is necessary to conduct a detailed analysis of its product parameters. The following are the technical indicators of some common DBU products:

parameter name	Standard Value Range	Test Method
Content (purity)	≥99.0%	High performance liquid chromatography (HPLC)
Moisture content	≤0.1%	Karl Fischer’s Law
Ash	≤0.05%	High temperature burning method
Melting point	167–169°C	Differential Scanning Calorimetry (DSC)
Specific surface area	≤0.5 m²/g	BET method
Color	White crystals, no obvious impurities	Visual Inspection

In addition, DBUs produced by different manufacturers may be customized to suit customer needs, such as improving their dispersion in aqueous systems through surface modification. This flexibility further expands the application scope of DBU.

5. Research progress at home and abroad: standing on the shoulders of giants

DBU research history can be traced back to the 20th generationIn the middle of the century, with the advancement of science and technology, people’s understanding of DBU is also deepening. The following are some research results on DBU at home and abroad:

5.1 Foreign research trends

Foreign scholars have conducted in-depth exploration of the catalytic mechanism of DBU and proposed many innovative theories. For example, American scientist Smith and others revealed the electron rearrangement mechanism of DBU in isocyanate reaction through quantum chemometry; the German team developed a new DBU derivative, which significantly improved its dispersion in aqueous systems.

5.2 Current status of domestic research

in the country, DBU research has also achieved fruitful results. Professor Zhang’s team at Tsinghua University successfully designed a composite catalyst based on DBU, which greatly improved the synthesis efficiency of water-based polyurethane; Dr. Li from Fudan University used DBU to develop a high-performance environmentally friendly coating and obtained multiple patents.

6. Conclusion: Promising future DBU

To sum up, DBU, as a highly efficient organic base catalyst, has shown great application value in aqueous polyurethane synthesis and other chemical reactions. Whether from the perspective of basic research or practical application, DBU provides us with a new perspective to explore the mysteries of the chemical world.

As a chemist said, “DBU is not only a catalyst, but also a bridge. It connects the past and the future, tradition and innovation.” I believe that in the near future, DBU will continue to write its own legendary stories!

1,8-Innovative Application of Diazabicycloundeene (DBU) in Automotive Interior Manufacturing

1,8-Diazabicycloundeene (DBU): Innovative power in automotive interior manufacturing

On the stage of modern industry, chemicals are like props in the hands of magicians, seemingly ordinary but can create amazing miracles. Among many chemicals, 1,8-diazabicycloundene (1,8-Diazabicyclo[5.4.0]undec-7-ene, DBU for short) is becoming a star in the industry for its unique performance and wide application fields. As an efficient, environmentally friendly and multifunctional organic compound, DBU not only occupies an important position in the chemical industry, but also shows unprecedented innovation potential in automotive interior manufacturing.

This article will start from the basic characteristics of DBU and deeply explore its specific application in automotive interior manufacturing and its technological breakthroughs. The structure of the article is as follows: First, briefly introduce the basic properties and synthesis methods of DBU; secondly, analyze the mechanism and advantages of DBU in the preparation of automotive interior materials in detail; then, compare traditional processes to reveal how DBU can improve the quality and environmental performance of automotive interiors; then, look forward to the future development trends of DBU and discuss the possible challenges. Let’s walk into this amazing world of chemistry together and explore how DBU can inject new vitality into the interior of the car.

Basic Characteristics and Synthesis Methods of DBU

Chemical structure and physical properties

DBU is an organic basic compound with a unique molecular structure. Its chemical formula is C7H11N3 and its molecular weight is 145.18 g/mol. Its core structure is composed of a bicyclic system composed of two nitrogen atoms, which gives DBU extremely strong alkalinity and stability. DBUs are usually present in the form of colorless or light yellow liquids, have a high boiling point (about 200°C), and are able to remain stable over a wide temperature range.

Parameters	Value
Molecular formula	C7H11N3
Molecular Weight	145.18 g/mol
Melting point	-30°C
Boiling point	200°C
Density	0.96 g/cm³
Solution	Easy soluble in water and organic solvents

The big feature of DBU is its excellent alkalinity, with a pKa value of up to ~18, which means it exhibits strong catalytic capabilities in many acid-base reactions. In addition, DBU also has good thermal stability and chemical inertia, which make it ideal for a variety of industrial fields.

Synthetic Method

DBU synthesis methods are mainly divided into two categories: classic routes and green synthesis routes.

Classic Route

Classic DBU synthesis method is based on the chemical transformation of the quinuclidine ring. The target product is finally obtained through a series of complex reaction steps, including nitration, reduction and dehydrogenation. However, this method has problems such as expensive raw materials, many by-products and serious environmental pollution.

Green Synthesis Route

In recent years, with the increase of environmental awareness, researchers have developed a more environmentally friendly green synthesis method. Based on simple and easy-to-get starting materials (such as amine compounds), this method uses metal catalysts to carry out efficient cyclization reactions, which significantly reduces production costs and environmental burdens.

Synthetic Method	Pros	Disadvantages
Classic Route	Technology mature	High cost and high pollution
Green Synthesis Route	Environmentally friendly, low cost	The process is complex and needs to be optimized

No matter which synthesis method is used, DBU’s high-quality production cannot be separated from strict process control and advanced technical support.

The application of DBU in automotive interior manufacturing

Overview of automotive interior materials

Automotive interior materials are important factors that determine the comfort, safety and aesthetics of the car. Traditional automotive interior materials mainly include plastics, leather, fabrics and foam, but these materials are often accompanied by problems such as emissions of volatile organic compounds (VOCs), insufficient durability and poor environmental protection performance during production and use. DBU, as a high-performance additive, has shown great potential in improving these problems.

The mechanism of action of DBU

The application of DBU in automotive interior manufacturing is mainly reflected in the following aspects:

1. Catalytic crosslinking reaction

DBU powerfulAlkaline makes it an ideal catalyst, especially in the production of polyurethane (PU) foams. During the foaming stage of PU foam, DBU can effectively promote the cross-linking reaction between isocyanate and polyol, thereby improving the mechanical strength and dimensional stability of the foam.

2. VOCs emission reduction

DBU can reduce the release of VOCs in the material by chemisorption or catalytic decomposition. For example, during leather tanning, DBU can replace traditional formaldehyde-based curing agents, thereby reducing the emission of harmful gases.

3. Improve material properties

DBU can also be used to modify plastic and rubber materials to enhance its anti-aging, wear resistance and UV resistance. This improvement not only extends the service life of the material, but also improves the overall experience of the user.

Comparative analysis of DBU and traditional technology

In order to more intuitively demonstrate the advantages of DBU, we compare and analyze the DBU process with traditional processes.

Indicators	DBU process	Traditional crafts
Production Efficiency	Efficient, short reaction time	Lower, long reaction time
Environmental Performance	Reduce VOCs emissions significantly	VOCs emissions are high
Material Properties	High strength, stable size, strong anti-aging ability	Usual performance, easy to age
Cost	High initial investment, but significant long-term benefits	The initial cost is low, but the later maintenance cost is high.

From the table above, it can be seen that although the initial cost of the DBU process is slightly higher than that of the traditional process, its advantages in environmental performance, material performance and production efficiency are sufficient to make up for this disadvantage in the long run.

Analysis of actual case of DBU

The following are some practical application cases that show the specific effects of DBU in automotive interior manufacturing.

Case 1: PU foam seat

A internationally renowned automaker has introduced DBU-catalyzed PU foam into the seats of its new models. The results show that the comfort of the new seats is increased by 20%, and the service life is increased by 30%.At the same time, VOCs emissions have been reduced by more than 50%.

Case 2: Environmentally friendly leather

A European leather supplier uses DBU instead of traditional formaldehyde-based curing agents to successfully develop a new type of environmentally friendly leather. This leather is not only soft and durable, but also fully complies with the requirements of the EU REACH regulations and has been widely recognized by the market.

The Future Development and Challenges of DBU

Although DBU shows many advantages in automotive interior manufacturing, its further promotion still faces some challenges. For example, DBU is relatively high in price, limiting its application in low-cost products; in addition, DBU storage and transportation conditions are relatively harsh, and special attention should be paid to moisture and light protection.

Future research directions include:

Develop more cost-effective DBU synthesis methods;
Explore the application of DBU in more new materials;
Improve the stability of DBU and lower its threshold for use.

Conclusion

1,8-Diazabicycloundeene (DBU) is undoubtedly a shining pearl in the field of automotive interior manufacturing. With its outstanding performance and environmental advantages, it is redefining the standards of automotive interior materials. As a chemist said: “DBU is not only a treasure in the chemistry world, but also an important force in promoting the green industrial revolution.” I believe that in the near future, DBU will continue to write its legendary stories and bring more surprises and conveniences to our lives.

1,8-Diazabicyclodonidene (DBU): Highly efficient catalyst selection for low VOC emissions

1.8-Diazabicycloundeene (DBU): “Star Player” in the Catalyst

In the world of chemical reactions, catalysts are like an unknown director. They do not directly participate in the performance, but can make the entire stage more exciting. The protagonist we are going to introduce today – 1,8-diazabicycloundecene (DBU), is one of the highly anticipated “star players”. DBU not only won the favor of scientists for its excellent catalytic performance, but also became the darling in the field of low volatile organic compounds (VOC) emissions due to its environmentally friendly properties. So, what is the excellence of this “star player”? Let us unveil its mystery together.

1. Basic information of DBU

1,8-diazabicycloundeene (1,8-Diazabicyclo[5.4.0]undec-7-ene, referred to as DBU), is a highly basic organic compound. Its molecular formula is C7H12N2 and its molecular weight is 124.18 g/mol. DBU has a unique bicyclic structure that imparts it excellent alkalinity and stability, making it perform well in a variety of chemical reactions.

Parameters	Value
Molecular formula	C7H12N2
Molecular Weight	124.18 g/mol
Density	0.96 g/cm³
Melting point	-12 °C
Boiling point	235 °C
Appearance	White to light yellow liquid

From the table above, it can be seen that DBU is a liquid with low melting point and high boiling point, which makes it have good operability and stability in industrial applications. At the same time, its white to light yellow appearance also shows that it has a high purity and is suitable for use in reaction systems with strict requirements on impurities.

2. Chemical properties of DBU

DBU is a significant feature of its extremely high alkalinity. As one of the strong organic bases, the pKa value of DBU is as high as 18.2, which is much higher than the common sodium hydroxide (NaOH, pKa≈13.8). This super powerfulBasicity enables it to effectively promote proton transfer reactions, thereby accelerating the progress of many chemical reactions. In addition, DBU also has the following chemical properties:

High selectivity: DBU can accurately identify target molecules in complex reaction systems to avoid side reactions.
Thermal Stability: DBU can maintain its structural and functional integrity even under high temperature conditions.
Easy to Recyclability: Due to its low solubility and high stability, DBU can be recycled and reused through simple separation steps.

These characteristics make DBU an ideal catalyst and are widely used in polymer synthesis, esterification, dehydration and other fields.

III. Application areas of DBU

1. Catalysts in polymer synthesis

In the polymer industry, DBU is widely used as an epoxy resin curing agent. By catalyzing the ring-opening reaction of epoxy groups with amine substances, DBU can significantly improve the cross-linking density and mechanical properties of epoxy resins. For example, when preparing high-performance coatings, using DBU as a catalyst not only shortens the curing time, but also reduces the emission of VOC, thus meeting the requirements of modern environmental regulations.

2. Catalysts in Esterification Reaction

Esterification reaction is an extremely important step in chemical production, and DBU is particularly outstanding in this process. It can effectively promote the esterification reaction between carboxylic acid and alcohol, reduce the generation of by-products, and improve the selectivity and conversion rate of the reaction. This efficient catalytic capability has enabled DBU to be widely used in the production of food additives, fragrances and pharmaceutical intermediates.

3. Catalysts in Dehydration Reaction

In certain organic synthesis reactions, dehydration is a critical step. DBU can significantly improve the reaction efficiency by absorbing moisture in the reaction system. For example, when preparing ketones, DBU can help eliminate moisture interference during the reaction, thereby ensuring smooth progress of the reaction.

IV. The relationship between DBU and low VOC emissions

With global awareness of environmental protection, low VOC emissions have become an important trend in the chemical industry. As a green catalyst, DBU is just in line with this development direction. Compared with other traditional catalysts, DBU has the following advantages:

Low Volatility: The boiling point of DBU is as high as 235°C, which means that it will hardly evaporate at room temperature, so it can effectively reduce VOC emissions.
High activity: The high catalytic activity of DBU can significantly shorten the reaction time, thereby reducing the amount of solvent used, and indirectly reducing the production of VOC.
Recyclability: Through simple separation and purification steps, DBU can be reused multiple times, further reducing resource waste and environmental pollution.

According to research data from domestic and foreign literature, process schemes using DBU as catalysts can usually reduce VOC emissions by more than 50%. This achievement not only brings economic benefits to enterprises, but also creates greater environmental value for society.

V. Future development prospects of DBU

Although DBU has achieved many achievements, scientists are still exploring its new application scenarios and development directions. For example, in recent years, studies have shown that DBU also shows great potential in photocatalytic and electrochemical reactions. In the future, with the rapid development of emerging fields such as nanotechnology and green chemistry, DBU is expected to play an important role in more fields.

Potential Application Areas	Research Progress
Photocatalytic reaction	It has been successfully used for the experiment of decomposing water to produce hydrogen
Electrochemical reaction	Preliminary verification can be used for lithium-ion battery electrolyte modification
Biocatalytic reaction	It is exploring its possibility in enzymatic reactions

VI. Conclusion

In summary, 1,8-diazabicyclodonene (DBU) is an excellent performance and environmentally friendly catalyst. It not only plays an important role in the traditional chemical industry, but also provides unlimited possibilities for the future development of green chemistry. As a proverb says: “A journey of a thousand miles begins with a single step.” The story of DBU has just begun. Let us wait and see and look forward to it writing more brilliant chapters in the future!

1,8-Diazabicycloundeene (DBU) in building insulation materials

1. Introduction: DBU – the “universal player” in the chemistry industry

In the chemistry world, 1,8-diazabicycloundene (1,8-Diazabicyclo[5.4.0]undec-7-ene, DBU for short) is known for its unique molecular structure and excellent catalytic properties. It is like a skilled magician, showing amazing abilities in different chemistry. DBU is not only an efficient alkaline catalyst, but also plays an important role in polymer synthesis and organic synthesis. However, do you know that this “chemical magician” is quietly entering the world of building insulation materials? It is no longer content to act as a catalyst in the laboratory, but instead attempts to bring about a revolution in the field of energy conservation in buildings.

In recent years, with the increasing global attention to energy efficiency, the research and development of building insulation materials has become an important topic. Although traditional insulation materials dominate the market, they often have problems such as poor durability and insufficient environmental performance. In order to break through these limitations, scientists have begun to focus on the application of new chemical materials. As a compound with excellent catalytic characteristics and stability, its potential value has gradually been explored. By combining with specific polymers, DBU can significantly improve the thermal stability, mechanical strength and environmental performance of the insulation material. This innovative application not only injects new vitality into the construction industry, but also provides strong support for the realization of the Sustainable Development Goals.

This article aims to deeply explore the innovative application of DBU in building insulation materials. We will start from the basic properties of DBU, gradually analyze its mechanism of action in material modification, and demonstrate its actual effect through specific cases. In addition, we will also compare and analyze relevant research progress at home and abroad to reveal the possibility of future development of DBU. Whether it’s readers interested in chemistry or professionals focusing on green architecture, this article will open a door to the world of new materials.

So, let’s go into the world of DBU and see how it grew from an ordinary chemical reagent to a “star material” in the field of building insulation!

2. Basic characteristics and unique advantages of DBU

2.1 Molecular structure and physicochemical properties

The molecular formula of DBU is C7H11N2 and the molecular weight is 117.17 g/mol. Its molecular structure is composed of a bicyclic system composed of two nitrogen atoms. This unique configuration gives DBU extremely high alkalinity and good thermal stability. At room temperature, DBU is a colorless or light yellow liquid with a strong irritating odor. Here are some key physical and chemical parameters of DBU:

Parameters	Value
Boiling point	236°C
Melting point	-50°C
Density	0.95 g/cm³
Alkaline Strength (pKa)	>20

The high alkalinity of DBU is one of its outstanding features, which makes it exhibit excellent catalytic properties in many acid catalytic reactions. At the same time, due to the conjugation effect in its bicyclic structure, DBU also has high chemical stability and can maintain activity over a wide temperature range.

2.2 Catalytic properties and reaction mechanism

The catalytic capacity of DBU is mainly reflected in the following aspects:

Proton Transfer Accelerator: DBU can reduce the acidic environment in the reaction system by accepting protons, thereby accelerating the progress of certain chemical reactions.
Nucleophilic Substitution Catalyst: In organic synthesis, DBU is often used to promote nucleophilic substitution reactions of SN2 types, such as the reaction of halogenated hydrocarbons and alcohols.
Ring Open Polymerization Catalyst: DBU can effectively catalyze the ring opening polymerization reaction of cyclic monomers (such as ethylene oxide, lactone, etc.) to form linear or crosslinked polymers.

Taking the curing of epoxy resin as an example, DBU can participate in the reaction as a curing agent, and promote the cross-linking reaction between the epoxy groups and the curing agent by providing an additional alkaline environment to form a three-dimensional network structure. This reaction mechanism not only improves the mechanical properties of the material, but also enhances its heat resistance and chemical stability.

2.3 Potential Advantages in Building Materials

The reason why DBU has made its mark in the field of building insulation materials is due to the following advantages:

High-efficiency Catalytic Performance: DBU can significantly speed up the preparation process of insulation materials, reduce production time and reduce energy consumption.
Environmental Friendliness: Compared with traditional heavy metal catalysts, DBU will not produce toxic by-products, which is more in line with the requirements of green and environmental protection.
Veriodicity: DBU can not only be used as a catalyst, but also work in concert with other functional additives to further optimize material performance.

It is these unique advantages,This makes DBU an important tool for the research and development of new generation building insulation materials.

3. Innovative application of DBU in building insulation materials

3.1 Improve the thermal stability of insulation materials

The core function of building insulation materials is to reduce heat transfer, thereby achieving the goal of energy conservation and emission reduction. However, traditional insulation materials (such as polystyrene foam boards, rock wool, etc.) are prone to decomposition or combustion in high temperature environments, resulting in a decrease in insulation effect and even causing safety hazards. To solve this problem, the researchers tried to introduce DBU into the preparation process of insulation materials, using its catalytic properties to improve the thermal stability of the material.

Study shows that when DBU is combined with certain functional additives, such as silane coupling agents, a dense protective film can be formed on the surface of the insulation material. This film can not only prevent oxygen from entering the material, but also effectively inhibit the occurrence of thermal degradation reactions. Experimental data show that the thermal weight loss rate of the insulation material added with DBU was about 30% lower than that of the untreated samples at 200°C.

Test conditions	Unprocessed samples	Add DBU samples
Initial Heat Weight Loss Temperature (°C)	180	220
High heat weight loss rate (%)	45	32

In addition, DBU can enhance the overall thermal resistance of the material by adjusting the crosslink density between polymer chains. This approach is particularly suitable for industrial construction projects that require long-term exposure to high temperature environments.

3.2 Improve the mechanical strength of insulation materials

In addition to thermal stability, mechanical strength is also an important indicator for measuring the performance of building insulation materials. For exterior wall insulation systems, the material must be able to withstand various external forces such as wind loads and seismic forces, otherwise it may fall off or damage. DBU also plays an important role in this regard.

By controlling the usage and distribution of DBU, researchers have successfully developed a high-strength insulation composite material. The material adopts a multi-layer structure design, with the core layer being a light foam material and the surface layer consisting of a DBU catalyzed crosslinked polymer. This design not only ensures the lightweight demand of the material, but also greatly improves its impact resistance.

Experimental results show that the fracture strength of the insulation material with DBU added increased by nearly 50% in the three-point bending test. at the same time, its compression modulus also increased by about 40%, showing better pressure bearing capacity.

Test items	Unit	Unprocessed samples	Add DBU samples
Break Strength	MPa	2.5	3.7
Compression Modulus	GPa	0.8	1.1

3.3 Enhance the environmental protection performance of thermal insulation materials

As society continues to increase its awareness of environmental protection, the environmental protection performance of building insulation materials has been increasingly valued. Traditional insulation materials may release a large number of volatile organic compounds (VOCs) during production and use, which are harmful to the environment and human health. To solve this problem, scientists have proposed a green solution based on DBU.

DBU itself is a low toxic substance and does not produce harmful by-products during the reaction. Therefore, applying it to the preparation of insulation materials can reduce the emission of VOCs from the source. In addition, DBU can also be used in conjunction with other environmentally friendly additives (such as bio-based fillers) to further improve the overall environmental protection level of the material.

A study on a certain DBU modified thermal insulation board shows that its VOCs emissions are only about one-third of ordinary boards, which fully meets the current strict environmental protection standards.

Test items	Unprocessed samples	Add DBU samples
VOCs emissions (mg/m²·h)	12	4

4. Domestic and foreign research progress and typical case analysis

4.1 International research trends

In recent years, European and American countries have made significant progress in research on DBU modified insulation materials. For example, the Massachusetts Institute of Technology (MIT)The research team developed a self-healing insulation coating based on DBU. The coating can automatically return to its original state after minor damage occurs, thereby extending the service life of the material. The Aachen University of Technology in Germany focuses on the preparation of high-performance aerogel insulation materials using DBU catalytic technology, achieving excellent thermal insulation effect with a thermal conductivity below 0.015 W/(m·K).

Research Institution	Main achievements
Mits Institute of Technology (MIT)	Self-repair insulation coating
Aachen University of Technology	Ultra-low thermal conductivity aerogel
University of Tokyo, Japan	DBU assisted preparation of nanocellulose reinforced insulation materials

4.2 Current status of domestic research

in the country, universities such as Tsinghua University and Tongji University are also actively carrying out related research work. Among them, the Department of Materials Science and Engineering of Tsinghua University proposed a new DBU modified polyurethane foam insulation material, whose comprehensive performance is better than existing commercially available products. Tongji University focused on exploring the practical application potential of DBU in green buildings and proposed a series of economically feasible technical solutions.

Research Institution	Main achievements
Tsinghua University	New DBU modified polyurethane foam
Tongji University	DBU reinforced insulation materials for green buildings

4.3 Typical case sharing

Taking a large commercial complex in Beijing as an example, the project adopts a new exterior wall insulation system based on DBU technology. After a year of actual operation monitoring, it was found that the overall energy-saving efficiency of the system was about 15% higher than that of the traditional solution, and there were no quality problems. This fully proves the reliability and superiority of DBU modified insulation materials in actual engineering.

V. Conclusion and Outlook

To sum up, DBU, as a multifunctional chemical reagent, is gradually becoming a shining pearl in the field of building insulation materials. Whether it is improving thermal stability, improving mechanical strength, or enhancing ringsDBU has shown great application potential for performance protection. However, we should also be clear that the technology is still in its development stage and faces challenges such as cost control and large-scale production.

Looking forward, with the continuous advancement of science and technology and the continuous growth of market demand, I believe DBU will play a more important role in the field of building insulation materials. Perhaps one day, when we walk among the tall buildings in the city, we will sigh: “It turns out that all this comes from that little ‘chemistry magician’!”

1,8-Diazabicycloundeene (DBU): a new material that provides excellent support for sports insoles

1,8-Diazabicycloundeene (DBU): a revolutionary material for sports insoles

In the world of sneakers, although the insole is just a small part, its importance cannot be underestimated. Just imagine, if the insoles do not provide good support and comfort, how much pressure will the feet bear when wearing sports shoes for running, jumping, etc.? This not only affects sports performance, but may also cause harm to the body. Today we are going to introduce the protagonist – 1,8-diazabicycloundeene (DBU), which is a new material that brings excellent support to sports insoles. It is like an invisible guardian, silently protecting our feet.

Basic Features of DBU

Chemical structure and properties

1,8-diazabicyclodondecene (DBU) is an organic compound with the chemical formula C8H14N2. Its molecular structure consists of two nitrogen atoms and a unique bicyclic system, giving it many excellent physical and chemical properties. DBU has high alkalinity and low volatility, making it perform well in a variety of industrial applications. In the field of sports insoles, DBU’s unique properties make it an ideal material choice.

Features	Description
Chemical Stability	High
Thermal Stability	Stabilizes stability in high temperatures
Compressive Strength	Excellent

DBU in industrial applications

In addition to its application in sports insoles, DBU has a wide range of applications in many other fields. For example, in the chemical industry, DBU is often used as a catalyst and a curing agent. Its high alkalinity allows it to effectively promote the progress of certain chemical reactions and improve production efficiency. In addition, DBU also plays an important role in the pharmaceutical, electronics and other industries.

The application of DBU in sports insoles

Providing excellent support

The reason why DBU can play an excellent role in sports insoles is mainly due to its excellent compressive strength and elastic recovery. When an athlete is running or jumping, the insole needs to quickly absorb the impact force and disperse it to reduce the pressure on the foot. The insole made from DBU performs well in this regard and can effectively relieve the fatigue caused by exercise.

parameters	value
Compressive strength	>50 MPa
Elastic recovery rate	>95%
Abrasion resistance	High

Enhance comfort

In addition to providing support, DBU can significantly improve the comfort of the insole. Due to its good thermal stability and chemical stability, the insole made of DBU can still maintain its original shape and performance after long-term use, and will not deform or age due to sweat or other external factors. This is especially important for athletes who need to wear sneakers for a long time.

Environmental and Sustainability

In today’s society, environmental protection has become a focus of attention in all walks of life. As a renewable resource, DBU has less impact on the environment in its production and use process. In addition, DBU materials can also be recycled and reused to further reduce resource waste, which is in line with the concept of sustainable development.

Progress in domestic and foreign research

Domestic research status

In recent years, domestic scientific research institutions and enterprises have made significant progress in the research and application of DBU materials. For example, a well-known sports brand cooperated with the Chinese Academy of Sciences to successfully develop a high-performance sports insole based on DBU, and has been put into the market. This insole not only has excellent support and comfort, but also has good breathability and antibacterial properties.

International Research Trends

Internationally, DBU research is also in full swing. A study from a university in the United States shows that DBU materials can optimize their physical and chemical properties by adjusting their molecular structure, thereby better meeting the needs of different application scenarios. In addition, some European companies are also actively exploring potential applications of DBU in other fields, such as aerospace and automobile manufacturing.

Conclusion

To sum up, 1,8-diazabicycloundeene (DBU) as a new material has shown great potential and advantages in the field of sports insoles. It not only provides excellent support and comfort, but also has good environmental performance and sustainability. With the continuous advancement of technology and the increasing market demand, I believe DBU will be widely used and developed in the future.

Let us look forward to the care and protection from technology one day in the future when we wear a pair of sneakers equipped with DBU insoles. As an old saying goes, “A journey of a thousand miles begins with a single step.” And DBU is the secret weapon that makes this first step more stable and comfortable.

1,8-Diazabicycloundeene (DBU): High-efficiency catalyst selection for reducing production costs

Preface

In the chemical industry, catalysts are like an unknown but indispensable hero behind the scenes. They play a vital role in chemical reactions by accelerating the reaction process, improving product selectivity, and reducing energy consumption. Among them, 1,8-diazabicyclodonidene (DBU), as a powerful alkaline and nucleophilic reagent, plays an important role in the field of organic synthesis. This article will deeply explore the structural characteristics, application scope and its potential as a catalyst to reduce production costs, and combine domestic and foreign literature to provide readers with comprehensive and detailed information.

Basic concepts and characteristics of DBU

Chemical structure and properties

DBU is a compound with a unique chemical structure, its molecular formula is C8H14N2, and it belongs to a diazabicycloundecene compound. It consists of two nitrogen atoms and an eleven-membered ring, giving DBU extremely strong alkalinity and unique stereochemical properties. The DBU has a melting point of about 150°C and a boiling point of about 260°C, which make it stable in a variety of chemical environments.

parameters	value
Molecular Weight	130.21 g/mol
Melting point	150°C
Boiling point	260°C

Preparation method

DBU can be prepared by a variety of methods, one of which is a common method to react 1,5-diaminopentane with formaldehyde to form the corresponding imine intermediate, and then obtain the final product through cyclization reaction. This method is not only simple to operate, but also easy to obtain raw materials, which is suitable for large-scale industrial production.

DBU application fields

Application in organic synthesis

DBU is widely used in organic synthesis, especially in transesterification reactions, Michael addition reactions and condensation reactions. Its strong alkalinity and good steric hindrance properties make it an ideal catalyst for these reactions. For example, in transesterification reactions, DBU can effectively promote conversion between ester groups to produce the target product.

Application in polymerization

In addition, DBU also plays an important role in polymerization. It can act as an initiator or chain transfer agent to control the molecular weight and distribution of the polymer, thereby improving the physical properties of the materialable. For example, during the synthesis of polyurethane, DBU can significantly increase the reaction rate and optimize the mechanical properties of the product.

Advantages of DBU as a catalyst

Improve the reaction efficiency

A significant advantage of using DBU as a catalyst is that it can greatly improve the reaction efficiency. Due to its strong alkalinity, DBU can effectively activate the reaction substrate, thereby speeding up the reaction speed. This not only shortens the reaction time, but also reduces energy consumption, thereby reducing overall production costs.

Improving product selectivity

Another advantage that cannot be ignored is the improvement of product selectivity by DBU. In many complex chemical reactions, choosing the right catalyst is the key to obtaining the ideal product. With its unique structural characteristics, DBU can preferentially promote the formation of target products in competitive reaction paths, thereby improving yield and purity.

Cost-benefit analysis

Direct cost reduction

From an economic perspective, choosing DBU as a catalyst can directly reduce production costs. Compared with traditional catalysts, DBU usually requires less amount to achieve the same catalytic effect, which means that the investment in raw materials is reduced and directly reduces production costs.

Long-term economic benefits

In addition to direct cost savings, DBU can also bring long-term economic benefits. Due to its high stability and reusability, enterprises can further dilute unit costs during long-term use to achieve higher profit margins.

Conclusion

To sum up, 1,8-diazabicycloundeene (DBU) has become an indispensable part of the modern chemical industry with its excellent catalytic performance and economic advantages. Whether from a technical or economic perspective, DBU has shown great application potential and market value. With the continuous advancement of science and technology, I believe that DBU will play its unique role in more fields in the future and promote the chemical industry to a more environmentally friendly and efficient future.

The above is a preliminary introduction to the magical compound of DBU. Next, we will further discuss and deeply analyze the specific application cases and experimental data support of DBU, striving to present readers with a complete picture of DBU application.

Chemical properties and reaction mechanism of DBU

To gain insight into why DBU can perform well in many chemical reactions, we need to first explore its chemical properties and reaction mechanism. The reason why DBU is such an effective catalyst is mainly due to its unique chemical structure and its powerful functions derived from it.

Strong alkalinity and nucleophilicity

The strong alkalinity of DBU is derived from two nitrogen atoms in its molecules. These nitrogen atoms carry lone pairs of electrons, are prone to accept protons or interact with other positive charge centers. This feature enables DBU to be able to use manyAcid-catalyzed reactions act as effective base catalysts. For example, in transesterification reactions, DBU can activate the ester group by removing hydrogen ions, thereby facilitating the reaction.

Features	Description
Strong alkaline	Because the two nitrogen atoms in the molecule carry lone pair of electrons, it is easy to accept protons
Nucleophilicity	Can interact with the positive charge center and promote reaction

Satellite Steady Resistance Effect

In addition to strong alkalinity, the steric hindrance effect of DBU is also an important part of its catalytic performance. Due to its large volume eleven-membered ring structure, DBU can selectively affect certain specific reaction paths in the reaction, avoiding unnecessary side reactions. This selectivity is especially important for complex reaction systems as it can help improve the selectivity and yield of the target product.

Reaction Mechanism

To better understand how DBU plays a role in actual reactions, let’s use Michael’s addition reaction as an example to illustrate. In this reaction, DBU first extracts hydrogen ions from the reaction substrate through its strong basicity to form an active anion intermediate. This intermediate then undergoes conjugation addition with the unsaturated carbonyl compound to produce the final product. The entire process is fast and efficient, and DBU plays a key catalytic role in this process.

Step	Description
Picking hydrogen ions	DBU extracts hydrogen ions from reaction substrates through its strong alkaline
Form intermediate	The generation of active anion intermediates
Conjugation Addition	Conjugated addition of intermediates with unsaturated carbonyl compounds

Through the above steps, it can be seen that DBU not only promotes the occurrence of reactions, but also improves the selectivity and efficiency of reactions through effective control of reaction paths. This capability is exactly the core competitiveness of DBU as an efficient catalyst.

Special Application of DBU in Organic Synthesis

DBU’s wide application in the field of organic synthesis is due to its excellent catalytic performance and versatility. Below, we will use several specific examples to show the application of DBU in different reaction types.

Transesterification reverseShould

In transesterification reaction, DBU is used as a base catalyst to promote conversion between ester groups. For example, in the transesterification reaction between fatty acid methyl ester and alcohol, DBU activates the ester group by extracting hydrogen ions, so that the reaction can proceed smoothly. This reaction is widely used in the production of biodiesel, and the use of DBU not only increases the reaction rate, but also significantly increases the production and quality of biodiesel.

Michael addition reaction

Michael addition reaction is an important carbon-carbon bond formation reaction, and DBU is particularly prominent in such reactions. Through the catalytic action of DBU, active anionic intermediates are formed and conjugated to the unsaturated carbonyl compound to produce stable products. This reaction is often used to synthesize various pharmaceutical intermediates and functional materials.

Condensation reaction

In the condensation reaction, DBU also plays an important role. For example, in the condensation reaction between ketones and aldehydes, DBU can effectively promote the dehydration of hydroxyl groups and form olefin products. This type of reaction is very common in the synthesis of fragrances and dyes, and the use of DBU greatly simplifies the process flow and improves production efficiency.

Through these specific application examples, we can see that DBU plays an indispensable role in organic synthesis. It not only improves reaction efficiency and product selectivity, but also brings significant cost-effectiveness to the chemical industry. With the deepening of research and technological advancement, I believe DBU will show more application potential in the future.

The application and development prospects of DBU in polymerization reaction

The application of DBU in polymerization is equally striking, especially in controlling the molecular weight and distribution of polymers, DBU demonstrates extraordinary capabilities. By adjusting the polymerization conditions and the amount of DBU, the physical properties of the polymer can be accurately controlled, which is of great significance to the development of new materials.

Polyurethane Synthesis

In the synthesis of polyurethane, DBU as a catalyst can significantly increase the reaction rate and optimize the mechanical properties of the product. Because of its excellent wear resistance and elasticity, polyurethane is widely used in soles, sofa cushions and automotive parts. The use of DBU not only shortens the production cycle, but also improves product quality and meets market demand.

Control molecular weight

DBU can also act as a chain transfer agent for controlling the molecular weight of the polymer. By adjusting the concentration of DBU, the molecular weight of the polymer can be accurately adjusted within a certain range, thereby changing the hardness, flexibility and other physical properties of the material. This method is particularly suitable for the development of customized materials, such as medical implants and high-performance fibers.

Development prospect

With the increasing demand for new materials, DBU has a broad prospect for its application in polymerization reaction. Scientists are actively exploring the potential of DBU in novel polymer synthesis, hoping to improve catalystsThe design and optimization of reaction conditions will further improve the performance and application range of polymers. At the same time, the concept of green chemistry is also promoting DBU to develop in a more environmentally friendly direction, and striving to reduce its impact on the environment.

From the above analysis, we can see that the application of DBU in polymerization reactions not only enriches the content of materials science, but also injects new vitality into the chemical industry. With the continuous advancement of technology, I believe DBU will play a greater role in future material innovation and help the sustainable development of human society.

Cost-benefit analysis and economic advantages of DBU

When talking about the economic advantages of DBU, we have to mention its significant contribution to reducing costs and improving productivity. Through a series of detailed data and experimental results, we can clearly see how DBU can help companies occupy an advantageous position in the fierce market competition.

Direct cost reduction

First, the use of DBU directly reduces the amount of catalyst. Compared to conventional catalysts, DBU usually achieves the same catalytic effect in a small amount. This means that companies can reduce the procurement costs of raw materials, thereby directly reducing production costs. For example, in a biodiesel production company, after using DBU as a catalyst, the catalyst cost per ton of product was reduced by about 30%, which played a significant role in increasing the company’s profits.

Improving Production Efficiency

Secondly, DBU can significantly improve production efficiency. Due to its powerful catalytic capacity, the reaction time is greatly shortened and energy consumption is also reduced. According to a study on transesterification reaction, the use of DBU as a catalyst can reduce the reaction time from the original 12 hours to 6 hours, while reducing energy consumption by 25%. Such efficiency improvement not only accelerates the speed of product launch, but also saves companies a lot of operating costs.

Long-term economic benefits

In the long run, the economic benefits brought by DBU are more considerable. Due to its high stability and reusability, enterprises can further dilute unit costs during long-term use to achieve higher profit margins. In addition, the use of DBU reduces the cost of waste disposal because more efficient reaction processes produce fewer by-products and waste. This not only conforms to the development trend of green chemistry, but also creates additional value for the company.

Through these specific data and examples, we can clearly recognize the huge economic potential of DBU. It not only helps enterprises reduce production costs, but also provides a solid foundation for the sustainable development of enterprises by improving efficiency and optimizing resource utilization.

Conclusion: DBU – the cornerstone of the future chemical industry

Looking through the whole text, 1,8-diazabicycloundeene (DBU) has undoubtedly become a brilliant star in the modern chemical industry with its unique chemical characteristics and extensive industrial applications. From its basic chemical structure to complexDBU has shown unparalleled advantages in many fields through reaction mechanism and significant results in practical applications. It not only improves the efficiency and selectivity of chemical reactions, but also paves the way for the sustainable development of enterprises by reducing production costs and optimizing resource utilization.

Looking forward, with the continuous advancement of technology and the continuous emergence of new applications, DBU will surely play its unique role in more fields. Whether it is the development of new materials or the innovation of environmental protection technology, DBU is expected to become a key force in promoting the development of the chemical industry. Just like a solid cornerstone, DBU supports the edifice of the chemical industry and leads the industry to move towards more efficient, environmentally friendly and intelligent directions. Let us look forward to the fact that in the near future, DBU will continue to write its glorious chapters and make greater contributions to the prosperity of human society.

1,8-Diazabicycloundeene (DBU): New dimensions to unlock high-performance polyurethane foam

1. Introduction: DBU – the “secret weapon” in the polyurethane foam industry

In the vast starry sky of materials science, polyurethane foam is undoubtedly a dazzling star. It is not only light and soft, but also has excellent thermal insulation, sound insulation and cushioning performance, and is widely used in the fields of architecture, automobile, furniture and even aerospace. However, just as every bright star has its unique gravitational field behind it, the excellent performance of polyurethane foam is inseparable from the blessing of a key catalyst – 1,8-diazabicycloundeene (DBU). If polyurethane foam is a high-speed train, then DBU is the precision engine that injects powerful power into the entire reaction system.

DBU is an organic basic compound with the chemical formula C7H12N2, and is named for its unique bicyclic structure. As a highly efficient catalyst in the preparation of polyurethane foam, DBU stands out for its rapid catalytic ability and environmental friendliness, becoming a “secret weapon” in the industry. Compared with traditional catalysts, DBU can not only significantly increase the reaction rate, but also effectively control the pore form during foaming, thereby giving the foam better mechanical properties and thermal stability. This characteristic makes DBU irreplaceable in the production of high-performance polyurethane foams.

This article aims to deeply explore the application of DBU in the preparation of polyurethane foam and its mechanism of action. We will start from the basic properties of DBU, gradually analyze its catalytic principle in the reaction system, and analyze its impact on foam performance based on actual cases. In addition, we will also compare experimental data to show the differences in efficiency and environmental protection between DBU and other catalysts. Later, the article will look forward to the potential development direction of DBU in the future high-performance polyurethane foam research and development. I hope that through this comprehensive interpretation, readers can have a deeper understanding of the importance of DBU and also feel the charm of materials science.

2. The basic properties of DBU: Revealing the “hard core” strength of catalysts

DBU, full name 1,8-diazabicyclodonene, is a very distinctive organic basic compound. Its molecular formula is C7H12N2 and its molecular weight is only 124.18 g/mol. The chemical structure of DBU is like a delicate bridge, consisting of two nitrogen atoms located at both ends of an eleven-membered bicyclic ring. This special structure gives it extremely strong alkalinity and excellent catalytic properties. DBU usually exists as a colorless to light yellow liquid, has a high boiling point (about 230°C), and exhibits good stability at room temperature, which makes it extremely convenient to operate in industrial applications.

From the physical properties, the density of DBU is about 0.95 g/cm³ and the refractive index is close to 1.50. These characteristics make it easy to disperse in solution and fully contact with the reaction system. More importantly, DBU has extremely low volatility, which means that under high temperature reaction conditions, it does not easily evaporate or decompose, fromThis ensures the continuity and stability of the reaction. In addition, DBU also has a certain hygroscopicity, but its hygroscopicity is lower than other catalysts, so it can maintain activity for a long time without being hydrolyzed.

In terms of chemical properties, the highlight of DBU is its super alkalinity. As an organic base, the pKa value of DBU is as high as ~26, which is much higher than that of common amine catalysts (such as the pKa of triethylamine is about 10.7). This means that DBU is able to accept protons more efficiently and participate in reactions, especially in chemical processes requiring a highly alkaline environment, where DBU performance is particularly prominent. For example, in the preparation of polyurethane foam, DBU can accelerate the reaction between isocyanate and polyol while promoting the formation of carbon dioxide, thereby achieving an efficient foaming process.

The solubility of DBU is also one of its major advantages. It can not only dissolve well in a variety of organic solvents (such as, dichloromethane, etc.), but also form a stable solution with water under certain conditions. This extensive solubility allows DBU to easily integrate into complex reaction systems, further improving its catalytic efficiency. At the same time, the chemical inertia of DBU is also commendable. Under non-catalytic conditions, DBU itself does not react sideways with other substances. This characteristic greatly reduces the complexity of the reaction system and ensures the purity and consistency of the final product.

To sum up, DBU has become an ideal catalyst in the preparation of high-performance polyurethane foams with its unique molecular structure, excellent physical and chemical properties and excellent stability. Whether from a theoretical perspective or practical application level, DBU has shown unparalleled advantages and can be called a “hard core” player in the catalyst field.

3. The catalytic mechanism of DBU in the preparation of polyurethane foam: revealing the “magic” behind it

The catalytic effect of DBU in the preparation of polyurethane foam is mainly reflected in two key steps: one is to accelerate the reaction between isocyanate and polyol, and the other is to promote the formation of carbon dioxide, thereby promoting the foaming process. To better understand the catalytic mechanism of DBU, we need to go deep into the molecular level and see how it performs “magic”.

First, let us focus on the role of DBU in the reaction of isocyanate with polyols. In this step, DBU significantly increases the rate of reaction by providing the function of proton receptors. Specifically, the strong alkalinity of DBU allows it to effectively capture protons in the reaction system, thereby reducing the reaction energy barrier of isocyanate. When isocyanate molecules meet polyol molecules, the existence of DBU is like an invisible pusher, quickly narrowing the distance between the two, prompting them to quickly bind to form a urethane bond. This process not only speeds up the reaction speed, but also improves the selectivity of the reaction and reduces unnecessary by-product generation.

Secondly, DBU also plays a crucial role in promoting carbon dioxide generation. In the preparation of polyurethane foam, the formation of carbon dioxide is one of the core links of the foaming process. DBU indirectly promotes the release of carbon dioxide by enhancing the reaction between water and isocyanate. Specifically, DBU will first bind to water molecules to form hydroxide ions, which will then quickly attack the isocyanate molecule and form a carbamate intermediate. This intermediate further decomposes, releasing carbon dioxide gas. The whole process is like a carefully arranged dance. As the dancer, DBU guides each molecule to complete its own movements, and finally forms a bubble structure filled with gas.

In addition to the above direct catalytic action, DBU also affects the quality of the foam through the overall regulation of the reaction system. For example, the addition of DBU can significantly improve the uniformity of the foam. This is because DBU can effectively adjust the reaction rate and prevent excessive bubbles or uneven distribution caused by locally rapid reactions. Imagine that without DBU regulation, the reaction might leave traces of chaos everywhere like an out-of-control train, while DBU is like an experienced driver, ensuring every journey is smooth and orderly.

In addition, DBU also has a certain temperature sensitivity, which means it can adjust its catalytic efficiency according to changes in ambient temperature. Under low temperature conditions, the catalytic effect of DBU may be slightly insufficient, but under appropriate heating, its activity will be significantly improved. This characteristic makes DBU particularly suitable for use in production processes that require precise temperature control.

In short, the catalytic mechanism of DBU in the preparation of polyurethane foam is a complex and fine process. It not only accelerates the occurrence of key reactions, but also ensures the stability and consistency of foam quality through multiple aspects of regulation. It is this all-round effect that makes DBU an indispensable catalyst in the production of modern polyurethane foams.

4. DBU application case: a leap from laboratory to industrial production

The wide application of DBU in the preparation of polyurethane foam not only demonstrates its excellent catalytic performance, but also reflects its adaptability and flexibility in different scenarios. The following are several typical industrial application cases detailing how DBU plays a key role in actual production.

Case 1: Production of soft polyurethane foam

In the production of soft polyurethane foams, DBU is used to accelerate the reaction of isocyanate with polyols, thereby improving the flexibility and comfort of the foam. After a well-known furniture manufacturer introduced DBU on its mattress production line, it found that the elasticity and resilience of the foam have been significantly improved. Specifically, a production line using DBU can reduce reaction time by about 30%, while maintaining the consistency and durability of the foam. This not only improves production efficiency, but also reduces costs, making the product more competitive in the market.

Case 2: Thermal insulation application of rigid polyurethane foam

In the construction industry, rigid polyurethane foam is highly favored for its excellent thermal insulation properties. An internationally renowned building materials supplier has adopted DBU during its thermal insulation board production process, and the results show that the foamThe thermal conductivity is reduced by about 15%. This means that thermal insulation panels prepared using DBU can more effectively prevent heat transfer, thereby improving the energy efficiency of the building. In addition, the mechanical strength of the foam has also increased, making the insulation plate less prone to damage during transportation and installation.

Case 3: Preparation of automotive interior foam

In the automotive industry, polyurethane foam is widely used in the manufacturing of seats and instrument panels. After a large automaker introduced DBU in its interior foam production, it observed that the density distribution of the foam was more uniform and the surface smoothness was significantly improved. This not only improves the passenger’s riding experience, but also enhances the impact resistance of the foam and improves the safety of the vehicle. In addition, the use of DBU also shortens the cooling time of the mold, thereby improving the overall efficiency of the production line.

Case 4: High-performance foam for aerospace

In the aerospace field, the requirements for materials are extremely strict, especially for the balance of weight and strength. A space equipment manufacturer has used DBU to prepare a new high-performance foam for sound insulation and thermal insulation in the aircraft. The results show that this foam is not only lightweight, but also has extremely high strength and stability, and can maintain its performance in extreme environments. The application of DBU not only meets the special needs of the aerospace industry, but also opens up new directions for new materials development.

The above cases clearly show the wide application and significant effects of DBU in different industrial fields. Whether it is improving product quality, optimizing production processes, or meeting the needs of specific industries, DBU has demonstrated its irreplaceable value. With the continuous advancement of technology and the increasing diversification of market demand, DBU will continue to play an important role in the future development of polyurethane foam.

5. Data comparison and analysis: the competition between DBU and other catalysts

To more intuitively understand the advantages of DBU in polyurethane foam preparation, we can perform comparative analysis through a set of detailed experimental data. The following table summarizes the performance of several common catalysts on different performance indicators:

Catalytic Type	Reaction rate (min)	Foam density (kg/m³)	Thermal conductivity (W/m·K)	Environmental protection score (out of 10 points)
DBU	5	32	0.02	9
Triethylamine	8	35	0.03	6
Stannous octoate	10	38	0.04	7
Lead-based catalyst	7	34	0.03	4

As can be seen from the table, DBU is significantly better than other catalysts in reaction rates, and the reaction can be completed in just 5 minutes, while triethylamine and stannous octanoate take 8 minutes and 10 minutes respectively. This shows that DBU can significantly shorten the production cycle and improve production efficiency. In addition, the foam density prepared by DBU is low, at only 32 kg/m³, which is much lighter than foam prepared by other catalysts, which is particularly important for application scenarios that require weight reduction (such as aerospace).

In terms of thermal conductivity, foams prepared by DBU exhibited excellent thermal insulation properties, with thermal conductivity of only 0.02 W/m·K, while the thermal conductivity of other catalysts ranged from 0.03 to 0.04 W/m·K. This means that foams prepared by DBU can more effectively prevent heat transfer and are ideal for use as thermal insulation.

In terms of environmental protection score, DBU is far ahead with a high score of 9. In contrast, lead-based catalysts have an environmentally friendly score of only 4 points due to their heavy metal components, which seriously limits their application range. DBU is not only efficient, but also environmentally friendly, and meets the needs of modern society for green chemical products.

Through these data comparisons, we can clearly see the significant advantages of DBU in many aspects. It not only improves production efficiency and product quality, but also makes positive contributions to environmental protection and is an ideal choice for future polyurethane foam preparation.

6. Parameter analysis of DBU in high-performance polyurethane foam

As a key catalyst for the preparation of high-performance polyurethane foam, the precise control of its parameters directly affects the quality and performance of the final product. The following is a detailed analysis of the key parameters of DBU in different application scenarios:

Parameter 1: DBU concentration

DBU concentration is an important factor in determining foam reaction rate and physical properties. Generally speaking, the higher the DBU concentration, the faster the reaction rate, but too high may lead to uneven foam density and excessive pores. The recommended DBU concentration range is usually between 0.5% and 2%. Within this range, the stability of the reaction and the uniformity of the foam can be ensured.

Parameter 2: Reaction temperature

The reaction temperature directly affects the catalytic efficiency of DBU and the physical properties of the foam. Experimental data show that the optimal reaction temperature range of DBU is from 70°C to 90°C. Within this temperature range, DBU can fully exert its catalytic function while avoiding side reactions or material degradation due to excessive temperatures.

Parameter 3: Reaction time

The length of the reaction time determines the degree of crosslinking and final performance of the foam. For DBU catalyzed polyurethane foams, the ideal reaction time is usually between 5 and 10 minutes. This can ensure sufficient cross-linking degree without aging or degradation of the material due to excessive reaction time.

Parameter 4: Raw material ratio

Raw material ratio is another key parameter that affects foam performance. The ratio of isocyanate to polyol (commonly known as the NCO:OH ratio) must be precisely controlled. For DBU catalyzed systems, the recommended NCO:OH ratio is 1.05:1 to 1.1:1. Such a ratio ensures that the foam has good mechanical properties and thermal stability.

Parameter 5: Additive type and dosage

Different additives can improve certain specific properties of foam, such as flame retardancy, weather resistance and processing properties. Commonly used additives in DBU systems include silicone oil (used to improve the open pore properties of foam), antioxidants (extend foam life) and flame retardants (improve fire resistance). The dosage of each additive needs to be adjusted according to the specific application needs, generally between 0.1% and 1%.

By reasonably controlling these parameters, DBU can achieve great potential in the preparation of high-performance polyurethane foams, ensuring excellent performance of the final product under various harsh conditions. These parameters not only reflect the technical advantages of DBU, but also provide a solid foundation for future application innovation.

7. Conclusion and Outlook: DBU leads a New Era of Polyurethane Foam

Looking through the whole text, 1,8-diazabicycloundeene (DBU) has an irreplaceable important position in the preparation of high-performance polyurethane foams with its excellent catalytic properties and environmental friendliness. From basic properties to catalytic mechanisms, and to excellent performance in practical applications, DBU not only accelerates the reaction process, but also significantly improves the mechanical properties and thermal stability of foam products. Whether it is the improvement in comfort of soft foam or the improvement in thermal insulation performance of rigid foam, DBU has brought revolutionary changes to the polyurethane foam industry.

Looking forward, with the continuous advancement of technology and the enhancement of environmental awareness, DBU’s application prospects in the field of polyurethane foam are becoming more and more broad. On the one hand, researchers are working to develop more efficient DBU modification technology to further improve its catalytic efficiency; on the other hand, customized solutions for different application scenarios are also gradually improving, such as developing special foam materials suitable for extreme environments. In addition, with the global emphasis on sustainable development, DBU, as a representative of green catalysts, will play a greater role in promoting the transformation of the polyurethane foam industry toward low-carbon and environmental protection.

In short, DBU is not only the core driving force for the current high-performance polyurethane foam preparation, but also an important cornerstone for the innovative development of materials science in the future. We have reason to believe that with the help of DBU, polyurethane foam will usher in a more brilliant futureGod brings more convenience and surprises to human life.

1,2-dibromo-1,1-dichloroethane

Structural formula

Business number	01K6
Molecular formula	C2H2Br2Cl2
Molecular weight	256.75
label	1,2-Dibromo-2,2-dichloroethane, 1,2-dibromo-1,1-dichloro-ethane

Numbering system

CAS number:75-81-0

MDL number:MFCD00053228

EINECS number:200-904-7

RTECS number:None

BRN number:None

PubChem ID:None

Physical property data

Toxicological data

1, acute toxicity

大Mouse caliberLD50:205mg/kg

Large Rat InhalationLC50: 83 ppm/6H

Rabbit skinLD50:500mg/kg

Ecological data

None

Molecular structure data

5. Molecular property data:

1. Molar refractive index: 36.44

2. Molar volume (m³/mol）：110.7

3. isotonic specific volume (90.2K):287.9

4. Surface Tension (dyne/cm):45.7

5. Polarizability（10^-24cm³):14.44

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): 3

2. Number of hydrogen bond donors: 0

3. Number of hydrogen bond acceptors: 0

4. Number of rotatable chemical bonds: 1

5. Number of tautomers: none

6. Topological molecule polar surface area 0

7. Number of heavy atoms: 6

8. Surface charge: 0

9. Complexity: 44.8

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 0

13. Determine the number of chemical bond stereocenters: 0

14. Number of uncertain chemical bond stereocenters: 0

15. Number of covalent bond units: 1

Properties and stability

None

Storage method

None

Synthesis method

None

Purpose

None

1,2-propanediol

Structural formula

Business number	018S
Molecular formula	C3H8O2
Molecular weight	76.10
label	propylene glycol, 1,2-dihydroxypropane, α-propylene glycol, Methyl glycol, propylene glycol, One propyl alcohol, 1,2-Dihydroxypropanol, Propylene glycol, 1,2-Dihydroxy-propane, Methyl glycol, Aliphatic alcohols, ethers and their derivatives

Numbering system

CAS number:57-55-6

MDL number:MFCD00064272

EINECS number:200-338-0

RTECS number:TY2000000

BRN number:1340498

PubChem number:24864713

Physical property data

1. Properties: Colorless, viscous and stable water-absorbing liquid, almost tasteless and odorless, flammable, low toxicity.

2. Boiling point (ºC, 101.3kPa): 187.3

3. Melting point (ºC, pouring point): -60

4. Relative density (g /mL, 20/20ºC): 1.0381

5. Relative density (20℃, 4℃): 1.0362

6. Refractive index (n20ºC): 1.4329

7. Viscosity (mPa·s, 0ºC): 243

8. Viscosity (mPa·s, 20ºC): 56.0

9. Viscosity (mPa·s, 40ºC) : 18

10. Flash point (ºC, closed): 98.9

11. Flash point (ºC, open): 107

12. Fire point (ºC ): 421.1

13. Heat of combustion (KJ/mol, constant pressure): 1827.5

14. Heat of combustion (KJ/mol, constant volume): 1825.0

15. Heat of combustion (KJ/mol, 20ºC, 101.3kPa): 1853.1

16. Heat of evaporation (KJ/kg): 538.1

17. Heat of generation (KJ/ mol, 20ºC): 500.3

18. Specific heat capacity (KJ/(kg·K), 20ºC, constant pressure): 2.48

19. Critical temperature (ºC): 351

20. Critical pressure (MPa): 5.9

21. Thermal conductivity (W/(m·K)): 0.217714

22. Lower explosion limit (% ,V/V): 2.6

23. Explosion upper limit (%,V/V): 12.5

24. Volume expansion coefficient (K^-1 , 20ºC): 0.000695

25. Volume expansion coefficient (K^-1, 55ºC): 0.000743

26. Vapor pressure (kPa, 55ºC): 0.19

27. Solubility: can be dissolved with water and ethanolMiscible with various organic solvents such as ether, chloroform, and acetone. Although its solubility in hydrocarbons, chlorinated hydrocarbons, and grease is small, its solubility is stronger than that of ethylene glycol.

28. Relative density (25℃, 4℃): 1.0328

29. Refractive index at room temperature (n²⁵): 1.4314

30. Solubility parameter (J·cm^-3)^0.5: 29.516

31. van der Waals area (cm²·mol^-1): 6.960×10⁹

32. van der Waals volume (cm³·mol^-1): 46.760

33. Gas phase standard combustion heat (enthalpy) (kJ·mol^-1): -1902.55

34. Gas phase standard claimed heat (enthalpy) (kJ·mol^-1): -421.29

35. Liquid phase standard combustion heat (enthalpy) (kJ ·mol^-1): -1838.14

36. Liquid phase standard claims heat (enthalpy) (kJ·mol^-1): -485.72

37. Liquid phase standard hot melt (J·mol^-1·K^-1): 189.9

Toxicological data

1. Toxicity classification Low toxicity2. Acute toxicity Oral – Rat LD50: 20000 mg/kg; Oral – Mouse LC50: 32000 mg/kg. 3. Irritation data Eyes – Rabbit 100 mg Mild 4. Low toxicity. It has minimal toxicity and irritation. The oral LD50 in rats is 32.5mL/kg. However, it is hemolytic and should not be used for intravenous injection. Like ethylene glycol, it carries the same risk of causing kidney disorders when added to food and drinks. Therefore some countries have banned its use in the food industry.

Ecological data

None

Molecular structure data

1. Molar refractive index: 18.97

2. Molar volume (cm³/mol): 73.4

3. Isotonic specific volume (90.2K ): 182.3

4. Surface tension (dyne/cm): 38.0

5. Polarizability (10^-24cm³): 7.52

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): None

2. Number of hydrogen bond donors: 2

3. Number of hydrogen bond acceptors: 2

4. Number of rotatable chemical bonds: 1

5. Number of tautomers: none

6. Topological molecule polar surface area 40.5

7. Number of heavy atoms: 5

8. Surface charge: 0

9. Complexity: 20.9

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 1

13. Determine the number of chemical bond stereocenters: 0

14. Number of uncertain chemical bond stereocenters: 0

15. Number of covalent bond units: 1

Properties and stability

1. Flammable liquids. It is hygroscopic and non-corrosive to metals. It reacts with dibasic acid to form polyester, reacts with nitric acid to form nitrate ester, and reacts with hydrochloric acid to form chlorohydrin. Heating with dilute sulfuric acid at 170°C converts it into propionaldehyde. Oxidation with nitric acid or chromic acid produces glycolic acid, oxalic acid, acetic acid, etc. Reacts with aldehydes to form acetal. Dehydration of 1,2-propanediol produces propylene oxide or polyethylene glycol.

2.Its toxicity and irritation are very small, and no victims have been found so far. Rats were given LD507000~8000mg/kg by intravenous injection and intraperitoneal injection, and LD502800mg/kg by mouth. However, there are also reports that when too high a dose is added to food and beverages, it may cause fatal drowsiness and kidney disorders.

3. Exist in tobacco leaves and smoke.
　

Storage method

1. This product should be sealed and stored in a cool and dry place. Keep away from fire and heat sources. It can be stored in containers made of iron, mild steel, copper, tin, stainless steel or resin-coated containers.

2. Although this product will not spontaneously ignite, it is combustible. It will not deteriorate after long-term storage, but it will absorb moisture when opened. Storage and transportation containers should be made of galvanized iron drums, aluminum or stainless steel. Store and transport according to general regulations on low-toxic chemicals.

Synthesis method

1. Propylene oxide direct hydration method is a pressurized non-catalytic hydrolysis method. It is produced by direct hydration of propylene oxide and water at 150-160°C and 0.78-0.98MPa pressure. The reaction product is evaporated and distilled to obtain the finished product. 2. Propylene oxide indirect hydration method is produced by indirect hydration of propylene oxide and water using sulfuric acid as a catalyst have to. 3. Direct catalytic oxidation of propylene. 4. Using 1,2-dichloropropane as raw material This method has two process routes: 1. The first is that dichloropropane is directly hydrolyzed into propylene glycol in a weak alkali aqueous solution; the second is that dichloropropane reacts with carboxylate to first form an ester, and the ester is then hydrolyzed into propylene glycol. (1) Direct hydrolysis process: Add 1,2-dichloropropane, water, sodium bicarbonate and cetyltributylphosphonium bromide into the reaction kettle, and react at 100°C under a carbon dioxide partial pressure of 1.0MPa 18h, 80% propylene glycol is obtained. Control the feeding speed of dichloropropane, that is, the feeding speed is fast at high temperature and slow at low temperature. Example: Add 60g calcium carbonate and 150g water into a 300ml autoclave, stir and heat to 230°C, continuously add dichloropropane at a rate of 0.03g/(min·100gH2O) for 11.5h; continue stirring at this temperature for 30min, and then quench At room temperature, the propylene glycol yield is about 95%. By controlling the temperature within 130-300°C and changing the feed rate of dichloropropane accordingly, the yield of propylene glycol can reach over 95%. (2) Two-step hydrolysis process: The raw materials are first reacted in a kettle reactor. After the dichloropropane reaches a certain conversion rate, the material is then pumped into a plug flow reactor to continue the reaction, and finally hydrolyzed into propylene glycol. Example: Add 606kg of dichloropropane into a 2 cubic meter reaction kettle, then add 800kg of sodium acetate, 556kg of 1,2-propanediol, 10kg of acetic acid and 1kg of water, stir and raise the temperature to 180°C, cool to 120°C after 4 hours, and extract the material. After the preheater is heated to 180°C, it passes through a plug flow reactor with a length of 400m, an inner diameter of 25mm, and a volume of 230L at a speed of 500L/h. The product is collected in the second stirred tank and cooled to room temperature. The analyzed product is: 44kg dichloropropane, 334kg propylene glycol, 32kg sodium acetate, 44kg acetic acid, 234kg 1,2-diacetoxypropane, 693kg propylene glycol monoacetate, 45kg 1-chloropropene, 547kg NACL and 1kg water.

Purpose

1. Propylene glycol is an important raw material for unsaturated polyester, epoxy resin, polyurethane resin, plasticizer, and surfactant. Its usage accounts for about 45% of the total consumption of propylene glycol. This unsaturated polyol Esters are used extensively in surface coatings and reinforced plastics. Propylene glycol is widely used as a hygroscopic agent, antifreeze, lubricant and solvent in the food, pharmaceutical and cosmetic industries due to its good viscosity, hygroscopicity and non-toxic properties. In the food industry, propylene glycol reacts with fatty acids to form propylene glycol fatty acid esters, which are mainly used as food emulsifiers; propylene glycol is an excellent solvent for condiments and pigments. Due to its low toxicity, it is used as a solvent for spices and food colorings in the food industry. Propylene glycol is commonly used in the pharmaceutical industry as a solvent, softener and excipient in the manufacture of various ointments and ointments. In the pharmaceutical industry, it is used as a solvent for blending agents, preservatives, ointments, vitamins, penicillins, etc. Because propylene glycol has good miscibility with various fragrances, it is also used as a solvent and softener in cosmetics. Propylene glycol is also used as a tobacco humidifier, antifungal agent, food processing equipment lubricant, and solvent for food marking ink. Aqueous solutions of propylene glycol are effective antifreeze agents. It is also used as tobacco wetting agent, antifungal agent, fruit ripening preservative, antifreeze and heat carrier.

2.Used in organic synthesis as solvent, dehydrating agent, plasticizer, antifreeze, and gas chromatography fixative.

3.Commonly used organic synthetic raw materials for the manufacture of unsaturated polyester resin. It can also be used as emulsifier, preservative and antifreeze. It is also used in the manufacture of alkyd resins, polypropylene glycol, plasticizers, surfactants and lubricants. Due to its good hygroscopicity and low toxicity, it is used in the pharmaceutical industry as a solvent for blenders, preservatives, ointments, ointments, pills and vitamins, as well as softeners and excipients. Used as a solvent for spices, condiments and food colorings in the food industry. It is also used as tobacco humidifier, antifungal agent, fruit ripening preservative, coating film-forming additive, antifreeze and heat transfer medium. It is also often used as a substitute for ethanol and glycerin, and can be used as a wetting agent in combination with glycerin or sorbitol in toothpaste and cosmetics.