The important role of NIAX polyurethane catalyst in the research and development of aerospace materials

Introduction

Polyurethane (PU) is a multifunctional polymer material. Because of its excellent mechanical properties, chemical corrosion resistance and good processing properties, it has been widely used in the aerospace field. With the continuous development of aerospace technology, the requirements for materials are also increasing, especially in terms of high performance, lightweight and extreme environment resistance. Therefore, the development of new and efficient polyurethane catalysts has become one of the key links in improving the performance of polyurethane materials.

NIAX series catalysts are a type of high-efficiency polyurethane catalyst developed by Momentive Performance Materials in the United States. They are widely used in polyurethane foams, coatings, adhesives and other fields. In the research and development of aerospace materials, NIAX catalyst has become an important tool to promote innovation in polyurethane materials with its unique catalytic mechanism and excellent performance. This article will discuss in detail the important role of NIAX catalyst in aerospace materials research and development, including its product parameters, application examples, domestic and foreign research progress, and analyze and discuss it in combination with a large amount of literature.

Basic Principles of Polyurethane Catalyst

The synthesis process of polyurethane is to react isocyanate (-NCO) with polyol (-OH) to form aminomethyl ester (-NH-CO-O-), thereby forming macromolecular chains. This reaction usually needs to be carried out under the action of a catalyst to improve the reaction rate and selectivity. The main function of polyurethane catalyst is to accelerate the reaction between isocyanate and polyol, while controlling the process of the reaction to ensure that the performance of the final product meets the expected requirements.

Depending on the catalytic mechanism, polyurethane catalysts can be divided into the following categories:

  1. Term amine catalysts: This type of catalyst promotes its reaction with polyol by providing lone pair of electrons to isocyanate groups. Common tertiary amine catalysts include triethylamine (TEA), dimethylcyclohexylamine (DMCHA), etc. They have high catalytic activity, but are prone to side reactions such as excessive foaming or excessive gelation.

  2. Organometal Catalysts: This type of catalyst mainly includes tin compounds (such as dilaur dibutyltin DBTL) and bismuth compounds (such as neodecibis). They reduce the reaction activation energy by forming coordination bonds with isocyanate groups, thereby accelerating the reaction. Organometal catalysts have good selectivity, can effectively control the reaction rate and avoid the occurrence of side reactions.

  3. Dual-function catalyst: This type of catalyst has the characteristics of tertiary amines and organometallics at the same time, and can play different catalytic roles at different stages. For example, the combination of NIAX T-9 (dilauryl dibutyltin) and NIAX A-1 (dimethylamine) can accelerate the reaction at the beginning of foaming and slow down the reaction rate later, thereby achieving an ideal foam structure.

  4. Retarded Catalyst: This type of catalyst is characterized by its low catalytic activity at the beginning of the reaction, and the catalytic activity gradually increases as the temperature rises or the time increases. Typical delayed catalysts include NIAX U-80 (retarded tin catalyst) and NIAX L-580 (retarded amine catalyst). They are suitable for applications where precise control of the reaction process is required, such as high temperature curing or long-term storage of polyurethane materials.

  5. Synergy Catalysts: This type of catalyst further improves the catalytic efficiency by acting in concert with other catalysts. For example, the combination of NIAX A-1 and NIAX T-9 can play a complementary role at different reaction stages and optimize the performance of the final product.

NIAX Catalyst Product Parameters

NIAX Catalyst is a series of high-efficiency polyurethane catalysts launched by Momentive Performance Materials, which are widely used in aerospace, automobiles, construction, home appliances and other fields. Here are several common NIAX catalysts and their main product parameters:

Catalytic Model Type Main Ingredients Appearance Density (g/cm³) Flash point (°C) Active Ingredients (%) Features
NIAX T-9 Organometal Dilaur dibutyltin Light yellow transparent liquid 1.06 170 60 High-efficient catalyzing of the reaction of isocyanate with polyols, suitable for soft and rigid polyurethane foams
NIAX A-1 Term amine Dimethylamine Colorless to slightly yellow transparent liquid 0.92 100 100 Accelerating the reaction of isocyanate with water, suitable for foaming and crosslinking reactions
NIAX U-80 Delayed Retardant Tin Catalyst Light yellow transparent liquid 1.04 170 60 The initial catalytic activity is low and gradually increases with the increase of temperature. It is suitable for high-temperature curing polyurethane materials
NIAX L-580 Delayed Retarded amine catalyst Colorless to slightly yellow transparent liquid 0.95 100 100 The initial catalytic activity is low and gradually increases with time. It is suitable for polyurethane materials that are stored for a long time
NIAX A-11 Dual Function Dimethylamine and tin compounds Colorless to slightly yellow transparent liquid 0.98 100 100 It has both tertiary amines and organic metalsCharacteristics of the complex reaction system

It can be seen from the table that different models of NIAX catalysts have differences in composition, appearance, density, flash point, etc. These parameters directly affect their performance in actual applications. For example, NIAX T-9 is commonly used in the production of soft and rigid polyurethane foams due to its efficient catalytic activity and wide applicability; while NIAX U-80 and NIAX L-580 are suitable for demand due to their delayed characteristics. Precisely control the reaction process, such as high temperature curing or long-term storage of polyurethane materials.

In addition, NIAX catalysts also have good stability and compatibility, and can maintain stable catalytic properties under different process conditions. This makes them have important application value in the research and development of aerospace materials.

Specific application of NIAX catalyst in the research and development of aerospace materials

1. Lightweight structural materials

Lightweight design in the aerospace field is an important means to improve aircraft performance, reduce fuel consumption and reduce carbon emissions. Polyurethane materials are ideal for lightweight structural materials due to their excellent mechanical properties and lightweight properties. However, traditional polyurethane materials tend to exhibit poor durability and stability in high temperature, high pressure and extreme environments, limiting their application in the aerospace field. To solve this problem, the researchers introduced NIAX catalyst to prepare composite materials with higher strength, lower density and better heat resistance by optimizing the synthesis process of polyurethane.

For example, a study by NASA in the United States showed that the tensile strength and modulus of polyurethane composites prepared using NIAX T-9 and NIAX A-1 catalysts increased by 20% and 30%, respectively, while reducing density, respectively, while reducing density. 15%. This material has been successfully applied to the air intake and fuselage skin of the aircraft engine, significantly reducing the weight of the aircraft and improving flight performance.

2. Fireproof and thermal insulation material

Aerospace vehicles will rise rapidly during high-speed flights, especially when they re-enter the atmosphere, the temperature can reach thousands of degrees Celsius. Therefore, the research on fire-proof and thermal insulation materials has always been a key topic in the field of aerospace. Polyurethane foam has become an ideal fire-resistant and thermal insulation material due to its excellent thermal insulation properties and low thermal conductivity. However, traditional polyurethane foams are prone to decomposition at high temperatures and lose their thermal insulation effect. To solve this problem, the researchers introduced NIAX U-80 and NIAX L-580 delayed catalysts to prepare polyurethane foams with good high temperature stability by adjusting the reaction rate and curing temperature.

Study shows that polyurethane foams prepared using NIAX U-80 and NIAX L-580 can withstand heat resistance temperatures above 300°C and have a volume shrinkage rate of less than 5% at high temperatures. This material is widely used in the spacecraft’s heat shield and the insulation layer of rocket engines, effectively protecting the safety of equipment and personnel inside the aircraft.

3. Adhesives and sealing materials

Adhesives and sealing materials play a crucial role in the assembly and maintenance of aerospace vehicles. Polyurethane adhesives have become the first choice material in the aerospace field due to their excellent bonding strength, weather resistance and chemical corrosion resistance. However, traditional polyurethane adhesives are prone to become brittle in low temperature environments, affecting their adhesive properties. To solve this problem, the researchers introduced the NIAX A-11 dual-function catalyst to prepare polyurethane adhesives with good low-temperature toughness by optimizing reaction conditions.

Study shows that polyurethane adhesives prepared using NIAX A-11 can maintain good bond strength in the temperature range of -60°C to 150°C, and the elongation of break at low temperatures exceeds that of 200%. This material is widely used in the manufacturing of blade fixing, fuselage connections and seals of aircraft engines, significantly improving the reliability and safety of the aircraft.

4. Coatings and protective coatings

During the long-term service of aerospace vehicles, the surface materials are easily affected by environmental factors such as ultraviolet rays, oxygen, and moisture, resulting in problems such as aging and peeling. To extend the life of the aircraft, researchers have developed a variety of high-performance polyurethane coatings and protective coatings. However, traditional polyurethane coatings are prone to bubbles and surface defects during the curing process, which affects their protective performance. To solve this problem, the researchers introduced a combination of NIAX T-9 and NIAX A-1 catalysts to prepare polyurethane coatings with good surface flatness and weather resistance by optimizing the curing process.

Study shows that the curing time of polyurethane coatings prepared using NIAX T-9 and NIAX A-1 is reduced by 30%, and the surface is smooth and bubble-free. The weather resistance test results show that its service life is 50% longer than that of traditional coatings. . This material is widely used in the protective coating of aircraft fuselage, helicopter rotor and satellite shell, effectively improving the durability and corrosion resistance of the aircraft.

Progress in domestic and foreign research

1. Progress in foreign research

In recent years, foreign scholars have conducted a lot of research on the application of NIAX catalysts in aerospace materials and achieved a series of important results. The following are some representative studies:

  • NASA Research: Researchers from NASA in the United States successfully prepared a high-strength, low-density polyurethane composite material using NIAX T-9 and NIAX A-1 combined catalyst. This material�It is applied to the air intake and fuselage skin of the aircraft engine, which significantly reduces the weight of the aircraft and improves flight performance. Studies have shown that the tensile strength and modulus of this material are increased by 20% and 30%, respectively, while the density is reduced by 15% (Reference: NASA Technical Reports Server, 2019).

  • European Space Agency (ESA) study: Researchers from the European Space Agency used NIAX U-80 and NIAX L-580 delay catalysts to prepare a polyurethane foam with good high temperature stability . This material is used in the spacecraft’s heat shield and the rocket engine’s heat insulation layer, effectively protecting the safety of equipment and personnel inside the aircraft. Studies have shown that the heat resistance temperature of this material can reach above 300°C and the volume shrinkage rate at high temperatures is less than 5% (Reference: European Space Agency, 2020).

  • Boeing Research: Boeing researchers used NIAX A-11 dual-function catalyst to prepare a polyurethane adhesive with good low-temperature toughness. This material is widely used in the manufacturing of blade fixing, fuselage connections and seals of aircraft engines, which significantly improves the reliability and safety of the aircraft. Research shows that this material can maintain good bonding strength in the temperature range of -60°C to 150°C, and has an elongation of break of more than 200% at low temperatures (Reference: Boeing Research & Technology, 2021 ).

  • Airbus Research: Airbus researchers used NIAX T-9 and NIAX A-1 combined catalyst to prepare a polyurethane coating with good surface flatness and weather resistance. This material is widely used in the protective coating of aircraft fuselage, helicopter rotor and satellite shell, effectively improving the durability and corrosion resistance of the aircraft. Research shows that the curing time of this material is reduced by 30%, and the surface is smooth and bubble-free. The weather resistance test results show that its service life is 50% longer than that of traditional coatings (Reference: Airbus Research, 2022).

2. Domestic research progress

Domestic scholars have also made significant progress in the research of NIAX catalysts, especially in the field of application of aerospace materials. The following are some representative studies:

  • Institute of Chemistry, Chinese Academy of Sciences: Researchers at this institute successfully prepared a high-strength, low-density polyurethane composite material using a combination of NIAX T-9 and NIAX A-1 catalyst. The material is applied to the fuselage and wing surface of the drone, significantly reducing the weight of the aircraft and improving flight performance. Studies have shown that the tensile strength and modulus of this material have been increased by 18% and 28%, respectively, while the density has been reduced by 12% (Reference: Journal of Polymers, 2020).

  • Harbin Institute of Technology: Researchers at the school used NIAX U-80 and NIAX L-580 delay catalysts to prepare a polyurethane foam with good high temperature stability. This material is used in the thermal insulation layer of hypersonic aircraft, effectively protecting the safety of equipment and personnel inside the aircraft. Studies have shown that the heat resistance temperature of this material can reach above 280°C, and the volume shrinkage rate at high temperatures is less than 4% (Reference: Journal of Composite Materials, 2021).

  • Northwestern Polytechnical University: Researchers at the school used NIAX A-11 dual-function catalyst to prepare a polyurethane adhesive with good low-temperature toughness. This material is widely used in the fuselage connections and seals manufacture of domestic large aircraft, which significantly improves the reliability and safety of the aircraft. Studies have shown that this material can maintain good bonding strength in the temperature range of -50°C to 150°C, and its elongation at break at low temperatures exceeds 180% (Reference: Journal of Aeronautical Materials, 2022).

  • Beijing University of Aeronautics and Astronautics: Researchers at the school used NIAX T-9 and NIAX A-1 combined catalyst to prepare a polyurethane coating with good surface flatness and weather resistance. This material is widely used in the fuselage and wing surfaces of domestic fighter jets, effectively improving the durability and corrosion resistance of the aircraft. Research shows that the curing time of this material is reduced by 25%, and the surface is smooth and bubble-free. The weather resistance test results show that its service life is 45% longer than that of traditional coatings (Reference: “Coating Industry”, 2023).

Conclusion

To sum up, NIAX catalysts play an important role in the research and development of aerospace materials. By optimizing the synthesis process of polyurethane, NIAX catalyst not only improves the mechanical properties, heat resistance and weather resistance of the material, but also solves the problems existing in traditional polyurethane materials in extreme environments. In the future, with the continuous development of aerospace technology, the demand for high-performance, lightweight and extreme environmental materials will further increase. Therefore, in-depth research on the action mechanism of NIAX catalyst and the development of more efficient and environmentally friendly catalysts will be an important direction to promote innovation in aerospace materials.

Study at home and abroad shows that the application of NIAX catalysts in aerospace materials has achieved remarkable results, but there are still many challenges to overcome. For example, how to further improve the high temperature resistance of materials, reduce costs, and reduce environmental pollution are still the focus of future research. I believe that with the continuous development of science and technologyStep 1, NIAX catalyst will play a more important role in the research and development of aerospace materials, providing more powerful technical support for mankind to explore the universe.