Applications of bismuth isooctanoate in sealants and adhesives and its impact on performance
Introduction
With the continuous development of industrial technology, sealants and adhesives have been widely used in construction, automobile manufacturing, aerospace and other fields. Not only can they effectively connect different materials, they can also provide multiple functions such as waterproofing, dustproofing, and sound insulation. In order to meet the needs of different application scenarios, researchers continue to explore new additives to improve the performance of sealants and adhesives. Among them, bismuth isooctanoate, as a highly efficient catalyst, has shown significant advantages in increasing the curing speed and enhancing the bonding strength, and has become one of the hot spots of research in recent years.
Basic properties of bismuth isooctanoate
Bismuth Neodecanoate is an organic bismuth compound with the chemical formula Bi(C8H15O2)3. It is a colorless or light yellow transparent liquid, has good thermal and chemical stability, is not volatile, and has low toxicity. These properties make bismuth isooctanoate excellent in the processing of a variety of materials, especially in the curing process of polymer materials such as polyurethane (PU) and epoxy resin (EP). It is particularly widely used as a catalyst.
The mechanism of action of bismuth isooctanoate in sealants and adhesives
In sealants and adhesives, bismuth isooctanoate mainly works in the following ways:
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Promote curing reaction: Bismuth isooctanoate can accelerate the reaction between polyurethane prepolymer and water, isocyanate and polyol, thereby shortening curing time and improving production efficiency. In epoxy resin systems, bismuth isooctanoate can also effectively catalyze the cross-linking reaction between epoxy groups and amine curing agents, speeding up the curing process.
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Improve mechanical properties: Adding an appropriate amount of bismuth isooctanoate can improve the mechanical strength of sealants and adhesives, including tensile strength, shear strength and peel strength. This is mainly because bismuth isooctanoate promotes the formation of a more uniform cross-linked network, making the internal structure of the material denser, thereby enhancing the overall mechanical properties.
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Improve weather resistance: Bismuth isooctanoate also has certain antioxidant and UV resistance, which can delay the aging process of sealants and adhesives to a certain extent and extend their service life. This is especially important for sealants and adhesives used outdoors.
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Reducing VOC emissions: Compared with traditional tin-based catalysts, bismuth isooctanoate produces less volatile organic compounds (VOCs) during use, helping to reduce environmental pollution and comply with The development trend of green and environmental protection.
Specific effects of bismuth isooctanoate on the properties of sealants and adhesives
1. Curing speed
Studies have shown that there is a positive correlation between the amount of bismuth isooctanoate and the curing speed. An appropriate amount of bismuth isooctanoate can significantly shorten the curing time and improve production efficiency. For example, adding 0.1% to 0.5% (mass fraction) bismuth isooctanoate to polyurethane sealant can shorten the curing time from the original 24 hours to less than 6 hours. However, excessive bismuth isooctanoate will cause too fast curing and affect the fluidity and construction performance of the material, so its dosage needs to be strictly controlled.
2. Bonding strength
Bismuth isooctanoate can significantly improve the bonding strength of sealants and adhesives. Experimental results show that the shear strength of polyurethane adhesives containing 0.2% bismuth isooctanoate on stainless steel and glass substrates increased by 20% and 30% respectively. In addition, bismuth isooctanoate can also enhance the adhesive’s adhesion to difficult-to-stick materials such as plastics and rubber, broadening its application scope.
3. Weather resistance
The addition of bismuth isooctanoate can significantly improve the weather resistance of sealants and adhesives. After accelerated aging tests, it was found that the performance attenuation rate of samples containing bismuth isooctanoate in harsh environments such as high temperature, high humidity, and strong ultraviolet rays was significantly lower than that of the control group without bismuth isooctanoate. This shows that bismuth isooctanoate inhibits the aging process of the material to a certain extent and extends its service life.
4. VOC emissions
Environmental protection is an important direction for the development of modern industry, and bismuth isooctanoate also performs well in this aspect. Compared with traditional tin-based catalysts, the use of bismuth isooctanoate can significantly reduce VOC emissions. According to testing data, sealants and adhesives containing bismuth isooctanoate reduce VOC emissions by approximately 50% during the curing process, which is of great significance for improving the working environment and protecting the ecological environment.
Application cases
1. Automobile manufacturing industry
In automobile manufacturing, sealants and adhesives are widely used in body sealing, windshield fixing, and interior parts bonding. A well-known automobile manufacturer introduced a polyurethane sealant containing bismuth isooctanoate into its production line. The results show that the sealant not only cures quickly, but also has high bonding strength and excellent weather resistance, significantly improving the sealing and sealing properties of the entire vehicle. Security.
2. Construction industry
There is a huge demand for sealants and adhesives in the construction sector, especially in large-scale engineering projects such as high-rise buildings, bridges, and tunnels. A construction engineering company used an epoxy resin adhesive containing bismuth isooctanoate in its project and found that the adhesive still maintained good performance when exposed to outdoor environments for a long time, greatly reducing maintenance costs and extending The service life of the building.
3. Electronic products
Electronic products have extremely demanding requirements for sealants and adhesives. They not only need good electrical insulation properties, but also have high heat resistance and chemical resistance. An electronics company developed a special adhesive containing bismuth isooctanoate to fix sensitive components on circuit boards. Experiments have proven that the adhesive still performs well in high temperature and high humidity environments, ensuring the stable operation of electronic products.
Conclusion
In summary, bismuth isooctanoate, as a highly efficient catalyst, shows significant advantages in sealants and adhesives. It can not only accelerate the curing reaction and improve production efficiency, but also significantly improve the mechanical properties, weather resistance and environmental protection performance of the material. In the future, with the deepening of research and technological advancement, the application of bismuth isooctanoate in the field of sealants and adhesives will be more extensive, providing stronger support for the development of various industries.
Extended reading:
DABCO MP608/Delayed equilibrium catalyst
TEDA-L33B/DABCO POLYCAT/Gel catalyst