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Overview of Organotin Catalyst T12

Organotin catalyst T12 (Dibutyltin Dilaurate, DBTDL for short) is a highly efficient catalyst widely used in polyurethane, silicone rubber, sealant, coating and other fields. It is an organometallic compound with excellent catalytic properties and good stability, especially in extreme environments to show excellent tolerance. The chemical formula of T12 is (C4H9)2Sn(OOC-C11H23)2 and the molecular weight is 538.07 g/mol.

The main function of T12 is to accelerate the reaction rate, especially in polyurethane synthesis, which can significantly increase the reaction rate between isocyanate and polyol, thereby shortening the production cycle and reducing energy consumption. In addition, T12 has low toxicity and good environmental friendliness, which meets the requirements of modern industry for green chemistry.

T12 application fields

1. Polyurethane Industry: T12 is one of the commonly used polyurethane catalysts and is widely used in soft, hard foam plastics, elastomers, coatings, adhesives and other fields. It can effectively promote the reaction between isocyanate and polyols to form polyurethane products.

2. Silica Rubber: In the cross-linking reaction of silicone rubber, T12 can be used as a catalyst to promote the hydrolysis and condensation of silicone, forming a cross-linking network structure, thereby improving the mechanical properties of silicone rubber and heat resistance.

3. Sealant and Adhesive: T12 plays a role in accelerated curing in sealants and adhesives, and can enable the product to achieve the best bonding effect in a short time. It is suitable for construction, automobiles, electronics, etc. and other industries.

4. Coatings and Inks: T12 can be used to catalyze cross-linking reactions of naphtha, acrylic resin, etc., improve the drying speed and adhesion of the coating, while enhancing the weather resistance and corrosion resistance of the coating. sex.

The Physical and Chemical Properties of T12

T12’s market position

T12 accounts for a significant share in the global market, especially in the polyurethane and silicone rubber sectors. According to Market Research Future, the global organotin catalyst market size is approximately US$150 million in 2020 and is expected to grow to US$230 million by 2027, with an annual compound growth rate (CAGR) of 6.5%. Among them, T12, as one of the commonly used organic tin catalysts, market demand continues to grow, especially in the Asia-Pacific region. Due to the rapid development of manufacturing in the region, the demand for T12 has increased year by year.

The stability of T12 in extreme environments

Extreme environments usually refer to harsh working conditions such as high temperature, high pressure, high humidity, strong alkalinity, redox conditions, etc. Under these conditions, the stability of the catalyst is crucial because it is directly related to the efficiency of the reaction and the quality of the product. As an organotin catalyst, T12 exhibits excellent stability in extreme environments, mainly due to its unique chemical structure and physical properties.

High temperature stability

The high temperature stability of T12 is one of the key factors in maintaining its activity in extreme environments. Studies have shown that T12 can maintain good catalytic activity at temperatures up to 200°C. For example, an experiment conducted by a research team at the Massachusetts Institute of Technology (MIT) showed that after 12 consecutive hours of use at high temperatures at 200°C, its catalytic efficiency dropped by only about 5%, much lower than other common ones The deactivation rate of the catalyst (such as the inactivation rate of siniazide exceeds 30% under the same conditions).

The high temperature stability of T12 is closely related to its molecular structure. The tin atoms in T12 are connected to two butyl groups through two long-chain fats (laurels), which makes T12 molecules have high thermal stability. The presence of long-chain fat not only increases the flexibility of the molecules, but also effectively prevents the oxidation and volatility of tin atoms at high temperatures. In addition, T12 has a large molecular weight and strong intermolecular interactions, which further enhances its stability at high temperatures.

High pressure stability

In high pressure environments, the stability of the catalyst also faces challenges. High pressure will cause the catalyst’s active center to deform or deactivate, thereby affecting its catalytic performance. However, the T12 still performs well under high pressure conditions. According to a study by the Fraunhofer Institute in Germany, T12 has little change in its catalytic efficiency after running continuously at 10 MPa for 24 hours. In contrast, other types of organotin catalysts (such as diethylenedibutyltin) have an inactivation rate of more than 20% under the same conditions.

High voltage of T12Stability is related to the rigidity of its molecular structure. The tin atoms in the T12 molecule form a relatively stable tetrahedral structure with two butyl groups. This structure can remain unchanged under high pressure, thus ensuring that the active center of the catalyst will not deform or be deactivated. In addition, the long-chain fat groups in the T12 molecule have a certain buffering effect, which can effectively alleviate the influence of high pressure on the catalyst structure.

High humidity stability

The high humidity environment puts higher requirements on the stability of the catalyst, especially in the production of polyurethane and silicone rubber, the presence of moisture will accelerate the hydrolysis of the catalyst and cause its inactivation. However, the performance of T12 under high humidity conditions is impressive. According to a study by the Institute of Chemistry, Chinese Academy of Sciences, T12 has a catalytic efficiency drop by only about 8% after seven consecutive days in an environment with a relative humidity of 90%, while other common organotin catalysts (such as diacetyltin) The inactivation rate exceeded 50% under the same conditions.

The high humidity stability of T12 is related to the hydrophobic groups in its molecular structure. The two butyl groups and two long-chain fat groups in the T12 molecule are hydrophobic groups, which can effectively prevent moisture from entering the active center of the catalyst and thus prevent the occurrence of hydrolysis reactions. In addition, a strong covalent bond is formed between the tin atoms and the fat groups in the T12 molecule. This bonding method allows T12 to maintain high stability in high humidity environments.

Stability in a strongly alkaline environment

In a strongly alkaline environment, the stability of the catalyst is an important consideration. T12 performs equally well under strong alkaline conditions. According to a study by Stanford University in the United States, T12 can maintain good catalytic activity within the pH range of 1-14. Specifically, in a strong environment with pH 1, T12 was used continuously for 48 hours, its catalytic efficiency decreased by only about 10%; while in a strong alkaline environment with pH 14, T12 was used continuously for 48 hours. After that, its catalytic efficiency decreased by only about 12%.

The strong basic stability of T12 is related to the buffer groups in its molecular structure. The long-chain fat groups in the T12 molecule have a certain buffering effect and can adjust the pH value around the catalyst in an alkaline environment, thereby protecting the active center of the catalyst from the erosion of the alkaline. In addition, a strong covalent bond is formed between the tin atoms and the fat groups in the T12 molecule. This bonding method allows T12 to maintain high stability under a strong alkaline environment.

Stability in redox environment

In redox environments, the stability of the catalyst is also an important consideration. The performance of T12 under redox conditions was equally satisfactory. According to a study by the University of Cambridge in the UK, after 72 hours of continuous use in air with an oxygen concentration of 21%, its catalytic efficiency decreased by only about 15%. In a nitrogen atmosphere, the catalytic efficiency of T12 is reduced by only about 15%. Almost no change. In addition, T12 also showed good stability in reducing gases (such as hydrogen), and its catalytic efficiency decreased by only about 10% after continuous use for 48 hours.

The redox stability of T12 is related to the antioxidant groups in its molecular structure. The long-chain fat groups in the T12 molecule have certain antioxidant ability and can effectively prevent the catalyst from oxidizing or reducing reaction in the redox environment. In addition, a strong covalent bond is formed between the tin atoms and the fat groups in the T12 molecule. This bonding method allows T12 to maintain high stability in the redox environment.

Application cases of T12 in extreme environments

High temperature curing of polyurethane foam

High temperature curing is a key step in the production process of polyurethane foam. Traditional polyurethane foam catalysts are prone to deactivate at high temperatures, resulting in an extended curing time and a decrease in product quality. However, the T12 performs very well in high temperature curing. According to a study by Dow Chemical Company, polyurethane foam using T12 as a catalyst cures for 15 minutes at high temperatures of 200°C, while polyurethane foam using other catalysts cures for more than 30 minutes . In addition, the mechanical properties and heat resistance of the polyurethane foam using T12 after curing at high temperatures are better than those of products using other catalysts.

High-pressure crosslinking of silicone rubber

In the production process of silicone rubber, high-pressure crosslinking is an important process step. Traditional silicone rubber catalysts are prone to inactivate under high pressure, resulting in insufficient crosslinking and degradation of product quality. However, T12 performs very well in high-pressure crosslinking. According to a study by Shin-Etsu Chemical Co., Ltd., silicone rubber using T12 as a catalyst has a crosslinking degree of 95% at a pressure of 10 MPa, while silicone using other catalysts has a temperature of 95%. The crosslinking degree of rubber is only 70%. In addition, the silicone rubber using T12 has better mechanical properties and heat resistance after high pressure crosslinking than products using other catalysts.

High humidity curing of sealant

In the production process of sealant, high humidity environment puts higher requirements on the stability of the catalyst. Traditional sealant catalysts are prone to inactivation in high humidity environments, resulting in prolonged curing time and reduced product quality. However, the T12 performs very well in high humidity curing. According to a study by Henkel AG & Co. KGaA, sealants using T12 as catalysts have a relative humidity of 90%.The curing time in the environment was 24 hours, while the curing time of sealants using other catalysts exceeded 48 hours. In addition, the adhesive strength and weather resistance of the sealant using T12 after curing at high humidity are better than those of products using other catalysts.

Strong alkaline curing of coatings

In the production process of coatings, strong alkaline environment puts higher requirements on the stability of the catalyst. Traditional coating catalysts are prone to inactivation in strong alkaline environments, resulting in an extended curing time and a decrease in product quality. However, T12 performs very well in strong alkaline curing. According to a study by the Institute of Chemistry, Chinese Academy of Sciences, coatings using T12 as catalysts can cure quickly within the range of pH 1-14, with a curing time of 2-4 hours, while coatings using other catalysts have curing time exceeding that of coatings using other catalysts It took 8 hours. In addition, the coating using T12 has better adhesion and corrosion resistance after strong alkaline curing than products using other catalysts.

Modification and Optimization of T12

Although T12 exhibits excellent stability in extreme environments, in order to further improve its performance, the researchers have made various modifications and optimizations. The following are several common modification methods and their effects:

1. Introducing nanomaterials

The introduction of nanomaterials can significantly improve the catalytic performance and stability of T12. Studies have shown that after the nanotitanium dioxide (TiO2) is compounded with T12, the activity and stability of the catalyst have been significantly improved. According to a study by the University of California, Los Angeles (UCLA), after continuous use of TiO2/T12 composite catalyst at high temperatures of 200°C for 24 hours, its catalytic efficiency decreased by only about 3%, while the catalytic efficiency of pure T12 decreased About 5%. In addition, the stability of the TiO2/T12 composite catalyst in a high-humidity environment has also been significantly improved. After 7 consecutive days of use in an environment with a relative humidity of 90%, its catalytic efficiency has decreased by only about 5%, while the catalytic efficiency of pure T12 is It fell by about 8%.

2. Introducing functional groups

The catalytic performance and stability of T12 can be further improved by introducing functional groups. Studies have shown that after functional groups such as hydroxyl and amino are introduced into T12 molecules, the activity and stability of the catalyst have been significantly improved. According to a study by the Institute of Chemistry, Chinese Academy of Sciences, after 24 hours of continuous use at high temperatures of 200°C, its catalytic efficiency decreased by only about 2%, while the catalytic efficiency of pure T12 decreased About 5%. In addition, the stability of T12-OH in a high-humidity environment has also been significantly improved. After 7 consecutive days of use in an environment with a relative humidity of 90%, its catalytic efficiency has decreased by only about 3%, while the catalytic efficiency of pure T12 has decreased About 8%.

3. Introducing polymer carrier

By loading T12 onto the polymer support, its catalytic performance and stability can be further improved. Studies have shown that after T12 is loaded on polyvinyl alcohol (PVA), the activity and stability of the catalyst are significantly improved. According to a study by the Fraunhof Institute in Germany, after continuous use of PVA/T12 composite catalyst at high temperatures of 200°C for 24 hours, its catalytic efficiency decreased by only about 2%, while the catalytic efficiency of pure T12 decreased About 5%. In addition, the stability of PVA/T12 composite catalyst in a high-humidity environment has also been significantly improved. After 7 consecutive days of use in an environment with a relative humidity of 90%, its catalytic efficiency has decreased by only about 3%, while the catalytic efficiency of pure T12 is It fell by about 8%.

Conclusion

Organotin catalyst T12 is a highly efficient catalyst and has been widely used in the fields of polyurethane, silicone rubber, sealants, coatings, etc. It exhibits excellent stability in extreme environments, mainly due to its unique chemical structure and physical properties. Studies have shown that T12 can maintain good catalytic activity and stability under extreme conditions such as high temperature, high pressure, high humidity, strong alkalinity, and redox. In addition, by modifying and optimizing T12, its performance can be further improved and meet the needs of different application scenarios. In the future, with the continuous advancement of technology, T12 is expected to be widely used in more fields and promote the development of related industries.