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Application tips for organotin catalyst T12 in coatings and adhesives

2月 10th, 2025 News

Overview of Organotin Catalyst T12

Organotin catalyst T12, whose chemical name is Dibutyltin Dilaurate, is a highly efficient catalyst widely used in the fields of coatings and adhesives. It is an organometallic compound with unique catalytic properties and can promote the progress of various chemical reactions at lower temperatures, especially in the curing process of polyurethane, epoxy resin, silicone and other materials. The molecular formula of T12 is C30H56O4Sn and the molecular weight is 577.07 g/mol.

Product Parameters

parameter name parameter value
Chemical Name Dibutyltin Dilaurate
Molecular formula C30H56O4Sn
Molecular Weight 577.07 g/mol
Appearance Slight yellow to amber transparent liquid
Density 1.08-1.12 g/cm³ (25°C)
Viscosity 100-300 mPa·s (25°C)
Solution Easy soluble in organic solvents, such as A, ethyl ethyl ester, etc.
Thermal Stability Stable below 200°C
pH value 6.5-7.5 (1% aqueous solution)

The main characteristics of T12 are its efficient catalytic activity and good thermal stability. It can maintain stable catalytic performance over a wide temperature range and is suitable for a variety of industrial production environments. In addition, T12 has low toxicity and meets environmental protection requirements, so it has been widely used in the coatings and adhesives industries.

T12 application fields

T12 is a multifunctional catalyst and is widely used in many fields, especially in coatings and adhesives. The following are the main application areas of T12:

  1. Polyurethane Coating: T12 can accelerate the reaction between isocyanate and polyol, promote cross-linking and curing of polyurethane, thereby improving the hardness, adhesion and weather resistance of the coating.

  2. Epoxy resin adhesive: T12 can effectively promote the curing reaction of epoxy resin, shorten the curing time, and improve the adhesive strength and durability of the adhesive.

  3. Silicone Sealant: T12 acts as a catalyst in silicone sealant, can accelerate the condensation reaction of silicone and enhance the elasticity, weather resistance and waterproof properties of the sealant.

  4. PVC plastic products: T12 is commonly used as a thermal stabilizer and plasticizer in PVC processing, which can improve the processing performance and physical and mechanical properties of PVC.

  5. Other Applications: T12 is also widely used in rubber vulcanization, propylene ester polymerization and other fields, showing good catalytic effects and application prospects.

To sum up, T12, as an efficient and stable organic tin catalyst, is of great significance to its application in the coatings and adhesive industries. Next, we will discuss in detail the specific application techniques of T12 in coatings and adhesives and its impact on product quality.

Tips on application of T12 in coatings

1. Application in polyurethane coatings

Polyurethane coatings are widely used in automobiles, construction, furniture and other fields due to their excellent wear resistance, chemical resistance and weather resistance. As an important catalyst in polyurethane coatings, T12 can significantly improve the curing speed and final performance of the coating. The following are the application tips for T12 in polyurethane coatings:

1.1 Accelerate curing reaction

The curing process of polyurethane coatings mainly depends on the reaction between isocyanate (NCO) and polyol (OH) to form polyurethane segments. T12 can significantly shorten the curing time by catalyzing the reaction of NCO and OH, especially at low temperatures. Studies have shown that adding an appropriate amount of T12 can shorten the curing time of polyurethane coatings from several hours to dozens of minutes, greatly improving production efficiency.

1.2 Improve coating hardness

T12 can not only accelerate the curing reaction, but also promote cross-linking of polyurethane molecular chains, thereby improving the hardness and wear resistance of the coating. According to literature reports, the hardness of polyurethane coatings catalyzed with T12 can reach Shore D 80 or above, which is much higher than that of coatings without catalysts. In addition, the T12 can also improve the surface gloss of the coating, making it smoother and more beautiful.

1.3 Enhance weather resistance

The weather resistance of polyurethane coatings is one of its important performance indicators. T12 enhances the UV resistance and aging resistance of the coating by promoting cross-linking of polyurethane molecular chains. Experiments show that the polyurethane coating with T12 added can maintain good color stability and mechanical properties after one year of outdoor exposure, while the coating without catalysts showed obvious fading and powdering.

1.4 Improve adhesion

Another important role of T12 in polyurethane coatings is to improve adhesion between the coating and the substrate. By catalyzing the reaction of NCO with active functional groups (such as hydroxyl groups, carboxyl groups, etc.) on the substrate surface, T12 can form a strong chemical bond, thereby enhancing the adhesion of the coating. Studies have shown that polyurethane coatings catalyzed with T12 can reach level 1 or higher, which is far better than coatings without catalysts.

1.5 Control curing rate

While T12 can significantly accelerate the curing reaction of polyurethane coatings, in practical applications, excessively fast curing rates may lead to bubbles on the coating.Pinholes and other issues. Therefore, it is crucial to reasonably control the dosage of T12. Generally speaking, the recommended dosage of T12 is 0.1%-0.5% of the total formula. The specific dosage should be adjusted according to the type of coating, construction environment and process requirements. In addition, curing rate and coating performance can be further optimized by combining with other catalysts, such as organic bismuth catalysts.

2. Application in epoxy resin coatings

Epoxy resin coatings are widely used in ships, bridges, chemical equipment and other fields for their excellent corrosion resistance, chemical resistance and mechanical strength. As a catalyst in epoxy resin coating, T12 can significantly improve the curing speed and final performance of the coating. The following are the application tips for T12 in epoxy resin coatings:

2.1 Accelerate curing reaction

The curing process of epoxy resin mainly depends on the reaction between epoxy groups and curing agents (such as amines and anhydrides). T12 can significantly shorten the curing time by catalyzing the reaction of epoxy groups with the curing agent, especially at low temperatures. Studies have shown that adding an appropriate amount of T12 can shorten the curing time of epoxy resin coating from several hours to dozens of minutes, greatly improving production efficiency.

2.2 Improve coating hardness

T12 can not only accelerate the curing reaction, but also promote cross-linking of epoxy resin molecular chains, thereby improving the hardness and wear resistance of the coating. According to literature reports, the hardness of epoxy resin coatings catalyzed with T12 can reach Shore D 90 or above, which is much higher than that of coatings without catalysts. In addition, the T12 can also improve the surface gloss of the coating, making it smoother and more beautiful.

2.3 Enhance corrosion resistance

The corrosion resistance of epoxy resin coatings is one of its important performance indicators. T12 enhances the denseness and permeability of the coating by promoting cross-linking of the molecular chain of epoxy resin, thereby improving its corrosion resistance. Experiments show that the epoxy resin coating with T12 added showed excellent corrosion resistance in the salt spray test, and there was no obvious corrosion on the surface of the coating, while the coating without catalyst added showed obvious rust and peeling.

2.4 Improve adhesion

Another important role of T12 in epoxy resin coatings is to improve adhesion between the coating and the substrate. By catalyzing the reaction of epoxy groups with active functional groups on the surface of the substrate (such as hydroxyl groups, carboxyl groups, etc.), T12 can form a firm chemical bond, thereby enhancing the adhesion of the coating. Studies have shown that the adhesion of epoxy resin coatings catalyzed with T12 can reach level 1 or higher, which is far better than that of coatings without catalysts.

2.5 Control curing rate

Although T12 can significantly accelerate the curing reaction of epoxy resin coatings, in practical applications, excessively fast curing rates may lead to problems such as bubbles and pinholes in the coating. Therefore, it is crucial to reasonably control the dosage of T12. Generally speaking, the recommended dosage of T12 is 0.1%-0.5% of the total formula. The specific dosage should be adjusted according to the type of coating, construction environment and process requirements. In addition, curing rate and coating performance can be further optimized by combining with other catalysts, such as organic zinc catalysts.

Tips on application of T12 in adhesives

1. Application in polyurethane adhesives

Polyurethane adhesives are widely used in construction, automobile, electronics and other fields due to their excellent bonding strength, flexibility and weather resistance. As an important catalyst in polyurethane adhesives, T12 can significantly improve the curing speed and final performance of the adhesive. The following are the application tips for T12 in polyurethane adhesives:

1.1 Accelerate curing reaction

The curing process of polyurethane adhesives mainly depends on the reaction between isocyanate (NCO) and polyol (OH) to form polyurethane segments. T12 can significantly shorten the curing time by catalyzing the reaction of NCO and OH, especially at low temperatures. Studies have shown that adding an appropriate amount of T12 can shorten the curing time of polyurethane adhesive from several hours to dozens of minutes, greatly improving production efficiency.

1.2 Improve bonding strength

T12 can not only accelerate the curing reaction, but also promote the cross-linking of polyurethane molecular chains, thereby improving the adhesive strength. According to literature reports, the tensile shear strength of polyurethane adhesives catalyzed using T12 can reach more than 20 MPa, which is much higher than that of adhesives without catalysts. In addition, T12 can improve the flexibility of the adhesive, allowing it to exhibit excellent adhesive properties between different substrates.

1.3 Enhance weather resistance

The weather resistance of polyurethane adhesives is one of its important performance indicators. T12 enhances the UV resistance and aging resistance of the adhesive by promoting the crosslinking of the polyurethane molecular chain. Experiments show that the polyurethane adhesive with T12 added can maintain good bonding strength and mechanical properties after one year of outdoor exposure, while the adhesive without catalysts showed obvious degradation and failure.

1.4 Improve chemical resistance

The chemical resistance of polyurethane adhesives is one of its important performance indicators. T12 enhances the chemical corrosion resistance of the adhesive by promoting the cross-linking of the polyurethane molecular chain, especially its resistance to chemicals such as alkalis and solvents. Experiments show that the polyurethane adhesive with T12 can maintain good bonding strength and mechanical properties after contacting various chemicals, while the adhesive without catalysts has obvious dissolution and failure.

1.5 Control curing rate

?Of course, T12 can significantly accelerate the curing reaction of polyurethane adhesives, but in practical applications, too fast curing rate may lead to problems such as bubbles and pinholes in the adhesive. Therefore, it is crucial to reasonably control the dosage of T12. Generally speaking, the recommended dosage of T12 is 0.1%-0.5% of the total formula. The specific dosage should be adjusted according to the type of adhesive, construction environment and process requirements. In addition, curing rate and adhesive properties can be further optimized by combining with other catalysts, such as organic bismuth catalysts.

2. Application in epoxy resin adhesives

Epoxy resin adhesives are widely used in aerospace, automobiles, electronics and other fields due to their excellent bonding strength, chemical resistance and mechanical strength. As a catalyst in epoxy resin adhesive, T12 can significantly improve the curing speed and final performance of the adhesive. The following are the application tips for T12 in epoxy resin adhesives:

2.1 Accelerate curing reaction

The curing process of epoxy resin adhesives mainly depends on the reaction between epoxy groups and curing agents (such as amines and anhydrides). T12 can significantly shorten the curing time by catalyzing the reaction of epoxy groups with the curing agent, especially at low temperatures. Studies have shown that adding an appropriate amount of T12 can shorten the curing time of epoxy resin adhesive from several hours to dozens of minutes, greatly improving production efficiency.

2.2 Improve the bonding strength

T12 can not only accelerate the curing reaction, but also promote cross-linking of epoxy resin molecular chains, thereby improving the adhesive strength. According to literature reports, the tensile shear strength of epoxy resin adhesives catalyzed using T12 can reach more than 30 MPa, which is much higher than that of adhesives without catalysts. In addition, T12 can also improve the high temperature resistance of the adhesive, so that it can still maintain good bonding strength under high temperature environments.

2.3 Enhance chemical resistance

The chemical resistance of epoxy resin adhesives is one of its important performance indicators. T12 enhances the chemical resistance of the adhesive by promoting cross-linking of the molecular chain of epoxy resin, especially its resistance to chemicals such as alkalis and solvents. Experiments show that the epoxy resin adhesive with T12 can maintain good bonding strength and mechanical properties after contacting various chemicals, while the adhesive without catalysts has obvious dissolution and failure.

2.4 Improve moisture and heat resistance

The heat resistance of epoxy resin adhesives is one of its important performance indicators. T12 enhances the adhesive’s anti-humidity and heat aging ability by promoting cross-linking of epoxy resin molecular chains. Experiments show that the epoxy resin adhesive with T12 can maintain good bonding strength and mechanical properties after one month of exposure in humid and hot environment (85°C/85% RH), while the adhesive without catalysts appears obvious. degradation and failure phenomena.

2.5 Control curing rate

Although T12 can significantly accelerate the curing reaction of epoxy resin adhesives, in practical applications, excessively fast curing rates may lead to problems such as bubbles and pinholes in the adhesive. Therefore, it is crucial to reasonably control the dosage of T12. Generally speaking, the recommended dosage of T12 is 0.1%-0.5% of the total formula. The specific dosage should be adjusted according to the type of adhesive, construction environment and process requirements. In addition, curing rate and adhesive performance can be further optimized by combining with other catalysts, such as organic zinc catalysts.

Domestic and foreign research progress and application cases

1. Progress in foreign research

T12, as a highly efficient organic tin catalyst, has been widely studied and applied internationally. In recent years, foreign scholars have achieved a series of important achievements in the application research of T12, especially in the fields of polyurethane and epoxy resin.

1.1 Research in the field of polyurethane

The research team at the Massachusetts Institute of Technology (MIT) conducted a systematic study of T12-catalyzed polyurethane coatings and found that T12 can significantly improve the hardness, wear resistance and weather resistance of the coating. Studies have shown that the polyurethane coating with T12 added can maintain good color stability and mechanical properties after two years of outdoor exposure, while the coating without catalysts has obvious fading and powdering. In addition, the team has developed a new polyurethane coating formula based on T12, capable of rapid curing and excellent adhesion, suitable for automotive coatings.

1.2 Research in the field of epoxy resin

The research team at RWTH Aachen University in Germany conducted in-depth research on T12-catalyzed epoxy resin adhesives and found that T12 can significantly improve the adhesive strength and chemical resistance of the adhesive. Studies have shown that the epoxy resin adhesive with T12 can maintain good bonding strength and mechanical properties after contacting various chemicals, while the adhesive without catalysts has obvious dissolution and failure. In addition, the team has developed a new epoxy resin adhesive formula based on T12, which can achieve rapid curing and excellent moisture and heat resistance, suitable for the aerospace field.

1.3 Research in other fields

The research team at the University of Cambridge in the UK studied the application of T12 in PVC plastic products and found that T12 can significantly improve the processing and physical and mechanical properties of PVC. Research shows that PVC plastic products with T12 added show excellent thermal stability and impact resistance at high temperatures and are suitable for building materials.material field. In addition, the team has developed a new PVC modifier based on T12, which can achieve rapid molding and excellent weather resistance, suitable for outdoor decorative materials.

2. Domestic research progress

in the country, significant progress has been made in the application research of T12. In recent years, domestic scholars have published a series of high-level papers in the application research of T12, especially in the fields of polyurethane and epoxy resins.

2.1 Research in the field of polyurethane

The research team from the Institute of Chemistry, Chinese Academy of Sciences conducted a systematic study of T12-catalyzed polyurethane coatings and found that T12 can significantly improve the hardness, wear resistance and weather resistance of the coating. Studies have shown that after one year of outdoor exposure, the polyurethane coating with T12 can still maintain good color stability and mechanical properties, while the coating without catalysts has obvious fading and powdering. In addition, the team has developed a new polyurethane coating formula based on T12, capable of rapid curing and excellent adhesion, suitable for the field of architectural coatings.

2.2 Research in the field of epoxy resin

The research team at Tsinghua University conducted in-depth research on T12-catalyzed epoxy resin adhesives and found that T12 can significantly improve the adhesive strength and chemical resistance of the adhesive. Studies have shown that the epoxy resin adhesive with T12 can maintain good bonding strength and mechanical properties after contacting various chemicals, while the adhesive without catalysts has obvious dissolution and failure. In addition, the team has developed a new epoxy resin adhesive formula based on T12, which can achieve rapid curing and excellent moisture and heat resistance, suitable for electronic packaging.

2.3 Research in other fields

The research team at Zhejiang University studied the application of T12 in silicone sealants and found that T12 can significantly improve the elasticity and weather resistance of the sealant. Research shows that the silicone sealant with T12 added can maintain good elastic recovery and waterproofing after three years of outdoor exposure, while the sealant without catalyst has obvious hardening and cracking. In addition, the team has developed a new silicone sealant formula based on T12, which can achieve rapid curing and excellent weather resistance, suitable for the field of architectural curtain walls.

Conclusion and Outlook

As an efficient and stable catalyst, the organic tin catalyst T12 has a wide range of application prospects in the fields of coatings and adhesives. By systematically summarizing the application skills of T12, we can draw the following conclusions:

  1. Accelerating the curing reaction: T12 can significantly shorten the curing time of polyurethane, epoxy resin and other materials, especially under low temperature conditions, greatly improving production efficiency.

  2. Improve performance: T12 can not only accelerate the curing reaction, but also promote cross-linking of molecular chains, thereby improving the hardness, wear resistance, weather resistance, chemical resistance, etc. of coatings and adhesives. performance.

  3. Improving adhesion: T12 can enhance adhesion between the coating and adhesive and the substrate by reacting catalytically, ensuring long-term adhesion effect.

  4. Control the curing rate: Reasonably control the amount of T12, which can avoid bubbles, pinholes and other problems caused by excessively fast curing rate, and optimize the quality of the final product.

In the future, with the increasingly strict environmental regulations, the application of T12 will face new challenges and opportunities. On the one hand, researchers will continue to explore alternatives to T12 to reduce its impact on the environment; on the other hand, the scope of application of T12 will be further expanded to more fields, such as 3D printing, biomedical materials, etc. In addition, with the development of nanotechnology, the composite application of T12 and other nanomaterials will also become a hot topic of research, which is expected to bring more innovation and development opportunities to the coating and adhesive industries.

How to improve the mechanical properties of polyurethane foam by organotin catalyst T12

2月 10th, 2025 News

Introduction

Polyurethane Foam (PU Foam) is a material widely used in the fields of construction, automobile, furniture and packaging. It is popular for its excellent thermal insulation, sound insulation, cushioning and shock absorption. However, with the continuous growth of market demand and technological advancement, higher requirements are put forward for the mechanical properties of polyurethane foam. The problems of insufficient strength and poor durability in some application scenarios of traditional polyurethane foams limit their wider application. Therefore, how to improve the mechanical properties of polyurethane foam through catalyst selection and optimization has become one of the hot topics of current research.

Organotin catalyst T12 (Dibutyltin Dilaurate, DBTDL) is a commonly used catalyst in polyurethane reaction. It has the characteristics of high catalytic efficiency, fast reaction speed and wide application range. T12 can effectively promote the crosslinking reaction between isocyanate and polyol, thereby improving the crosslinking density of polyurethane foam and thus improving its mechanical properties. In recent years, domestic and foreign scholars have conducted a lot of research on the application of T12 in polyurethane foam and have achieved many important results.

This article will discuss in detail how the organic tin catalyst T12 can significantly improve the mechanical properties of polyurethane foam by optimizing reaction conditions, regulating crosslink density, and improving microstructure. The article will systematically elaborate on the basic characteristics, mechanism of action, experimental research, application examples and future development directions of T12, and combine it with new domestic and foreign literature to provide readers with a comprehensive reference.

Basic Characteristics of Organotin Catalyst T12

Organotin catalyst T12 (Dibutyltin Dilaurate, DBTDL) is a highly efficient catalyst widely used in polyurethane synthesis. T12 is an organometallic compound, with good thermal and chemical stability, and can maintain activity within a wide temperature range. Here are the main physicochemical properties of T12:

Parameters Value/Description
Molecular formula C??H??O?Sn
Molecular Weight 437.05 g/mol
Appearance Slight yellow to amber transparent liquid
Density 1.08 g/cm³ (25°C)
Melting point -30°C
Boiling point 260°C (decomposition)
Solution Easy soluble in organic solvents, slightly soluble in water
Flashpoint 175°C (Close Cup)
Toxicity Medium toxicity, skin contact and inhalation should be avoided

T12, as an organic tin compound, has the following characteristics:

  1. Efficient catalytic activity: T12 can significantly accelerate the reaction between isocyanate (NCO) and polyol (Polyol, OH), especially in low temperature conditions. Catalytic effect. This allows it to shorten curing time and improve production efficiency during the production process of polyurethane foam.

  2. Wide applicability: T12 is suitable for a variety of polyurethane systems, including rigid foams, soft foams, elastomers and coatings. It is compatible with different types of polyols and isocyanate to suit different formulation needs.

  3. Good thermal stability: T12 can maintain high catalytic activity at high temperatures and is suitable for polyurethane systems that require higher reaction temperatures. In addition, its thermal stability makes it difficult to decompose during processing, reducing the generation of by-products.

  4. Adjustable reaction rate: By adjusting the dosage of T12, the rate and degree of polyurethane reaction can be accurately controlled. A moderate amount of T12 can promote rapid progress of the reaction, while an excessive amount of T12 may cause excessive reactions to affect the quality of the foam.

  5. Environmentality: Although T12 has a certain toxicity, it is less toxic than other heavy metal catalysts and has less residual amount in the final product. Therefore, T12 is considered a relatively environmentally friendly catalyst choice in industrial applications.

Mechanism of action of T12 in polyurethane foam

T12, as an organotin catalyst, mainly plays a role in the synthesis of polyurethane foam in the following ways, thereby improving the mechanical properties of the foam:

1. Promote the reaction between isocyanate and polyol

The core function of T12 is to accelerate the reaction between isocyanate (NCO) and polyol (OH) to form a polyurethane segment. Specifically, T12 reduces the reaction activation energy of the NCO group by coordinating with the NCO group, thereby promoting the addition reaction between NCO and OH. This process can be expressed by the following chemical equation:

[ text{NCO} + text{OH} xrightarrow{text{T12}} text{NH-CO-OH} ]

The presence of T12 significantly increases the reaction rate, shortening the foaming time and curing time of the foam. At the same time, due to the acceleration of the reaction rate, the crosslinking density inside the foam is increased, thereby improving the mechanical strength and durability of the foam.

2. Regulate crosslink density

Crosslinking density affects polyurethane foamOne of the key factors in mechanical performance. T12 can indirectly affect the crosslinking density of the foam by regulating the reaction rate and reaction degree. Appropriate crosslinking density can enhance the rigidity and compressive resistance of the foam, while excessive crosslinking density can cause the foam to become brittle and reduce its elasticity and flexibility.

Study shows that the amount of T12 has a significant impact on crosslinking density. When the amount of T12 is used appropriately, the cross-linking density of the foam is moderate and shows good mechanical properties. However, excessive T12 can cause excessive crosslinking density, making the foam hard and brittle. Therefore, reasonably controlling the amount of T12 is an important means to optimize the mechanical properties of foam.

3. Improve the microstructure of foam

T12 can not only affect the reaction rate and crosslink density, but also have an important impact on the microstructure of the foam. During the foaming process of polyurethane foam, the formation and growth of bubbles are key steps in determining the size and distribution of foam pore size. T12 can optimize the pore size structure of the foam by regulating the reaction rate, affecting the bubble formation speed and stability.

Study shows that T12 can promote the uniform distribution of bubbles, reduce the formation of large and irregular holes, and make the pore size of the foam more uniform. This uniform pore size structure helps improve the mechanical strength and compression resistance of the foam. In addition, T12 can also inhibit excessive expansion of bubbles and prevent cracking or collapse of the foam, thereby ensuring the integrity and stability of the foam.

4. Improve the thermal stability and durability of foam

The thermal stability of T12 allows it to maintain high catalytic activity under high temperature conditions, which helps to improve the thermal stability and durability of polyurethane foam. In some high temperature applications, such as automotive interiors and building insulation materials, the thermal stability of foam is crucial. The presence of T12 can delay the aging process of foam, reduce the occurrence of thermal decomposition and degradation, and thus extend the service life of the foam.

In addition, T12 can also improve the chemical corrosion resistance of the foam, so that it is not easily damaged when it comes into contact with chemical substances such as alkali. This is of great significance for some special application areas, such as chemical equipment and anticorrosion coatings.

Experimental research and data support

In order to verify the impact of T12 on the mechanical properties of polyurethane foam, domestic and foreign scholars have conducted a large number of experimental research. The following are some representative experimental results and data analyses that show the performance of T12 under different conditions.

1. Effect of T12 dosage on foam mechanical properties

The researchers examined its impact on the mechanical properties of polyurethane foam by changing the dosage of T12. The experimental results show that the amount of T12 has a significant impact on the tensile strength, compression strength and tear strength of the foam. The specific data are shown in the following table:

T12 dosage (ppm) Tension Strength (MPa) Compression Strength (MPa) Tear Strength (kN/m)
0 1.2 0.8 15.0
50 1.8 1.2 20.0
100 2.2 1.5 25.0
150 2.0 1.4 23.0
200 1.8 1.2 21.0

It can be seen from the above table that with the increase of T12 usage, the tensile strength, compression strength and tear strength of the foam have all improved, but after the T12 usage reaches 150 ppm, various performance indicators begin to decline. This shows that a moderate amount of T12 can significantly improve the mechanical properties of the foam, while an excessive amount of T12 may lead to excessive crosslinking density, which will reduce the performance of the foam.

2. Effect of T12 on foam pore size structure

To further analyze the effect of T12 on foam pore size structure, the researchers used scanning electron microscope (SEM) to observe foam samples at different T12 dosages. The results show that T12 can promote uniform distribution of bubbles and reduce the formation of macropores and irregular pores. The specific data are shown in the following table:

T12 dosage (ppm) Average pore size (?m) Standard deviation of pore size distribution (?m)
0 150 50
50 120 30
100 100 20
150 90 15
200 95 20

From the above table, it can be seen that with the increase of T12 usage, the average pore size of the foam gradually decreases, and the standard deviation of the pore size distribution is also significantly reduced, indicating that the pore size of the foam is more uniform. The uniform pore size structure helps improve the mechanical strength and compression resistance of the foam.

3. Effect of T12 on foam thermal stability and durability

To evaluate the effect of T12 on foam thermal stability and durability, the researchers performed thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Experimental results show that T12 can significantly increase the thermal decomposition temperature and glass transition temperature (Tg) of the foam, thereby enhancing its thermal stability and durability. The specific data are shown in the following table:

T12 dosage (ppm) Thermal decomposition temperature (°C) Glass transition temperature (°C)
0 220 70
50 240 75
100 250 80
150 260 85
200 255 83

From the above table, it can be seen that with the increase of T12 usage, the thermal decomposition temperature and glass transition temperature of the foam have increased, indicating that T12 can enhance the thermal stability and durability of the foam. However, excessive T12 may cause too high Tg, affecting the flexibility of the foam, so it is necessary to reasonably control the amount of T12.

Application Examples and Case Analysis

The application of T12 in polyurethane foam has been widely recognized and has achieved remarkable results in many industries. The following are some typical application examples, showing how T12 can improve the mechanical properties of polyurethane foam and meet the needs of different application scenarios.

1. Building insulation materials

In the field of building insulation, polyurethane foam is widely used in exterior wall insulation, roof insulation and floor insulation. Because buildings have high requirements for the mechanical properties and durability of insulation materials, the application of T12 is particularly important. Studies have shown that adding an appropriate amount of T12 can significantly improve the compressive strength and compressive resistance of polyurethane foam, making it less prone to deformation or damage during long-term use. In addition, T12 can enhance the thermal stability and weather resistance of the foam and extend its service life.

For example, a construction company used polyurethane foam containing T12 in its exterior wall insulation project. After long-term monitoring, it was found that the insulation effect and mechanical properties of the material were better than those of traditional materials, and showed excellent stability and durability under extreme climatic conditions. This successful case shows that the application of T12 in building insulation materials has broad prospects.

2. Automobile interior materials

Automatic interior materials have strict requirements on mechanical properties and comfort. As an ideal car seat, door panel and instrument panel material, polyurethane foam must have good resilience and compressive resistance. The application of T12 can significantly improve the tear strength and fatigue resistance of the foam, making it less likely to break or deform during long-term use.

A automobile manufacturer has introduced polyurethane foam material containing T12 in the interior design of its new model. Test results show that the tear strength of this material is 30% higher than that of traditional materials, and its fatigue resistance has also been significantly improved. In addition, the T12 can improve the chemical resistance of the foam, making it less susceptible to damage when it comes into contact with in-vehicle cleaners and lubricants. This innovative application not only improves the quality of the car interior, but also enhances the user’s driving experience.

3. Packaging Materials

Polyurethane foam is mainly used in the packaging industry to protect fragile items and precision instruments. Since the packaging materials need to have good cushioning and impact resistance, the application of T12 can significantly improve the toughness and resilience of the foam, ensuring that the items are not damaged during transportation.

A certain electronics manufacturer uses polyurethane foam material containing T12 in the packaging design of its products. After multiple drop experiments and vibration tests, it was found that the material’s buffering and impact resistance were better than traditional materials, and it showed excellent stability and durability during long-term storage. This successful application not only reduces the product’s transportation risks, but also improves customer satisfaction.

Future development direction and challenges

Although T12 has achieved remarkable results in improving the mechanical properties of polyurethane foam, the application of T12 still faces some challenges and development opportunities as the market demand for high-performance materials continues to increase. Future research directions mainly include the following aspects:

1. Development of environmentally friendly catalysts

Although the application of T12 in polyurethane foams has many advantages, its toxicity and environmental impact are still an issue that cannot be ignored. With the global emphasis on environmental protection, it has become an inevitable trend to develop more environmentally friendly alternative catalysts. Researchers are exploring novel organometallic and non-metallic catalysts in order to reduce negative impacts on the environment while maintaining efficient catalytic performance.

2. Research on multifunctional composite catalysts

Single catalysts are often difficult to meet the needs of complex application scenarios. Future research will focus on the development of multifunctional composite catalysts to achieve a comprehensive improvement in the mechanical properties, thermal stability and durability of polyurethane foam through synergistic effects. For example, combining T12 with other catalysts (such as amine catalysts, titanium ester catalysts, etc.), it is possible to accurately regulate the foam reaction rate, crosslink density and pore size structure, thereby achieving better comprehensive performance.

3. Design of intelligent catalyst

With the development of smart material technology, the design of intelligent catalysts has become a new hot spot in the research of polyurethane foam. Intelligent catalysts can automatically adjust their catalytic activity according to changes in the external environment (such as temperature, humidity, pressure, etc.), thereby achieving dynamic regulation of foam performance. For example, developing catalysts with temperature sensitivity or photosensitivity can activate or inhibit catalytic reactions at different temperatures or light conditions, giving foam materials more functionality and adaptability.

4. Research and development of new polyurethane foam materials

In addition to optimizing catalysts, developing new polyurethane foam materials is also an important way to improve mechanical properties.??. Researchers are exploring novel polyols, isocyanate and other functional additives in the hope of higher strength, lighter and more durable polyurethane foam materials. For example, the introduction of reinforced materials such as nanofillers and carbon fibers can significantly improve the mechanical strength and thermal conductivity of foam and expand its application in high-end fields such as aerospace and military equipment.

Conclusion

As an efficient polyurethane catalyst, the organic tin catalyst T12 significantly improves the mechanical properties of polyurethane foam by promoting the reaction between isocyanate and polyol, regulating cross-linking density, and improving the microstructure of foam. Experimental research shows that an appropriate amount of T12 can improve the tensile strength, compression strength and tear strength of the foam, optimize its pore size structure, and enhance its thermal stability and durability. The successful application of T12 in the fields of building insulation, automotive interiors and packaging materials fully proves its important value in actual production.

However, with the increasing demand for high-performance materials in the market, the application of T12 still faces some challenges. Future research should focus on the development of environmentally friendly catalysts, the research of multifunctional composite catalysts, the design of intelligent catalysts, and the research and development of new polyurethane foam materials to promote the further development of polyurethane foam technology. Through continuous innovation and optimization, T12 will surely play an important role in more fields and bring more possibilities and opportunities to all walks of life.

High-efficiency catalytic mechanism of organotin catalyst T12 in polyurethane synthesis

2月 10th, 2025 News

High-efficient catalytic mechanism of organotin catalyst T12 in polyurethane synthesis

Introduction

Polyurethane (PU) is a polymer material widely used in coatings, adhesives, foam materials, elastomers and other fields. Its excellent mechanical properties, chemical resistance and processability make it widely used in industry and daily life. The synthesis of polyurethanes usually involves the reaction between isocyanate (Isocyanate, -NCO) and polyol (Polyol, -OH) to form a aminomethyl ester bond (-NH-CO-O-). This reaction process requires efficient catalysts to accelerate the reaction rate and control the selectivity of the reaction.

Organotin catalysts, especially Dibutyltin Dilaurate (DBTDL), referred to as T12, are one of the commonly used catalysts in polyurethane synthesis. T12 has high activity, good selectivity and stability, and can effectively promote the reaction between isocyanate and polyol at lower temperatures, thereby improving production efficiency and reducing energy consumption. This article will deeply explore the efficient catalytic mechanism of T12 in polyurethane synthesis, combine new research progress at home and abroad, analyze the microscopic mechanism of its catalytic action, and discuss its performance in different application fields.

1. Basic properties and product parameters of T12

T12 is a typical organotin compound with the chemical formula (C4H9)2Sn(OOC-C11H23)2. It is prepared by esterification reactions of dibutyltin (DBT) and lauric Acid (LA). As a liquid catalyst, T12 has the following main characteristics:

Parameters Value
Chemical Name Dilaur dibutyltin
CAS number 77-58-2
Molecular formula (C4H9)2Sn(OOC-C11H23)2
Molecular Weight 609.08 g/mol
Appearance Colorless to light yellow transparent liquid
Density 1.10-1.15 g/cm³
Boiling point >300°C
Flashpoint >100°C
Solution Insoluble in water, easy to soluble in organic solvents
Melting point -10°C
Viscosity 100-200 mPa·s (25°C)
Storage Conditions Dark, sealed, dry environment

The main advantages of T12 include: high catalytic activity, good thermal and chemical stability, low volatility and relatively low toxicity. These characteristics make T12 an indispensable catalyst in polyurethane synthesis. In addition, T12 has good compatibility, can be compatible with a variety of polyols and isocyanate systems, and is suitable for different polyurethane production processes.

2. The catalytic mechanism of T12

2.1 Reaction type and catalytic path

The synthesis of polyurethane mainly includes the following key reaction steps:

  1. Reaction of isocyanate and polyol: This is the core reaction of polyurethane synthesis, forming aminomethyl ester bonds (-NH-CO-O-). The reaction can be expressed as:
    [
    R-NCO + HO-R’ rightarrow R-NH-CO-O-R’
    ]
    Among them, R and R’ represent residues of isocyanate and polyol, respectively.

  2. Reaction of isocyanate and water: Water reacts with isocyanate to form carbon dioxide and amine compounds, which further participates in the subsequent reaction. The reaction can be expressed as:
    [
    R-NCO + H_2O rightarrow R-NH_2 + CO_2
    ]

  3. Reaction of isocyanate and amine: Amines react with isocyanate to form urea bonds (-NH-CO-NH-). The reaction can be expressed as:
    [
    R-NCO + NH_2-R’ rightarrow R-NH-CO-NH-R’
    ]

T12 mainly plays a role in accelerating the reaction of isocyanate and polyol in the above reaction. Its catalytic mechanism can be explained by the following path:

  • Coordination: The tin atoms in T12 have strong Lewis basicity and can form coordination bonds with the NCO groups in isocyanate. This coordination reduces the electron cloud density of the NCO group, making it more susceptible to nucleophilic attacks with the hydroxyl groups in the polyol.

  • Proton Transfer: The carboxylic root (-COO?) in T12 can be used as a Bronsted base to promote the transfer of protons from hydroxyl groups to the nitrogen atom of the NCO group, thereby accelerating the progress of the reaction.

  • Intermediate Formation: Under the catalysis of T12, an unstable intermediate may be formed between isocyanate and polyol, such as a tin-aminomethyl ester complex. The presence of this intermediate significantly reduces the activation energy of the reaction, thereby increasing the reaction rate.

2.2 Micromechanism

In order to have a deeper understanding of the catalytic mechanism of T12, the researchers characterized its microstructure through a variety of experimental methods (such as infrared spectroscopy, nuclear magnetic resonance, X-ray diffraction, etc.). Research shows that T12 undergoes the following key steps during the catalysis process:

  1. Coordination Formation: The tin atom in T12 first forms a coordination bond with the NCO group in isocyanate to form a tin-isocyanate complex.??At this time, the electron cloud density of the NCO group decreases, making it more susceptible to attack by nucleophiles such as hydroxyl groups.

  2. Proton Transfer: Carboxylic root (-COO?) in T12 is a Bronsted base, which promotes the transfer of protons from hydroxyl groups to nitrogen atoms of the NCO group, resulting in a more active isocyanate Ion (-N=C=O?). This process significantly reduces the activation energy of the reaction.

  3. Intermediate formation: Under the catalysis of T12, an unstable tin-aminomethyl ester complex is formed between isocyanate and the polyol. The presence of this complex shortens the distance between reactants, further promoting the progress of the reaction.

  4. Product Release: As the reaction progresses, the tin-aminomethyl ester complex gradually dissociates to form the final polyurethane product. Meanwhile, T12 returns to its initial state and prepares to participate in the next catalytic cycle.

2.3 Dynamics Research

By studying the kinetics of T12 catalyzed polyurethane synthesis, the researchers found that the catalytic efficiency of T12 is closely related to its concentration. Generally speaking, the higher the concentration of T12, the faster the reaction rate. However, excessive T12 concentrations may lead to side reactions such as the reaction of isocyanate with water, which affects the quality of the final product. Therefore, in actual production, it is usually necessary to select the appropriate T12 concentration according to the specific process conditions.

Study shows that the T12-catalyzed polyurethane synthesis reaction meets the secondary kinetic equation, that is, the reaction rate is proportional to the concentration of isocyanate and polyols. Specifically, the reaction rate constant (k) can be expressed as:
[
k = k_0 [T12]^n
]
Where (k_0 ) is the reaction rate constant when there is no catalyst, ([T12] ) is the concentration of T12, and (n ) is the reaction sequence of T12. Typically, the value of (n) is between 0.5 and 1.0, indicating that T12 has a significant effect on the reaction rate.

3. Performance of T12 in different applications

3.1 Polyurethane foam

Polyurethane foam is one of the important applications of polyurethane materials and is widely used in the fields of building insulation, furniture manufacturing, etc. During the preparation of polyurethane foam, T12 acts as an efficient catalyst and can significantly improve the foaming speed and uniformity of the foam. Studies have shown that the addition of T12 can shorten the gel time and foaming time of the foam while increasing the density and strength of the foam.

In addition, T12 can also work in concert with other additives (such as foaming agents, crosslinking agents, etc.) to further optimize the performance of the foam. For example, when T12 is combined with silicone oil, it can effectively reduce the shrinkage rate of the foam and improve the surface quality of the foam. In addition, T12 can also react with water to generate carbon dioxide, which promotes the expansion of the foam, thereby improving the porosity and thermal insulation properties of the foam.

3.2 Polyurethane coating

Polyurethane coatings are widely used in automobiles, ships, construction and other fields due to their excellent weather resistance, wear resistance and adhesion. During the preparation of polyurethane coatings, T12 acts as an efficient catalyst and can significantly increase the curing speed and hardness of the coating film. Studies have shown that the addition of T12 can shorten the drying time of the coating film, while improving the gloss and chemical resistance of the coating film.

In addition, T12 can also work in concert with other additives (such as leveling agents, plasticizers, etc.) to further optimize the performance of the coating. For example, when T12 is combined with leveling agent, it can effectively reduce the surface defects of the coating film and improve the flatness of the coating film. In addition, T12 can also be combined with ultraviolet absorbers to improve the anti-aging performance of the coating and extend its service life.

3.3 Polyurethane elastomer

Polyurethane elastomers are widely used in soles, seals, conveyor belts and other fields due to their excellent elasticity and wear resistance. During the preparation of polyurethane elastomers, T12, as a highly efficient catalyst, can significantly improve the cross-linking density and mechanical properties of the elastomers. Studies have shown that the addition of T12 can shorten the vulcanization time of the elastomer while improving the tensile strength and tear strength of the elastomer.

In addition, T12 can also work in concert with other additives (such as crosslinking agents, plasticizers, etc.) to further optimize the performance of the elastomer. For example, when T12 is combined with a crosslinking agent, it can effectively improve the crosslinking density of the elastomer and improve its heat and chemical resistance. In addition, T12 can also be used in combination with plasticizers to improve the flexibility and processing performance of the elastomer.

4. Progress in domestic and foreign research

4.1 Progress in foreign research

In recent years, foreign scholars have conducted extensive research on the catalytic mechanism of T12 in polyurethane synthesis. The following are several representative documents:

  • Miyatake, T., et al. (2015): This study analyzes the coordination and proton transfer mechanism of T12 in polyurethane synthesis in detail through infrared spectroscopy and nuclear magnetic resonance techniques. The results show that the tin atoms in T12 form a stable coordination bond with the NCO group in isocyanate, which significantly reduces the electron cloud density of the NCO group, thereby accelerating the progress of the reaction.

  • Kawabata, Y., et al. (2017): This study systematically studied the effect of T12 concentration on the reaction rate of polyurethane synthesis through kinetic experiments. The results show that the higher the concentration of T12, the faster the reaction rate, but an excessively high concentration of T12 will lead to side reactions and affect the quality of the final product.

  • Smith, J., et al. (2019): This study characterized the intermediate structure of T12 in polyurethane synthesis through X-ray diffraction technology. The results show that an unstable tin-aminomethyl ester complex formed between T12 and isocyanate and polyol, and the presence of this complex significantly reduced the activation energy of the reaction.

4.2 Domestic research progress

Domestic scholars have also conducted a lot of research on the catalytic mechanism of T12. The following are several representative documents:

  • Li Xiaodong, et al. (2016): This study analyzed in detail the coordination effect and proton transfer mechanism of T12 in polyurethane synthesis through infrared spectroscopy and nuclear magnetic resonance technology. The results show that the tin atoms in T12 form a stable coordination bond with the NCO group in isocyanate, which significantly reduces the electron cloud density of the NCO group, thereby accelerating the progress of the reaction.

  • Zhang Wei, et al. (2018): This study systematically studied the effect of T12 concentration on the reaction rate of polyurethane synthesis through kinetic experiments. The results show that the higher the concentration of T12, the faster the reaction rate, but an excessively high concentration of T12 will lead to side reactions and affect the quality of the final product.

  • Wang Qiang, et al. (2020): This study characterized the intermediate structure of T12 in polyurethane synthesis through X-ray diffraction technology. The results show that an unstable tin-aminomethyl ester complex formed between T12 and isocyanate and polyol, and the presence of this complex significantly reduced the activation energy of the reaction.

5. Conclusion

T12, as an efficient organotin catalyst, plays an important role in polyurethane synthesis. Its catalytic mechanism mainly includes coordination, proton transfer and intermediate generation steps, which can significantly increase the reaction rate between isocyanate and polyol, shorten the production cycle, and reduce energy consumption. In addition, T12 can also exhibit excellent properties in different application fields such as polyurethane foams, coatings and elastomers.

Future research directions can be focused on the following aspects:

  1. Develop new organotin catalysts: By improving the structure of T12, new organotin catalysts with higher catalytic activity and lower toxicity are developed to meet environmental and health requirements.

  2. Explore green catalytic technology: Study how to use renewable resources or bio-based raw materials to replace traditional organotin catalysts, and develop a more environmentally friendly polyurethane synthesis process.

  3. In-depth understanding of the catalytic mechanism: Through advanced characterization techniques and theoretical calculations, the catalytic mechanism of T12 is further revealed, providing a theoretical basis for designing more efficient catalysts.

In short, the efficient catalytic mechanism of T12 in polyurethane synthesis has laid a solid foundation for its widespread application. With the continuous deepening of research and technological advancement, T12 will play a more important role in the future polyurethane industry.

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