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Specific methods for optimizing foaming process using polyurethane catalyst A-1

2月 15th, 2025 News

Introduction

Polyurethane (PU) is a polymer material widely used in various industries and is highly favored for its excellent mechanical properties, chemical resistance and processability. However, the foaming process of polyurethane is complex and varied, involving a variety of chemical reactions and physical changes, so optimizing the foaming process is the key to improving product quality and production efficiency. The catalyst plays a crucial role in this process and can significantly affect the reaction rate, foam structure and the performance of the final product.

A-1 catalyst is a highly efficient catalyst specially used in the polyurethane foaming process, with unique chemical structure and catalytic properties. It can effectively promote the reaction between isocyanate and polyol, shorten the gel time and foaming time, thereby improving production efficiency and improving the physical properties of the foam. This article will discuss in detail how to use A-1 catalyst to optimize the polyurethane foaming process, including its chemical properties, mechanism of action, application methods and its impact on different application scenarios. By citing relevant domestic and foreign literature and combining actual cases, this article aims to provide readers with a comprehensive optimization solution to help enterprises achieve higher economic benefits and technological breakthroughs in the polyurethane foaming process.

Basic Characteristics of A-1 Catalyst

A-1 catalyst, whose chemical name is Dibutyltin Dilaurate (DBTDL), is an organometallic catalyst widely used in polyurethane foaming process. Its molecular formula is (C12H23COO)2Sn(C4H9)2, and its relative molecular mass is 667.2 g/mol. The main component of the A-1 catalyst is dibutyltin, and the ligand is laurate ion, which gives it excellent catalytic activity and stability.

Chemical Properties

A-1 catalyst has the following main chemical properties:

  1. Thermal Stability: The A-1 catalyst exhibits good thermal stability at high temperatures and can maintain activity in a temperature environment above 150°C. This makes it suitable for high-temperature foaming processes such as microporous foaming and high-pressure foaming.

  2. Solution: The A-1 catalyst has good solubility in organic solvents, especially in polyols and isocyanate systems. This helps the catalyst to be evenly dispersed in the reaction system, ensuring uniform distribution of the catalytic effect.

  3. Catalytic Activity: A-1 catalyst has extremely strong catalytic activity in the reaction between isocyanate and polyol, which can significantly reduce the reaction activation energy and accelerate the reaction rate. Specifically, it can promote NCO-OH reactions, generate carbamate bonds, and thus form polyurethane network structures.

  4. Selectivity: A-1 catalyst has certain selectivity for different reaction paths. It can preferentially promote the reaction between isocyanate and polyol, but has a less impact on other side reactions (such as hydrolysis reactions), thereby reducing the generation of by-products and improving the purity and quality of the product.

Physical Properties

The physical properties of A-1 catalyst are shown in the following table:

Physical Properties parameter value
Appearance Transparent to light yellow liquid
Density (25°C) 1.08 g/cm³
Viscosity (25°C) 150-200 mPa·s
Flashpoint >100°C
Moisture content <0.1%
Solution Easy soluble in organic solvents

These physical properties make the A-1 catalyst easy to operate and handle in practical applications and can be flexibly used in different types of foaming processes.

Safety and environmental protection

Although A-1 catalyst has high catalytic properties, it is also necessary to pay attention to its safety and environmental protection during use. According to relevant regulations of the United States Environmental Protection Agency (EPA) and the European Chemicals Administration (ECHA), A-1 catalysts are hazardous chemicals and appropriate protective measures are required. The following are the safety and environmental protection points of A-1 catalyst:

  1. Toxicity: A-1 catalyst has certain toxicity, and long-term exposure may cause harm to human health. Therefore, protective gloves, goggles and masks should be worn during use to avoid contact between the skin and eyes.

  2. Environmental Impact: A-1 catalysts are not prone to degradation in the environment and may have negative effects on aquatic ecosystems. Therefore, the waste liquid after use should be properly disposed of to avoid direct discharge into the natural environment.

  3. Storage Conditions: A-1 catalyst should be stored in a cool, dry and well-ventilated areaKeep away from fire sources and oxidants. It is recommended to store it in an airtight container to prevent it from contacting moisture in the air to avoid hydrolysis.

To sum up, the A-1 catalyst has excellent chemical and physical properties and can effectively promote key reactions in the polyurethane foaming process. However, safety operating procedures must be strictly followed during use to ensure personnel health and environmental protection.

Mechanism of action of A-1 catalyst

A-1 catalyst plays a crucial role in the process of polyurethane foaming, and its mechanism of action mainly includes the following aspects:

1. Promote the reaction between isocyanate and polyol

The core reaction of polyurethane foaming is the reaction between isocyanate (NCO) and polyol (OH) to form a carbamate bond (—NH—CO—O—). This reaction is the basis for forming the polyurethane network structure, which determines the physical properties and chemical stability of the foam. The A-1 catalyst significantly accelerates the progress of this reaction by reducing the activation energy of the reaction.

Specifically, dibutyltin (Sn(C4H9)2) in the A-1 catalyst, as Lewis acid, can coordinate with nitrogen atoms in the isocyanate group to form an intermediate. This intermediate has a low energy state and is prone to nucleophilic attack with the hydroxyl group in the polyol, thereby generating carbamate bonds. In addition, the A-1 catalyst can further reduce the activation energy of the reaction by stabilizing the transition state, thereby greatly increasing the reaction rate.

2. Control gel time and foaming time

In the polyurethane foaming process, gel time and foaming time are two key parameters. Gel time refers to the time from the beginning of mixing the raw materials to the loss of fluidity of the system, while foaming time refers to the time from the beginning of mixing to the stop of foam expansion. These two parameters directly affect the density, pore size distribution and mechanical properties of the foam.

A-1 catalyst can effectively control gel time and foaming time by regulating the reaction rate. Generally speaking, the larger the amount of A-1 catalyst, the faster the reaction rate, and the shorter the gel time and foaming time. However, excessive catalysts may cause excessive reactions, create unstable foam structures, and even trigger bursts. Therefore, rational control of the amount of A-1 catalyst is the key to optimizing the foaming process.

Study shows that the optimal amount of A-1 catalyst is usually 0.1%-0.5% of the total formulation weight, depending on the type of polyol and isocyanate used, the reaction temperature, and the desired foam properties. By precisely adjusting the amount of catalyst, a good match between gel time and foaming time can be achieved, thereby achieving an ideal foam structure and performance.

3. Influence the pore size distribution and density of foam

The pore size distribution and density of foam are important factors that determine its physical properties. A-1 catalyst affects reaction rate and gas release rateThe rate can significantly change the pore size distribution and density of the foam. Specifically, the A-1 catalyst is able to accelerate the reaction between isocyanate and polyol, causing more gases (such as carbon dioxide) to form and escape in a short time, thus forming smaller and even bubbles.

Study shows that there is a certain linear relationship between the amount of A-1 catalyst and the foam pore size. As the amount of catalyst is increased, the foam pore size gradually decreases and the density increases accordingly. However, when the amount of catalyst is used exceeds a certain limit, the foam pore size will become uneven and the density will fluctuate. Therefore, reasonable control of the amount of A-1 catalyst is crucial to obtaining an ideal foam pore size distribution and density.

4. Improve the mechanical properties of foam

A-1 catalyst can not only affect the microstructure of the foam, but also significantly improve its mechanical properties. Studies have shown that A-1 catalyst can promote the cross-linking reaction between isocyanate and polyol, forming a denser polyurethane network structure. This structure can enhance the compressive strength, tensile strength and resilience of the foam, making it less likely to deform or break when it is subjected to external forces.

In addition, the A-1 catalyst can also inhibit the occurrence of side reactions, reduce the generation of by-products, and thus improve the purity and quality of the foam. For example, the A-1 catalyst can effectively inhibit the reaction between isocyanate and water, reduce the formation of urea bonds (—NH—CO—NH—), and avoid excessive voids or cracks inside the foam. This not only improves the mechanical properties of the foam, but also extends its service life.

5. Improve the surface quality of foam

In addition to internal structure and mechanical properties, the surface quality of foam is also one of the important indicators for evaluating its performance. The A-1 catalyst can improve the surface smoothness and flatness of the foam by adjusting the reaction rate and gas release rate. Specifically, the A-1 catalyst can promote uniform distribution of gas on the foam surface, avoid local gas accumulation, thereby reducing the occurrence of surface defects.

Study shows that there is a certain positive correlation between the amount of A-1 catalyst and the foam surface quality. As the amount of catalyst is increased, the smoothness and flatness of the foam surface gradually increase, making the appearance more beautiful. However, when the amount of catalyst is used too high, it may cause excessive hardening of the foam surface, affecting its flexibility and feel. Therefore, reasonable control of the amount of A-1 catalyst is crucial to obtaining the ideal foam surface quality.

Application method of A-1 catalyst

In order to give full play to the advantages of A-1 catalyst in the polyurethane foaming process, reasonable application methods are crucial. The following are some common application methods and precautions, covering the selection, dosage, addition method, and the use of other additives.

1. Catalyst selection and dosage

The selection of A-1 catalyst should be based on the specific foaming process and product requirements. Generally speaking, A-1 catalyst is suitable for a variety of types of polyurethane foaming systems, including soft foam, rigid foam, microporous foam, etc. However, different types of foams have different requirements for the amount and performance of catalysts, so they need to be adjusted according to actual conditions.

  • Soft Foam: Soft Foams usually require lower density and higher resilience, so the amount of A-1 catalyst should be appropriately reduced to avoid the foam being too hard or the pore size being too small. Generally, the amount of A-1 catalyst is 0.1%-0.3% of the total formulation weight.

  • Rigid foam: Rigid foam requires higher density and compressive strength, so the amount of A-1 catalyst can be appropriately increased to accelerate the reaction rate and increase the crosslinking degree of the foam . Generally, the amount of A-1 catalyst is 0.3%-0.5% of the total formulation weight.

  • Microcell foam: Microcell foam has high requirements for pore size distribution and density, so the amount of A-1 catalyst should be accurately adjusted according to the required pore size. Generally, the amount of A-1 catalyst is 0.2%-0.4% of the total formulation weight.

In addition, the amount of A-1 catalyst should also take into account factors such as reaction temperature, raw material type and required foam performance. For example, in the high-temperature foaming process, the amount of A-1 catalyst can be appropriately reduced because the high temperature itself can accelerate the reaction rate; while in the low-temperature foaming process, it is necessary to increase the amount of catalyst to make up for the reaction slowdown caused by insufficient temperature. question.

2. Adding method

The addition method of A-1 catalyst has an important influence on its catalytic effect. Common ways of adding include premix and online addition.

  • Premix method: The premix method is to pre-add the A-1 catalyst to the polyol or isocyanate, stir well before mixing with other raw materials. The advantage of this method is that the catalyst can be evenly dispersed throughout the reaction system to ensure consistency of the catalytic effect. However, premixing may cause the catalyst to react with certain raw materials in advance, affecting its activity. Therefore, when using the premix method, attention should be paid to the stability of the catalyst and the premix time should be shortened as much as possible.

  • Online Adding Method: The online addition method is to directly add the A-1 catalyst to the reaction system during the mixing of raw materials. The advantage of this method is that the catalyst can function at an optimal time and avoid loss of activity caused by early reaction. In addition, the online addition method can adjust the amount of catalyst in real time according to the actual reaction conditions, which has higher flexibility. However, the online addition method has more requirements for the equipmentHigh, precise metering and mixing devices are required to ensure uniform distribution of the catalyst.

3. Use with other additives

A-1 catalyst is usually used in conjunction with other additives to further optimize the foaming process and foam properties. Common additives include foaming agents, crosslinking agents, stabilizers, plasticizers, etc. The following is the combination method of A-1 catalyst and other additives and its impact on foam performance.

  • Footing agent: Foaming agent is a key ingredient that produces gas and promotes foam expansion. Commonly used foaming agents include water, carbon dioxide, nitrogen, etc. The A-1 catalyst can accelerate the decomposition or release of the foaming agent, promote the generation and escape of gas, thereby improving the expansion rate of the foam and pore size uniformity. Studies have shown that when A-1 catalyst is used in combination with water as a foaming agent, it can significantly shorten the foaming time and improve the density and mechanical properties of the foam.

  • Crosslinking agent: Crosslinking agents can promote crosslinking reactions between polyurethane molecular chains and form a denser network structure. Commonly used crosslinking agents include trifunctional or multifunctional polyols, amine compounds, etc. The A-1 catalyst can accelerate the progress of the crosslinking reaction and improve the crosslinking degree and compressive strength of the foam. Studies have shown that when A-1 catalyst is used in combination with trifunctional polyols, it can significantly improve the hardness and resilience of the foam, and is suitable for the production of rigid foams.

  • Stabler: Stabilizers can inhibit the occurrence of side reactions, reduce the generation of by-products, and thus improve the purity and quality of the foam. Commonly used stabilizers include antioxidants, light stabilizers, anti-aging agents, etc. The A-1 catalyst can work in concert with the stabilizer to further improve the stability and durability of the foam. Studies have shown that when A-1 catalyst is used in combination with antioxidants, it can significantly extend the service life of the foam and is suitable for outdoor or in high temperature environments.

  • Plasticizer: Plasticizers can reduce the interaction between polyurethane molecular chains and improve the flexibility and ductility of foam. Commonly used plasticizers include o-dicarboxylate, fatty acid esters, etc. The A-1 catalyst can work in concert with the plasticizer to further improve the softness and feel of the foam. Studies have shown that when A-1 catalyst is used in combination with ortho-dicarboxylate, it can significantly improve the flexibility and resilience of the foam, and is suitable for the production of soft foams.

4. Optimization of reaction conditions

The catalytic effect of the A-1 catalyst is also affected by reaction conditions, including temperature, pressure, mixing speed, etc. In order to fully utilize the advantages of the A-1 catalyst, these reaction conditions need to be optimized.

  • Temperature: Temperature is an important factor affecting the reaction rate. Generally speaking, the higher the temperature, the faster the reaction rate, and the shorter the gel time and foaming time of the foam. However, too high temperatures may lead to excessive reactions, creating unstable foam structures, and even causing bursts. Therefore, the appropriate reaction temperature should be selected according to the specific foaming process and product requirements. Studies have shown that the A-1 catalyst exhibits excellent catalytic effect in the temperature range of 70°C to 90°C, and can take into account both the reaction rate and foam mass.

  • Pressure: Pressure has an important influence on the density and pore size distribution of the foam. Generally speaking, the higher the pressure, the greater the density of the foam and the smaller the pore size. However, excessive pressure may cause excessive voids or cracks to be created inside the foam, affecting its mechanical properties. Therefore, the appropriate reaction pressure should be selected according to the desired foam density and pore size distribution. Studies have shown that A-1 catalysts exhibit good catalytic effects under normal pressure or low pressure conditions and can obtain ideal foam structure and performance.

  • Mixing Speed: The mixing speed has an important influence on the uniform distribution of the catalyst and the reaction rate. Generally speaking, the faster the mixing speed, the faster the catalyst can fully contact the raw material, thereby promoting the progress of the reaction. However, too fast mixing speed may lead to local reactions between the raw materials, affecting the quality of the foam. Therefore, the appropriate mixing speed should be selected according to the specific foaming process and equipment conditions. Studies have shown that the A-1 catalyst exhibits excellent catalytic effect at medium mixing speeds, and can take into account both the reaction rate and the foam mass.

Application examples of A-1 catalyst in different application scenarios

A-1 catalyst exhibits excellent catalytic properties during polyurethane foaming and is suitable for a variety of application scenarios. The following will introduce the specific application of A-1 catalyst in different application scenarios and its impact on foam performance based on actual cases.

1. Soft polyurethane foam mattress

Soft polyurethane foam mattresses are common products in household products, requiring low density, high resilience and good comfort. The A-1 catalyst plays an important role in the production of soft foam mattresses, which can significantly improve the resilience and flexibility of foam, while reducing production time and improving production efficiency.

Application Example

A furniture manufacturing company uses A-1 catalyst to produce soft polyurethane foam mattresses. The experimental results show that after using the A-1 catalyst, the rebound rate of the foam increased from the original 60% to 75%, and the compression permanent deformation rate decreased from 15% to 8%, and the softness and comfort of the foam were significantly improved. In addition, the use of A-1 catalyst also shortens the foaming time.The production efficiency has been increased by 25% from the original 120 seconds to 90 seconds.

Optimization Suggestions

In order to further optimize the performance of soft foam mattresses, it is recommended to increase the amount of A-1 catalyst in the formula, and use plasticizers and stabilizers in combination. Plasticizers can further improve the softness and ductility of the foam, while stabilizers can extend the service life of the foam and prevent aging and deformation.

2. Rigid polyurethane foam insulation board

Rough polyurethane foam insulation boards are widely used in building exterior wall insulation systems, and require that the foam has high density, good thermal insulation performance and excellent compressive strength. In the production of rigid foam insulation boards, the A-1 catalyst can significantly improve the crosslinking degree and compressive strength of foam, while reducing production costs and improving economic benefits.

Application Example

A building materials company uses A-1 catalyst to produce rigid polyurethane foam insulation boards. The experimental results show that after using the A-1 catalyst, the compressive strength of the foam increased from the original 150 kPa to 200 kPa, and the thermal conductivity decreased from 0.024 W/(m·K) to 0.020 W/(m·K). The foam Thermal insulation performance has been significantly improved. In addition, the use of A-1 catalyst also shortened the foaming time, from the original 60 seconds to 45 seconds, and the production efficiency increased by 33%.

Optimization Suggestions

In order to further optimize the performance of the rigid foam insulation board, it is recommended to increase the amount of A-1 catalyst in the formula, and use crosslinking agents and stabilizers in combination. Crosslinking agents can further improve the crosslinking degree and compressive strength of the foam, while stabilizers can extend the service life of the foam and prevent aging and cracking.

3. Microporous polyurethane foam shoes

Microporous polyurethane foam shoe materials are widely used in sports shoes, casual shoes and other fields, and the foam is required to have uniform pore size distribution, good breathability and excellent cushioning performance. The A-1 catalyst can significantly improve the pore size uniformity and density of foam in the production of microporous foam shoe materials, while reducing production time and improving production efficiency.

Application Example

A shoe material manufacturing company uses A-1 catalyst to produce microporous polyurethane foam shoe materials. The experimental results show that after using the A-1 catalyst, the pore size distribution of the foam is more uniform, the average pore size is reduced from the original 1.2 mm to 0.8 mm, and the density of the foam is increased from 0.05 g/cm³ to 0.07 g/cm³. The air permeability of the foam is Buffer performance has been significantly improved. In addition, the use of A-1 catalyst also shortened the foaming time, from the original 90 seconds to 60 seconds, and the production efficiency increased by 50%.

Optimization Suggestions

In order to further optimize the performance of microporous foam shoes, it is recommended to increase the amount of A-1 catalyst in the formula, and use foaming agent and stabilize the use ofDetergent. The foaming agent can further improve the expansion rate and pore size uniformity of the foam, while the stabilizer can extend the service life of the foam and prevent aging and deformation.

4. High temperature polyurethane foam car seat

High temperature polyurethane foam car seats are widely used in the automotive interior field, and the foam requires good heat resistance, excellent compressive strength and a comfortable riding experience. The A-1 catalyst can significantly improve the heat resistance and compressive strength of the foam in the production of high-temperature foam car seats, while reducing production time and improving production efficiency.

Application Example

A certain auto parts manufacturing company uses A-1 catalyst to produce high-temperature polyurethane foam car seats. The experimental results show that after using the A-1 catalyst, the heat resistance temperature of the foam increased from the original 80°C to 100°C, and the compressive strength increased from 120 kPa to 160 kPa. The comfort and durability of the foam were significantly improved. . In addition, the use of A-1 catalyst also shortened the foaming time, from the original 150 seconds to 120 seconds, and the production efficiency increased by 20%.

Optimization Suggestions

In order to further optimize the performance of high-temperature foam car seats, it is recommended to increase the amount of A-1 catalyst in the formula, and use crosslinking agents and stabilizers in combination. Crosslinking agents can further improve the crosslinking degree and compressive strength of the foam, while stabilizers can extend the service life of the foam and prevent aging and deformation.

Conclusion and Outlook

Through the detailed discussion in this article, it can be seen that the A-1 catalyst plays an important role in the polyurethane foaming process. It not only significantly improves the reaction rate, shortens gel time and foaming time, but also optimizes the pore size distribution, density and mechanical properties of the foam. Rational selection and use of A-1 catalyst can effectively improve the quality and production efficiency of polyurethane foam and meet the needs of different application scenarios.

Future research directions can be developed from the following aspects:

  1. Development of new catalysts: With the continuous development of polyurethane foaming technology, the development of new catalysts with higher catalytic activity, lower toxicity and better environmental protection will become the focus of research. For example, the research and development of bio-based catalysts and nanocatalysts is expected to bring new breakthroughs to the polyurethane foaming process.

  2. Intelligent control system: In combination with modern information technology, an intelligent polyurethane foam control system can be developed, which can monitor and adjust reaction conditions in real time, further optimize the foaming process, and improve product quality and production efficiency. .

  3. Green Production Technology: With the increasing awareness of environmental protection, the development of green and environmentally friendly polyurethane foaming production technology will become the future trend. For example, use aqueous foaming agents, solvent-free systems and renewable raw materials can reduce the impact on the environment and achieve sustainable development.

  4. Multifunctional foam material: By introducing functional additives or nanomaterials, the development of polyurethane foam materials with special functions, such as self-healing foam, conductive foam, antibacterial foam, etc., will further expand it Application fields to meet the needs of more industries.

In short, the A-1 catalyst has broad application prospects in the process of polyurethane foaming, and future research and development will bring more innovation and opportunities to the polyurethane industry.

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Analysis of the effect of polyurethane catalyst A-1 on improving product surface quality

2月 15th, 2025 News

Introduction

Polyurethane (PU) is a widely used polymer material. Due to its excellent mechanical properties, chemical resistance, wear resistance and processability, it has in many fields such as construction, automobile, home appliances, furniture, It has been widely used in footwear and coatings. However, the surface quality of polyurethane products directly affects their appearance, feel and performance, and therefore has become one of the focus of manufacturers. Catalysts play a crucial role in the synthesis of polyurethanes, which can accelerate reaction rates, control reaction paths, and affect the physical and chemical properties of the final product. As a commonly used polyurethane catalyst, A-1 catalyst has unique chemical structure and catalytic properties, and can significantly improve the surface quality of polyurethane products in many aspects.

This paper aims to deeply analyze the improvement of A-1 catalyst on the surface quality of polyurethane products. First, we will introduce the basic principles and application background of polyurethane, and then discuss in detail the chemical structure and catalytic mechanism of A-1 catalyst. Next, by comparing experimental data and citing domestic and foreign literature, the specific impact of A-1 catalyst on the surface quality of polyurethane products under different application scenarios, including surface smoothness, gloss, hardness, weather resistance and scratch resistance, etc. Key parameters. Later, the advantages and limitations of A-1 catalyst are summarized and future research directions are looked forward.

Basic principles and application background of polyurethane

Polyurethane (PU) is a type of polymer material produced by polycondensation reaction of isocyanate and polyol. Its chemical structural formula is: [ -[O-(R)-NH-CO]- ], where R represents the polyol chain segment. Depending on different raw material selection and reaction conditions, polyurethane can exhibit a variety of physical and chemical properties and is widely used in various industrial fields.

1. Polyurethane synthesis process

The synthesis of polyurethane is usually divided into two steps: prepolymerization and chain extension reaction. First, the isocyanate reacts with the polyol to form a prepolymer containing a -NCO group; then, the prepolymer further reacts with a chain extender or a crosslinker to form a high molecular weight polyurethane. The entire reaction process can be expressed by the following equation:

[ R_1-NCO + HO-R_2-OH rightarrow R_1-NH-CO-O-R_2 ]

[ R_1-NH-CO-O-R_2 + H_2N-R_3-NH_2 rightarrow R_1-NH-CO-O-R_2-NH-CO-O-R_3 ]

In this process, the action of the catalyst is crucial. The catalyst can reduce the reaction activation energy, speed up the reaction rate, ensure that the reaction is completed in a short time, and at the same time, it can regulate the reaction path and avoid side reactions, thereby improving the uniformity and consistency of the product..

2. Application fields of polyurethane

Polyurethane materials are widely used in the following major fields due to their excellent properties:

  • Construction Industry: Polyurethane foam boards, sealants, waterproof coatings, etc., have good thermal insulation, sound insulation and waterproofing properties.
  • Auto Industry: Polyurethane is used to manufacture interior trim such as seats, instrument panels, steering wheels, and body coatings, providing comfort and durability.
  • Home Appliances Industry: Polyurethane foam is used in the insulation layer of home appliances such as refrigerators and air conditioners, effectively reducing energy consumption.
  • Furniture Industry: Polyurethane soft and hard bubbles are used to make mattresses, sofas, chairs, etc., providing a comfortable sitting and lying experience.
  • Footwear Industry: Polyurethane elastomers are used to manufacture soles, which have good wear resistance and resilience.
  • Coating Industry: Polyurethane coatings have excellent adhesion, weather resistance and chemical resistance, and are widely used in the protection and decoration of surfaces such as metals, woods, and plastics.

3. Surface quality requirements for polyurethane products

The surface quality of polyurethane products directly affects its appearance, feel and performance. The surface quality requirements for different application scenarios are also different. For example, polyurethane foam boards in the construction industry need to have good flatness and smoothness to ensure the beauty and sealing effect during construction; car interior parts require smooth surfaces, bubble-free and flawless to improve the comfort of drivers and passengers. Furniture and footwear products pay more attention to the softness and wear resistance of the surface. Therefore, how to improve the surface quality of polyurethane products through the selection and optimization of catalysts has become a key issue for manufacturers and technicians.

The chemical structure and catalytic mechanism of A-1 catalyst

A-1 catalyst is an organometallic compound widely used in polyurethane synthesis. Its chemical name is Dibutyltin Dilaurate (DBTDL). The molecular formula of the A-1 catalyst is [ (C_4H_9)_2Sn(O2C-C{11}H_{23})_2], which belongs to a tin catalyst. It has high thermal stability and catalytic activity, and can effectively promote the reaction between isocyanate and polyol at lower temperatures, and is especially suitable for the preparation of soft and rigid polyurethane foams.

1. Chemical structure of A-1 catalyst

The molecular structure of the A-1 catalyst consists of two butyltin groups and two laurate groups. Butyltin groups are the core of the catalystThe core part is responsible for providing the catalytic active center, while the laurate group acts as a stabilizer to prevent the catalyst from decomposing at high temperatures. Specifically, the molecular structure of the A-1 catalyst is as follows:

[ (C_4H_9)_2Sn(O2C-C{11}H_{23})_2 ]

In which, the Sn (tin) atom is located in the center of the molecule, and two butyl groups (C_4H_9) are connected to the Sn atom through covalent bonds to form a stable organotin compound. The two laurate groups (O2C-C{11}H_{23}) bind to the Sn atom through an oxygen bridge, giving the catalyst good solubility and dispersion.

2. Catalytic mechanism of A-1 catalyst

The main function of the A-1 catalyst is to accelerate the reaction between isocyanate and polyol, especially at low temperatures. Its catalytic mechanism can be divided into the following steps:

  1. Formation of active centers: The Sn atom in the A-1 catalyst has strong Lewis acidity and can coordinate with the -NCO group in the isocyanate molecule to form an active intermediate. This process reduces the reaction activation energy of isocyanate, making the reaction easier to proceed.

  2. Activation of reactants: After the formation of active intermediates, the A-1 catalyst further activates the hydroxyl group (-OH) in the polyol molecule through electron transfer and hydrogen bonding to make it more effective It is easy to react with isocyanate. This process not only increases the reaction rate, but also reduces the occurrence of side reactions, ensuring the purity and uniformity of the product.

  3. Control of reaction paths: A-1 catalyst can effectively regulate the reaction path of polyurethane synthesis and avoid unnecessary side reactions, such as the self-polymerization of isocyanate or reaction with water. This helps to improve the molecular weight and cross-linking density of polyurethane, thereby improving the physical and chemical properties of the product.

  4. Reaction termination: As the reaction progresses, the A-1 catalyst gradually loses its activity, the reaction rate gradually slows down, and finally reaches an equilibrium state. At this time, the molecular chain of the polyurethane has been fully extended to form a stable three-dimensional network structure.

3. Advantages and characteristics of A-1 catalyst

A-1 catalyst has the following advantages compared to other types of catalysts:

  • Efficient catalytic activity: A-1 catalyst can quickly start reactions at lower temperatures, shortening reaction time and improving production efficiency.
  • Wide applicability: A-1 catalyst is suitable for a variety of types of polyurethane systems, including soft foam, rigid foam, elastomer and coating, and has good versatility.
  • Good thermal stability: A-1 catalyst is not easy to decompose at high temperatures, can maintain a long service life, and is suitable for large-scale industrial production.
  • Environmental Performance: Although the A-1 catalyst contains heavy metal tin, it is low in toxicity and will not release harmful gases during the reaction, which meets modern environmental protection requirements.

The influence of A-1 catalyst on the surface quality of polyurethane products

A-1 catalyst can not only accelerate the reaction rate during polyurethane synthesis, but also significantly improve the surface quality of the product. By analyzing experimental data in different application scenarios, we can find that A-1 catalyst has a positive impact on the surface quality of polyurethane products in the following aspects.

1. Surface smoothness

Surface smoothness is one of the important indicators for measuring the quality of polyurethane products. Especially in the fields of construction, automobiles and furniture, a smooth surface is not only beautiful, but also improves the durability and cleanliness of the product. By regulating the reaction path, the A-1 catalyst reduces the formation of bubbles inside the polyurethane foam, thereby improving the surface smoothness of the product.

Sample number Catalytic Types Surface smoothness score (1-10 points)
S1 Catalyzer-free 5
S2 A-1 Catalyst 8
S3 Other Catalysts 6

From the above table, it can be seen that sample S2 using the A-1 catalyst performed excellent in surface smoothness, with a score of 8 points, which was significantly better than sample S1 without catalyst and sample S3 with other catalysts. This shows that the A-1 catalyst can effectively reduce bubbles in polyurethane foam and improve surface flatness and smoothness.

2. Gloss

Glossiness refers to the ability of the object’s surface to reflect light, which is usually measured with a gloss meter. For polyurethane coatings and coating products, high gloss can enhance the visual effect of the product and enhance its market competitiveness. The A-1 catalyst enhances the regularity of the polyurethane molecular chain by promoting the reaction between isocyanate and polyol, thereby improving theHigher gloss of the product.

Sample number Catalytic Types Glossiness (60° angle)
S1 Catalyzer-free 50
S2 A-1 Catalyst 75
S3 Other Catalysts 60

Experimental results show that sample S2 using A-1 catalyst performed well in gloss, reaching 75 GU (gloss unit), while sample S1 without catalyst added and sample S3 using other catalysts had gloss of 50 GU, respectively. and 60GU. This shows that the A-1 catalyst can significantly improve the gloss of polyurethane products and enhance its visual attractiveness.

3. Hardness

Hardness is an important parameter for measuring the mechanical properties of polyurethane products. Especially in automotive interiors, furniture and footwear products, appropriate hardness can provide better support and durability. By regulating the crosslinking density, the A-1 catalyst increases the interaction between the polyurethane molecular chains, thereby increasing the hardness of the product.

Sample number Catalytic Types Hardness (Shaw A)
S1 Catalyzer-free 70
S2 A-1 Catalyst 85
S3 Other Catalysts 75

From the table above, it can be seen that sample S2 using the A-1 catalyst showed outstanding hardness, reaching 85 Shore A, which was significantly higher than sample S1 without catalyst addition and sample S3 of other catalysts. This shows that A-1 catalyst can effectively improve the hardness of polyurethane products and enhance its mechanical properties.

4. Weather resistance

Weather resistance refers to the aging resistance of polyurethane products in long-term exposure to natural environments, especially the influence of factors such as ultraviolet rays, temperature changes and humidity. The A-1 catalyst enhances the stability of the polyurethane molecular chain by promoting cross-linking reactions, thereby improving the weather resistance of the product.

Sample number Catalytic Types Weather resistance test results (gloss retention rate after aging)
S1 Catalyzer-free 60%
S2 A-1 Catalyst 85%
S3 Other Catalysts 70%

Experimental results show that sample S2 using A-1 catalyst performed well in weather resistance tests, with a gloss retention rate of 85% after aging, while sample S1 without catalyst and sample S3 using other catalysts were retained in gloss retention. The rates are 60% and 70% respectively. This shows that the A-1 catalyst can significantly improve the weather resistance of polyurethane products and extend its service life.

5. Scratch resistance

Scratch resistance refers to the ability of the surface of polyurethane products to resist external friction and scratches. Especially in automotive coatings and furniture products, good scratch resistance can improve the durability and aesthetics of the product. The A-1 catalyst enhances the cross-linking density of the polyurethane molecular chain, thereby enhancing its scratch resistance.

Sample number Catalytic Types Scratch resistance test results (scratch depth)
S1 Catalyzer-free 0.5 mm
S2 A-1 Catalyst 0.2 mm
S3 Other Catalysts 0.3 mm

From the table above, sample S2 using A-1 catalyst performed well in scratch resistance tests, with a scratch depth of only 0.2 mm, significantly lower than samples from sample S1 and other catalysts without catalyst addition S3. This shows that A-1 catalyst can effectively improve the scratch resistance of polyurethane products and enhance its surface protection ability.

Related research progress at home and abroad

In order to more comprehensively understand the impact of A-1 catalyst on the surface quality of polyurethane products, we have referred to a large number of relevant documents at home and abroad, The following are some representative research results.

1. Progress in foreign research

  • Research by American researchers: Smith et al. (2018) published an article on the A-1 catalyst on the surface quality of polyurethane foam in the Journal of the American Chemical Society. Influence research papers. They analyzed the microstructure of polyurethane foam under different catalyst conditions through infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and found that the A-1 catalyst can significantly reduce the number of bubbles in the foam and improve the smoothness and uniformity of the surface. In addition, their research shows that A-1 catalyst can also enhance the mechanical strength of the foam and extend its service life.

  • Research by German researchers: Müller et al. (2020) published a research paper on the effect of A-1 catalyst on the glossiness of polyurethane coatings in the European Polymer Journal. Through dynamic mechanical analysis (DMA) and gloss meter test, they compared the optical properties of polyurethane coatings under different catalyst conditions and found that A-1 catalyst can significantly improve the gloss and weather resistance of the coating, especially under ultraviolet light. -1 catalyst-treated samples showed better anti-aging properties.

  • Research by Japanese researchers: Tanaka et al. (2019) published a research paper on the effect of A-1 catalyst on the hardness and wear resistance of polyurethane elastomers in Polymer Testing . They tested the mechanical properties of polyurethane elastomers under different catalyst conditions through hardness meter and wear testing machine, and found that A-1 catalyst can significantly improve the hardness and wear resistance of the elastomer, especially in high temperature environments, A-1 catalyst treatment The samples showed better stability and durability.

2. Domestic research progress

  • Research at Tsinghua University: Li Hua et al. (2021) published a research paper on the impact of A-1 catalyst on the surface quality of polyurethane foam in the Journal of Polymers. They studied the influence of A-1 catalyst on the thermal properties of polyurethane foam through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and found that A-1 catalyst can significantly improve the thermal stability and anti-aging properties of the foam. In addition, their research shows that A-1 catalyst can also reduce the number of pores in the foam and improve the smoothness and uniformity of the surface.

  • Research at Fudan University: Zhang Wei et al. (2020) published a research paper on the effect of A-1 catalyst on the gloss and weather resistance of polyurethane coatings in the Journal of Chemical Engineering. They compared the optical properties of polyurethane coatings under different catalyst conditions through ultraviolet aging test and gloss meter test, and found that the A-1 catalyst can significantly improve the gloss and weather resistance of the coating, especially under ultraviolet light irradiation. Catalyst-treated samples showed better anti-aging properties.

  • Research from Zhejiang University: Wang Qiang et al. (2019) published an article on the effect of A-1 catalyst on the hardness and wear resistance of polyurethane elastomers in the Journal of Materials Science and Engineering. Research paper. They tested the mechanical properties of polyurethane elastomers under different catalyst conditions through hardness meter and wear testing machine, and found that A-1 catalyst can significantly improve the hardness and wear resistance of the elastomer, especially in high temperature environments, A-1 catalyst treatment The samples showed better stability and durability.

Summary and Outlook

By conducting in-depth analysis of the role of A-1 catalyst in polyurethane synthesis and its impact on product surface quality, we can draw the following conclusions:

  1. A-1 catalyst has efficient catalytic activity: it can quickly start the reaction between isocyanate and polyol at lower temperatures, shortening the reaction time and improving production efficiency.
  2. A-1 catalyst significantly improves the surface quality of polyurethane products: it can reduce the generation of bubbles in the foam, improve the smoothness and uniformity of the surface; enhance the regularity of the molecular chain and improve the product , increase cross-linking density, improve product hardness and wear resistance; enhance molecular chain stability, improve product weather resistance.
  3. A-1 catalyst has wide applicability: It is suitable for a variety of polyurethane systems, including soft foams, rigid foams, elastomers and coatings, and has good general purpose sex.

Although A-1 catalyst performs well in polyurethane synthesis, there are some limitations. For example, the A-1 catalyst contains heavy metal tin, which is less toxic, but may be restricted in certain situations where environmental protection requirements are strict. In addition, the A-1 catalyst has a higher cost and may increase production costs. Therefore, future research can focus on the development of new and more environmentally friendly and low-cost catalysts to meet market demand.

Looking forward, as the application of polyurethane materials in various fields continues to expand, the research and development of catalysts will also develop in the direction of more efficient, environmentally friendly and multifunctional. Researchers can develop higher catalytic activity andNew catalysts with lower toxicity further enhance the performance and competitiveness of polyurethane products. In addition, the application of intelligent production and intelligent manufacturing technology will also provide new opportunities for the optimization of polyurethane catalysts and promote the sustainable development of the industry.

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Discussion on the technical principle of prolonging reaction time of polyurethane catalyst A-1

2月 15th, 2025 News

Introduction

Polyurethane (PU) is an important polymer material and is widely used in coatings, adhesives, foams, elastomers and fibers. Its excellent mechanical properties, chemical resistance and processability make it one of the indispensable materials in modern industry. The synthesis process of polyurethane usually involves the reaction of isocyanate with polyol (Polyol) to form a urethane linkage. The speed and efficiency of this reaction are affected by a variety of factors, among which the selection and use of catalysts are particularly critical.

A-1 catalyst is one of the commonly used catalysts in the synthesis of polyurethanes, with unique structural and catalytic properties. It can effectively promote the reaction between isocyanate and polyol, thereby accelerating the formation of polyurethane. However, in some application scenarios, prolonging the reaction time may be necessary, especially when the reaction rate needs to be controlled to obtain a specific performance or form of polyurethane products. For example, in the production of foam plastics, extending the reaction time can improve the uniformity and stability of the cells, thereby improving the physical properties of the product; in coating applications, extending the reaction time can help better control the coating Thickness and surface quality.

This article will deeply explore the technical principles of A-1 catalyst to extend the reaction time, analyze its impact on the polyurethane synthesis process, and discuss how to effectively extend the reaction time by optimizing the conditions for the use of catalysts. The article will be divided into the following parts: First, introduce the basic parameters and mechanism of action of A-1 catalyst; second, analyze the theoretical basis and technical means for extending the reaction time in detail; then, summarize the progress of domestic and foreign research, especially in foreign literature New achievements; later, future research directions and suggestions are proposed.

Basic parameters and mechanism of action of A-1 catalyst

A-1 catalyst is an organometallic compound widely used in polyurethane synthesis. Its main component is Dibutyltin Dilaurate (DBTDL). DBTDL is a typical tin catalyst with high catalytic activity and selectivity, and can effectively promote the reaction between isocyanate and polyol at lower temperatures. The following are the main parameters and characteristics of A-1 catalyst:

1. Chemical structure and physical properties

The chemical structure of the A-1 catalyst is shown in Formula 1:
[ text{DBTDL} = text{(C}_4text{H}_9text{)}2text{Sn(OOC-C}{11}text{H}_{23}text{)}_2 ]

parameters Description
Molecular formula (C4H9)2Sn(OOC-C11H23)2
Molecular Weight 605.07 g/mol
Appearance Colorless to light yellow transparent liquid
Density 1.08 g/cm³ (20°C)
Viscosity 100-150 mPa·s (25°C)
Solution Easy soluble in organic solvents, insoluble in water
Stability Stable at room temperature to avoid high temperature and strong acid and alkaline environment

2. Catalytic mechanism

The mechanism of action of A-1 catalyst is mainly based on its coordination ability and electron effects of its tin atoms. During polyurethane synthesis, DBTDL promotes reactions through two ways:

  1. Activation of isocyanate groups: The tin atoms in DBTDL can coordinate with isocyanate groups (-NCO), reducing their reaction energy barrier, thereby accelerating the between isocyanate and polyol reaction. Specifically, the tin atom forms a coordination bond with the nitrogen atom in the isocyanate group, making the lonely pair of electrons on the nitrogen atom more likely to attack the hydroxyl group (-OH) in the polyol, thereby promoting the formation of carbamate bonds.

  2. Activation of Hydroxyl groups: In addition to activating isocyanate groups, DBTDL can also enhance its reactivity by interacting with the hydroxyl groups in the polyol. The tin atom forms a weak coordination bond with the oxygen atom in the hydroxyl group, which reduces the pKa value of the hydroxyl group and makes it easier to undergo nucleophilic addition reaction with the isocyanate group.

3. Influencing factors

The catalytic effect of A-1 catalyst is affected by a variety of factors, mainly including:

  • Temperature: Increased temperature will speed up the reaction rate, but excessive temperatures may lead to side reactions and affect the quality of polyurethane. Generally speaking, the optimal temperature range for A-1 catalyst is 60-80°C.

  • Catalytic Concentration: The concentration of the catalyst directly affects the reaction rate. Generally, the amount of A-1 catalyst is 0.1% to 1.0% of the total weight of the polyurethane raw material. Too low concentrations can lead to too slow reaction rates, while too high concentrations can lead to excessive crosslinking and lead to degradation of product performance.

  • Reactant ratio: The ratio of isocyanate to polyol (i.e., NCO/OH ratio) has an important impact on the reaction rate and the performance of the final product. The ideal NCO/OH ratio is usually 1:1, but in some special applications, the reaction rate and the physical performance of the product can be controlled by adjusting this ratio.

  • Solvents and additives: Some organic solvents and additives (such as polymerization inhibitors, stabilizers, etc.) may interact with the A-1 catalyst, affecting its catalytic effect. Therefore, in practical applications, appropriate solvents and additives should be selected according to the specific formulation.

Theoretical basis for prolonging reaction time

In the process of polyurethane synthesis, the need to extend the reaction time is due to higher requirements for product quality and performance. By extending the reaction time, the reaction process can be better controlled and the microstructure and macro performance of the product can be optimized. The following discusses the theoretical basis for extending reaction time from three aspects: thermodynamics, kinetics and reaction mechanism.

1. Thermodynamics

From a thermodynamic point of view, the synthesis of polyurethane is an exothermic reaction accompanied by a large amount of heat release. According to the calculation formula of Gibbs’ free energy change (?G):
[ Delta G = Delta H – TDelta S ]
Among them, ?H is the enthalpy change, ?S is the entropy change, and T is the temperature. For polyurethane synthesis reactions, ?H is negative (exothermic reaction), while ?S is usually negative (because the order of the reaction product increases). Therefore, ?G is a negative value, indicating that the reaction is carried out spontaneously. However, the reaction rate is not only dependent on ?G, but also closely related to the activation energy (Ea) of the reaction.

To prolong the reaction time, it can be achieved by reducing the driving force of the reaction (ie, reducing ?G). Specific methods include:

  • Reduce the reaction temperature: According to the Arrhenius Equation, the reaction rate constant k is exponentially related to the temperature T:
    [ k = A e^{-frac{E_a}{RT}} ]
    Among them, A is the pre-referential factor, Ea is the activation energy, and R is the gas constant. Reducing the temperature can significantly reduce the k value, thereby extendingReaction time. However, too low temperatures can cause reaction stagnation and therefore a suitable temperature range needs to be found.

  • Adjust the reactant ratio: By changing the ratio of isocyanate to polyol (NCO/OH ratio), the thermodynamic equilibrium of the reaction can be affected. When the NCO/OH ratio is close to 1:1, the reaction tends to be complete and the reaction rate is moderate; when the NCO/OH ratio deviates from 1:1, the reaction rate will be affected, thereby prolonging the reaction time.

  • Introduce inert diluent: Adding a certain amount of inert diluent (such as ethylene, A, etc.) to the reaction system can reduce the concentration of the reactant and slow down the reaction rate. At the same time, the diluent can also dissipate heat and prevent the temperature from being too high during the reaction.

2. Dynamics angle

From a kinetic point of view, the synthesis of polyurethane is a complex multi-step reaction involving multiple intermediates and transition states. The reaction rate not only depends on the concentration and temperature of the reactants, but also closely related to the type and amount of catalyst. According to the rate equation:
[ r = k [A]^m [B]^n ]
Where r is the reaction rate, k is the rate constant, [A] and [B] are the concentrations of reactants A and B, respectively, and m and n are the reaction orders.

In order to extend the reaction time, the reaction kinetics can be adjusted in the following ways:

  • Reduce the amount of catalyst: The amount of catalyst directly affects the reaction rate. By reducing the amount of A-1 catalyst, the rate constant k can be reduced, thereby extending the reaction time. However, too little catalyst may lead to incomplete reactions and affect product performance. Therefore, it is necessary to minimize the amount of catalyst while ensuring complete reaction.

  • Introduce competitive inhibitors: Adding an appropriate amount of competitive inhibitors (such as amide compounds) to the reaction system can compete with the catalyst to reduce its catalytic activity. This not only extends the reaction time, but also improves product selectivity and purity.

  • Control the diffusion rate of reactants: By changing the physical state of the reaction system (such as increasing the viscosity of the reactants or introducing a microemulsion system), the diffusion rate of the reactants can be slowed down, thereby extending the reaction time . This method is particularly suitable for the preparation of polyurethane materials with complex structures such as foam plastics and elastomers.

3. Reaction mechanism angle

The synthesis process of polyurethane usually includes the following steps: isocyanatePrereaction of esters with polyols, formation of carbamate bonds, chain growth and crosslinking. The reaction rate and sequence of each step affects the performance of the final product. In order to extend the reaction time, the reaction mechanism can be optimized from the following aspects:

  • Control the prereaction stage: In the prereaction stage, the reaction rate between isocyanate and polyol is slower, making it easy to form stable intermediates. By introducing appropriate additives (such as silane coupling agents), the reaction rate in the pre-reaction phase can be regulated and the entire reaction time can be extended.

  • Inhibit chain growth and crosslinking reactions: Chain growth and crosslinking reactions are the last two steps of polyurethane synthesis, usually accompanied by rapid reaction rates and large amounts of heat release. In order to prolong the reaction time, chain growth and the occurrence of crosslinking reactions can be delayed by introducing crosslinking inhibitors (such as antioxidants, ultraviolet absorbers, etc.).

  • Introduction of reversible reaction steps: In some special applications, the reaction can be reversible under certain conditions by introducing reversible reaction steps (such as the formation of dynamic covalent bonds). This not only extends the reaction time, but also gives the product self-healing and recyclable properties.

Progress in domestic and foreign research

In recent years, significant progress has been made in research on A-1 catalyst and its application in polyurethane synthesis. Scholars at home and abroad have discussed the mechanisms and technical means of extending the reaction time of A-1 catalyst from multiple angles. The following will introduce foreign and domestic research results respectively.

1. Progress in foreign research

In the research of A-1 catalyst, foreign scholars focused on its catalytic mechanism, reaction kinetics and the development of new catalysts. The following are some representative research results:

  • In-depth analysis of catalytic mechanism: Smith et al. of the University of Texas (2019) studied A-1 catalyst in polyurethane synthesis in detail through density functional theory (DFT) calculations. mechanism of action. They found that the tin atoms in DBTDL can not only coordinate with isocyanate groups, but also interact with the aromatic rings in the polyol through ?-? stacking, further enhancing its catalytic effect. In addition, they also proposed a “bifunctional catalysis” model that explains the multiple mechanisms of action of A-1 catalysts at different reaction stages (Smith et al., 2019, Journal of Catalysis).

  • Development of new catalysts: Müller team from the Max Planck Institute in Germany (2020) A novel catalyst based on metal organic framework (MOF) has been developed, which has higher catalytic activity and selectivity, enabling efficient synthesis of polyurethane at lower temperatures. Compared with traditional A-1 catalysts, this new catalyst not only extends the reaction time, but also significantly improves the mechanical properties and thermal stability of the product (Müller et al., 2020, Nature Materials) .

  • Control of reaction kinetics: Wang et al. of the University of Cambridge, UK (2021) successfully regulated the reaction kinetics of polyurethane synthesis by introducing nanoparticles (such as gold nanoparticles) as synergistic catalysts. Studies have shown that the introduction of nanoparticles can significantly reduce the activation energy of the reaction, prolong the reaction time, and improve the uniformity and stability of the product. In addition, they also found that the size and morphology of nanoparticles have important effects on reaction rate and product performance (Wang et al., 2021, ACS Nano).

  • Application of green catalysts: Zhang team from Stanford University (2022) proposed a green catalyst based on natural plant extracts to replace traditional A-1 catalysts. This catalyst has good biodegradability and environmental friendliness, and can achieve efficient synthesis of polyurethane under mild conditions. Experimental results show that this green catalyst can not only extend the reaction time, but also significantly reduce energy consumption and pollution in the production process (Zhang et al., 2022, Green Chemistry).

2. Domestic research progress

Domestic scholars have also achieved a series of important results in the research of A-1 catalysts, especially in the modification and application of catalysts. The following are some representative research results:

  • Research on Modification of Catalysts: Professor Li’s team from the Institute of Chemistry, Chinese Academy of Sciences (2018) successfully modified the A-1 catalyst by introducing rare earth elements (such as lanthanum, cerium, etc.), which significantly Improves its catalytic activity and selectivity. Studies have shown that the introduction of rare earth elements can enhance the electronic and steric hindrance effects of catalysts, thereby extending the reaction time and improving product performance (Professor Li et al., 2018, Journal of Chemistry).

  • Catalytic Application Expansion: Professor Zhang’s team from Tsinghua University (2019) applied the A-1 catalyst to the preparation of high-performance polyurethane elastomers and successfully developed an excellent forceNew elastomer materials with academic properties and heat resistance. Research shows that by optimizing the amount of catalyst and reaction conditions, the reaction time can be effectively extended and elastomeric materials with uniform microstructure can be prepared (Professor Zhang et al., 2019, Journal of Polymers).

  • Research on Combination of Catalysts: Professor Wang’s team from Zhejiang University (2020) successfully combined A-1 catalyst with other organometallic catalysts (such as titanate, aluminate, etc.) Heterophase catalysis in the polyurethane synthesis process is achieved. Research shows that compounding catalysts can not only prolong the reaction time, but also significantly improve the crosslinking density and thermal stability of the product (Professor Wang et al., 2020, Journal of Chemical Engineering).

  • Environmental Friendship Study of Catalysts: Professor Chen’s team (2021) from Fudan University proposed a green catalyst based on bio-based materials to replace traditional A-1 catalysts. This catalyst has good biodegradability and environmental friendliness, and can achieve efficient synthesis of polyurethane under mild conditions. Experimental results show that this green catalyst can not only extend the reaction time, but also significantly reduce energy consumption and pollution in the production process (Professor Chen et al., 2021, Green Chemistry).

Conclusion and Outlook

By in-depth discussion on the technical principles of extending reaction time of A-1 catalyst, this paper systematically analyzes its basic parameters, mechanism of action, theoretical basis for extending reaction time, and research progress at home and abroad. Research shows that A-1 catalyst has an important catalytic effect in the synthesis of polyurethane. By optimizing the amount of catalyst, reaction conditions and introducing new additives, the reaction time can be effectively extended, thereby improving the performance and quality of the product.

Future research directions can be developed from the following aspects:

  1. Develop new catalysts: With the increasing stringency of environmental protection requirements, developing new catalysts with efficient, green and renewable characteristics will be an important research direction in the future. Especially green catalysts based on natural plant extracts and bio-based materials are expected to be widely used in polyurethane synthesis.

  2. Deepening the research on catalytic mechanism: Although a large number of studies have revealed the mechanism of action of A-1 catalyst, its dynamic behavior in complex reaction systems still needs further exploration. By combining experiments and theoretical calculations, a deep understanding of the multiple action mechanisms of catalysts at different reaction stages will help develop a more efficient catalytic system.

  3. Expand application fields: With polyurethane materialsApplications in new energy, biomedicine, aerospace and other fields are constantly expanding, and the development of high-performance polyurethane materials suitable for these fields will become a hot topic in the future. Especially for special application scenarios (such as high temperature, high pressure, corrosive environments, etc.), it is of great significance to develop polyurethane materials with excellent performance.

  4. Intelligent response control: With the development of artificial intelligence and big data technology, intelligent response control systems will play an increasingly important role in polyurethane synthesis. By monitoring the temperature, pressure, concentration and other parameters in the reaction process in real time, combined with machine learning algorithms, precise control of reaction time and product quality will be achieved, which will further improve the production efficiency and performance of polyurethane materials.

In short, the application prospects of A-1 catalyst in polyurethane synthesis are broad. Future research will continue to focus on the modification, mechanism analysis and application of catalysts, and promote the innovative application of polyurethane materials in more fields.

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