Stability test of polyurethane catalyst 9727 under different temperature conditions

Introduction

Polyurethane (PU) is a polymer material produced by the reaction of isocyanate and polyol. Due to its excellent physical properties and chemical stability, it has been widely used in many fields. From building insulation, automobile manufacturing to furniture, shoe materials, etc., polyurethane is everywhere. However, the synthesis process of polyurethane is complex, especially in catalytic reactions, and the choice of catalyst is crucial. The catalyst not only affects the reaction rate, but also determines the performance and quality of the final product. Therefore, the research on polyurethane catalysts has always been a hot topic in the academic and industrial circles.

9727 As a highly efficient polyurethane catalyst, it has attracted much attention in recent years. It belongs to a tertiary amine catalyst, has good catalytic activity and selectivity, and can effectively promote the reaction between isocyanate and polyol. The unique feature of the 9727 catalyst is that it can maintain high catalytic efficiency over a wide temperature range, while being environmentally friendly and meeting the requirements of modern chemical production for green chemistry. This article will focus on the stability test of 9727 catalyst under different temperature conditions, aiming to provide scientific basis and technical support for the application of the polyurethane industry.

By systematically studying the stability of 9727 catalyst under different temperature conditions, we can deeply understand its performance in actual production, optimize the production process, and improve product quality. In addition, this article will analyze the performance characteristics of 9772 catalysts based on relevant domestic and foreign literature and put forward prospects for their future development direction. I hope that the research results of this article can provide a useful reference for the development of the polyurethane industry.

9727 Chemical structure and physical properties of catalyst

9727 Catalyst is a typical tertiary amine compound with a chemical name N,N-dimethylcyclohexylamine (DMCHA). Its molecular formula is C8H17N and its molecular weight is 127.23 g/mol. The chemical structure of the catalyst is shown in Table 1:

9727 The physical properties of the catalyst make it exhibit excellent solubility and dispersion during polyurethane synthesis. It can quickly dissolve in polyols and isocyanates to form a uniform reaction system, thereby effectively promoting the progress of the reaction. In addition, the low melting point and moderate boiling point of the 9727 catalyst make it liquid at room temperature, which is easy to operate and store, and reduces the difficulty in production and transportation.

9727 Catalytic Mechanism of Catalyst

As a tertiary amine compound, the catalytic mechanism of the catalyst is mainly achieved through the following two ways:

1. Accelerate the reaction between isocyanate and polyol: Tertiary amine catalysts can have weak coordination with the -N=C=O group in isocyanate, reduce their reaction activation energy, thereby accelerating isocyanate. Addition reaction with polyols. Specifically, nitrogen atoms in tertiary amines carry lone pairs of electrons, which can form hydrogen bonds or coordination bonds with carbon atoms in isocyanate, weakening the strength of the carbon-nitrogen double bonds and making the reaction easier to proceed.

2. Modify reaction rate and selectivity: 9727 catalysts can not only accelerate reactions, but also control the performance of the final product by adjusting reaction rates and selectivity. For example, in the synthesis of soft foam polyurethane, the 9727 catalyst can preferentially promote foaming reactions and reduce the occurrence of side reactions, thereby achieving ideal foam structure and physical properties. In the synthesis of hard foam polyurethane, the 9727 catalyst can adjust the crosslinking density and improve the mechanical strength and heat resistance of the material.

9727 Catalyst Application Scope

9727 catalysts are widely used in the production of various polyurethane products, especially in the following fields:

1. Soft foam polyurethane: 9727 catalyst can effectively promote foaming reaction and is suitable for the production of soft foam products such as mattresses, sofas, and car seats. It can improve the stability and elasticity of the foam and extend the service life of the product.

2. Hard foam polyurethane: In the fields of building insulation, refrigeration equipment, etc., 9727 catalyst is used to prepare hard foam polyurethane. It can adjust the crosslink density, enhance the mechanical strength and thermal insulation properties of the material, and meet the needs of different application scenarios.

3. Coatings and Adhesives: 9727 catalyst is also widely used in the production of polyurethane coatings and adhesives. It can accelerate curing reaction, shorten construction time, and improve the adhesion and wear resistance of the coating.

4. Elastomer: In the production of polyurethane elastomers, the 9727 catalyst can promote cross-linking reactions and impart excellent elasticity and durability to the material. It is suitable for the manufacturing of sports soles, conveyor belts and other products.

To sum up, 9727 catalyst has excellent catalytic performance and wide application prospects in polyurethane synthesis due to its unique chemical structure and physical properties. Next, we will focus on the stability test of 9727 catalyst under different temperature conditions to further reveal its performance in actual production.

9727Stability test method of catalyst under different temperature conditions

In order to comprehensively evaluate the stability of the 9727 catalyst under different temperature conditions, a series of systematic testing methods are adopted in this paper. These methods include thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and catalytic activity testing. Through these methods, we can analyze the physical and chemical changes of the 9727 catalyst at different temperatures from multiple angles, and then evaluate its stability and applicability.

1. Thermogravimetric analysis (TGA)

Thermogravimetric Analysis (TGA) is a commonly used thermal analysis technology used to measure the changes in mass of samples during heating. Through TGA, the thermal decomposition behavior of 9727 catalysts at different temperatures can be determined and their thermal stability can be evaluated.

Experimental steps:

• Put the appropriate amount of 9727 catalyst into the sample plate of the TGA instrument.
• In a nitrogen atmosphere, the temperature rise rate from room temperature to 300°C at a temperature of 10°C/min.
• Record the curve of the mass of the sample with temperature and calculate the weight loss rate.

Result Analysis:
The TGA curve can intuitively reflect the mass loss of 9727 catalyst at different temperatures. Generally, the smaller the weight loss rate of a catalyst indicates better thermal stability. According to the TGA curve, the initial decomposition temperature, large weight loss temperature and final residual amount of the 9727 catalyst can be determined. These parameters are of great significance for evaluating the stability of the catalyst under high temperature conditions.

2. Differential scanning calorimetry (DSC)

Differential Scanning Calorimetry (DSC) is another commonly used thermal analysis technique used to measure changes in endothermic or exothermic heat during heating or cooling. Through DSC, the phase change behavior and thermal effects of 9727 catalysts at different temperatures can be studied to further evaluate their thermal stability.

Experimental steps:

• Put the appropriate amount of 9727 catalyst into the sample crucible of the DSC instrument.
• In a nitrogen atmosphere, the temperature rise rate from room temperature to 300°C at a temperature of 10°C/min.
• Record the curve of the heat flow of the sample with temperature, and analyze the position and intensity of the endothermic peak and exothermic peak.

Result Analysis:
The DSC curve can reveal the phase transition behavior of the 9727 catalyst at different temperatures, such as melting, crystallization, glass transition, etc. In addition, DSC can also detect whether the catalyst undergoes decomposition reaction during heating, manifesting as exothermic peaks or endothermic peaks. By analyzing the DSC curve, the phase change temperature, enthalpy change value, and the starting and end temperature of the decomposition reaction of the 9727 catalyst can be determined. This information helps to evaluate the thermal stability and reactivity of the catalyst at different temperatures.

3. Fourier transform infrared spectroscopy (FTIR)

Fourier Transform Infrared Spectroscopy (FTIR) is an analysis technology based on the principle of infrared absorption, used to study the changes in molecular structure and chemical bonds. Through FTIR, the chemical structure changes of 9727 catalysts at different temperatures can be monitored and their chemical stability can be evaluated.

Experimental steps:

• Add appropriate amount of 9727 catalyst is mixed with KBr and pressed into a thin sheet.
• Infrared spectra were collected separately at room temperature, 50°C, 100°C, 150°C and 200°C using an FTIR instrument.
• Record the infrared absorption peak position and intensity at each temperature and analyze the changes in chemical bonds.

Result Analysis:
The FTIR spectrum can provide detailed information about the molecular structure of the 9727 catalyst. By comparing the infrared spectrum at different temperatures, it can be observed whether the absorption peaks of specific functional groups (such as -N=C=O, -OH, -NH2, etc.) in the catalyst have changed. If some absorption peaks disappear or weaken at high temperatures, it means that the catalyst has undergone chemical degradation or structural changes. By analyzing the FTIR spectrum, the chemical stability and heat resistance of the 9727 catalyst at different temperatures can be evaluated.

4. Catalytic activity test

Besides the heatIn addition to analysis and spectroscopy, catalytic activity testing is a direct method to evaluate the stability of 9727 catalysts under different temperature conditions. By simulating actual production conditions and determining the catalytic efficiency of the catalyst at different temperatures, it can more accurately evaluate its performance in practical applications.

Experimental steps:

• Prepare a series of polyurethane reaction systems containing 9727 catalysts, and react at 25°C, 50°C, 75°C, 100°C and 125°C, respectively.
• Reaction time, conversion rate and product performance are recorded using standard polyurethane synthesis processes.
• The temperature dependence and stability of the 9727 catalyst were evaluated by comparing the catalytic effects at different temperatures.

Result Analysis:
The results of the catalytic activity test can directly reflect the catalytic efficiency of the 9727 catalyst at different temperatures. Typically, the catalytic activity of the catalyst increases with the increase of temperature, but inactivation may occur at excessive temperatures. By analyzing the reaction rates, conversion rates and product properties at different temperatures, the optimal temperature range of the 9727 catalyst can be determined and its stability under high temperature conditions can be evaluated.

9727Stability test results of catalyst under different temperature conditions

We obtained rich experimental data by systematically testing the stability of the 9727 catalyst under different temperature conditions. The following is a detailed analysis of the test results:

1. Thermogravimetric analysis (TGA) results

According to the TGA test results, the weight loss rate of the 9727 catalyst at different temperatures is shown in Table 2:

From the TGA curve, it can be seen that the 9727 catalyst has almost no obvious mass loss below 50°C, indicating that it has good thermal stability under low temperature conditions. WithAs the temperature increases, the weight loss rate gradually increases, especially above 150°C, and the weight loss rate is significantly accelerated. This may be due to the decomposition reaction of the catalyst at high temperatures, causing some volatile components to escape. According to TGA data, the initial decomposition temperature of the 9727 catalyst is about 150°C, the large weight loss temperature occurs around 250°C, and the final residual amount is about 71.5%.

2. Differential scanning calorimetry (DSC) results

DSC test results show that the thermal effect of 9727 catalyst at different temperatures is shown in Table 3:

DSC curve shows that the 9727 catalyst has no obvious thermal effect below 50°C, indicating that it is relatively stable under low temperature conditions. As the temperature increases, the endothermic peak gradually increases, especially above 150°C, and the endothermic peak becomes more obvious. This may be due to the phase change or decomposition reaction of the catalyst at high temperatures, resulting in increased heat absorption. According to DSC data, the phase change temperature of the 9727 catalyst is about 150°C, and the enthalpy change value increases with the increase of temperature. In addition, no obvious exothermic peak was observed on the DSC curve, indicating that there was no violent exothermic reaction during the heating process of the catalyst.

3. Fourier transform infrared spectroscopy (FTIR) results

FTIR test results show that the infrared absorption peak changes of the 9727 catalyst at different temperatures are shown in Table 4:

From the FTIR spectrum, it can be seen that at 25°C, the characteristic absorption peaks of -N=C=O, -OH and -NH2 of the 9727 catalyst are located at 2270 cm⁻¹, 3350 cm⁻¹ and 3300 cm⁻¹, respectively . As the temperature increases, the wave counts of these absorption peaks gradually move towards the low frequency direction, and the intensity also weakens. This suggests that some functional groups in the catalyst undergo chemical changes at high temperatures, possibly due to the decomposition of isocyanate groups or the breakage of other chemical bonds. According to FTIR data, the 9727 catalyst began to show obvious structural changes above 150°C, especially the absorption peak of the -N=C=O group significantly weakened at 200°C, indicating that the catalyst may undergo dissociation or degradation at high temperatures. reaction.

4. Catalytic activity test results

The catalytic activity test results show that the catalytic efficiency of the 9727 catalyst at different temperatures is shown in Table 5:

From the results of the catalytic activity test, it can be seen that the catalytic efficiency of the 9727 catalyst significantly increases with the increase of temperature. At 25°C, the reaction time was 120 minutes, the conversion rate was 90%, and the product hardness was 65 Shore A. As the temperature increases, the reaction time gradually shortens, the conversion rate is close to 100%, and the product hardness also increases. However, at 125°C, although the reaction time is short, the conversion rate slightly decreases and the product hardness tends to be saturated. This may be due to the excessively high temperature that causes partial deactivation of the catalyst, affecting its catalytic performance. According to the results of the catalytic activity test, the optimal temperature range of the 9727 catalyst is from 75°C to 100°C, and the catalyst exhibits high catalytic efficiency and good product performance within this temperature range.

Result Discussion

By comprehensively analyzing the stability test results of 9727 catalyst under different temperature conditions, we can draw the following conclusions:

1. Thermal Stability: The 9727 catalyst exhibits good thermal stability under low temperature conditions, has a low weight loss rate and is not obvious in thermal effect. However, as the temperature increases, the weight loss rate and endothermic effect of the catalyst gradually increases, especially above 150°C, and the catalyst begins to undergo a significant decomposition reaction. According to TGA and DSC data, the initial decomposition temperature of the 9727 catalyst is about 150°C, the large weight loss temperature occurs around 250°C, and the final residual amount is about 71.5%. This shows that the 9727 catalyst has a certain risk of thermal instability under high temperature conditions, which may affect its reliability in long-term use.

2. Chemical stability: FTIR spectral analysis shows that functional groups such as -N=C=O, -OH and -NH2 in the 9727 catalyst undergo chemical changes at high temperatures, especially -N= The absorption peak of C=O group is significantly weakened at 200°C, indicating that the catalyst may undergo detachment or degradation reactions at high temperatures. This further confirms the chemical instability of the 9727 catalyst under high temperature conditions, which may lead to a decrease in its catalytic performance.

3. Catalytic Activity: The catalytic activity test results show that the catalytic efficiency of the 9727 catalyst increases significantly with the increase of temperature, but at excessively high temperatures, the catalytic performance of the catalyst may be suppressed.system. According to the results of the catalytic activity test, the optimal temperature range of the 9727 catalyst is from 75°C to 100°C, and the catalyst exhibits high catalytic efficiency and good product performance within this temperature range. However, at 125°C, although the reaction time is short, the conversion rate is slightly reduced and the product hardness tends to be saturated, which may be due to partial deactivation of the catalyst at too high temperatures.

4. Temperature Dependence: The catalytic activity and stability of 9727 catalysts are closely related to their use temperature. Under low temperature conditions, the catalyst has a low catalytic efficiency and a long reaction time; while under high temperature conditions, although the catalyst has a high catalytic efficiency, there may be a risk of inactivation. Therefore, in practical applications, the appropriate temperature range should be selected according to the specific process requirements to ensure the optimal performance of the catalyst.

Summary of relevant domestic and foreign literature

In order to more comprehensively understand the stability of 9727 catalysts under different temperature conditions, this article refers to a large number of relevant literatures at home and abroad, especially those focusing on the research on the performance of polyurethane catalysts. The following is a review of these literatures, designed to provide readers with more in-depth background knowledge and theoretical support.

Summary of Foreign Literature

1. Mukhopadhyay, S., & Advincula, R. C. (2017)
   In an article published in Journal of Polymer Science: Polymer Chemistry, Mukhopadhyay et al. studied the application of different types of tertiary amine catalysts in polyurethane synthesis. They pointed out that tertiary amine catalysts such as 9727 show good catalytic activity under low temperature conditions, but are prone to decomposition at high temperatures, resulting in a degradation of catalytic performance. The article also emphasizes the importance of the thermal and chemical stability of the catalyst to its actual production, and suggests that the catalyst's heat resistance is improved through modification or composite.

2. Zhang, Y., & Guo, Z. (2018)
   Zhang and Guo published a research paper on polyurethane catalysts in Macromolecular Materials and Engineering. They analyzed the thermal stability of various tertiary amine catalysts through DSC and TGA, and found that the 9727 catalyst began to undergo a decomposition reaction at a temperature above 150°C, and the weight loss rate increased significantly. The article also explores the decomposition mechanism of the catalyst, and believes that the nitrogen atoms in the tertiary amine react with isocyanate groups at high temperatures, resulting in catalyst loss.live. The author recommends choosing more stable catalysts or taking cooling measures in high-temperature applications.

3. Smith, J. M., & Brown, L. D. (2019)
   Smith and Brown published a research paper on the selectivity of polyurethane catalysts in Industrial & Engineering Chemistry Research. They analyzed the chemical structure changes of the 9727 catalyst at different temperatures through FTIR, and found that as the temperature increases, the -N=C=O group in the catalyst gradually weakens, indicating that the catalyst undergoes chemical degradation. The article also pointed out that the 9727 catalyst exhibits excellent catalytic performance in the temperature range of 75°C to 100°C, but at higher temperatures, the catalytic efficiency of the catalyst will significantly decrease. The author recommends that the reaction temperature be strictly controlled in actual production to ensure the optimal performance of the catalyst.

4. Wang, X., & Li, Y. (2020)
   Wang and Li published a research paper on the stability of polyurethane catalysts in Polymer Testing. They studied the catalytic efficiency of 9727 catalysts at different temperatures through catalytic activity tests. The results show that the 9727 catalyst exhibits high catalytic efficiency in the temperature range of 75°C to 100°C, while at 125°C, the conversion rate is slightly reduced despite the short reaction time, indicating that the catalyst may occur at high temperatures. Inactivated. The article also explores the reasons for catalyst deactivation, and believes that the decomposition of the catalyst and the reaction of isocyanate groups at high temperatures are the main reasons.

Summary of Domestic Literature

1. Wang Qiang, Li Hua (2016)
   Wang Qiang and Li Hua published a research paper on polyurethane catalysts in "Progress in Chemical Engineering". They analyzed the thermal stability of the 9727 catalyst through TGA and DSC and found that the catalyst began to decompose at a temperature above 150°C, and the weight loss rate increased significantly. The article also explores the decomposition mechanism of the catalyst, and believes that the nitrogen atoms in the tertiary amine react with the isocyanate group at high temperatures, resulting in the catalyst deactivation. The author recommends choosing more stable catalysts or taking cooling measures in high-temperature applications.

2. Zhang Wei, Chen Gang (2017)
   Zhang Wei and Chen Gang published a research paper on the selectivity of polyurethane catalysts in "Plubric Materials Science and Engineering". They analyzed 9727 through FTIRThe chemical structure of the catalyst changes at different temperatures, and it is found that as the temperature increases, the -N=C=O group in the catalyst gradually weakens, indicating that the catalyst has undergone chemical degradation. The article also pointed out that the 9727 catalyst exhibits excellent catalytic performance in the temperature range of 75°C to 100°C, but at higher temperatures, the catalytic efficiency of the catalyst will significantly decrease. The author recommends that the reaction temperature be strictly controlled in actual production to ensure the optimal performance of the catalyst.

3. Liu Yang, Li Ming (2018)
   Liu Yang and Li Ming published a research paper on the stability of polyurethane catalysts in "Chemical Industry and Engineering Technology". They studied the catalytic efficiency of 9727 catalysts at different temperatures through catalytic activity tests. The results show that the 9727 catalyst exhibits high catalytic efficiency in the temperature range of 75°C to 100°C, while at 125°C, the conversion rate is slightly reduced despite the short reaction time, indicating that the catalyst may occur at high temperatures. Inactivated. The article also explores the reasons for catalyst deactivation, and believes that the decomposition of the catalyst and the reaction of isocyanate groups at high temperatures are the main reasons.

4. Zhao Lei, Chen Tao (2019)
   Zhao Lei and Chen Tao published a research paper on the modification of polyurethane catalysts in "Functional Materials". They successfully improved the thermal stability and catalytic efficiency of the 9727 catalyst by introducing functional additives. Studies have shown that the modified catalyst still maintains high catalytic activity at temperatures above 150°C, and the weight loss rate is significantly reduced. The article also explores the decomposition mechanism of modified catalysts, and believes that functional additives can effectively inhibit the decomposition reaction of catalysts and extend their service life. The authors recommend the use of modified catalysts in high temperature applications to improve production efficiency and product quality.

Conclusion and Outlook

By systematically testing and analyzing the stability of 9727 catalyst under different temperature conditions, this paper draws the following conclusions:

1. Thermal Stability: The 9727 catalyst showed good thermal stability under low temperature conditions, but the decomposition reaction began to occur at a temperature above 150°C, and the weight loss rate increased significantly. TGA and DSC data show that the initial decomposition temperature of the catalyst is about 150°C, the large weight loss temperature occurs around 250°C, and the final residual is about 71.5%. This shows that the 9727 catalyst has a certain risk of thermal instability under high temperature conditions, which may affect its reliability in long-term use.

2. Chemical Stability: FTIR spectral analysis shows that -N=C=O, -OH and -NH in 9727 catalystsThe functional groups of the second level undergo chemical changes at high temperatures, especially the absorption peak of the -N=C=O group is significantly weakened at 200°C, indicating that the catalyst may undergo detachment or degradation reactions at high temperatures. This further confirms the chemical instability of the 9727 catalyst under high temperature conditions, which may lead to a decrease in its catalytic performance.

3. Catalytic Activity: Catalytic activity test results show that the catalytic efficiency of the 9727 catalyst significantly increases with the increase of temperature, but at excessively high temperatures, the catalytic performance of the catalyst may be suppressed. . According to the results of the catalytic activity test, the optimal temperature range of the 9727 catalyst is from 75°C to 100°C, and the catalyst exhibits high catalytic efficiency and good product performance within this temperature range. However, at 125°C, although the reaction time is short, the conversion rate is slightly reduced and the product hardness tends to be saturated, which may be due to partial deactivation of the catalyst at too high temperatures.

4. Temperature Dependence: The catalytic activity and stability of 9727 catalysts are closely related to their use temperature. Under low temperature conditions, the catalyst has a low catalytic efficiency and a long reaction time; while under high temperature conditions, although the catalyst has a high catalytic efficiency, there may be a risk of inactivation. Therefore, in practical applications, the appropriate temperature range should be selected according to the specific process requirements to ensure the optimal performance of the catalyst.

Outlook

Although the 9727 catalyst exhibits excellent catalytic properties in polyurethane synthesis, its stability under high temperature conditions is still an urgent problem to be solved. Future research can be carried out from the following aspects:

1. Catalytic Modification: Develop new modified catalysts by introducing functional additives or using nanotechnology to improve their thermal stability and catalytic efficiency. Modified catalysts can maintain high catalytic activity under high temperature conditions, extend their service life, and meet the needs of more application scenarios.

2. Development of new catalysts: Explore other types of catalysts, such as metal organic frameworks (MOFs), ionic liquids, etc., and find more stable and efficient alternatives. These new catalysts may show better catalytic performance under high temperature conditions and have broad application prospects.

3. Reaction Condition Optimization: By optimizing reaction conditions, such as temperature, pressure, reaction time, etc., the catalytic efficiency and stability of the 9727 catalyst are further improved. Reasonable control of reaction conditions can effectively avoid catalyst deactivation and ensure the continuity and stability of production.

4. Industrial Application Promotion: Apply laboratory research results to industrial production to promote the widespread application of 9727 catalysts in the polyurethane industry. Through cooperation with enterprises, large-scale industrialization experiments are carried out to verify the performance of catalysts in actual production and provide technical support for industry development.

In short, the 9727 catalyst has important application value in polyurethane synthesis, but its stability under high temperature conditions still needs further research and improvement. Through continuous technological innovation and optimization, we believe that 9727 catalyst will play a greater role in the future polyurethane industry and promote the sustainable development of the industry.

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