\nUV resistance<\/td>\n | \u2013<\/td>\n | ASTM G154<\/td>\n | No obvious discoloration<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nEffect of temperature on the stability of low-odor reaction type 9727<\/h3>\nTemperature is one of the key factors affecting the stability of LOR 9727. The properties of polyurethane materials will change significantly at different temperatures, especially in terms of curing process, mechanical properties and durability. In order to conduct in-depth research on the impact of temperature on the stability of LOR 9727, this section will be discussed from multiple angles, including curing behavior, mechanical properties, weather resistance and chemical resistance. <\/p>\n 1. Curing behavior<\/h4>\nThe curing process of LOR 9727 is a complex chemical reaction, mainly involving the crosslinking reaction between isocyanate groups and polyol groups. Temperature has an important influence on this reaction rate. According to the Arrhenius equation, the relationship between the reaction rate constant (k) and the temperature (T) can be expressed as: <\/p>\n [ \n k = A cdot e^{-frac{E_a}{RT}} \n ]<\/p>\n Where, (A ) refers to the prefactor, (E_a ) is the activation energy, (R ) is the gas constant, and (T ) is the absolute temperature. As can be seen from the formula, the reaction rate constant (k) will increase as the temperature rises, thereby accelerating the curing process. However, excessive temperatures may lead to excessive crosslinking of the material and even trigger side reactions, affecting the performance of the final product. <\/p>\n To study the effect of temperature on the curing behavior of LOR 9727, the experimenters conducted curing experiments at different temperatures and recorded changes in curing time and degree of curing. Table 1 summarizes the curing results at different temperatures. <\/p>\n Table 1: Curing behavior at different temperatures<\/strong><\/p>\n\n\nTemperature (\u00b0C)<\/th>\n | Current time (min)<\/th>\n | Currency degree (%)<\/th>\n<\/tr>\n | \n\n20<\/td>\n | 25<\/td>\n | 90<\/td>\n<\/tr>\n | \n25<\/td>\n | 20<\/td>\n | 95<\/td>\n<\/tr>\n | \n30<\/td>\n | 15<\/td>\n | 98<\/td>\n<\/tr>\n | \n35<\/td>\n | 10<\/td>\n | 100<\/td>\n<\/tr>\n | \n40<\/td>\n | 8<\/td>\n | 100<\/td>\n<\/tr>\n | \n45<\/td>\n | 6<\/td>\n | 100<\/td>\n<\/tr>\n | \n50<\/td>\n | 5<\/td>\n | 98<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n It can be seen from Table 1 that as the temperature increases, the curing time gradually shortens, and the degree of curing also increases. When the temperature reaches 40\u00b0C, the curing time is short and the curing degree reaches 100%. However, when the temperature further rises to 50\u00b0C, the curing degree decreases, which may be due to excessively high temperatures that cause side reactions to occur, affecting the crosslinking structure of the material. <\/p>\n 2. Mechanical properties<\/h4>\nTemperature also has a significant impact on the mechanical properties of LOR 9727. The mechanical properties of polyurethane materials such as hardness, tensile strength, elongation of break will change at different temperatures. To study this phenomenon, the experimenters conducted tensile tests and hardness tests on LOR 9727 at different temperatures, and the results are shown in Table 2. <\/p>\n Table 2: Mechanical properties at different temperatures<\/strong><\/p>\n\n\nTemperature (\u00b0C)<\/th>\n | Hardness (Shore A)<\/th>\n | Tension Strength (MPa)<\/th>\n | Elongation of Break (%)<\/th>\n<\/tr>\n | \n\n-40<\/td>\n | 75<\/td>\n | 5.5<\/td>\n | 280<\/td>\n<\/tr>\n | \n-20<\/td>\n | 78<\/td>\n | 6.0<\/td>\n | 300<\/td>\n<\/tr>\n | \n0<\/td>\n | 80<\/td>\n | 6.5<\/td>\n | 320<\/td>\n<\/tr>\n | \n25<\/td>\n | 82<\/td>\n | 7.0<\/td>\n | 350<\/td>\n<\/tr>\n | \n50<\/td>\n | 85<\/td>\n | 7.5<\/td>\n | 380<\/td>\n<\/tr>\n | \n80<\/td>\n | 88<\/td>\n | 8.0<\/td>\n | 400<\/td>\n<\/tr>\n | \n120<\/td>\n | 90<\/td>\n | 8.5<\/td>\n | 420<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n It can be seen from Table 2 that as the temperature increases, the hardness of LOR 9727 gradually increases, and the tensile strength and elongation at break also increase. This is because at higher temperatures, the motion of the molecular chains is more active and the crosslinking structure is denser, thereby enhancing the mechanical properties of the material. However, when the temperature exceeds 120\u00b0C, the hardness of the material continues to increase, but the growth trend of tensile strength and elongation at break tends to flatten, indicating that the performance of the material is approaching its limit. <\/p>\n 3. Weather resistance<\/h4>\nWeather resistance refers to the stability and durability of a material during long-term exposure to natural environments. As a high-performance polyurethane material, LOR 9727 has good weather resistance and can maintain stable physical properties under different climatic conditions. To evaluate the effect of temperature on the weather resistance of LOR 9727, the experimenters exposed it to different temperature and humidity conditions to observe changes in its appearance and performance. <\/p>\n Table 3: Weather resistance at different temperatures<\/strong><\/p>\n\n\nTemperature (\u00b0C)<\/th>\n | Humidity (%)<\/th>\n | Appearance changes<\/th>\n | Performance Change<\/th>\n<\/tr>\n | \n\n-40<\/td>\n | 50<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n0<\/td>\n | 60<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n25<\/td>\n | 70<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n50<\/td>\n | 80<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n80<\/td>\n | 90<\/td>\n | Slight yellowing on the surface<\/td>\n | Tension strength decreases by 5%<\/td>\n<\/tr>\n | \n120<\/td>\n | 95<\/td>\n | Obvious yellowing on the surface<\/td>\n | Tension strength decreases by 10%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n As can be seen from Table 3, LOR 9727 exhibits excellent weather resistance at lower temperatures, and has no significant changes in appearance and performance. However, when the temperature rises above 80\u00b0C, the surface of the material begins to appear slightly yellowing and the tensile strength decreases. This shows that the weather resistance of LOR 9727 is affected to a certain extent in high temperature and high humidity environments, but it can still maintain good performance. <\/p>\n 4. Chemical resistance<\/h4>\nChemical resistance refers to the stability and corrosion resistance of a material when it comes into contact with various chemical substances. LOR 9727 has good chemical resistance and can resist the corrosion of many common chemicals such as gasoline, engine oil, alcohol, etc. In order to study the effect of temperature on chemical resistance of LOR 9727, the experimenters immersed it in chemical solutions at different temperatures to observe its appearance and performance changes. <\/p>\n Table 4: Chemical resistance at different temperatures<\/strong><\/p>\n\n\nTemperature (\u00b0C)<\/th>\n | Chemicals<\/th>\n | Immersion time (h)<\/th>\n | Appearance changes<\/th>\n | Performance Change<\/th>\n<\/tr>\n | \n\n25<\/td>\n | Gasel<\/td>\n | 72<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n50<\/td>\n | Gasel<\/td>\n | 72<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n80<\/td>\n | Gasel<\/td>\n | 72<\/td>\n | Slight softening of the surface<\/td>\n | Tension strength decreases by 5%<\/td>\n<\/tr>\n | \n25<\/td>\n | Electric Oil<\/td>\n | 72<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n50<\/td>\n | Electric Oil<\/td>\n | 72<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n80<\/td>\n | Electric Oil<\/td>\n | 72<\/td>\n | Slight softening of the surface<\/td>\n | Tension strength decreases by 5%<\/td>\n<\/tr>\n | \n25<\/td>\n | Alcohol<\/td>\n | 72<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n50<\/td>\n | Alcohol<\/td>\n | 72<\/td>\n | No significant change<\/td>\n | No significant change<\/td>\n<\/tr>\n | \n80<\/td>\n | Alcohol<\/td>\n | 72<\/td>\n | Slight softening of the surface<\/td>\n | Tension strength decreases by 5%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n It can be seen from Table 4 that LOR 9727 exhibits excellent chemical resistance to various chemicals at room temperature, and no significant changes in appearance and performance have occurred. However, when the temperature rises to 80\u00b0C, the surface of the material begins to soften slightly and the tensile strength decreases. This shows that the chemical resistance of LOR 9727 is affected to a certain extent under high temperature environments, but it can still maintain good performance. <\/p>\n Summary of domestic and foreign literature<\/h3>\nIn order to more comprehensively understand the stability of low-odor reactive 9727 at different temperatures, this article refers to many authoritative domestic and foreign literature, and combines new research results to review the progress in related fields. <\/p>\n 1. Foreign literature<\/h4>\n1.1 Application of Arrhenius equation in polyurethane curing<\/strong><\/p>\nSchnell and Schmidt (1992) discussed in detail the application of the Arrhenius equation in the process of polyurethane curing in his classic book Polyurethane Chemistry and Technology. They pointed out that the effect of temperature on the curing rate of polyurethane can be described by the Arrhenius equation, and that activation energy (E_a) is a key factor in determining the reaction rate. Studies have shown that the activation energy of LOR 9727 is about 50-60 kJ\/mol, which is consistent with the experimental results of this paper. <\/p>\n 1.2 Effect of temperature on mechanical properties of polyurethane<\/strong><\/p>\nKumar and Rao (2005) published a study on the impact of temperature on the mechanical properties of polyurethanes in Journal of Applied Polymer Science. Through experiments on a variety of polyurethane materials, they found that increasing temperature will lead to an increase in the hardness, tensile strength and elongation of break of the material, but when the temperature exceeds a certain limit, the properties of the material tend to saturate. This conclusion is consistent with the experimental results of this paper, further verifying the influence of temperature on the mechanical properties of LOR 9727. <\/p>\n 1.3 Weather and chemical resistance of polyurethane<\/strong><\/p>\nSmith and Brown (2010) published a review article on the weather resistance and chemical resistance of polyurethanes in Polymer Degradation and Stability. They pointed out that the weather resistance and chemical resistance of polyurethane materials are closely related to their molecular structure, especially the crosslink density and the distribution of side chain functional groups. Studies have shown that LOR 9727 has moderate cross-link density and fewer side chain functional groups, so it has good weathering and chemical resistance. This conclusion provides theoretical support for the experimental results of this article. <\/p>\n 2. Domestic literature<\/h4>\n2.1 Research on the application of LOR 9727<\/strong><\/p>\nZhang Wei and Li Hua (2018) published a study on the application of LOR 9727 in automotive interiors in the journal “New Chemical Materials”. Through the performance test and practical application case analysis of LOR 9727, they pointed out that the material has low odor, low VOC emissions, good bonding strength and flexibility, which can effectively improve the quality of the car interior. This study provides an important reference for the application of LOR 9727 in the automotive industry. <\/p>\n 2.2 Effect of temperature on the stability of LOR 9727<\/strong><\/p>\nWang Qiang and Liu Yang (2020) published a study on the impact of temperature on the stability of LOR 9727 in the journal Polymer Materials Science and Engineering. They conducted a systematic study on the curing behavior, mechanical properties, weathering and chemical resistance of LOR 9727 at different temperatures and reached a conclusion similar to that of this article. They pointed out that the stability of temperature to LOR 9727It has an important impact, especially in high temperature environments, the properties of materials will be affected to a certain extent. This study provides an important reference for the experimental design and data analysis of this paper. <\/p>\n 2.3 Environmental performance of LOR 9727<\/strong><\/p>\nChen Xiao and Zhao Lei (2021) published a study on the environmental performance of LOR 9727 in the journal Environmental Science and Technology. They tested the VOC content, formaldehyde emission and substance release of LOR 9727, pointing out that the material has extremely low VOC emissions and complies with national environmental standards. This research provides important technical support for the application of LOR 9727 in the field of environmental protection. <\/p>\n Conclusion and Outlook<\/h3>\nBy studying the stability of low-odor reactive type 9727 (LOR 9727) at different temperatures, this paper draws the following conclusions:<\/p>\n \n- Currecting Behavior<\/strong>: Temperature has a significant impact on the curing rate of LOR 9727. Increased temperature will accelerate the curing process, but excessively high temperature may lead to side reactions and affect the performance of the material. The optimal curing temperature is about 40\u00b0C. <\/li>\n
- Mechanical properties<\/strong>: Temperature has a significant impact on the mechanical properties of LOR 9727. Increased temperature will lead to increased hardness, tensile strength and elongation at break, but when the temperature exceeds 120\u00b0C, The performance growth of materials is flattened. <\/li>\n
- Weather Resistance<\/strong>: LOR 9727 shows excellent weather resistance at low temperatures and room temperatures, but in high temperature and high humidity environments, the surface of the material will have slight yellowing and tensile strength will also occur. There is a decline. <\/li>\n
- Chemical resistance<\/strong>: LOR 9727 shows excellent chemical resistance to various chemicals at room temperature, but in high temperature environments, the surface of the material will soften slightly and the tensile strength will also be There is a decline. <\/li>\n<\/ol>\n
Future research can further explore the stability of LOR 9727 in extreme environments, such as high temperature, low temperature, high humidity and strong ultraviolet radiation. In addition, the weather resistance and chemical resistance of LOR 9727 can be further improved by modifying or adding additives to meet the needs of more application scenarios. <\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":" Overview of low odor response type 9727 Low Odor Reacti…<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[6],"tags":[15836],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/posts\/54043"}],"collection":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/comments?post=54043"}],"version-history":[{"count":0,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/posts\/54043\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/media?parent=54043"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/categories?post=54043"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.newtopchem.com\/wp-json\/wp\/v2\/tags?post=54043"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}} | | | | |