High-weather-resistance high-temperature-resistant polyurethane elastomer and preparation method thereof

Abstract

The invention belongs to the technical field of polyurethane elastomers, and particularly relates to a high-weather-resistant high-temperature-resistant polyurethane elastomer and a preparation method thereof. The high-weather-resistance and high-temperature-resistance polyurethane elastomer is composed of a polyurethane prepolymer and a chain extender according to the mass ratio of 100: (10.5-12.8), and the polyurethane prepolymer is prepared from the following raw materials: modified polyol, diisocyanate, an antioxidant and an anti-hydrolysis agent; the modified polyol is prepared by taking polycarbonate diol and polytetrahydrofuran ether as raw materials and carrying out copolymerization modification under the action of a catalyst, the number-average molecular weight is 1250-1700, and the functionality is 2. The high-weather-resistance and high-temperature-resistance polyurethane elastomer is excellent in product mechanical property, still has good tensile strength under the conditions that the humidity is 90% and the temperature is 100 DEG C, has low-temperature rebound resilience, is low in system viscosity and is convenient to operate, and meanwhile, the invention further provides a preparation method of the high-weather-resistance and high-temperature-resistance polyurethane elastomer.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane elastomers, and particularly relates to a highly weather-resistant and high-temperature-resistant polyurethane elastomer and a preparation method thereof. Background Art

[0002] Polyurethane elastomer is a block copolymer polymer material containing a large number of carbamate groups in the main chain of the molecule. It is usually made by addition polymerization with polyether or polyester polyols, isocyanates, chain extenders, cross-linking agents, catalysts and a small amount of additives as raw materials. It is a polymer material between rubber and plastic, with a wide range of hardness and good physical and chemical properties.

[0003] The heat-resistant temperature range of polyurethane is generally between -20℃ and 120℃, but in actual use, the long-term use temperature of polyurethane is generally below 80℃, and the short-term use temperature cannot exceed 120℃. There are few polyurethane products that can be used for a long time at 100-120℃. This makes polyurethane more affected by the environment during use, especially in harsh environments such as high temperature (≥100℃) and high humidity (humidity ≥90%).

[0004] CN112679694A discloses a method for preparing a high-performance polyurethane elastomer. The modified polyol is prepared using polyol and isocyanate as raw materials, and then mixed with isocyanate and a chain extender to prepare a polyurethane elastomer. By using different types of isocyanate-modified polyols, the physical and mechanical properties of the polyurethane are significantly improved. The polyurethane elastomer has excellent mechanical properties and a high mechanical property retention rate under high temperature (80°C, 10h) conditions. However, due to the influence of the use environment, the performance retention rates under 100°C and 80°C conditions are extremely different. Therefore, this method cannot guarantee the performance of the polyurethane elastomer above 100°C. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a highly weather-resistant and high-temperature resistant polyurethane elastomer. The product has excellent mechanical properties, still has good tensile strength under conditions of 90% humidity and 100°C temperature, and has low-temperature resilience, low system viscosity and easy operation. The present invention also provides a preparation method thereof.

[0006] The high weather resistance and high temperature resistance polyurethane elastomer of the present invention is composed of a polyurethane prepolymer and a chain extender in a mass ratio of 100:(10.5-12.8), wherein the polyurethane prepolymer includes the following raw materials in mass percentage: 68-79% modified polyol, 20-30% diisocyanate, 0.5-1% antioxidant, and 0.5-1% anti-hydrolysis agent.

[0007] The modified polyol is prepared by copolymerization and modification at 230-240°C with polycarbonate diol and polytetramethylene ether as raw materials under the action of a catalyst, and has a number average molecular weight of 1250-1700 and a functionality of 2. Preferably, one of PC1250 and PC1700 produced by Shandong Yinuowei Polyurethane Co., Ltd. is used.

[0008] The diisocyanate is one of TDI-100, TDI-80, MDI-50, MDI-100 and carbodiimide-modified MDI, preferably one of TDI-100 and MDI-100.

[0009] The antioxidant is one of 1076, 292 and UV-1.

[0010] The anti-hydrolysis agent is a carbodiimide anti-hydrolysis agent, preferably HyMax ® 1010, produced by Shanghai Langyi Functional Materials Co., Ltd.

[0011] The chain extender is one of dimethylthiotoluene diamine (DMTDA), 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), hydroquinone dihydroxyethyl ether (HQEE), and 4,4'-methylenebis(3-chloro-2,6-diethylaniline) (MCDEA).

[0012] The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: Modified polyol, diisocyanate, antioxidant and anti-hydrolysis agent are mixed and reacted, and then bubbles are removed to obtain a polyurethane prepolymer with an isocyanate content of 4.5-5.5%; (2) When in use, the temperature of the polyurethane prepolymer is 80-85°C, and the temperature of the chain extender is 60-120°C. The polyurethane prepolymer and the chain extender are mixed according to the mass ratio, first reacted and cured in a mold, and then matured to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0013] In the step (1), the reaction temperature is 75-90°C.

[0014] In the step (2), during the reaction curing, the mold temperature is 100-120°C.

[0015] In the step (2), the aging temperature is 100-110°C and the time is 8-10 hours.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The highly weather-resistant and high-temperature-resistant polyurethane elastomer of the present invention is prepared by copolymerizing the modified polyol with polycarbonate diol and polytetramethylene furan ether as raw materials. The polycarbonate diol makes the polyurethane elastomer have excellent high-temperature resistance. The introduction of polytetramethylene furan ether makes the polyurethane elastomer have excellent weather resistance. By copolymerizing the two, the product has excellent mechanical properties and is resistant to high temperatures and has high weather resistance.

[0017] (2) The highly weather-resistant and high-temperature-resistant polyurethane elastomer of the present invention uses modified polyols and diisocyanates as raw materials, and introduces antioxidants and anti-hydrolysis agents at the same time. Due to the introduction of polytetramethylene ether partial segments into the molecular chain segments after copolymerization modification, the product can maintain a high rebound under low temperature conditions, with a rebound of more than 20% at -20°C. In addition, the product has low viscosity, fast molding, and convenient operation.

[0018] (3) The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer of the present invention has a simple process flow and is easy to operate. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the embodiments and comparative examples. The raw materials used in the embodiments and comparative examples are conventional commercially available raw materials unless otherwise specified, and the process methods used are conventional methods in the art unless otherwise specified. The percentages involved in the raw materials in the embodiments and comparative examples are all mass percentages.

[0020] The raw materials used in the embodiments and comparative examples are described as follows: MDI-100: Wanhua Chemical Group Co., Ltd. TDI-100: Wanhua Chemical Group Co., Ltd. PC1250: Shandong Yinuowei Polyurethane Co., Ltd. PC1700: Shandong Yinuowei Polyurethane Co., Ltd. HyMax ® 1010: Shanghai Langyi Functional Materials Co., Ltd.; Antioxidant 1076: BASF SE; DMTDA: Zhangjiagang Yarui Chemical Co., Ltd.; MOCA: Suzhou Xiangyuan New Materials Co., Ltd. HQEE: Suzhou Xiangyuan New Materials Co., Ltd. MCDEA: Zhangjiagang Yarui Chemical Co., Ltd.; Antioxidant UV-1: Double Bond Chemical Co., Ltd. Antioxidant 292: Double Bond Chemical Co., Ltd. Polyester polyol PE-2315: number average molecular weight 1500, functionality 2, Shandong Yinuowei Polyurethane Co., Ltd.; Polycarbonate diol UH-CARB100: number average molecular weight 1000, functionality 2, Ube Kosan Co., Ltd. of Japan; Polytetramethylene glycol ether PTMG1000: number average molecular weight 1000, functionality 2, BASF AG.

[0021] The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: Modified polyol, diisocyanate, antioxidant and anti-hydrolysis agent are mixed, reacted at 75-90°C for 3 hours, and air bubbles are removed under a vacuum degree of -0.095 MPa to obtain a polyurethane prepolymer with an isocyanate content of 4.5-5.5%; (2) When in use, the temperature of the polyurethane prepolymer is 82.5±2.5℃, the temperature of the chain extender is 60-120℃, the polyurethane prepolymer and the chain extender are mixed in a mass ratio of 100:(10.5-12.8), and the reaction is cured at a mold temperature of 100-120℃. After opening the mold for 30 minutes, the mixture is aged at 100-110℃ for 8-10 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0022] Example 1 The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: 77% PC1250, 22% TDI-100, 0.5% 1076, 0.5% HyMax ® 1010 were mixed, the reaction temperature was 80°C for 3 hours, and the bubbles were removed under a vacuum degree of -0.095 MPa to obtain a polyurethane prepolymer with an isocyanate content of 5.0%; (2) When in use, DMTDA is used as the chain extender, the chain extender temperature is 60°C, the polyurethane prepolymer temperature is 82.5±2.5°C, the polyurethane prepolymer and the chain extender are mixed in a mass ratio of 100:11.7, and the reaction is cured at a mold temperature of 110°C. After the mold is opened for 30 minutes, it is aged at 100°C for 10 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0023] Example 2 The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: 79% PC1700, 20% TDI-100, 0.5% 292, 0.5% HyMax ® 10:10, react at 80°C for 3h, remove air bubbles under vacuum at -0.095MPa to obtain a polyurethane prepolymer with an isocyanate content of 5.5%; (2) When in use, MOCA is used as the chain extender, the chain extender temperature is 120°C, the polyurethane prepolymer temperature is 82.5±2.5°C, the polyurethane prepolymer and the chain extender are mixed in a mass ratio of 100:12.8, and the reaction is cured under a mold temperature of 120°C. After the mold is opened for 30 minutes, it is aged at 110°C for 8 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0024] Example 3 The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: 68% PC1250, 30% MDI-100, 1% UV-1, 1% HyMax ® 1010 were mixed, the reaction temperature was 75°C for 3 hours, and the bubbles were removed under a vacuum degree of -0.095 MPa to obtain a polyurethane prepolymer with an isocyanate content of 5.0%; (2) When in use, HQEE is used as the chain extender, the chain extender temperature is 60°C, the polyurethane prepolymer temperature is 82.5±2.5°C, the polyurethane prepolymer and the chain extender are mixed in a mass ratio of 100:11.7, and the reaction is cured under a mold temperature of 100°C. After the mold is opened for 30 minutes, it is aged at 110°C for 9 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0025] Example 4 The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: 78% PC1250, 21% TDI-100, 0.5% 292, 0.5% HyMax ® 10:10 mixture, react at 90°C for 3h, remove air bubbles under vacuum at -0.095MPa to obtain a polyurethane prepolymer with an isocyanate content of 4.5%; (2) When in use, MCDEA is used as a chain extender, the chain extender temperature is 110°C, the polyurethane prepolymer temperature is 82.5±2.5°C, the polyurethane prepolymer and the chain extender are mixed at a mass ratio of 100:10.5, and the reaction is cured under a mold temperature of 110°C. After the mold is opened for 30 minutes, it is aged at 110°C for 10 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0026] Comparative Example 1 This comparative example is the same as Example 2, except that the PC1700 in Example 2 is replaced by the same mass percentage of polyester polyol PE-2315, produced by Shandong Yinuowei Polyurethane Co., Ltd., with a number average molecular weight of 1500 and a functionality of 2; The method for preparing the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: 79% PE-2315, 20% TDI-100, 0.5% 292, 0.5% HyMax ® 10:10, react at 80°C for 3h, remove air bubbles under vacuum at -0.095MPa to obtain a polyurethane prepolymer with an isocyanate content of 5.5%; (2) When in use, MOCA is used as the chain extender, the chain extender temperature is 120°C, the polyurethane prepolymer temperature is 82.5±2.5°C, the polyurethane prepolymer and the chain extender are mixed in a mass ratio of 100:12.8, and the reaction is cured under a mold temperature of 120°C. After the mold is opened for 30 minutes, it is aged at 110°C for 8 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0027] Comparative Example 2 This comparative example is the same as Example 1, except that polytetramethylene ether PTMG1000 and TDI-100 are used to synthesize the polyurethane prepolymer. The preparation method of the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: 75% PTMG1000, 24% TDI-100, 0.5% 1076, 0.5% HyMax ® 1010 were mixed, the reaction temperature was 80°C for 3 hours, and the bubbles were removed under a vacuum degree of -0.095 MPa to obtain a polyurethane prepolymer with an isocyanate content of 5.0%; (2) When in use, DMTDA is used as the chain extender, the chain extender temperature is 60°C, the polyurethane prepolymer temperature is 82.5±2.5°C, the polyurethane prepolymer and the chain extender are mixed at a mass ratio of 100:11.7, the mold temperature is 110°C, the mold is opened for 30 minutes, and then the mixture is aged at 100°C for 10 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0028] Comparative Example 3 This comparative example is the same as Example 1, except that polycarbonate diol UH-CARB100 and TDI-100 are used to synthesize the polyurethane prepolymer. The preparation method of the highly weather-resistant and high-temperature-resistant polyurethane elastomer comprises the following steps: (1) Preparation of polyurethane prepolymer: 75% UH-CARB100, 24% TDI-100, 0.5% 1076, 0.5% HyMax ® 1010 were mixed, the reaction temperature was 80°C for 3 hours, and the bubbles were removed under a vacuum degree of -0.095 MPa to obtain a polyurethane prepolymer with an isocyanate content of 5.0%; (2) When in use, DMTDA is used as the chain extender, the chain extender temperature is 60°C, the polyurethane prepolymer temperature is 82.5±2.5°C, the polyurethane prepolymer and the chain extender are mixed at a mass ratio of 100:11.7, the mold temperature is 110°C, the mold is opened for 30 minutes, and then the mixture is aged at 100°C for 10 hours to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

[0029] The products prepared in Examples 1-4 and Comparative Examples 1-3 were tested according to the following standards. The results are shown in Table 1.

[0030] The hardness is tested according to GB / T531.1-2008; the tensile strength and elongation at break are tested according to GB / T528-2009; the tensile strength of the product is tested according to GB / T528-2009 at 100°C, and then the product is placed under 90% humidity and 100°C temperature for 72 hours to measure the tensile strength retention rate of the product; the melting point is determined using a melting point apparatus; the low-temperature rebound of the product is tested after freezing at -20°C for 24 hours; the viscosity is determined using a cone and plate viscometer.

[0031] Table 1 Test results

[0032] As can be seen from Table 1, compared with Example 2, the PE-2315 polyester polyol and the PC1700 modified polyol have different structures in Comparative Example 1, the polyester contains more ester groups and has a large polarity. Although the prepared polyurethane elastomer has high tensile strength, it is limited by the different polyol structures, and its -20°C rebound is low, and the melting point and tensile strength retention rate are low, that is, the high temperature, high humidity and low temperature resistance are poor; Comparative Examples 2 and 3 compared with Example 1 show that polycarbonate diol makes the polyurethane elastomer have excellent mechanical properties and high temperature resistance, and the introduction of polytetramethylene ether makes the polyurethane elastomer have excellent low temperature resilience and weather resistance. The partial chain segments of polytetramethylene ether are introduced into the polyester polyol molecular chain segment by copolymerization modification, which can make the polyurethane elastomer have weather resistance and low temperature resilience while maintaining mechanical properties. Through the overall comparison of the embodiments and the comparative examples, it can be seen that the polyurethane elastomer prepared by the present invention has good tensile strength, elongation, and low-temperature resilience, and has the characteristics of high tensile retention rate under high temperature and high humidity environment. At the same time, the system viscosity is low, and the polyurethane elastomer has excellent comprehensive performance, which meets the requirements of high weather resistance and high temperature resistance.

Claims

1. A highly weather-resistant and high-temperature resistant polyurethane elastomer, characterized in that: It is composed of a polyurethane prepolymer and a chain extender in a mass ratio of 100:(10.5-12.8), wherein the polyurethane prepolymer includes the following raw materials in mass percentage: 68-79% modified polyol, 20-30% diisocyanate, 0.5-1% antioxidant, and 0.5-1% anti-hydrolysis agent; The modified polyol is prepared by copolymerization and modification at 230-240° C. with polycarbonate diol and polytetramethylene ether as raw materials under the action of a catalyst, and has a number average molecular weight of 1250-1700 and a functionality of 2.

2. The highly weather-resistant and high-temperature-resistant polyurethane elastomer according to claim 1, characterized in that: The diisocyanate is one of TDI-100, TDI-80, MDI-50, MDI-100 and carbodiimide-modified MDI.

3. The highly weather-resistant and high-temperature-resistant polyurethane elastomer according to claim 1, characterized in that: The antioxidant is one of 1076, UV-1 and 292.

4. The highly weather-resistant and high-temperature-resistant polyurethane elastomer according to claim 1, characterized in that: The anti-hydrolysis agent is a carbodiimide anti-hydrolysis agent.

5. The highly weather-resistant and high-temperature-resistant polyurethane elastomer according to claim 1, characterized in that: The chain extender is one of dimethylthiotoluene diamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, hydroquinone dihydroxyethyl ether, and 4,4'-methylenebis(3-chloro-2,6-diethylaniline).

6. A method for preparing a highly weather-resistant and high-temperature-resistant polyurethane elastomer according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Preparation of polyurethane prepolymer: Modified polyol, diisocyanate, antioxidant and anti-hydrolysis agent are mixed and reacted, and then bubbles are removed to obtain a polyurethane prepolymer with an isocyanate content of 4.5-5.5%; (2) When in use, the temperature of the polyurethane prepolymer is 80-85°C, and the temperature of the chain extender is 60-120°C. The polyurethane prepolymer and the chain extender are mixed according to the mass ratio, first reacted and cured in a mold, and then matured to obtain a highly weather-resistant and high-temperature resistant polyurethane elastomer.

7. The method for preparing a highly weather-resistant and high-temperature-resistant polyurethane elastomer according to claim 6, characterized in that: In the step (1), the reaction temperature is 75-90°C.

8. The method for preparing a highly weather-resistant and high-temperature-resistant polyurethane elastomer according to claim 6, characterized in that: In the step (2), during the reaction curing, the mold temperature is 100-120°C.

9. The method for preparing a highly weather-resistant and high-temperature-resistant polyurethane elastomer according to claim 6, characterized in that: In the step (2), the aging temperature is 100-110°C and the time is 8-10 hours.

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