High and low temperature resistant ethylene propylene diene monomer rubber compound and preparation method thereof

Abstract

The invention relates to the field of EPDM (Ethylene-Propylene-Diene Monomer) rubber, and particularly discloses a high and low temperature resistant EPDM rubber compound and a preparation method thereof. The high and low temperature resistant ethylene-propylene-diene monomer rubber compound comprises the following raw material components in parts by weight: 100 parts of ethylene-propylene-diene monomer; 20 to 25 parts of compound gutta-percha; 40 to 45 parts of carbon black; 20 to 25 parts of white carbon black; 5 to 10 parts of paraffin oil; 2-3 parts of zinc oxide; 1-2 parts of stearic acid; 1.5 to 2.5 parts of peroxide; 2 to 2.5 parts of a crosslinking auxiliary agent; 2-3 parts of an anti-aging agent; 1 part of sulfur; and 2-3 parts of an accelerant. The ethylene-propylene-diene monomer rubber compound can still keep good rebound resilience and mechanical performance at-20 DEG C or below, the mass change rate of the ethylene-propylene-diene monomer rubber compound subjected to heat treatment at 150 DEG C for 96 h does not exceed 1.4 wt%, the stable performance in a high-temperature environment is ensured, the low-temperature characteristic T10 rigid modulus of the ethylene-propylene-diene monomer rubber compound reaches-50 DEG C or even lower, and the application range is wide.

Description

Technical Field

[0001] The present application relates to the technical field of EPDM rubber, and in particular to an EPDM rubber compound resistant to high and low temperatures and a preparation method thereof. Background Art

[0002] In the field of industrial materials, rubber materials have always played a vital role. With the continuous advancement of science and technology and the gradual improvement of material performance requirements in various industries, rubber materials are also continuously developing and innovating. As one of the rubber materials, EPDM rubber has attracted much attention due to its unique performance advantages. It is the product of uniformly mixing EPDM rubber with reinforcing fillers and other additives through internal or open mixing processes. EPDM raw rubber is blended with ethylene, propylene and a third monomer. The ethylene segment gives it good heat resistance and rigidity. The propylene segment destroys the regularity of the ethylene segment through the methyl side chain, improving the overall flexibility and low temperature resistance. The reasonable combination of the two can bring balanced temperature resistance and appropriate rigidity and toughness. The third monomer is responsible for regulating the vulcanization activity. This rubber compound plays an important role in many industrial fields with its advantages such as aging resistance, excellent mechanical properties, balanced high and low temperature resistance and flexible processing. It has extremely high use value in the fields of seals, shock absorbers and waterproof membranes, and has promoted the development and progress of these industries.

[0003] In the past, the industry has adopted a variety of conventional means to deal with the problem of improving the performance of EPDM rubber compounds. In order to improve the overall performance of the rubber compound, it is usually necessary to start with adjusting the proportion of raw materials. For example, the content ratio of ethylene and propylene in EPDM rubber is changed in the hope of optimizing the high and low temperature resistance of the rubber compound. At the same time, it is also common to select suitable reinforcing fillers and other additives, such as using different types of carbon black, white carbon black, etc. to enhance the mechanical properties of the rubber compound. In addition, the various raw materials are mixed more evenly by adjusting the internal or open mixing process parameters, such as temperature and time, so as to improve the quality and performance of the rubber compound. However, although these methods can improve certain properties of the rubber compound to a certain extent, they still have great limitations when facing increasingly complex and harsh use environments.

[0004] With the continuous development of production and living needs of human society, conventional EPDM rubber compounds are facing more severe tests. In low temperature environments, such as -20°C and below, the material's resilience will be severely reduced, and its mechanical properties will be partially lost, making it difficult to meet the requirements of long-term use in large temperature differences and low temperature environments. Some researchers have tried to use EPDM raw rubber with lower ethylene content and higher propylene content to improve low temperature resistance, but this will lead to a significant reduction in heat resistance. Therefore, how to further optimize the low-temperature rigidity of EPDM rubber compounds while maintaining balanced high and low temperature resistance has become a difficult problem that needs to be solved urgently in existing technologies. Summary of the invention

[0005] To solve the above technical problems, the present application provides a ternary ethylene propylene rubber compound resistant to high and low temperatures and a preparation method thereof.

[0006] The ternary ethylene propylene rubber compound resistant to high and low temperatures provided by the present application, by weight, the raw materials used include the following components: 100 parts of ethylene propylene diene monomer rubber; 20 - 25 parts of compounded eucommia gum; 40 - 45 parts of carbon black; 20 - 25 parts of white carbon black; 5 - 10 parts of paraffin oil; 2 - 3 parts of zinc oxide; 1 - 2 parts of stearic acid; 1.5 - 2.5 parts of peroxide; 2 - 2.5 parts of crosslinking aid; 2 - 3 parts of antioxidant; 1 part of sulfur; 2 - 3 parts of accelerator.

[0007] By adopting the above technical solution, the present application selects an ethylene propylene diene monomer rubber with an ethylene content of 55 wt% and a third monomer (ethylidene norbornene) content of 2.3 wt%, which has good low-temperature resistance. A certain ratio of carbon black and white carbon black can be fully dispersed in the system and provide a good improvement in high-temperature and low-temperature resistance. The eucommia gum matrix in the compounded eucommia gum has rubber duality and plasticity, its glass transition temperature is not higher than -60 °C, and it has very good low-temperature rigidity. When used in a low-temperature environment, it can maintain sufficient toughness and structural stability. Adding it to the ternary ethylene propylene rubber compound in a certain proportion can fully improve the low-temperature resistance of the ternary ethylene propylene rubber compound. Zinc oxide and stearic acid will generate zinc stearate during the preparation process, which can improve the activity of sulfur and peroxide, making the vulcanization degree in the system more sufficient. The unreacted stearic acid can reduce the viscosity of the rubber compound, improve the mixing efficiency, and play an anti-scorching role. The unreacted zinc oxide will generate an electrostatic interaction with carbon black, promoting the further full dispersion of carbon black in the system. Combined with other additives, on the premise of maintaining balanced high and low-temperature resistance, the present application significantly optimizes the low-temperature rigidity of the ternary ethylene propylene rubber compound, ensuring that the material can still maintain good resilience and mechanical properties at -20 °C and below, and the mass change rate after heat treatment at 150 °C for 96 h does not exceed 1.4 wt%, ensuring stable performance in a high-temperature environment, making the low-temperature characteristic T10 rigidity modulus of the rubber compound reach -50 °C or even lower, greatly broadening the application range of the material, especially improving the reliability in a low-temperature environment. The crosslinking aid in the present application is triallyl isocyanurate, and the antioxidant is antioxidant RD and antioxidant MB with a weight ratio of 1:1.

[0008] Preferably, the compounded eucommia gum includes dithiazole ring-modified epoxidized eucommia gum, FeCl3, and epoxidized eucommia gum.

[0009] Preferably, the weight ratio of the dithiazole ring-modified epoxidized eucommia gum, FeCl3, and epoxidized eucommia gum is (40 - 50):(1.5 - 2):(50 - 60).

[0010] By adopting the above technical solution, the present application adds dithiolane-modified epoxidized eucommia gum, which has good compatibility with ethylene propylene diene monomer rubber, and also has high molecular chain flexibility, and can maintain good resilience when used at -20°C and below; FeCl3 and epoxidized eucommia gum will form a material with metal coordination bonds during mixing, which also has the property of being fully compatible with ethylene propylene diene monomer rubber, and the metal coordination bonds therein will play a role in stabilizing the structure when the temperature of the mixed rubber changes or under a certain external force, broadening the suitable temperature range of the mixed rubber and improving its mechanical strength to a certain extent; epoxidized eucommia gum can also fully improve the dispersion effect of silica in the rubber matrix.

[0011] Preferably, the weight ratio of the dithiolane-modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum is (40 - 50):1.8:55.

[0012] By adopting the above technical solution, the present application strictly controls the weight ratio of the dithiolane-modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum, and maximally optimizes the improvement effect of the compounded eucommia gum on the various properties of the mixed rubber.

[0013] Preferably, the epoxidized eucommia gum is prepared by the following method: Eucommia gum, formic acid and hydrogen peroxide are dispersed in an organic solvent according to a molar ratio of 1:(0.35 - 0.45):(0.3 - 0.4), stirred and reacted, and after completion, ethanol is added for precipitation, washed and dried to obtain epoxidized eucommia gum.

[0014] Preferably, the dithiolane-modified epoxidized eucommia gum is prepared by the following method: Eucommia gum, formic acid and hydrogen peroxide are dispersed in an organic solvent according to a molar ratio of 1:(0.35 - 0.45):(0.3 - 0.4), stirred and reacted, and after completion, ethanol is added for precipitation, washed and dried to obtain epoxidized eucommia gum. Subsequently, it is dispersed in an organic solvent with lipoic acid according to a weight ratio of 1:(0.35 - 0.4), stirred until completely dissolved, concentrated sulfuric acid is added dropwise, and after reacting for 3 - 4 h, the product is precipitated with alcohol and dried to obtain dithiolane-modified epoxidized eucommia gum.

[0015] Preferably, the accelerator includes accelerator DM and accelerator NS with a weight ratio of 1:1.

[0016] Preferably, the peroxide is 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

[0017] Second aspect, the present application provides a preparation method of a ternary ethylene propylene rubber compound resistant to high and low temperatures, comprising the following steps: mixing the ternary ethylene propylene rubber, zinc oxide, stearic acid, antioxidant, compounded eucommia gum, carbon black, silica and paraffin oil at a temperature of 90-110°C, then adding peroxide and crosslinking aid, mixing evenly, cooling to 40-45°C and adding sulfur and accelerator to continue mixing, mixing evenly, standing overnight, and then vulcanizing under the conditions of a temperature of 160-170°C and a pressure of 14-15 MPa, standing overnight after the vulcanization is completed to obtain the ternary ethylene propylene rubber compound.

[0018] Preferably, the compounded eucommia gum comprises dithiazole ring-modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum, and is added to the system for mixing in portions, specifically: before the first mixing, first blend 8-10 wt% of epoxidized eucommia gum with silica evenly, and then mix with the remaining all epoxidized eucommia gum, FeCl3, ternary ethylene propylene rubber, zinc oxide, stearic acid, antioxidant, dithiazole ring-modified epoxidized eucommia gum, carbon black and paraffin oil at a temperature of 90-110°C.

[0019] By adopting the above technical solution, in the present application, before the first mixing, a certain proportion of epoxidized eucommia gum is first blended evenly with silica, and the two can interact with each other by virtue of the active groups on the surface, and the epoxidized eucommia gum also has a good compatibility effect with the ternary ethylene propylene rubber. Therefore, in the subsequent continuous mixing process, the silica can be more evenly dispersed inside the rubber matrix.

[0020] In summary, the present application has the following beneficial technical effects: 1. On the premise of maintaining balanced high and low temperature resistance, the present application significantly optimizes the low temperature rigidity of the ternary ethylene propylene rubber compound, ensuring that the material can still maintain good resilience and mechanical properties at -20°C and below, and the mass change rate after heat treatment at 150°C for 96 h does not exceed 1.4 wt%, ensuring stable performance in high temperature environments, making the low temperature characteristic T10 rigidity modulus of the rubber compound reach -50°C or even lower, greatly broadening the application range of the material, especially improving the reliability in low temperature environments; 2. In the preparation method of the present application, when adding dithiazole ring-modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum, before the first mixing, a certain proportion of epoxidized eucommia gum is first blended evenly with silica, and the two can interact with each other by virtue of the active groups on the surface, and the epoxidized eucommia gum also has a good compatibility effect with the ternary ethylene propylene rubber. Therefore, in the subsequent continuous mixing process, the silica can be more evenly dispersed inside the rubber matrix. Detailed implementation mode

[0021] Material source Unless otherwise specified, the raw materials used in this application are all commercially available products, specifically: Eucommia gum, industrial grade, purchased from Shandong Bellon Eucommia Biological Engineering Co., Ltd.; Ethylene propylene diene monomer rubber was purchased from Mitsui Chemicals, with the grade of 2060M, ethylene 55 wt%, ethylidene norbornene 2.3 wt%, and Mooney viscosity = 40; Carbon black was purchased from Ningbo Detai Chemical Co., Ltd., with the grade of N550; Silica was purchased from Rhodia Silica (Qingdao) Co., Ltd., with the grade of Z1165MP.

[0022] The following further elaborates on this application in conjunction with Preparation Examples, Examples, and Comparative Examples.

[0023] Preparation Example 1.1 The preparation method of epoxidized Eucommia gum includes the following steps: Disperse Eucommia gum in cyclohexane to form a solution with a concentration of 8 wt%, stir at 50 °C until completely dissolved, keep warm at 40 °C for 2 h, add formic acid, let stand for 10 min, then add hydrogen peroxide, and control the dropping to be completed within 10 min. After reacting for 3 h, add sodium bicarbonate to stop the reaction. Precipitate the product with ethanol, wash it, and dry it in a vacuum oven at 40 °C for 48 h and then take it out to obtain epoxidized Eucommia gum. Control the molar ratio of Eucommia gum, formic acid, and hydrogen peroxide to be 1:0.35:0.4.

[0024] Preparation Example 1.2 The preparation method of epoxidized Eucommia gum includes the following steps: Disperse Eucommia gum in cyclohexane to form a solution with a concentration of 8 wt%, stir at 50 °C until completely dissolved, keep warm at 40 °C for 2 h, add formic acid, let stand for 10 min, then add hydrogen peroxide, and control the dropping to be completed within 10 min. After reacting for 3 h, add sodium bicarbonate to stop the reaction. Precipitate the product with ethanol, wash it, and dry it in a vacuum oven at 40 °C for 48 h and then take it out to obtain epoxidized Eucommia gum. Control the molar ratio of Eucommia gum, formic acid, and hydrogen peroxide to be 1:0.45:0.3.

[0025] Preparation Example 2.1 The preparation method of dithiazole ring-modified epoxidized Eucommia gum includes the following steps: Disperse gutta-percha in cyclohexane to form a solution with a concentration of 8 wt%, and stir at 50 °C until completely dissolved. After maintaining the temperature at 40 °C for 2 h, add formic acid. After standing for 10 min, add hydrogen peroxide and control the dropping to be completed within 10 min. After reacting for 3 h, add sodium bicarbonate to stop the reaction. Precipitate the product with ethanol, wash it, and take it out after drying in a vacuum oven at 40 °C for 48 h to obtain epoxidized gutta-percha. Control the molar ratio of gutta-percha, formic acid, and hydrogen peroxide to be 1:0.35:0.4; Disperse 5 mol of epoxidized gutta-percha in toluene to form a solution with a concentration of 2 wt%, and stir at 60 °C under nitrogen protection until completely dissolved. Then add 1.75 mol of lipoic acid and stir until completely dissolved. Then add 20 mL of concentrated sulfuric acid and stir. After reacting for 3 h, add methanol to precipitate the product, wash it, and take it out after drying in a vacuum oven at 40 °C to constant weight to obtain dithiolane-modified epoxidized gutta-percha.

[0026] Preparation Example 2.2 A preparation method of dithiolane-modified epoxidized gutta-percha, comprising the following steps: Disperse gutta-percha in cyclohexane to form a solution with a concentration of 8 wt%, and stir at 50 °C until completely dissolved. After maintaining the temperature at 40 °C for 2 h, add formic acid. After standing for 10 min, add hydrogen peroxide and control the dropping to be completed within 10 min. After reacting for 3 h, add sodium bicarbonate to stop the reaction. Precipitate the product with ethanol, wash it, and take it out after drying in a vacuum oven at 40 °C for 48 h to obtain epoxidized gutta-percha. Control the molar ratio of gutta-percha, formic acid, and hydrogen peroxide to be 1:0.45:0.3; Disperse 5 mol of epoxidized gutta-percha in toluene to form a solution with a concentration of 2 wt%, and stir at 60 °C under nitrogen protection until completely dissolved. Then add 2 mol of lipoic acid and stir until completely dissolved. Then add 20 mL of concentrated sulfuric acid and stir. After reacting for 3 h, add methanol to precipitate the product, wash it, and take it out after drying in a vacuum oven at 40 °C to constant weight to obtain dithiolane-modified epoxidized gutta-percha.

[0027] Example 1.1 A preparation method of a ternary ethylene-propylene rubber compound resistant to high and low temperatures, comprising the following steps (the dosage of each substance is shown in Table 1): S1. Place ethylene-propylene-diene monomer rubber, carbon black, and white carbon black in a drying oven at 80 °C for 12 h to remove moisture, and set aside; S2. Take out 8 wt% of the epoxidized Eucommia ulmoides gum prepared in Preparation Example 1.1, mix it with the dried silica in Step S1, stir for 20 min to obtain a mixture, and then mix it with the remaining all epoxidized Eucommia ulmoides gum, FeCl3, ethylene propylene diene monomer (EPDM), zinc oxide, stearic acid, anti-aging agents (anti-aging agent RD and anti-aging agent MB with a weight ratio of 1:1) and the dithiazole ring-modified epoxidized Eucommia ulmoides gum prepared in Preparation Example 2.1, carbon black and paraffin oil at a temperature of 90 °C and a rotation speed of 30 r / min for 5 min, add peroxide (1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane) and crosslinking aid (triallyl isocyanurate), keep the original temperature and rotation speed and continue to mix for 4 min, then increase the rotation speed to 45 r / min, mix for 5 min, discharge the rubber, put it into a two-roll mill, and mix at a roll temperature of 45 °C for 2 min to obtain a vulcanization-ready mixture; S3. Add sulfur and accelerators (accelerator DM and accelerator NS with a weight ratio of 1:1) to the vulcanization-ready mixture and continue to mix for 5 min, take off the sheet, let it stand overnight, and then vulcanize at a temperature of 170 °C, a pressure of 14 MPa, and a time of the optimum vulcanization time. After the vulcanization is completed, let it stand overnight to obtain the EPDM mixture.

[0028] Example 1.2 A preparation method of a high and low temperature resistant EPDM mixture, comprising the following steps (the dosage of each substance is shown in Table 1): S1. Place the EPDM, carbon black and silica in an 80 °C drying oven for 12 h to remove moisture and reserve; S2. Take out 10 wt% of the epoxidized Eucommia ulmoides gum prepared in Preparation Example 1.2, mix it with the dried silica in Step S1, stir for 20 min to obtain a mixture, and then mix it with the remaining all epoxidized Eucommia ulmoides gum, FeCl3, EPDM, zinc oxide, stearic acid, anti-aging agents (anti-aging agent RD and anti-aging agent MB with a weight ratio of 1:1) and the dithiazole ring-modified epoxidized Eucommia ulmoides gum prepared in Preparation Example 2.2, carbon black and paraffin oil at a temperature of 110 °C and a rotation speed of 30 r / min for 4 min, add peroxide (1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane) and crosslinking aid (triallyl isocyanurate), keep the original temperature and rotation speed and continue to mix for 4 min, then increase the rotation speed to 45 r / min, mix for 5 min, discharge the rubber, put it into a two-roll mill, and mix at a roll temperature of 40 °C for 2 min to obtain a vulcanization-ready mixture; S3. Add sulfur and accelerators (accelerator DM and accelerator NS with a weight ratio of 1:1) to the compound to be vulcanized, continue mixing for 5 min, sheet down, let stand overnight, and then vulcanize under the conditions of a temperature of 160 °C, a pressure of 15 MPa, and a time of the optimum vulcanization time. After vulcanization, let stand overnight to obtain the ethylene-propylene-diene terpolymer compound.

[0029] Table 1 Dosages of each component in Examples 1.1 - 1.2 (kg)

[0030] Example 2.1 A preparation method of an ethylene-propylene-diene terpolymer compound resistant to high and low temperatures, which is different from Example 1.1 in that: the dosage of the epoxidized eucommia gum obtained in Preparation Example 1.1 is 0.826 kg, the dosage of FeCl3 is 0.038 kg, the dosage of the disulfide heterocyclic modified epoxidized eucommia gum obtained in Preparation Example 2.1 is 1.136 kg, and the rest are the same as in Example 1.1.

[0031] Example 2.2 A preparation method of an ethylene-propylene-diene terpolymer compound resistant to high and low temperatures, which is different from Example 1.1 in that: the dosage of the epoxidized eucommia gum obtained in Preparation Example 1.1 is 0.936 kg, the dosage of FeCl3 is 0.034 kg, the dosage of the disulfide heterocyclic modified epoxidized eucommia gum obtained in Preparation Example 2.1 is 1.03 kg, and the rest are the same as in Example 1.1.

[0032] Example 3.1 A preparation method of an ethylene-propylene-diene terpolymer compound resistant to high and low temperatures, which is different from Example 2.1 in that: in step S3, the weight ratio of accelerator DM to accelerator NS is 2:1, and the rest are the same as in Example 1.1.

[0033] Example 3.2 A preparation method of an ethylene-propylene-diene terpolymer compound resistant to high and low temperatures, which is different from Example 2.1 in that: in step S3, the weight ratio of accelerator DM to accelerator NS is 1:2, and the rest are the same as in Example 1.1.

[0034] Example 4.1 A preparation method of an ethylene-propylene-diene terpolymer compound resistant to high and low temperatures, which is different from Example 2.1 in that: in step S2, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane is replaced with dicumyl peroxide, and the rest are the same as in Example 1.1.

[0035] Example 4.2 A preparation method of a ternary ethylene-propylene-diene rubber compound resistant to high and low temperatures, which is different from Example 2.1 in that: in step S2, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane is replaced with di-tert-butyl peroxide diisopropylbenzene, and the rest are the same as in Example 1.1.

[0036] Example 4.3 A preparation method of a ternary ethylene-propylene-diene rubber compound resistant to high and low temperatures, which is different from Example 2.1 in that: in step S2, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane is replaced with 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and the rest are the same as in Example 1.1.

[0037] Comparative Example 1 The difference from Example 1.1 is that: the compounded Eucommia rubber is removed, and the rest are the same as in Example 1.1.

[0038] Comparative Example 2.1 The difference from Example 1.1 is that: the compounded Eucommia rubber is completely replaced with the epoxidized Eucommia rubber prepared in Preparation Example 1.1, and the rest are the same as in Example 1.1.

[0039] Comparative Example 2.2 The difference from Example 1.1 is that: the compounded Eucommia rubber is completely replaced with the dithiazole ring-modified epoxidized Eucommia rubber prepared in Preparation Example 2.1, and the rest are the same as in Example 1.1.

[0040] Performance testing High-temperature resistance testing: Cut the materials obtained in the examples and comparative examples into specimens of 75±0.25 mm×25±0.25 mm×2 mm, and test their mass change rate (wt%) at 150±2 °C, and record it in Table 2; Low-temperature resistance testing: Refer to Standard ISO 2912 to detect the low-temperature characteristic T10 rigidity modulus (°C) of the materials obtained in the examples and comparative examples, and record it in Table 2.

[0041] Table 2 Performance testing table

[0042] Data analysis: As can be seen from Table 2, the heat treatment mass change rate of the materials in Examples 1.1 - 1.2 is 1.37 - 1.39 wt%, and the low-temperature characteristic T10 rigidity modulus is -52°C to -50°C. This proves that under the premise of maintaining balanced high and low temperature resistance, the present application significantly optimizes the low-temperature rigidity of ethylene propylene diene monomer (EPDM) mixed rubber, ensuring that the material can still maintain good resilience and mechanical properties at -20°C and below. The mass change rate after heat treatment at 150°C for 96 h does not exceed 1.4 wt%, ensuring stable performance in high-temperature environments, enabling the low-temperature characteristic T10 rigidity modulus of the mixed rubber to reach -50°C or even lower, greatly broadening the application range of the material, especially enhancing the reliability in low-temperature environments.

[0043] The difference between Examples 2.1 - 2.2 and Example 1.1 is that the present application changes the dosage of epoxidized eucommia gum, the dosage of FeCl3, and the disulfide heterocyclic modified epoxidized eucommia gum. The results show that the heat treatment mass change rate of Examples 2.1 - 2.2 decreases, and the low-temperature characteristic T10 rigidity modulus also decreases significantly. This proves that by strictly controlling the weight ratio of disulfide heterocyclic modified epoxidized eucommia gum, FeCl3, and epoxidized eucommia gum, the improvement effect of the compounded eucommia gum on the various properties of the mixed rubber can be optimized to the greatest extent.

[0044] The difference between Comparative Example 1 and Example 1.1 is that the present application removes the compounded eucommia gum. The results show that both the heat treatment mass change rate and the low-temperature characteristic T10 rigidity modulus increase. The difference between Comparative Examples 2.1 - 2.2 and Example 1.1 is that the present application replaces the compounded eucommia gum with epoxidized eucommia gum and disulfide heterocyclic modified epoxidized eucommia gum respectively. The results show that the heat treatment mass change rate of Comparative Example 2.1 increases, and the low-temperature characteristic T10 rigidity modulus of Comparative Example 2.2 increases. This proves that there is good compatibility between disulfide heterocyclic modified epoxidized eucommia gum and ethylene propylene diene monomer rubber, and it also has high molecular chain flexibility, and can maintain good resilience when used at -20°C and below; FeCl3 and epoxidized eucommia gum will form materials with metal coordination bonds during mixing, which also have the property of being fully compatible with ethylene propylene diene monomer rubber, and the metal coordination bonds therein will play a role in stabilizing the structure when the use temperature of the mixed rubber changes or under a certain external force, broadening the applicable temperature range of the mixed rubber and improving its mechanical strength to a certain extent; epoxidized eucommia gum can also fully improve the dispersion effect of silica in the rubber matrix.

[0045] The examples of this specific embodiment are all preferred embodiments of the present application, and do not limit the protection scope of the present application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. An ethylene propylene diene monomer (EPDM) compound resistant to high and low temperatures, characterized in that, By weight, the raw materials used include the following components: 100 parts of ethylene propylene diene monomer rubber; 20 - 25 parts of compounded eucommia gum; 40 - 45 parts of carbon black; 20 - 25 parts of white carbon black; 5 - 10 parts of paraffin oil; 2 - 3 parts of zinc oxide; 1 - 2 parts of stearic acid; 1.5 - 2.5 parts of peroxide; 2 - 2.5 parts of cross - linking aid; 2 - 3 parts of antioxidant; 1 part of sulfur; 2 - 3 parts of accelerator.

2. The ethylene propylene diene monomer (EPDM) compound resistant to high and low temperatures according to claim 1, wherein The compounded eucommia gum includes dithiazole - modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum.

3. The ethylene propylene diene monomer (EPDM) masterbatch resistant to high and low temperatures according to claim 2, wherein The weight ratio of the dithiazole - modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum is (40 - 50):(1.5 - 2):(50 - 60).

4. A ternary ethylene propylene rubber compound resistant to high and low temperatures according to claim 3, characterized in that, The weight ratio of the dithiazole - modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum is (40 - 50):1.8:

55.

5. The ethylene propylene diene monomer (EPDM) masterbatch resistant to high and low temperatures according to claim 2, characterized in that, The epoxidized eucommia gum is prepared by the following method: Eucommia gum, formic acid and hydrogen peroxide are dispersed in an organic solvent according to a molar ratio of 1:(0.35 - 0.45):(0.3 - 0.4), stirred for reaction, after completion, ethanol is added for precipitation, washed and dried to obtain epoxidized eucommia gum.

6. The ethylene propylene diene monomer (EPDM) compound resistant to high and low temperatures according to claim 2, characterized in that, The dithiazole - modified epoxidized eucommia gum is prepared by the following method: Eucommia gum, formic acid and hydrogen peroxide are dispersed in an organic solvent according to a molar ratio of 1:(0.35 - 0.45):(0.3 - 0.4), stirred for reaction, after completion, ethanol is added for precipitation, washed and dried to obtain epoxidized eucommia gum. Subsequently, it is dispersed in an organic solvent with lipoic acid according to a weight ratio of 1:(0.35 - 0.4) under the protection of inert gas, stirred until completely dissolved, then concentrated sulfuric acid is added dropwise, after reacting for 3 - 4 h, the product is subjected to alcohol precipitation and dried to obtain dithiazole - modified epoxidized eucommia gum.

7. An ethylene propylene diene monomer (EPDM) compound resistant to high and low temperatures according to claim 1, characterized in that, The accelerator includes accelerator DM and accelerator NS with a weight ratio of 1:

1.

8. An ethylene propylene diene monomer (EPDM) masterbatch resistant to high and low temperatures according to claim 1, characterized in that, The peroxide is 1,1 - bis(tert - butylperoxy) - 3,3,5 - trimethylcyclohexane.

9. A method for preparing the ethylene-propylene-diene monomer (EPDM) compound resistant to high and low temperatures according to claim 1, characterized in that, It includes the following steps: The ethylene propylene diene monomer rubber, zinc oxide, stearic acid, antioxidant, compounded eucommia gum, carbon black, white carbon black and paraffin oil are kneaded at a temperature of 90 - 110 °C, then peroxide and cross - linking aid are added, kneaded evenly, cooled to 40 - 45 °C, sulfur and accelerator are added and kneaded continuously, kneaded evenly, left overnight, and then vulcanized under the conditions of a temperature of 160 - 170 °C and a pressure of 14 - 15 MPa. After vulcanization is completed, it is left overnight to obtain ethylene propylene diene monomer mixed rubber.

10. The preparation method of a ternary ethylene propylene rubber compound resistant to high and low temperatures according to claim 9, characterized in that, The compounded eucommia gum includes dithiazole - modified epoxidized eucommia gum, FeCl3 and epoxidized eucommia gum, and is added to the system for kneading separately. Specifically: Before the first kneading, 8 - 10 wt% of epoxidized eucommia gum is first blended evenly with white carbon black, and then kneaded with the remaining all epoxidized eucommia gum, FeCl3, ethylene propylene diene monomer rubber, zinc oxide, stearic acid, antioxidant, dithiazole - modified epoxidized eucommia gum, carbon black and paraffin oil at a temperature of 90 - 110 °C.

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