High-performance ethylene-vinyl acetate-glycidyl methacrylate rubber, preparation method and method for adjusting positive vulcanization time

Abstract

The invention discloses high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber, a preparation method and a method for adjusting positive vulcanization time, after high-temperature treatment, the mechanical property retention rate of the rubber is 85-98%, the repeated processing property recovery rate is greater than or equal to 80%, and the properties comprise tensile strength, elongation at break and / or 100% stress at definite elongation; the preparation method comprises the following steps: by taking a sulfur-containing copolymer as a cross-linking agent, cross-linking an ethylene-vinyl acetate-glycidyl methacrylate terpolymer (EVM-GMA) under the action of organic alkali. According to the invention, the problems of poor mechanical properties of EVM-GMA after crosslinking, unstable mechanical properties after high-temperature treatment and incapability of repeated processing at present are solved in a targeted manner, and cross-linking is realized by subjecting polysulfide bonds in the sulfur-containing copolymer to different cracks and to sulfydryl-epoxy reaction with epoxy groups in EVM-GMA; the novel rubber material with excellent mechanical property and repeated processing recovery rate is obtained.

Description

Technical Field

[0001] The invention belongs to the field of rubber materials, and in particular relates to a high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber, a preparation method and a method for adjusting the positive vulcanization time. Background Art

[0002] Ethylene-vinyl acetate rubber (EVM) is widely used in the fields of wires and cables, household appliances, etc. due to its heat resistance, weather resistance, oil resistance and flame retardancy. In order to make EVM elastic and dimensional stability, it must be chemically cross-linked. EVM is generally cross-linked by vulcanization using peroxides, etc., but the use of peroxide vulcanization will release small molecule organic volatile gases, and there are problems such as scorch and difficult to control the vulcanization time. In order to vulcanize EVM more efficiently, people introduce glycidyl methacrylate as a cross-linking monomer into EVM to obtain ethylene-vinyl acetate-glycidyl methacrylate terpolymer (EVM-GMA). EVM-GMA can be vulcanized using traditional peroxides, or it can be vulcanized using acid anhydrides and dibasic acids. In the process of implementing the present invention, the inventors found that there are at least the following problems in the above-mentioned vulcanized EVM-GMA:

[0003] When using traditional peroxide crosslinking agents to vulcanize EVM-GMA, the following problems exist: the crosslinking bonds are carbon-carbon single bonds, and the strength and tear properties of the crosslinked network are poor; the crosslinked network is insoluble and infusible, and cannot be processed and reused; the scorch and vulcanization time are difficult to control. In recent years, it has been proposed to use anhydrides and dibasic acids as crosslinking agents to achieve crosslinking of EVM-GMA through the reaction of carboxyl groups with epoxy groups in GMA. The main problems in the process include: the crosslinking agent will corrode the equipment, there is a reaction between the epoxy group and the hydroxyl group in β-hydroxy ester (the group generated by the reaction of carboxyl groups and epoxy groups), and side reactions such as self-polymerization of epoxy groups, making the crosslinked network structure uncontrollable, especially at high temperatures, the performance of the sample changes significantly, and there is also the problem of being unable to be processed repeatedly. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber, a preparation method and a method for adjusting the positive vulcanization time in view of the deficiencies of the above-mentioned prior art.

[0005] In order to solve the above technical problems, on the one hand, a high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber is provided, which has excellent mechanical property retention rate after high-temperature treatment and high repeated processing performance recovery rate, wherein the mechanical property retention rate after high-temperature treatment is 85% to 98%, the high temperature conditions are 150°C, 4 hours, and the repeated processing performance recovery rate is ≥80%.

[0006] On the other hand, a method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber is provided, comprising: using a sulfur-containing copolymer as a crosslinking agent, crosslinking the ethylene-vinyl acetate-glycidyl methacrylate terpolymer under the action of an organic base.

[0007] On the other hand, a method for adjusting the positive vulcanization time is provided, comprising: in a system containing a sulfur-containing copolymer, an organic base and an ethylene-vinyl acetate-glycidyl methacrylate terpolymer, adjusting the amount of the sulfur-containing copolymer added to achieve the adjustment of the positive vulcanization time.

[0008] Compared with the prior art, the present invention has the following advantages:

[0009] 1. The present invention provides a method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber, comprising: using a sulfur-containing copolymer as a crosslinking agent to crosslink an ethylene-vinyl acetate-glycidyl methacrylate terpolymer under the action of an organic base. The high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber has a high mechanical property retention rate after high-temperature treatment and a high recovery rate of repeated processing performance. The present invention uses a sulfur-containing copolymer as a crosslinking agent to crosslink an ethylene-vinyl acetate-glycidyl methacrylate terpolymer under the action of an organic base to prepare an ethylene-vinyl acetate-glycidyl methacrylate rubber, which specifically solves the problems of poor mechanical properties, unstable high-temperature performance, and inability to be repeatedly processed of the current ethylene-vinyl acetate-glycidyl methacrylate rubber.

[0010] The technical solution of the present invention is further described in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0011] The technical solution will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0012] In the following description, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural.

[0013] In the following description, the terms "include", "comprising", "having" and "containing" are open-ended terms, meaning including but not limited to.

[0014] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0015] Those skilled in the art will appreciate that the numerical ranges in the embodiments of the present application are to be understood as each intermediate value between the upper and lower limits of the scope also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present application. The upper and lower limits of these smaller ranges may be independently included or excluded in the scope.

[0016] Unless otherwise specified, the technical / scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs. Although this application only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0017] The technical principle adopted by the present invention is that under the catalytic action of an organic base, the polysulfide bonds in the sulfur-containing copolymer are heterolytically cleaved into sulfur cations and anions, which react with the epoxy groups in the glycidyl methacrylate unit in the ethylene-vinyl acetate-glycidyl methacrylate terpolymer to form a thiol-epoxy reaction to achieve crosslinking. After crosslinking, the crosslinking points in the product are connected by polysulfide bonds, and the product has excellent elasticity and toughness. In addition, the connection between the polysulfide bonds and the epoxy groups can be reversibly broken and reconstructed under the action of heat, so that the crosslinking network is rearranged, and the product has repeatable processing performance.

[0018] On the one hand, a method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber is provided, comprising: using a sulfur-containing copolymer as a crosslinking agent, crosslinking an ethylene-vinyl acetate-glycidyl methacrylate terpolymer under the action of an organic base. The high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber is a rubber having a high mechanical property retention rate after high-temperature treatment and a high recovery rate of repeated processing performance.

[0019] The invention provides a method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber by crosslinking ethylene-vinyl acetate-glycidyl methacrylate terpolymer (EVM-GMA) with a sulfur-containing copolymer as a crosslinking agent under the action of an organic base, and specifically solves the problems of poor mechanical properties, unstable high-temperature properties and non-repeatable processing of the current EVM-GMA after crosslinking.

[0020] The sulfur-containing copolymer is a polymer obtained by bulk copolymerization of sulfur and vinyl monomers, which contains highly flexible polysulfide bonds (the structural formula is shown below). The inventors have found that the reaction between thiol and epoxy groups can be achieved by controlling the cross-linking environment, and then the cross-linking of EVM-GMA by the sulfur-containing copolymer can be achieved. Specifically, the sulfur-containing copolymer is used as a cross-linking agent and cross-linking is carried out under the catalysis of an organic base.

[0021] In the following structural formula, n≥2, R is the part other than the vinyl group in the vinyl monomer:

[0022]

[0023] In some embodiments, in the EVM-GMA, the mass percentage of vinyl acetate (VA) is 40-60wt%, and the mass percentage of glycidyl methacrylate (GMA) is 2-10wt%; in some preferred embodiments, the mass percentage of VA in the EVM-GMA is 60wt%, and the mass percentage of GMA is 2.9wt%.

[0024] The crosslinking method realizes crosslinking by heterolytic cleavage of polysulfide bonds in the sulfur-containing copolymer and then reacting with epoxy groups in EVM-GMA to generate a thiol-epoxy reaction, wherein the mass percentage of VA is 40-60wt%, and the mass percentage of GMA is 2-10wt%. When the VA content is lower than 40wt%, the low-temperature resistance of the product rubber decreases, which may be due to the high glass transition temperature caused by the low VA content. When the VA content is higher than 60wt%, the high-temperature stability of the rubber decreases. When the GMA content is lower than 2wt%, the strength and modulus of the rubber are insufficient, which may be due to the low crosslinking density caused by the low GMA content. When the GMA content is higher than 10wt%, the brittleness of the rubber increases and the toughness is lower.

[0025] In some embodiments, the mass ratio of the sulfur-containing copolymer to the mass ratio of EVM-GMA is (0.5-8):100.

[0026] When the content of sulfur-containing copolymer is too low, the cross-linking density of rubber is insufficient and the mechanical properties decrease; when the content of sulfur-containing copolymer is too high, it cannot fully participate in the cross-linking reaction and excess sulfur-containing copolymer precipitates from the sample surface.

[0027] In some embodiments, the preparation method of the sulfur-containing copolymer includes: adding vinyl monomer to molten sulfur, stirring and reacting at 130-180° C., dissolving the reaction system and filtering it, and drying the filtrate obtained by filtration to obtain the sulfur-containing copolymer.

[0028] If the temperature is too low, the sulfur cannot open its ring and cannot react; if the temperature is too high, a large amount of hydrogen sulfide will be released during the reaction and the structure of the sulfur-containing copolymer will be uncontrollable.

[0029] In a preferred embodiment, the sulfur-containing copolymer includes a sulfur-containing copolymer obtained using styrene or divinylbenzene as a vinyl monomer.

[0030] In some embodiments, the average sulfur chain order of the sulfur-containing copolymer is 2.7 to 5.2.

[0031] If the average sulfur chain order is too low, the material cross-linking degree is low and the mechanical properties are poor; if the average sulfur chain order is too high, the sulfur-containing copolymer is unstable and the proportion of polysulfide bonds in the cross-linked network is too high, the environmental stability is poor, and the anti-aging ability is reduced.

[0032] In some embodiments, the mass ratio of the organic base to the EVM-GMA is (0.05-3):100.

[0033] If the organic alkali content is too low, the vulcanization time will be long and the production efficiency will be reduced. If the organic alkali content is too high, the scorch time will be short, affecting the operation safety.

[0034] In some embodiments, the organic base is one or more of 1,2-dimethylimidazole, diphenylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicycloundec-7-ene and 4-dimethylaminopyridine.

[0035] Based on the nucleophilic activation effect of organic base, the sulfur-containing copolymer is catalyzed to generate sulfur anions and react with epoxy groups to achieve efficient cross-linking of EVM-GVA.

[0036] In some embodiments, the raw materials further include carbon black, and the mass ratio of the carbon black to the mass ratio of the ethylene-vinyl acetate-glycidyl methacrylate terpolymer is ≤0.6.

[0037] In some embodiments, the cross-linking temperature is 120-180° C. If the cross-linking temperature is too high or too low, the vulcanization time will be affected, and the vulcanization rate will be too fast or too slow, resulting in scorch (poor processing safety) or incomplete cross-linking.

[0038] On the other hand, there is provided an application of a sulfur-containing copolymer in a cross-linked EVM-GMA, including adjusting the amount of sulfur-containing copolymer added to achieve the adjustment of the positive vulcanization time in the cross-linked EVM-GMA, specifically including: mixing the sulfur-containing copolymer, EVM-GMA and organic base according to a preset mass ratio and then stopping, and measuring the positive vulcanization time of the material after stopping at a preset vulcanization temperature; when the positive vulcanization time needs to be extended, reducing the amount of sulfur-containing copolymer added, and when the positive vulcanization time needs to be shortened, increasing the amount of sulfur-containing copolymer added. In other embodiments, the application includes: mixing the sulfur-containing copolymer, EVM-GMA and organic base according to a preset mass ratio and then stopping, and measuring the positive vulcanization time of the material after stopping at a preset vulcanization temperature; when the positive vulcanization time needs to be extended, reducing the amount of sulfur-containing copolymer added, reducing the amount of organic base added and / or using a low-alkalinity organic base, when the positive vulcanization time needs to be shortened, increasing the amount of sulfur-containing copolymer added, increasing the amount of organic base added and / or using a high-alkalinity organic base.

[0039] In the process of cross-linking EVM-GMA using a sulfur-containing copolymer as a cross-linking agent, the inventors unexpectedly discovered that the sulfur-containing copolymer and the organic base can also be used as a positive vulcanization time regulator. By limiting the amount of sulfur-containing copolymer added, the amount of organic base added and / or the type of organic base, the performance of EVM-GMA after cross-linking and the controllable adjustment of the processing time can be achieved, which can specifically solve the current defects of poor performance of the terpolymer after cross-linking and difficult to control scorching and vulcanization time during the cross-linking process.

[0040] On the other hand, provided is an ethylene-vinyl acetate-glycidyl methacrylate rubber obtained based on the above method, wherein the mechanical property retention rate of the rubber after high-temperature treatment is 85% to 98%, and the repeated processing performance recovery rate is ≥80%, and the properties include tensile strength, elongation at break and / or 100% tensile stress; the repeated processing recovery rate is the mechanical properties of the ethylene-vinyl acetate-glycidyl methacrylate rubber after repeated processing relative to the mechanical properties of the ethylene-vinyl acetate-glycidyl methacrylate rubber before repeated processing, and the preparation method of the ethylene-vinyl acetate-glycidyl methacrylate rubber after repeated processing comprises: crushing and sieving the ethylene-vinyl acetate-glycidyl methacrylate rubber and then hot pressing to obtain the ethylene-vinyl acetate-glycidyl methacrylate rubber after repeated processing.

[0041] The invention provides an ethylene-vinyl acetate-glycidyl methacrylate rubber with more excellent high-temperature mechanical property stability and repeatable processing, which can be reused after being properly recycled after being discarded, thereby solving the pollution damage to the environment and the waste of resources caused by a large amount of waste rubber materials at present.

[0042] The present invention has been subjected to a series of experiments before the application is filed. A part of the experimental results are listed here to further describe the invention in detail, and the following is a detailed description in conjunction with the embodiments.

[0043] Example 1

[0044] Sulfur-containing copolymers A1, A2 and A3 were prepared respectively according to the following methods.

[0045] 7 g of sulfur was heated to 130° C. to melt, and 3 g of styrene was added after the molten sulfur turned orange-yellow. The mixture was stirred and reacted at 130° C. for 6 h. The system after the reaction was dissolved in 50 mL of tetrahydrofuran, filtered to remove unreacted raw materials, and the filtrate was dried at 50° C. to constant weight to obtain a sulfur-containing copolymer A1. The average sulfur chain rank (S rank) of the sulfur-containing copolymer A1 was 5.13.

[0046] 5 g of sulfur was heated to 180° C. to melt, and 5 g of styrene was added after the molten sulfur turned orange-yellow. The mixture was stirred and reacted at 180° C. for 6 h. The system after the reaction was dissolved in 50 mL of tetrahydrofuran, filtered to remove unreacted raw materials, and the filtrate was dried at 50° C. to constant weight to obtain a sulfur-containing copolymer A2, wherein the average sulfur chain rank (S rank) of the sulfur-containing copolymer A2 was 2.75.

[0047] 7 g of sulfur was heated to 130° C. to melt, and 3 g of divinylbenzene was added after the molten sulfur turned orange-yellow. The reaction was stirred at 160° C. for 6 h, and the system after the reaction was dissolved in 50 mL of tetrahydrofuran. The unreacted raw materials were filtered to remove the filtrate, and the filtrate was dried at 50° C. to constant weight to obtain a sulfur-containing copolymer A3, wherein the average sulfur chain rank (S rank) of the sulfur-containing copolymer A3 was 3.32; there was no restriction on the configuration of divinylbenzene, which could be a single configuration, or a mixture of two or three configurations. In this embodiment, it was a mixture of three configurations.

[0048] The average sulfur chain order is calculated based on the elemental analysis results, and the calculation formula is as follows:

[0049]

[0050] Among them, m s is the mass fraction of sulfur in the sulfur-containing copolymer, m v is the mass fraction of vinyl monomer in the sulfur-containing copolymer, M v is the molar mass of the vinyl monomer; n is the functionality of the vinyl monomer, and the elemental analysis is performed using an elemental analyzer via dynamic flash combustion-chromatographic separation method. The elemental analysis results are shown in Table 1;

[0051] Table 1 Elemental analysis results of sulfur-containing copolymers A1 to A3

[0052] Weight(mg) serial number C％ H％ S％ S rank 1.925 A1 35.81 3.195 61.22 5.13 2.012 A2 50.01 2.763 45.83 2.75 1.896 A3 35.43 2.011 62.74 3.32

[0053] This embodiment provides a method for cross-linking an ethylene-vinyl acetate-glycidyl methacrylate terpolymer, comprising using a sulfur-containing copolymer as a cross-linking agent and performing cross-linking under the action of an organic base, specifically comprising:

[0054] According to the formula of samples 1 to 13 in Table 2, ethylene-vinyl acetate-glycidyl methacrylate terpolymer, carbon black N330, sulfur-containing copolymer and organic base were mixed in an open mill for 20 minutes to obtain a rubber mix; the rubber mix was left at room temperature for 24 hours, and the positive vulcanization time was measured at a preset vulcanization temperature using a rotorless vulcanizer, the preset vulcanization temperature is shown in Table 2, and then compression vulcanization was performed, the compression vulcanization temperature was the preset vulcanization temperature, and the compression vulcanization time was the positive vulcanization time, to obtain corresponding samples 1 to 13;

[0055] The ethylene-vinyl acetate-glycidyl methacrylate terpolymer is commercially available and has the brand name Levapren NPG, wherein the mass percentage of vinyl acetate (VA) is 60wt% and the mass percentage of glycidyl methacrylate (GMA) is 2.9wt%. The addition amount of each component in Table 2 is in g.

[0056] Comparative Example 1

[0057] This comparative example examines the effect of the type of crosslinking agent on the crosslinked ethylene-vinyl acetate-glycidyl methacrylate terpolymer. The method is the same as Example 1, except that the crosslinking agent is sebacic acid, and no organic base is added. The amount of each raw material added is shown in Table 2, recorded as Comparative Sample 1.

[0058] Comparative Example 2

[0059] This comparative example examines the effect of the type of crosslinking agent on the crosslinked ethylene-vinyl acetate-glycidyl methacrylate terpolymer. The method is the same as Example 1, except that the crosslinking agent is methyltetrahydrophthalic anhydride, and no organic base is added. The amount of each raw material added is shown in Table 2, recorded as Comparative Sample 2.

[0060] Comparative Example 3

[0061] This comparative example examines the effect of organic base on the cross-linked ethylene-vinyl acetate-glycidyl methacrylate terpolymer. The method is the same as Example 1, and the cross-linking agent is the same as Sample 6, except that no organic base is added. The amount of each raw material added is shown in Table 2, recorded as Comparative Sample 3.

[0062] Table 2 Ingredients of samples 1 to 3 and comparison samples 1 to 3

[0063]

[0064]

[0065] According to Table 2 and Table 3, based on Samples 1 to 3, Sample 5 and Sample 10, it can be seen that the material obtained by crosslinking ethylene-vinyl acetate-glycidyl methacrylate terpolymer using the sulfur-containing copolymer as a crosslinking agent has high mechanical properties, mechanical property retention rate after high-temperature treatment and repeatable processing performance, indicating that the present invention can give the rubber a high mechanical property retention rate after high-temperature treatment and repeat processing performance recovery rate by crosslinking EVM-GMA with the sulfur-containing copolymer, and can specifically solve the current problems of poor mechanical properties, unstable high-temperature performance and non-repeatable processing of ethylene-vinyl acetate-glycidyl methacrylate rubber.

[0066] According to samples 1 to 3, it can be seen that the material obtained by crosslinking ethylene-vinyl acetate-glycidyl methacrylate terpolymer with sulfur-containing copolymer A1 as a crosslinking agent has high mechanical properties and repeatable processing performance. As the amount of sulfur-containing copolymer A1 added increases, the positive vulcanization time is significantly reduced, that is, the positive vulcanization time of crosslinked EVM-GMA is related to the amount of sulfur-containing copolymer A1 added, indicating that the sulfur-containing copolymer A1 of the present invention can be used as a vulcanization time regulator in the crosslinking material process on the basis of maintaining stable material properties, and achieves positive vulcanization time matching based on engineering practice. Based on samples 1 to 3 and samples 11 to 13, it can be seen that the sulfur-containing copolymer A1 can be used as a vulcanization time regulator on the basis of maintaining stable material properties.

[0067] The products obtained from Comparative Samples 1 and 2 have rough surfaces and are full of defects after repeated processing, and cannot meet the requirements of mechanical property test. Based on samples 1 to 3, comparative samples 1 and comparative samples 2, it can be seen that compared with sebacic acid or methyltetrahydrophthalic anhydride as a crosslinking agent, the material obtained by using sulfur-containing copolymer A1 as a crosslinking agent has significantly higher material mechanical properties, high temperature stability and repeatable processing performance, which is specifically reflected in the higher tensile strength, elongation at break and 100% tensile stress under the same conditions, and the elongation at break after high temperature treatment at 150°C is as high as 90%, and the 100% tensile stress is maintained at about 95%, and the tensile strength recovery rate after repeated processing is between 92% and 98%, the elongation at break is between 80% and 90%, and the 100% tensile stress recovery rate is between 83% and 90%. In addition, compared with the comparative sample, the use of sulfur-containing copolymer A1 as a crosslinking agent in sample 3 can effectively shorten the positive vulcanization time, and the positive vulcanization time is shortened by nearly half.

[0068] Based on samples 1 to 4, it can be seen that when the addition amount of the sulfur-containing copolymer A1 is 0.5 to 6 and the addition amount of the organic base is 1 to 3 (the addition amount is the added mass of the sulfur-containing copolymer A1 or the organic base, in g, based on 100 g of EVM-GMA), the material has high mechanical properties and a significantly shortened vulcanization time.

[0069] Based on Sample 2 and Sample 5, it can be seen that the sulfur content and average sulfur chain order of the same sulfur-containing copolymer affect the material properties and vulcanization time after cross-linking. When the sulfur content and the average sulfur chain order decrease, the vulcanization time is prolonged, and the mechanical properties and repeated processing recovery rate show a downward trend, which is manifested in a significant decrease in tensile strength, 100% elongation stress and repeated processing mechanical property recovery rate.

[0070] Based on samples 6 to 8 and comparative sample 3, relative to the sample of comparative sample 3 without adding organic base, the vulcanization time in the method of introducing organic base of the present invention is significantly reduced, and when the organic bases are diphenylguanidine, 4-dimethylaminopyridine and 1,8-diazabicycloundec-7-ene in sequence, the vulcanization time gradually decreases, indicating that the present invention uses organic base as a catalyst, which can effectively shorten the vulcanization time while ensuring the rubber properties of the product, and the vulcanization time can be reduced by selecting a high-alkalinity organic base.

[0071] Table 3 Vulcanization time, mechanical properties and performance recovery rate after repeated processing of each sample

[0072]

[0073]

[0074]

[0075] In Table 3, the positive vulcanization time is measured by a rotorless vulcanizer; the tensile strength, elongation at break and 100% tensile stress are measured based on ISO37-2005, the test temperature is room temperature, and the tensile rate is 500 mm / min; the test method of the retention rate includes: placing each sample under a high temperature condition of 150°C and an air atmosphere for 4 hours to obtain a treated sample, using the treated sample as a test sample, testing its elongation at break and 100% tensile stress, and each retention rate in Table 3 is the mechanical properties of the treated sample / the mechanical properties of the sample; the test method of the recovery rate includes: crushing each sample and passing it through an 80-mesh sieve, hot pressing the sieved powder at 150°C and 10MPa for 20 minutes to obtain a repeatedly processed sample, using the repeatedly processed sample as a test sample, testing its tensile strength, elongation at break and 100% tensile stress, and each recovery rate in Table 3 is the mechanical properties of the repeatedly processed sample / the mechanical properties of the sample.

Claims

1. A method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber, characterized in that: include: The sulfur-containing copolymer is used as a crosslinking agent to crosslink the ethylene-vinyl acetate-glycidyl methacrylate terpolymer under the action of an organic base.

2. The method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: In the ethylene-vinyl acetate-glycidyl methacrylate terpolymer, the mass percentage of vinyl acetate is 40-60wt%, and the mass percentage of glycidyl methacrylate is 2-10wt%.

3. The method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: The mass ratio of the sulfur-containing copolymer to the mass ratio of the ethylene-vinyl acetate-glycidyl methacrylate terpolymer is (0.5-8):

100.

4. The method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: The preparation method of the sulfur-containing copolymer comprises: adding vinyl monomer to molten sulfur, stirring and reacting at 130-180° C., dissolving the reaction system and filtering it, and drying the filtrate obtained by filtration to obtain the sulfur-containing copolymer.

5. The method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: The average sulfur chain order of the sulfur-containing copolymer is 2.7 to 5.

2.

6. The method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: The mass ratio of the organic base to the mass ratio of the ethylene-vinyl acetate-glycidyl methacrylate terpolymer is (0.05-3):

100.

7. The method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: The organic base is one or more of 1,2-dimethylimidazole, diphenylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicycloundec-7-ene and 4-dimethylaminopyridine.

8. The method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: The cross-linking temperature is 120-180°C.

9. Use of a sulfur-containing copolymer in cross-linking ethylene-vinyl acetate-glycidyl methacrylate, characterized in that: The method comprises adjusting the amount of the added sulfur-containing copolymer to adjust the positive vulcanization time in the cross-linked ethylene-vinyl acetate-glycidyl methacrylate.

10. An ethylene-vinyl acetate-glycidyl methacrylate rubber prepared by the method for preparing high-performance ethylene-vinyl acetate-glycidyl methacrylate rubber according to claim 1, characterized in that: The mechanical property retention rate of the ethylene-vinyl acetate-glycidyl methacrylate rubber after high-temperature treatment is 85% to 98%, and the repeated processing performance recovery rate is ≥80%.

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