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CN-121991437-A - Hydrogen peroxide-resistant ethylene propylene diene monomer rubber and preparation method thereof

CN121991437ACN 121991437 ACN121991437 ACN 121991437ACN-121991437-A

Abstract

The invention provides a hydrogen peroxide-resistant ethylene propylene diene monomer and a preparation method thereof, wherein the hydrogen peroxide-resistant ethylene propylene diene monomer comprises, by weight, 70-90 parts of ethylene propylene diene monomer raw rubber, 10-30 parts of fluorosilicone modified materials, 40-80 parts of reinforcing fillers, 3-8 parts of vulcanization active agents, 0.5-2 parts of lubricants, 4-8 parts of peroxide vulcanizing agents and 1-4 parts of auxiliary crosslinking agents, the preparation method of the hydrogen peroxide-resistant ethylene propylene diene monomer adopts a two-stage mixing process, one-stage mixing is that the ethylene propylene diene monomer is plasticated firstly, then components except a vulcanization system are gradually added for uniform mixing, and the two-stage mixing is that the vulcanizing agents and the auxiliary crosslinking agents are added at a low temperature (less than or equal to 70 ℃) for rapid mixing after the rubber is cooled to avoid scorching, and finally vulcanization molding is carried out. The material remarkably improves the hydrogen peroxide resistance through the synergistic effect of the fluorine-silicon modified material and a peroxide vulcanization system, and has a volume change rate of <5% and a tensile strength retention rate of >90% after being soaked in 90% solubility H2O2 for >12 hours.

Inventors

  • HUANG MING
  • ZONG LEI
  • XIAO YONG
  • WANG RANG
  • MA BAOHE
  • CHEN HAIYA
  • YANG LEI
  • SU XUEYUAN
  • HU ZHUANG
  • LI CHENGYU

Assignees

  • 湖北航聚科技股份有限公司

Dates

Publication Date
20260508
Application Date
20251231

Claims (10)

  1. 1. The hydrogen peroxide-resistant ethylene propylene diene monomer rubber is characterized by comprising, by weight, 70-90 parts of ethylene propylene diene monomer rubber raw rubber, 10-30 parts of a fluorine-silicon modified material, 40-80 parts of a reinforcing filler, 3-8 parts of a vulcanization active agent, 0.5-2 parts of a lubricant, 4-8 parts of a peroxide vulcanizing agent and 1-4 parts of a crosslinking assistant; The fluorosilicon modified material is one of poly (methyl trifluoro propyl silsesquioxane-co-methyl silsesquioxane), poly (methyl trifluoro propyl silsesquioxane-co-methyl phenyl silsesquioxane-co-methyl silsesquioxane) and poly (perfluoroalkoxy) -block-poly (methyl silsesquioxane); the reinforcing filler is a mixture of fumed silica and carbon black.
  2. 2. The hydrogen peroxide-resistant ethylene propylene diene monomer rubber of claim 1, wherein the weight ratio of fumed silica to carbon black in the reinforcing filler is (1:0.5) - (1:2), and the carbon black is one of N550, N660, N770 or N990.
  3. 3. The hydrogen peroxide resistant ethylene propylene diene monomer of claim 1, wherein the peroxide vulcanizing agent is one or more of bis- (tert-butylperoxyisopropyl) benzene, dicumyl peroxide and 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane.
  4. 4. The hydrogen peroxide-resistant ethylene propylene diene monomer rubber as claimed in claim 1, wherein ethylene content of the ethylene propylene diene monomer rubber raw rubber is 50-70 wt%, content of the third monomer ENB is 4-10 wt%, and Mooney viscosity [ ML (1+4) 125 ℃ is 40-80.
  5. 5. The hydrogen peroxide-resistant ethylene propylene diene monomer rubber of claim 1, wherein the vulcanization activator is a compound system of zinc oxide and zinc stearate, and the zinc oxide is 2-5 parts and the zinc stearate is 1-3 parts.
  6. 6. The hydrogen peroxide resistant ethylene propylene diene monomer of claim 1, wherein the lubricant comprises at least one of stearic acid or polyethylene wax.
  7. 7. The hydrogen peroxide resistant ethylene propylene diene monomer of claim 1, wherein the auxiliary crosslinking agent is at least one of trimethylolpropane trimethacrylate, triallyl isocyanurate and N, N' -m-phenylene bismaleimide.
  8. 8. The preparation method of the hydrogen peroxide-resistant ethylene propylene diene monomer rubber according to any one of claims 1 to 7, which is characterized by comprising the following steps of; s1, one-stage mixing, namely wrapping ethylene propylene diene monomer rubber on a roller of an open rubber mixing mill, and sequentially adding a fluorine-silicon modified material, a reinforcing filler, a lubricant and a vulcanization active agent after the roller is wrapped uniformly to ensure that all the components are fully and uniformly mixed; S2, two-stage mixing, namely re-rolling the first-stage mixed rubber on an open rubber mixing machine at a low temperature, and adding a peroxide vulcanizing agent and a crosslinking assistant under the condition that the roller temperature is controlled to be less than or equal to 70 ℃, wherein the mixing is performed quickly and uniformly within 3-5 min, and then thin passing is performed to obtain final rubber; S3, vulcanization molding, namely placing the parked final rubber into a mold for vulcanization molding to obtain the hydrogen peroxide-resistant ethylene propylene diene monomer rubber.
  9. 9. The preparation method of claim 8, wherein in the step S2, the number of times of the thin-pass sizing material is 4-10 times, the roll gap during thin-pass is 0.3-0.5 mm, and in the step S3, the vulcanization temperature is 145-155 ℃ and the vulcanization time is 55-65 min.
  10. 10. The application of the hydrogen peroxide-resistant ethylene propylene diene monomer rubber in the hydrogen peroxide-contacting sealing product, which is characterized in that after the ethylene propylene diene monomer rubber is soaked in hydrogen peroxide of which the temperature is 60 ℃ and the hydrogen peroxide is 90% for 12 hours, the retention rate of the tensile strength of the rubber is more than or equal to 90% and the volume change rate is less than or equal to 5%.

Description

Hydrogen peroxide-resistant ethylene propylene diene monomer rubber and preparation method thereof Technical Field The invention belongs to the technical field of special rubber materials, and particularly relates to a hydrogen peroxide-resistant ethylene propylene diene monomer rubber and a preparation method thereof. Background Ethylene Propylene Diene Monomer (EPDM) enjoys excellent ozone resistance, weather resistance, aging resistance and chemical medium resistance (especially polar chemicals and hot water/steam) due to its molecular structure with a fully saturated main chain, and is widely used in the fields of automobiles, buildings, wires and cables, and the like. Hydrogen peroxide (hydrogen peroxide, H 2O2) is widely used as a strong oxidant in medical disinfection, textile bleaching, semiconductor cleaning, food packaging sterilization and chemical synthesis. In these applications, rubber seals (e.g., gaskets, O-rings) and piping systems are required to withstand the attack of high concentrations of hydrogen peroxide for long periods of time. Although EPDM is generally more resistant to oxidation than unsaturated rubbers (e.g., NBR, SBR), conventional sulfur vulcanization system EPDM is extremely susceptible to oxidative scission of polysulfide bonds and disulfide bonds in its network structure when exposed to high concentration (e.g., 90%) and high temperature (e.g., 60 ℃) hydrogen peroxide environments for a long period of time, resulting in destruction of the crosslinked structure, which in turn causes severe softening, viscous flow and even cracking failure of rubber products, failing to meet long-term use requirements under severe conditions. In order to improve oxidation resistance, peroxide curing systems are commonly used in the industry to replace sulfur systems. The carbon-carbon (C-C) single bond crosslinking bond energy formed by peroxide vulcanization is higher, the structure is more stable, and the heat and oxidation resistance of the vulcanized rubber can be obviously improved. However, peroxide curing systems present new process challenges in that, firstly, peroxide curing agents are sensitive to temperature and shear, a large amount of mechanical shearing heat is generated in the conventional mixing process of an internal mixer, peroxide is extremely easy to decompose in advance in the mixing stage, scorching (scorch) of the rubber material is caused, the processing safety of the rubber material is poor and difficult to control, and secondly, the investment of equipment of the internal mixer is large and the cleaning is difficult, so that the economical efficiency and the flexibility are insufficient for the production of special rubber materials with various varieties and small batches. Therefore, developing an ethylene propylene diene monomer rubber material which can not only keep the advantage of hydrogen peroxide resistance of a peroxide vulcanization system, but also realize stable processing on simple and low-cost equipment and a preparation method thereof becomes a technical problem to be solved in the field. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides the hydrogen peroxide-resistant ethylene propylene diene monomer rubber and the preparation method thereof, which improve the corrosion resistance and mechanical stability of rubber in a strong oxidation environment and ensure the feasibility of the process and the cost effectiveness. The invention provides the following technical scheme: The invention provides a hydrogen peroxide-resistant ethylene propylene diene monomer, which comprises, by weight, 70-90 parts of ethylene propylene diene monomer raw rubber, 10-30 parts of a fluorine-silicon modified material, 40-80 parts of a reinforcing filler, 3-8 parts of a vulcanization active agent, 0.5-2 parts of a lubricant, 4-8 parts of a peroxide vulcanizing agent and 1-4 parts of a crosslinking assistant; The fluorosilicon modified material is one of poly (methyl trifluoro propyl silsesquioxane-co-methyl silsesquioxane), poly (methyl trifluoro propyl silsesquioxane-co-methyl phenyl silsesquioxane-co-methyl silsesquioxane) and poly (perfluoroalkoxy) -block-poly (methyl silsesquioxane); the reinforcing filler is a mixture of fumed silica and carbon black. The siloxane structure in the fluorosilicon modified material can form a firm organic-inorganic hybridization interface with the silicon hydroxyl on the surface of the fumed silica, hydrogen peroxide permeation is effectively blocked, and carbon black is used as an efficient reinforcing agent to provide excellent mechanical strength, elasticity and processability, and the silicon black can be compounded with the fumed silica to make up for the partial shortages of the fumed silica sizing material in the aspects of tensile strength and tear resistance, so that the balance of the performance and the cost is realized. Further, in the reinforcing filler, the weight ratio of the f