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CN-121975218-A - Thermoplastic vulcanized rubber elastomer and application thereof

CN121975218ACN 121975218 ACN121975218 ACN 121975218ACN-121975218-A

Abstract

The application relates to a thermoplastic vulcanized rubber elastomer and application thereof. The thermoplastic vulcanized rubber elastomer is obtained by mixing 20-50% of high-density polyethylene and 50-80% of ethylene-alpha-olefin copolymer in a mass ratio, melting, adding a vulcanizing agent, and vulcanizing and mixing, wherein the vulcanizing agent is a peroxide crosslinking agent, and the addition amount of the vulcanizing agent is 1.5-2.5wt% of the mass of the ethylene-alpha-olefin copolymer. The TPV material takes the HDPE structure as a framework and disperses POE materials, so that good material strength, toughness and elastic recovery capability are obtained.

Inventors

  • ZHANG RUIJUN
  • QIAN JIANHUA
  • Guan Zongchi
  • WANG JIAHUAN
  • LI JUNHUA

Assignees

  • 辽宁石油化工大学
  • 中国石油大学(华东)
  • 辽宁省石化产业技术创新研究院有限公司

Dates

Publication Date
20260505
Application Date
20260202

Claims (10)

  1. 1. The thermoplastic vulcanized rubber elastomer is characterized by being obtained by mixing 20% -50% of high-density polyethylene and 50% -80% of ethylene-alpha-olefin copolymer in mass ratio, melting, adding a vulcanizing agent, and vulcanizing and mixing, wherein the vulcanizing agent is a peroxide cross-linking agent, and the addition amount of the vulcanizing agent is 1.5% -2.5% of the mass of the ethylene-alpha-olefin copolymer.
  2. 2. Thermoplastic vulcanizate according to claim 1, wherein the melt mass flow rate of the high density polyethylene is below 30g/10min, preferably 0.5 to 21g/10min, further preferably 0.8 to 1.2g/10min at 190 ℃ under a pressure of 2.16kg, determined by the method of ASTM D1238.
  3. 3. Thermoplastic vulcanizate according to claim 1 or 2, characterized in that the melt mass flow rate of the ethylene-a-olefin copolymer is below 10g/10min, preferably 0.5 to 3g/10min, more preferably 0.5 to 1.2g/10min, at 190 ℃ and under a pressure of 2.16kg, determined by the method of ASTM D1238.
  4. 4. A thermoplastic vulcanizate according to any one of claims 1 to 3, wherein the ethylene-a-olefin copolymer has a density of from 0.850 to 0.890g/cm 3 , more preferably from 0.860 to 0.880g/cm 3 , as determined by the method of ASTM D1505.
  5. 5. Thermoplastic vulcanizate according to one of claims 1 to 4, wherein in the ethylene-alpha-olefin copolymer the alpha-olefin has 4 to 10 carbon atoms, preferably comprising 1-butene, 1-hexene and 1-octene, more preferably 1-octene.
  6. 6. Thermoplastic vulcanizate according to one of claims 1 to 5, characterized in that the peroxide crosslinking agent comprises 2, 5-dimethyl-2, 5-bis- (tert-butylperoxy) hexane, bis (tert-butylperoxyisopropyl) benzene or benzoyl peroxide, preferably 2, 5-dimethyl-2, 5-bis- (tert-butylperoxy) hexane.
  7. 7. Thermoplastic vulcanizate according to one of claims 1 to 6, characterized in that an antioxidant is also added during the mixing; preferably, the antioxidant comprises pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and tris (2, 4-di-tert-butylphenyl) phosphite in a mass ratio of 1:1-1:2.
  8. 8. Thermoplastic vulcanizate elastomer according to one of claims 1 to 7, characterized in that it is obtained by the preparation of: Mixing high-density polyethylene and ethylene-alpha-octene copolymer according to the mass ratio of 20% -50% to 50% -80% to obtain a mixed matrix, then melting and mixing the mixed matrix at 190-210 ℃ and 55-65 rpm, and then adding 2, 5-dimethyl-2, 5-bis- (tert-butylperoxy) hexane for vulcanization to obtain a thermoplastic vulcanized rubber elastomer, wherein the addition amount of the 2, 5-dimethyl-2, 5-bis- (tert-butylperoxy) hexane is 1.5-2.5wt% of the mass of the ethylene-alpha-olefin copolymer; preferably, after the mixed matrix is melted, pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and tris (2, 4-di-tert-butylphenyl) phosphite are added in an amount of 0.07-0.10 wt% of the mixed matrix.
  9. 9. Use of a thermoplastic vulcanizate elastomer according to one of claims 1 to 8 for toughening high density polyethylene materials.
  10. 10. A toughening blend comprising 100 parts by weight of a high density polyethylene substrate and 10 to 20 parts by weight of a thermoplastic vulcanizate elastomer according to one of the objects.

Description

Thermoplastic vulcanized rubber elastomer and application thereof Technical Field The invention belongs to the technical field of high polymer materials, and particularly relates to a thermoplastic vulcanized rubber elastomer and application thereof. Background Thermoplastic elastomer (TPE) has both the elasticity of rubber and the thermoplastic processability of plastic, and is a novel recyclable polymer material. The thermoplastic vulcanized rubber (TPV) is prepared by a dynamic vulcanization process, and a crosslinked rubber phase of the TPV is dispersed in a plastic continuous phase in micron-sized particles, so that the TPV has excellent mechanical properties, heat resistance and oil resistance, and is widely applied to the fields of automobiles, electronics, medical treatment and the like. The TPV systems of the prior art are mostly based on a polypropylene (PP) continuous phase, such as ethylene propylene diene monomer/polypropylene (EPDM/PP) systems. However, polypropylene molecular chains are susceptible to β -scission degradation under the high temperatures and shear required for dynamic vulcanization, particularly in peroxide crosslinking systems, resulting in degradation of material properties. This typically requires the addition of additional stabilizers or the use of complex processes to control degradation, increasing formulation costs and process difficulties. Therefore, it is of great importance to develop new TPV matrix materials that are more stable and easier to process. Accordingly, there is a need in the art to develop a thermoplastic vulcanizate having better mechanical properties. Disclosure of Invention In view of the deficiencies of the prior art, it is an object of the present invention to provide a thermoplastic vulcanizate (TPV) based on High Density Polyethylene (HDPE) and ethylene- α -olefin copolymers. The TPV provided by the invention has good processability, excellent mechanical property and shape memory function, and can be used for toughening HDPE effectively. The invention provides a thermoplastic vulcanized rubber elastomer, which is obtained by mixing high-density polyethylene and ethylene-alpha-olefin copolymer according to the mass ratio of 20% -50% to 50% -80%, adding a vulcanizing agent after melting, and vulcanizing and mixing, wherein the vulcanizing agent is a peroxide crosslinking agent, and the addition amount is 0.8% -3.0wt% of the mass of the ethylene-alpha-olefin copolymer. The mass ratio of the HDPE to the ethylene-alpha-olefin copolymer is limited to 20% -50% by 50% -80%, so that the rubber phase (the ethylene-alpha-olefin copolymer) is a continuous phase or is easy to form a co-continuous structure in the initial blend, a basis is provided for shearing breaking and dispersing in the subsequent dynamic vulcanization process, and the HDPE serving as the continuous phase after vulcanization is ensured to have enough content to provide necessary mechanical strength and thermoplastic processability. In preparing TPVs, the initial ratio of plastic to rubber phase is critical in determining whether the final "sea-island" structure (i.e., the dispersion of rubber particles in the plastic matrix) will be successfully formed (i.e., the "phase inversion") and whether the material properties are biased toward plastic or rubber. Outside the range of ratios described in the present application, incomplete phase inversion, insufficient strength of the continuous phase, or poor elastic recovery may result. On the other hand, in the preparation process of the thermoplastic vulcanized rubber elastomer, a proper peroxide crosslinking agent (especially the thermoplastic vulcanized rubber elastomer) is selected, so that a proper crosslinking degree can be obtained, and the material has proper elastic recovery rate and toughness. Preferably, the high density polyethylene has a melt mass flow rate of 30g/10min or less, preferably 0.5 to 21g/10min, more preferably 0.8 to 1.2g/10min, at 190℃under a pressure of 2.16kg, as determined by the method of ASTM D1238. Preferably, the melt mass flow rate of the ethylene-alpha-olefin copolymer is 10g/10min or less, preferably 0.5 to 3g/10min, more preferably 0.5 to 1.2g/10min, at 190℃under a pressure of 2.16kg, as determined by the method of ASTM D1238. Preferably, the ethylene-alpha-olefin copolymer has a density of 0.850 to 0.780 g/cm 3, more preferably 0.860 to 0.880g/cm 3, as measured by the method of ASTM D1505. The further selection of the raw materials provided by the application can improve the mechanical property, shape memory function and high-efficiency toughening effect of the thermoplastic vulcanized rubber elastomer. HDPE with the melt mass flow rate lower than 30g/10min is selected, namely HDPE with middle and low melt fingers and higher molecular weight is selected, so that the material can be endowed with basic mechanical strength, a continuous phase framework with enough strength, rigidity and thermoplastic processabili