Irradiation crosslinking modified thermoplastic elastomer and preparation method thereof

Abstract

The invention relates to an irradiation crosslinking modified thermoplastic elastomer and a preparation method thereof. The thermoplastic elastomer consists of 50-80 parts of a styrene thermoplastic elastomer, 30-50 parts of a thermoplastic polyester elastomer, 10-15 parts of a maleic anhydride grafted polymer, 10-15 parts of allyl-terminated modified liquid polyether resin, 0.5-1 part of an amino-terminated polyether curing agent and 5-10 parts of a plasticizer. According to the prepared modified thermoplastic elastomer, the mechanical property, the compression resistance, the rebound resilience and the skid resistance of the modified thermoplastic elastomer are remarkably improved through an irradiation cross-linking technology. Besides, the material has outstanding processability, is suitable for various molding processes, has environmental protection and economical efficiency, and has application prospects in the fields of automobile parts, electric wires and cables, sealing elements and the like.

Description

Technical Field

[0001] The invention belongs to the field of radiation technology and thermoplastic elastomer, and specifically relates to a radiation cross-linked modified thermoplastic elastomer and a preparation method thereof. Background Art

[0002] In modern industry and daily life, thermoplastic elastomers (TPE) are widely used in various fields because they have both the elasticity of rubber and the processability of plastic. However, traditional TPE materials have limited mechanical properties, poor resilience and insufficient anti-slip properties in certain specific application environments, which limits their application in special fields such as automotive parts, wires and cables, and seals. At present, the existing TPE modification methods mainly include physical blending and chemical crosslinking. Although they can improve the material properties to a certain extent, they are also accompanied by many problems. For example, physical blending usually requires the addition of reinforcing fillers. Patent CN108329638A forms a mild physical crosslinking system by blending silane-grafted styrene thermoplastic elastomer with silica. The system has high mechanical strength and toughness. However, a large amount of inorganic fillers in the system greatly affects the processing performance and compatibility of the material. Chemical crosslinking usually requires the use of an organic peroxide crosslinking agent represented by diisopropylbenzene peroxide (DCP). For example, patent CN115058086A discloses a thermoplastic vulcanizate and a preparation method thereof. The method uses multiple organic peroxide vulcanizers with different reaction rates and long-chain branched EPDM rubber with a large molecular weight to achieve uniform mixing of the rubber phase and the extrusion-grade polypropylene resin, and the resulting thermoplastic vulcanized rubber has good mechanical properties. However, multiple organic peroxide vulcanizers with different reaction rates can achieve a specific vulcanization effect to a certain extent, but also increase the complexity and uncontrollability of the reaction, making it difficult to accurately control the vulcanization time and degree. In addition, the patent uses DCP as the vulcanizer, which emits a strong odor during use and has poor environmental protection.

[0003] Therefore, a new modified thermoplastic elastomer is needed to overcome the problems existing in the traditional method, improve the mechanical properties and stability of the system, and expand its application range. Summary of the invention

[0004] In view of the above problems, the present invention provides a radiation cross-linked modified thermoplastic elastomer and a preparation method thereof. The elastomer has high wear resistance and anti-slip properties, and the liquid polyether resin main chain used has a certain crystallinity. The discrete crystalline domains in the network provide stress support points, thereby improving the overall mechanical properties and resilience of the material.

[0005] To achieve the above object, the present invention adopts the following technical solution: A radiation cross-linked modified thermoplastic elastomer, wherein the radiation cross-linked modified thermoplastic elastomer is obtained by cross-linking a semi-finished product by electron beam radiation, and the semi-finished product comprises the following components in parts by weight: 50~80 parts of styrene thermoplastic elastomer, 30~50 parts of thermoplastic polyester elastomer, 10-15 parts of maleic anhydride grafted polymer, 10~15 parts of allyl-terminated modified liquid polyether resin, 0.5~1 part of amino-terminated polyether curing agent, 5~10 parts of plasticizer.

[0006] Preferably, the styrene-based thermoplastic elastomer is one of SEBS YH-501, SEBS YH-502, SEBS YH-504 and SEBS YH-602.

[0007] Preferably, the thermoplastic polyester elastomer is one of the polyether-type TPEE Hytrel3078 and TPEE Riteflex640.

[0008] Preferably, the maleic anhydride grafted polymer is one of maleic anhydride grafted PP, maleic anhydride grafted POE or maleic anhydride grafted SEBS.

[0009] Preferably, the allyl-terminated modified liquid polyether resin is obtained by reacting an isocyanate-terminated liquid polyether resin prepolymer obtained by reacting a liquid polyether polyol with isocyanate and then reacting with triallyl citrate.

[0010] Preferably, the liquid polyether polyol is one of polytetrahydrofuran diol or polyethylene glycol.

[0011] Preferably, the amino-terminated polyether curing agent is one of D-230 and D-400.

[0012] Preferably, the plasticizer is one of di(2-ethylhexyl) phosphate, palmitate, tri(2-ethylhexyl) citrate or epoxidized soybean oil.

[0013] The second object of the present invention is to provide a method for preparing the above-mentioned radiation cross-linked modified thermoplastic elastomer, comprising the following steps: (1) Preparation of isocyanate-terminated liquid polyether resin prepolymer: add 5-8 parts of hexamethylene diisocyanate to 20-30 parts of liquid polyether polyol, control the molar ratio of -OH in the liquid polyether polyol to -NCO in the isocyanate to be 2:1, add 0.03-0.04 parts of an organic tin catalyst, mix well, react at 50°C-70°C for 3-5 hours under inert gas protection, and obtain an isocyanate-terminated liquid polyether resin prepolymer; (2) Preparation of allyl-terminated modified liquid polyether resin: reacting the isocyanate-terminated liquid polyether resin prepolymer obtained in step (1) with triallyl citrate, and reacting at 60° C. to 80° C. for 4 to 6 hours under inert gas protection to obtain an allyl-terminated modified liquid polyether resin; (3) uniformly mixing a styrene-based thermoplastic elastomer, a thermoplastic polyester elastomer, a maleic anhydride grafted polymer, the allyl-terminated modified liquid polyether resin obtained in step (2), an amino-terminated polyether curing agent and a plasticizer, and melt-blending and extruding the mixture at 160-190° C. to obtain a semi-finished product; (4) The semi-finished product is cross-linked by electron beam irradiation to obtain the product.

[0014] Preferably, the electron beam irradiation cross-linking is performed using an electron accelerator, the electron beam energy is 1 Mev~4 Mev, the beam current is 10 mA~50 mA, and the irradiation dose is 40 kGy~200 kGy.

[0015] Preferably, the organotin catalyst is one of stannous octoate or dibutyltin dilaurate.

[0016] The beneficial effects of the present invention are: (1) The present invention adopts electron beam irradiation technology to crosslink and modify thermoplastic elastomers. Electron beam irradiation generates free radicals by breaking CC bonds in polymer chains. Active free radicals can form crosslinking reactions between styrene-based thermoplastic elastomers, thermoplastic polyester elastomers, maleic anhydride grafted polymers and allyl-terminated modified liquid polyether resins. This process transforms the linear structure of the thermoplastic elastomer into a crosslinked network structure, significantly improving the mechanical properties, resilience, wear resistance and anti-slip properties of the material. The electron beam irradiation crosslinking process does not require the use of traditional crosslinking agents such as DCP, and has the advantages of high efficiency, strong controllability and environmental protection. In addition, by adjusting the energy of the electron beam (usually 1MeV~4MeV), beam intensity (10mA~50mA) and irradiation dose (40kGy~200kGy), the crosslinking density of the elastomer can be adjusted, thereby adjusting the performance of the material, achieving a 44%~101% increase in the tensile strength of the material, an 8%~22% increase in the hardness, and a 26%~41% increase in the rebound rate.

[0017] (2) In the present invention, liquid polyether polyol is reacted with hexamethylene diisocyanate and triallyl citrate to obtain an allyl-terminated modified liquid polyether resin. A part of the double bond in the allyl group can undergo addition reaction with the active amino group in the amino-terminated polyether curing agent, and another part can undergo cross-linking reaction with the free radicals generated by electron beam irradiation cross-linking. In addition, the active amino group in the amino-terminated polyether curing agent can undergo addition reaction with the double bond in the maleic anhydride grafted polymer. Therefore, both irradiation cross-linking and chemical addition cross-linking exist in the system, and the cross-linking reaction occurs between multiple components, which promotes the interaction between the components. This cross-linking reaction improves the tightness between the molecular chains, so that the tensile strength and hardness of the material are significantly enhanced.

[0018] (3) The main chain of the allyl-terminated modified liquid polyether resin synthesized in the present invention is a polyether structure, which has good compatibility with the polyether segment structure in the thermoplastic polyester elastomer. At the same time, the allyl group reacts with the amino-terminated polyether curing agent, and the amino-terminated polyether curing agent reacts with the maleic anhydride grafted polymer. The main chain of maleic anhydride grafted PP, POE and SEBS is a non-polar structure, which is similar in polarity to the structure of styrene thermoplastic elastomer and has good compatibility. Therefore, by designing the reaction of the structures between the components of the present invention, the compatibility between styrene thermoplastic elastomer and thermoplastic polyester elastomer can be enhanced.

[0019] (4) The main chain of the allyl-terminated modified liquid polyether resin synthesized in the present invention is composed of multiple ether units connected to form a linear structure, thereby giving the material a certain degree of flexibility. At the same time, the main chain of the liquid polyether resin has a certain degree of crystallinity. The discrete crystalline domains in the entire network can provide certain stress support points, thereby improving mechanical properties and resilience. The oxidized groups (such as alcohol groups and hydroxyl groups) on the surface of TPEE and the functional groups (such as amino groups and carboxyl groups) at the ends of the molecular chains can react with the allyl groups to form stable covalent bonds. DETAILED DESCRIPTION

[0020] The present invention is further described and explained below in conjunction with preferred embodiments and experimental data. Example

[0021] Step 1: Preparation of isocyanate-terminated liquid polyether resin prepolymer: Weigh 28 parts of polyether polyol and 6 parts of hexamethylene diisocyanate, mix them according to the molar ratio of polyether polyol (-OH) to isocyanate group (-NCO) in isocyanate at 2:1, and add 0.04 parts of stannous octoate. After stirring the above materials evenly at room temperature, transfer them to a dry reaction vessel. The reaction system is heated to 60°C under nitrogen protection to prevent side reactions between moisture in the air and isocyanate. Keep the reaction temperature at 60°C and continue the reaction for 5 hours. After the reaction is completed, cool the material and obtain an isocyanate-terminated liquid polyether resin prepolymer.

[0022] Step 2: Preparation of allyl-terminated modified liquid polyether resin: Add isocyanate-terminated liquid polyether resin prepolymer and triallyl citrate into a reaction vessel, stir and react under nitrogen protection, control the reaction temperature at 60°C, and continue for 6 hours. When the isocyanate group is completely reacted, stop the reaction and gradually cool to room temperature to obtain an allyl-terminated modified liquid polyether resin.

[0023] Step 3: Weigh 71 parts of SEBS YH-501, 47 parts of TPEE Hytrel3078, 13 parts of maleic anhydride grafted PP, 10 parts of allyl terminated modified liquid polyether resin, 0.8 parts of curing agent D-230, and 6 parts of trioctyl isodecanoate, add them to the high-speed mixer in sequence, and mix them evenly at 1500r / min for 5 minutes at room temperature. Then transfer the mixed material to the twin-screw extruder, set the extruder zone 165℃, zone 2 170℃, zone 3 175℃, zone 4 180℃, zone 5 180℃, zone 6 180℃, die head 180℃, screw speed 40 / rpm, ensure that each component is fully mixed and melted and extruded smoothly. The extrusion port is the sheet die port (width 50mm×thickness 2mm), and a continuous sheet sample of about 50mm width and 2mm thickness is obtained.

[0024] Step 4: Cut a sheet sample of 500 mm long, 20 mm wide and 2 mm thick, lay it flat on the conveyor belt of the electron beam irradiation device, and use an electron accelerator to perform electron beam irradiation cross-linking modification. Set the electron beam energy to 3 MeV, the beam current to 40 mA, and the irradiation dose to 150 kGy. Start the electron accelerator to ensure that each sheet is evenly irradiated on both sides for 3 seconds. Example

[0025] Step 1: Preparation of isocyanate-terminated liquid polyether resin prepolymer: Weigh 25 parts of polyether polyol and 7 parts of hexamethylene diisocyanate, mix them according to the molar ratio of polyether polyol (-OH) to isocyanate group (-NCO) in isocyanate at 2:1, and add 0.03 parts of dibutyltin dilaurate. After stirring the above materials evenly at room temperature, transfer them to a dry reaction vessel. The reaction system is heated to 60°C under nitrogen protection to prevent side reactions between moisture in the air and isocyanate. Keep the reaction temperature at 60°C and continue the reaction for 5 hours. After the reaction is completed, cool the material and obtain an isocyanate-terminated liquid polyether resin prepolymer.

[0026] Step 2: Preparation of allyl-terminated modified liquid polyether resin: Add isocyanate-terminated liquid polyether resin prepolymer and triallyl citrate into a reaction vessel, stir and react under nitrogen protection, and control the reaction temperature at 60°C for 6 hours. When the isocyanate group is completely reacted, the reaction is stopped and gradually cooled to room temperature to obtain an allyl-terminated modified liquid polyether resin.

[0027] Step 3: Weigh 62 parts of SEBS YH-502, 41 parts of TPEE Riteflex640, 12 parts of maleic anhydride grafted POE, 12 parts of allyl terminated modified liquid polyether resin, 0.7 parts of curing agent D-400, and 7 parts of epoxidized soybean oil, add them to the high-speed mixer in sequence, and mix them evenly at 1500r / min for 5 minutes at room temperature. Then transfer the mixed material to the twin-screw extruder, set the extruder zone 165℃, zone 2 170℃, zone 3 175℃, zone 4 180℃, zone 5 180℃, zone 6 180℃, die head 180℃, screw speed 40 / rpm, ensure that each component is fully mixed and melted and extruded smoothly. The extrusion port is the sheet die port (width 50mm×thickness 2mm), and a continuous sheet sample of about 50mm width and 2mm thickness is obtained.

[0028] Step 4: Cut a sheet sample of 500 mm long, 20 mm wide and 2 mm thick, lay it flat on the conveyor belt of the electron beam irradiation device, and use an electron accelerator to perform electron beam irradiation cross-linking modification. Set the electron beam energy to 2 MeV, the beam current to 30 mA, and the irradiation dose to 120 kGy. Start the electron accelerator to ensure that each sheet is evenly irradiated on both sides for 3 seconds. Example

[0029] Step 1: Preparation of isocyanate-terminated liquid polyether resin prepolymer: Weigh 24 parts of polyether polyol and 5 parts of hexamethylene diisocyanate, mix them according to the molar ratio of polyether polyol (-OH) to isocyanate group (-NCO) in isocyanate at 2:1, and add 0.03 parts of stannous octoate. After stirring the above materials evenly at room temperature, transfer them to a dry reaction vessel. The reaction system is heated to 60°C under nitrogen protection to prevent side reactions between moisture in the air and isocyanate. Keep the reaction temperature at 60°C and continue the reaction for 5 hours. After the reaction is completed, cool the material and obtain an isocyanate-terminated liquid polyether resin prepolymer.

[0030] Step 2: Preparation of allyl-terminated modified liquid polyether resin: Add isocyanate-terminated liquid polyether resin prepolymer and triallyl citrate into a reaction vessel, stir and react under nitrogen protection, and control the reaction temperature at 60°C for 6 hours. When the isocyanate group is completely reacted, the reaction is stopped and gradually cooled to room temperature to obtain an allyl-terminated modified liquid polyether resin.

[0031] Step 3: Weigh 55 parts of SEBS YH-602, 38 parts of TPEE Riteflex640, 14 parts of maleic anhydride grafted SEBS, 11 parts of allyl terminated modified liquid polyether resin, 0.6 parts of curing agent D-400, and 9 parts of tri (2-ethylhexyl) citrate, add them to the high-speed mixer in sequence, and mix them evenly at 1500r / min for 5 minutes at room temperature. Then transfer the mixed material to the twin-screw extruder, set the extruder zone 165℃, zone 2 170℃, zone 3 175℃, zone 4 180℃, zone 5 180℃, zone 6 180℃, die head 180℃, screw speed 40 / rpm, to ensure that each component is fully mixed and melted and then extruded smoothly. The extrusion port is the sheet die port (width 50mm×thickness 2mm), and a continuous sheet sample of about 50mm width and 2mm thickness is obtained.

[0032] Step 4: Cut a sheet sample of 500 mm long, 20 mm wide and 2 mm thick, lay it flat on the conveyor belt of the electron beam irradiation device, and use an electron accelerator to perform electron beam irradiation cross-linking modification. Set the electron beam energy to 2 MeV, the beam current to 30 mA, and the irradiation dose to 100 kGy. Start the electron accelerator to ensure that each sheet is evenly irradiated on both sides for 3 seconds. Example

[0033] Step 1: Preparation of isocyanate-terminated liquid polyether resin prepolymer: Weigh 21 parts of polyether polyol and 5 parts of hexamethylene diisocyanate, mix them according to the molar ratio of polyether polyol (-OH) to isocyanate group (-NCO) in isocyanate at 2:1, and add 0.03 parts of dibutyltin dilaurate. After stirring the above materials evenly at room temperature, transfer them to a dry reaction vessel. The reaction system is heated to 60°C under nitrogen protection to prevent side reactions between moisture in the air and isocyanate. Keep the reaction temperature at 60°C and continue the reaction for 5 hours. After the reaction is completed, cool the material to obtain an isocyanate-terminated liquid polyether resin prepolymer.

[0034] Step 2: Preparation of allyl-terminated modified liquid polyether resin: Add isocyanate-terminated liquid polyether resin prepolymer and triallyl citrate into a reaction vessel, stir and react under nitrogen protection, and control the reaction temperature at 60°C for 6 hours. When the isocyanate group is completely reacted, the reaction is stopped and gradually cooled to room temperature to obtain an allyl-terminated modified liquid polyether resin.

[0035] Step 3: Weigh 50 parts of SEBS YH-504, 35 parts of TPEE Hytrel3078, 10 parts of maleic anhydride grafted SEBS, 10 parts of allyl terminated modified liquid polyether resin, 0.5 parts of curing agent D-230, and 7 parts of epoxidized soybean oil, add them to the high-speed mixer in sequence, and mix them evenly at 1500r / min for 5 minutes at room temperature. Then transfer the mixed material to the twin-screw extruder, set the extruder zone 165℃, zone 2 170℃, zone 3 175℃, zone 4 180℃, zone 5 180℃, zone 6 180℃, die head 180℃, screw speed 40 / rpm, to ensure that each component is fully mixed and melted and extruded smoothly. The extrusion port is the sheet die port (width 50mm×thickness 2mm), and a continuous sheet sample of about 50mm width and 2mm thickness is obtained.

[0036] Step 4: Cut a sheet sample of 500 mm long, 20 mm wide and 2 mm thick, lay it flat on the conveyor belt of the electron beam irradiation device, and use an electron accelerator to perform electron beam irradiation cross-linking modification. Set the electron beam energy to 1 MeV, the beam current to 15 mA, and the irradiation dose to 80 kGy. Start the electron accelerator to ensure that each sheet is evenly irradiated on both sides for 3 seconds.

[0037] Step 1: Weigh 71 parts of SEBS YH-501, 47 parts of TPEE Hytrel3078, 13 parts of maleic anhydride grafted PP, and 6 parts of trioctyl isodecanoate, add them to the high-speed mixer in turn, and mix them evenly at 1500r / min for 5 minutes at room temperature. Then transfer the mixed material to the twin-screw extruder, set the extruder zone 1 to 165℃, zone 2 to 170℃, zone 3 to 175℃, zone 4 to 180℃, zone 5 to 180℃, zone 6 to 180℃, die head to 180℃, screw speed to 40 / rpm, to ensure that all components are fully mixed and melted and then extruded smoothly. The extrusion port is the sheet die port (width 50mm×thickness 2mm), and a continuous sheet sample of about 50mm width and 2mm thickness is obtained. Cut a sheet sample of 500mm length, 20mm width and 2mm thickness.

[0038] Step 2: Cut a sheet sample of 500 mm long, 20 mm wide and 2 mm thick, lay it flat on the conveyor belt of the electron beam irradiation device, and use an electron accelerator to perform electron beam irradiation cross-linking modification. Set the electron beam energy to 3 MeV, the beam current to 40 mA, and the irradiation dose to 150 kGy. Start the electron accelerator to ensure that each sheet is evenly irradiated on both sides for 3 seconds.

[0039] The mechanical properties of the materials obtained in each embodiment and comparative example were tested, and the results are shown in Table 1:

[0040] sample Tensile strength (MPa) Elongation (%) Shore Hardness A Rebound rate (%) Abrasion index (g / 1000r) Slip resistance value (BPN) Example 1 11.74 391 78 41.3 0.29 58 Example 2 10.21 373 74 39.9 0.33 56 Example 3 8.85 357 71 37.4 0.40 54 Example 4 8.37 340 69 36.7 0.46 53 Comparative Example 1 5.83 295 64 29.2 0.87 42 From the data in Table 1, it can be seen that the sample of Example 1 exhibits the highest tensile strength (11.74 MPa) and a higher rebound rate (41.3%), which indicates that the addition of the combination of isocyanate-terminated liquid polyether resin prepolymer and allyl-terminated modified liquid polyether resin significantly improves the tensile properties and rebound properties of the material. This is because the isocyanate group reacts with the hydroxyl group in the polyether polyol, and the resulting cross-linked structure increases the interaction force between the molecular chains, thereby improving the tensile strength. The improvement in rebound rate is related to the flexibility and cross-linking density of the polymer. Through appropriate electron beam irradiation conditions (energy 3 MeV, beam current 40mA, dose 150kGy), the optimal degree of cross-linking can be achieved, and the elastic recovery ability of the material can be enhanced. In contrast, the performance indicators of the sample of Comparative Example 1 are significantly lower than those of Examples 1-4. In particular, the gap in tensile strength (5.83 MPa) and anti-slip value (42BPN) is particularly obvious, indicating that the lack of effective cross-linking modification treatment will lead to a decrease in the mechanical properties of the material and deterioration of the surface friction properties. This further verifies that the use of electron beam irradiation cross-linking modification technology and optimized material ratio can significantly improve the mechanical properties and service life of thermoplastic elastomers, and has high application value.

[0041] This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. Those skilled in the art can modify this embodiment as needed after reading this specification.

Claims

1. A radiation cross-linked modified thermoplastic elastomer, characterized in that: The radiation cross-linked modified thermoplastic elastomer is obtained by cross-linking a semi-finished product by electron beam radiation. The semi-finished product comprises the following components in parts by weight: 50~80 parts of styrene thermoplastic elastomer, 30~50 parts of thermoplastic polyester elastomer, 10-15 parts of maleic anhydride grafted polymer, 10~15 parts of allyl-terminated modified liquid polyether resin, 0.5~1 part of amino-terminated polyether curing agent, 5~10 parts of plasticizer.

2. The radiation cross-linked modified thermoplastic elastomer according to claim 1, characterized in that: The styrene-based thermoplastic elastomer is one of SEBS YH-501, SEBS YH-502, SEBS YH-504 and SEBS YH-602.

3. The radiation cross-linked modified thermoplastic elastomer according to claim 1, characterized in that: The thermoplastic polyester elastomer is one of the polyether-type TPEE Hytrel3078 and TPEE Riteflex640.

4. The radiation cross-linked modified thermoplastic elastomer according to claim 1, characterized in that: The maleic anhydride grafted polymer is one of maleic anhydride grafted PP, maleic anhydride grafted POE or maleic anhydride grafted SEBS.

5. The radiation cross-linked modified thermoplastic elastomer according to claim 1, characterized in that: The allyl-terminated modified liquid polyether resin is obtained by reacting an isocyanate-terminated liquid polyether resin prepolymer obtained by reacting a liquid polyether polyol with isocyanate and then reacting with triallyl citrate.

6. The radiation cross-linked modified thermoplastic elastomer according to claim 5, characterized in that: The liquid polyether polyol is one of polytetrahydrofuran diol or polyethylene glycol.

7. The radiation cross-linked modified thermoplastic elastomer according to claim 1, characterized in that: The amino-terminated polyether curing agent is one of D-230 and D-400.

8. The radiation cross-linked modified thermoplastic elastomer according to claim 1, characterized in that: The plasticizer is one of di(2-ethylhexyl) phosphate, palmitate, tri(2-ethylhexyl) citrate or epoxidized soybean oil.

9. The method for preparing the radiation cross-linked modified thermoplastic elastomer according to any one of claims 1 to 8, characterized in that: The steps include: (1) Preparation of isocyanate-terminated liquid polyether resin prepolymer: add 5-8 parts of hexamethylene diisocyanate to 20-30 parts of liquid polyether polyol, control the molar ratio of -OH in the liquid polyether polyol to -NCO in the isocyanate to be 2:1, add 0.03-0.04 parts of an organic tin catalyst, mix well, react at 50°C-70°C for 3-5 hours under inert gas protection, and obtain an isocyanate-terminated liquid polyether resin prepolymer; preferably, the organic tin catalyst is one of stannous octoate or dibutyltin dilaurate; (2) Preparation of allyl-terminated modified liquid polyether resin: reacting the isocyanate-terminated liquid polyether resin prepolymer obtained in step (1) with triallyl citrate, and reacting at 60° C. to 80° C. for 4 to 6 hours under inert gas protection to obtain an allyl-terminated modified liquid polyether resin; (3) uniformly mixing a styrene-based thermoplastic elastomer, a thermoplastic polyester elastomer, a maleic anhydride grafted polymer, the allyl-terminated modified liquid polyether resin obtained in step (2), an amino-terminated polyether curing agent and a plasticizer, and melt-blending and extruding the mixture at 160-190° C. to obtain a semi-finished product; (4) The semi-finished product is cross-linked by electron beam irradiation to obtain the product.

10. The preparation method according to claim 9, characterized in that: The electron beam irradiation cross-linking is performed using an electron accelerator, the electron beam energy is 1Mev~4Mev, the beam current is 10mA~50mA, and the irradiation dose is 40kGy~200kGy.