Wear-resistant thermoplastic elastomer and preparation method thereof

Abstract

The invention relates to a wear-resistant thermoplastic elastomer and a preparation method thereof. The wear-resistant thermoplastic elastomer is prepared from the following raw materials in parts by mass: 80 to 120 parts of thermoplastic polyurethane, 10 to 30 parts of fluorine-treated mesoporous silicon dioxide, 1 to 3 parts of graphene oxide, 1 to 2 parts of silane coupling agent, 5 to 15 parts of SEBS copolymer, 5 to 15 parts of flexibilizer, 1 to 5 parts of compatilizer, 5 to 15 parts of ammonium polyphosphate, 1 to 5 parts of calcium pyrophosphate whisker, 1 to 2 parts of melamine cyanurate and 1 to 3 parts of calcium stearate. 1-2 parts of an ultraviolet light absorber, 1-2 parts of a light stabilizer, 1-2 parts of an antioxidant and 1-2 parts of a heat-resistant agent. The mechanical property of the thermoplastic elastomer material can be remarkably improved, the thermoplastic elastomer material has good flexibility and elastic property, the flame retardant property of the material is remarkably improved, and the toughness and wear resistance of the material are further enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of cable sheaths, and particularly relates to a wear-resistant thermoplastic elastomer and a preparation method thereof. Background Art

[0002] As the core protective layer of the cable structure, the cable sheath undertakes the key mission of resisting the erosion of the external environment and ensuring the long-term stable operation of the cable. Under complex working conditions, the sheath material needs to meet multiple performance requirements such as mechanical protection, weather resistance, and chemical stability.

[0003] Currently, the global industrial field has shown a significant growth trend in the demand for special cables. For the wires and cables used in some harsh environments, the outer sheaths of the cables are often abraded and damaged, and finally the entire cable is scrapped. The main reason is that the cable outer sheath is not wear-resistant, or not wear-resistant at high temperatures. Cables such as those used in frequently moving equipment, marine cables, drag chain cables, mining cables, and oilfield pumping unit cables all need to select cable sheath materials with high wear resistance.

[0004] Although traditional rubber-based sheaths have good elasticity, they are prone to failure phenomena such as surface cracking and material peeling under long-term friction conditions. Although wear-resistant materials represented by polyurethane can reduce the wear rate, their flexibility is poor at low temperatures; while the inorganic filler modification technology can improve wear resistance, but too high a filler load will lead to a decrease in the fracture ability of the material, seriously affecting the bending life of the cable.

[0005] With the current improvement in the requirements for equipment reliability, developing a cable sheath material that does not affect the mechanical properties of the cable sheath and can improve its wear resistance has excellent research prospects. Summary of the Invention

[0006] The purpose of the present invention is to solve the deficiencies in the prior art and propose a wear-resistant thermoplastic elastomer and a preparation method thereof.

[0007] A wear-resistant thermoplastic elastomer, the raw materials of which by mass include: 80 - 120 parts of thermoplastic polyurethane, 10 - 30 parts of fluorine-treated mesoporous silica, 1 - 3 parts of graphene oxide, 1 - 2 parts of silane coupling agent, 5 - 15 parts of SEBS copolymer, 5 - 15 parts of toughening agent, 1 - 5 parts of compatibilizer, 5 - 15 parts of ammonium polyphosphate, 1 - 5 parts of calcium pyrophosphate whiskers, 1 - 2 parts of melamine cyanurate, 1 - 3 parts of calcium stearate, 1 - 2 parts of ultraviolet absorber, 1 - 2 parts of light stabilizer, 1 - 2 parts of antioxidant, and 1 - 2 parts of heat-resistant agent.

[0008] Preferably, the hardness of the thermoplastic polyurethane is 65 - 85A.

[0009] Preferably, the styrene content of the SEBS copolymer is 30 - 40%.

[0010] Preferably, the toughening agent is methyl methacrylate-butadiene-styrene copolymer.

[0011] Preferably, the compatibilizer is maleic anhydride grafted SEBS.

[0012] Preferably, the ultraviolet absorber is ultraviolet absorber UV-329.

[0013] Preferably, the light stabilizer includes: light stabilizer 944 or / and light stabilizer 622.

[0014] Preferably, the heat-resistant agent is N-phenyl maleimide.

[0015] Preferably, the antioxidant includes: antioxidant 1010 or / and antioxidant 168.

[0016] Preferably, the fluorine-treated mesoporous silica is prepared by the following steps: adding mesoporous silica and perfluoroalkyltrimethoxysilane into an ethanol aqueous solution, ultrasonically treating for 1-2 h, filtering, washing, and vacuum drying.

[0017] More preferably, the mass ratio of mesoporous silica to perfluoroalkyltrimethoxysilane is 5-15:1-2.

[0018] The preparation method of the above-mentioned wear-resistant thermoplastic elastomer includes the following steps: S1. Mix thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, silane coupling agent, ultraviolet absorber, light stabilizer, antioxidant, and heat-resistant agent evenly, and carry out internal mixing at 160-180 °C for 5-15 min to obtain premix a; S2. Mix ammonium polyphosphate, calcium pyrophosphate whisker, melamine cyanurate, and calcium stearate evenly, extrude, granulate, and vacuum dry to obtain a composite flame retardant; mix SEBS copolymer, toughening agent, compatibilizer, and composite flame retardant to obtain premix b; S3. Mix premix a and premix b evenly, extrude and mold, and dry.

[0019] The above-mentioned wear-resistant thermoplastic elastomer is used for cable sheaths.

[0020] Beneficial effects: The present invention utilizes mesoporous silica treated with organofluorine to significantly reduce its surface energy. It not only has good dispersibility with thermoplastic polyurethane, but also the fluorocarbon chains interact with the hard segments of thermoplastic polyurethane and effectively reduce the aggregation of hard segments through steric hindrance. Combined with the action of silane coupling agent, it can enhance the interfacial bonding force, form a stable reinforcing network, jointly hinder crack propagation, and has excellent wear resistance. Further combined with the action of graphene oxide, a barrier layer is formed through lamellar stacking. At the same time, it can improve the material's ability to resist crack propagation, and further cooperate with the hydrophobic effect of the fluorocarbon chain layer to jointly achieve waterproof performance.

[0021] The present invention uses ammonium polyphosphate and calcium pyrophosphate compounded under the action of calcium stearate. Calcium pyrophosphate acts as a heterogeneous nucleating agent during the decomposition of ammonium polyphosphate to promote the densification of the expanded carbon layer. Calcium stearate can accelerate the crystallization of the carbon layer and reduce the porosity, with a significant flame retardant effect. Melamine cyanurate decomposes upon heating to release inert gases, diluting the concentration of combustible gases, and synergistically blocking the transfer of heat and oxygen with the carbon layer.

[0022] The present invention uses thermoplastic polyurethane and SEBS copolymer compounded, and with the action of toughening agent and compatibilizer, it can significantly improve the mechanical properties of thermoplastic elastomer materials, making them have good flexibility and elastic properties. Combined with the action of composite flame retardant, it significantly improves the flame retardant performance of the materials, and can reduce the addition amount of flame retardant, further enhancing the toughness and wear resistance of the materials. Description of the Drawings

[0023] Figure 1 It is a comparison chart of the tensile strength and tear strength of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2.

[0024] Figure 2 It is a comparison chart of the volume wear rate and oxygen index of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2.

[0025] Figure 3 It is a comparison chart of the tensile strength change rate and smoke density of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2. Detailed Description of the Invention

[0026] The present invention will be further illustrated below with specific examples.

[0027] The thermoplastic polyurethane used below is from Covestro, with the brand name Desmopan® 9370AU. The SEBS copolymer used below is from Yueyang Petrochemical, with the brand name YH-503T. The methyl methacrylate-butadiene-styrene copolymer used below is from Nippon Zeon, with the brand name M-210. The maleic anhydride-grafted SEBS used below is from Kraton, with the brand name FG1901GT and a grafting rate of 1.5%.

[0028] Example 1 A wear-resistant thermoplastic elastomer, the raw materials of which include: 80 g of thermoplastic polyurethane, 10 g of fluorine-treated mesoporous silica, 1 g of graphene oxide, 1 g of KH550 coupling agent, 5 g of SEBS copolymer, 5 g of methyl methacrylate-butadiene-styrene copolymer, 1 g of maleic anhydride-grafted SEBS, 5 g of ammonium polyphosphate, 1 g of calcium pyrophosphate whiskers, 1 g of melamine cyanurate, 1 g of calcium stearate, 1 g of ultraviolet absorber UV-329, 0.5 g of light stabilizer 944, 0.5 g of light stabilizer 622, 1 g of antioxidant 168, and 1 g of N-phenylmaleimide.

[0029] The fluorine-treated mesoporous silica is prepared by the following steps: adding 5 g of mesoporous silica and 1 g of perfluoroalkyltrimethoxysilane to 40 g of an ethanol aqueous solution with a mass fraction of 40%, ultrasonically treating for 1 h, with an ultrasonic frequency of 40 kHz, filtering, washing, and vacuum drying.

[0030] The preparation method of the above wear-resistant thermoplastic elastomer includes the following steps: S1. Mix thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, KH550 coupling agent, ultraviolet absorber UV-329, light stabilizer 944, light stabilizer 622, antioxidant 168, and N-phenylmaleimide evenly, and knead them in a two-roll open mill at a temperature of 160 °C for 5 min to obtain a premix a; S2. Mix ammonium polyphosphate, calcium pyrophosphate whiskers, melamine cyanurate, and calcium stearate evenly, feed them into a twin-screw extruder for extrusion, pelletize, and vacuum dry at a temperature of 80 °C to obtain a composite flame retardant; mix SEBS copolymer, methyl methacrylate-butadiene-styrene copolymer, maleic anhydride-grafted SEBS, and the composite flame retardant, and stir at a speed of 500 r / min for 5 min to obtain a premix b; S3. Mix premix a and premix b evenly, feed them into a twin-screw extruder for extrusion molding, where the length-diameter ratio is 45:1, the extrusion temperature is 200 °C, the rotation speed is 200 r / min, and dry.

[0031] Example 2 A wear-resistant thermoplastic elastomer, the raw materials of which include: 120 g of thermoplastic polyurethane, 30 g of fluorine-treated mesoporous silica, 3 g of graphene oxide, 2 g of KH550 coupling agent, 15 g of SEBS copolymer, 15 g of methyl methacrylate-butadiene-styrene copolymer, 5 g of maleic anhydride-grafted SEBS, 15 g of ammonium polyphosphate, 5 g of calcium pyrophosphate whiskers, 2 g of melamine cyanurate, 3 g of calcium stearate, 2 g of ultraviolet absorber UV-329, 0.5 g of light stabilizer 944, 1.5 g of light stabilizer 622, 2 g of antioxidant 168, and 2 g of N-phenylmaleimide.

[0032] The fluorine-treated mesoporous silica is prepared by the following steps: 15 g of mesoporous silica and 2 g of perfluoroalkyltrimethoxysilane are added to 60 g of an ethanol aqueous solution with a mass fraction of 60%, and ultrasonic treatment is carried out for 2 h at an ultrasonic frequency of 70 kHz, followed by filtration, washing, and vacuum drying.

[0033] The preparation method of the above-mentioned wear-resistant thermoplastic elastomer includes the following steps: S1. Thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, KH550 coupling agent, ultraviolet absorber UV-329, light stabilizer 944, light stabilizer 622, antioxidant 168, and N-phenylmaleimide are mixed evenly, and kneaded in a two-roll mill at a temperature of 180 °C for 15 min to obtain a premix a; S2. Ammonium polyphosphate, calcium pyrophosphate whiskers, melamine cyanurate, and calcium stearate are mixed evenly, fed into a twin-screw extruder for extrusion, granulated, and vacuum dried at a temperature of 100 °C to obtain a composite flame retardant; SEBS copolymer, methyl methacrylate-butadiene-styrene copolymer, maleic anhydride-grafted SEBS, and the composite flame retardant are mixed and stirred at a speed of 800 r / min for 15 min to obtain a premix b; S3. The premix a and the premix b are mixed evenly, fed into a twin-screw extruder for extrusion molding, where the length-diameter ratio is 50:1, the extrusion temperature is 210 °C, the rotation speed is 300 r / min, and then dried.

[0034] Example 3 A wear-resistant thermoplastic elastomer, the raw materials of which include: 90 g of thermoplastic polyurethane, 25 g of fluorine-treated mesoporous silica, 1.5 g of graphene oxide, 1.8 g of KH550 coupling agent, 8 g of SEBS copolymer, 12 g of methyl methacrylate-butadiene-styrene copolymer, 2 g of maleic anhydride-grafted SEBS, 12 g of ammonium polyphosphate, 2 g of calcium pyrophosphate whiskers, 1.7 g of melamine cyanurate, 1.5 g of calcium stearate, 1.7 g of ultraviolet absorber UV-329, 1.2 g of light stabilizer 622, 1.8 g of antioxidant 168, and 1.2 g of N-phenylmaleimide.

[0035] The fluorine-treated mesoporous silica is prepared by the following steps: 12 g of mesoporous silica and 1.2 g of perfluoroalkyltrimethoxysilane are added to 55 g of an ethanol aqueous solution with a mass fraction of 45%, and ultrasonic treatment is carried out for 100 min at an ultrasonic frequency of 50 kHz, followed by filtration, washing, and vacuum drying.

[0036] The preparation method of the above-mentioned wear-resistant thermoplastic elastomer includes the following steps: S1. Mix thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, KH550 coupling agent, ultraviolet absorber UV-329, light stabilizer 622, antioxidant 168, and N-phenyl maleimide evenly, and knead them in a two-roll mill at 175 °C for 8 min to obtain premix a; S2. Mix ammonium polyphosphate, calcium pyrophosphate whiskers, melamine cyanurate, and calcium stearate evenly, feed them into a twin-screw extruder for extrusion and granulation, and dry them in a vacuum at 95 °C to obtain a composite flame retardant; Mix SEBS copolymer, methyl methacrylate-butadiene-styrene copolymer, maleic anhydride-grafted SEBS, and the composite flame retardant, and stir them at a speed of 600 r / min for 12 min to obtain premix b; S3. Mix premix a and premix b evenly, feed them into a twin-screw extruder for extrusion molding, with a length-diameter ratio of 47:1, an extrusion temperature of 208 °C, a rotation speed of 220 r / min, and dry them.

[0037] Example 4 A wear-resistant thermoplastic elastomer, whose raw materials include: 110 g of thermoplastic polyurethane, 15 g of fluorine-treated mesoporous silica, 2.5 g of graphene oxide, 1.2 g of KH550 coupling agent, 12 g of SEBS copolymer, 8 g of methyl methacrylate-butadiene-styrene copolymer, 4 g of maleic anhydride-grafted SEBS, 8 g of ammonium polyphosphate, 4 g of calcium pyrophosphate whiskers, 1.3 g of melamine cyanurate, 2.5 g of calcium stearate, 1.3 g of ultraviolet absorber UV-329, 1.8 g of light stabilizer 622, 1.2 g of antioxidant 1010, and 1.8 g of N-phenyl maleimide.

[0038] The fluorine-treated mesoporous silica is prepared by the following steps: Add 8 g of mesoporous silica and 1.8 g of perfluoroalkyltrimethoxysilane to 45 g of an ethanol aqueous solution with a mass fraction of 55%, ultrasonically treat it for 80 min, with an ultrasonic frequency of 60 kHz, filter, wash, and dry it in a vacuum.

[0039] The preparation method of the above wear-resistant thermoplastic elastomer includes the following steps: S1. Mix thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, KH550 coupling agent, ultraviolet absorber UV-329, light stabilizer 622, antioxidant 1010, and N-phenyl maleimide evenly, and knead them in a two-roll mill at 165 °C for 12 min to obtain premix a; S2. Mix ammonium polyphosphate, calcium pyrophosphate whiskers, melamine cyanurate, and calcium stearate evenly, feed them into a twin-screw extruder for extrusion, granulation, and vacuum drying at 85 °C to obtain a composite flame retardant; mix the SEBS copolymer, methyl methacrylate-butadiene-styrene copolymer, maleic anhydride-grafted SEBS, and the composite flame retardant, and stir at a speed of 700 r / min for 8 min to obtain premix b; S3. Mix premix a and premix b evenly, feed them into a twin-screw extruder for extrusion molding, with a length-to-diameter ratio of 49:1, an extrusion temperature of 202 °C, a rotation speed of 280 r / min, and dry.

[0040] Example 5 A wear-resistant thermoplastic elastomer, the raw materials of which include: 100 g of thermoplastic polyurethane, 20 g of fluorine-treated mesoporous silica, 2 g of graphene oxide, 1.5 g of KH550 coupling agent, 10 g of SEBS copolymer, 10 g of methyl methacrylate-butadiene-styrene copolymer, 3 g of maleic anhydride-grafted SEBS, 10 g of ammonium polyphosphate, 3 g of calcium pyrophosphate whiskers, 1.5 g of melamine cyanurate, 2 g of calcium stearate, 1.5 g of ultraviolet absorber UV-329, 1.5 g of light stabilizer 944, 1.5 g of antioxidant 1010, and 1.5 g of N-phenylmaleimide.

[0041] The fluorine-treated mesoporous silica is prepared by the following steps: Add 10 g of mesoporous silica and 1.5 g of perfluoroalkyltrimethoxysilane to 50 g of an ethanol aqueous solution with a mass fraction of 50% for ultrasonic treatment for 90 min, with an ultrasonic frequency of 55 kHz, filter, wash, and vacuum dry.

[0042] The preparation method of the above-mentioned wear-resistant thermoplastic elastomer includes the following steps: S1. Mix thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, KH550 coupling agent, ultraviolet absorber UV-329, light stabilizer 944, antioxidant 1010, and N-phenylmaleimide evenly, and knead them in a two-roll mill at 170 °C for 10 min to obtain premix a; S2. Mix ammonium polyphosphate, calcium pyrophosphate whiskers, melamine cyanurate, and calcium stearate evenly, feed them into a twin-screw extruder for extrusion, granulation, and vacuum drying at 90 °C to obtain a composite flame retardant; mix the SEBS copolymer, methyl methacrylate-butadiene-styrene copolymer, maleic anhydride-grafted SEBS, and the composite flame retardant, and stir at a speed of 650 r / min for 10 min to obtain premix b; S3. Mix premix a and premix b evenly, feed them into a twin-screw extruder for extrusion molding, with a length-to-diameter ratio of 48:1, an extrusion temperature of 205 °C, a rotation speed of 240 r / min, and dry.

[0043] Comparative Example 1 A wear-resistant thermoplastic elastomer, the raw materials of which include: 100 g of thermoplastic polyurethane, 20 g of fluorine-treated mesoporous silica, 2 g of graphene oxide, 1.5 g of KH550 coupling agent, 10 g of SEBS copolymer, 10 g of methyl methacrylate-butadiene-styrene copolymer, 3 g of maleic anhydride grafted SEBS, 10 g of ammonium polyphosphate, 3 g of calcium pyrophosphate whiskers, 1.5 g of melamine cyanurate, 2 g of calcium stearate, 1.5 g of ultraviolet absorber UV-329, 1.5 g of light stabilizer 944, 1.5 g of antioxidant 1010, and 1.5 g of N-phenylmaleimide.

[0044] The fluorine-treated mesoporous silica is prepared by the following steps: Mix 10 g of mesoporous silica and 1.5 g of perfluoroalkyltrimethoxysilane evenly.

[0045] The preparation method of the above wear-resistant thermoplastic elastomer includes the following steps: S1. Mix thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, KH550 coupling agent, ultraviolet absorber UV-329, light stabilizer 944, antioxidant 1010, and N-phenylmaleimide evenly, and knead them for 10 min on a two-roll mill at a temperature of 170 °C to obtain a premix a; S2. Mix ammonium polyphosphate, calcium pyrophosphate whiskers, melamine cyanurate, and calcium stearate evenly, feed them into a twin-screw extruder for extrusion and granulation, and dry them under vacuum at a temperature of 90 °C to obtain a composite flame retardant; Mix SEBS copolymer, methyl methacrylate-butadiene-styrene copolymer, maleic anhydride grafted SEBS, and the composite flame retardant, and stir them at a speed of 650 r / min for 10 min to obtain a premix b; S3. Mix the premix a and the premix b evenly, feed them into a twin-screw extruder for extrusion molding, where the length-diameter ratio is 48:1, the extrusion temperature is 205 °C, the rotation speed is 240 r / min, and then dry.

[0046] Comparative Example 2 A wear-resistant thermoplastic elastomer, the raw materials of which include: 100 g of thermoplastic polyurethane, 20 g of fluorine-treated mesoporous silica, 2 g of graphene oxide, 1.5 g of KH550 coupling agent, 10 g of SEBS copolymer, 10 g of methyl methacrylate-butadiene-styrene copolymer, 3 g of maleic anhydride grafted SEBS, 13 g of ammonium polyphosphate, 1.5 g of melamine cyanurate, 2 g of calcium stearate, 1.5 g of ultraviolet absorber UV-329, 1.5 g of light stabilizer 944, 1.5 g of antioxidant 1010, and 1.5 g of N-phenylmaleimide.

[0047] The fluorine-treated mesoporous silica is prepared by the following steps: 10 g of mesoporous silica and 1.5 g of perfluoroalkyltrimethoxysilane are added to 50 g of an ethanol aqueous solution with a mass fraction of 50%, and ultrasonically treated for 90 min at an ultrasonic frequency of 55 kHz, filtered, washed, and vacuum dried.

[0048] The preparation method of the above wear-resistant thermoplastic elastomer includes the following steps: S1. Thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, KH550 coupling agent, ultraviolet absorber UV-329, light stabilizer 944, antioxidant 1010, and N-phenylmaleimide are mixed evenly, and kneaded in a two-roll mill at a temperature of 170 °C for 10 min to obtain a premix a; S2. Ammonium polyphosphate, melamine cyanurate, and calcium stearate are mixed evenly, fed into a twin-screw extruder for extrusion, granulated, and vacuum dried at a temperature of 90 °C to obtain a composite flame retardant; SEBS copolymer, methyl methacrylate-butadiene-styrene copolymer, maleic anhydride-grafted SEBS, and the composite flame retardant are mixed and stirred at a speed of 650 r / min for 10 min to obtain a premix b; S3. The premix a and the premix b are mixed evenly, fed into a twin-screw extruder for extrusion molding, with a length-to-diameter ratio of 48:1, an extrusion temperature of 205 °C, a rotation speed of 240 r / min, and dried.

[0049] Refer to GB / T 528-2009 "Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties" to measure the tensile strength of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2. Refer to GB / T 529-2008 "Rubber, vulcanized or thermoplastic - Determination of tear strength (trouser, right-angle and crescent test pieces)" to measure the tear strength of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2.

[0050] As Figure 1 shown, the thermoplastic elastomer obtained in Example 5 has the highest tensile strength and tear strength, which is better than those of Comparative Examples 1-2 (P < 0.05).

[0051] Refer to ISO 4649:2024 "Rubber, vulcanized or thermoplastic - Determination of abrasion resistance using a rotating cylinder device" to measure the volume wear rate of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2. Refer to GB / T 2406.2-2009 "Plastics - Determination of burning behavior by oxygen index - Part 2: Ambient temperature test" to measure the oxygen index of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2.

[0052] As Figure 2As shown, the volume wear rate of the thermoplastic elastomer obtained in Example 5 is the smallest, and the oxygen index is the highest, which is superior to Comparative Examples 1-2 (P < 0.05).

[0053] The flame retardant properties of the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2 were determined with reference to the vertical burning method in UL94-2023. The thermoplastic elastomer obtained in Example 5 is of V0 grade, and the thermoplastic elastomers obtained in Comparative Examples 1-2 are both of V1 grade.

[0054] With reference to HG / T 5113-2016 "Styrenic Materials for Thermoplastic Elastomers - Used in Wire and Cable", the thermoplastic elastomers obtained in Example 5 and Comparative Examples 1-2 were subjected to hot water immersion test, heat air aging test and smoke density test, and the change rate of tensile strength was used to characterize the resistance to hot water and heat air aging properties.

[0055] As Figure 3 shown, the change rate of tensile strength of the thermoplastic elastomer obtained in Example 5 is the smallest in the hot water immersion test and heat air aging test, and the smoke density is also the smallest, which is superior to Comparative Examples 1-2 (P < 0.05).

[0056] The reasons for the above results are as follows: In the present invention, mesoporous silica is treated with organofluorine, which significantly reduces its surface energy. It not only has good dispersibility with thermoplastic polyurethane, but also the fluorocarbon chain acts with the hard segment of thermoplastic polyurethane and effectively reduces the aggregation of hard segments through steric hindrance. Together with the action of silane coupling agent, it can enhance the interfacial bonding force and form a stable reinforcing network, jointly hindering the crack propagation, and thus has excellent wear resistance; further combined with the action of graphene oxide, a barrier layer is formed through lamellar stacking, and at the same time it can improve the ability of the material to resist crack propagation, and further cooperate with the hydrophobic action of the fluorocarbon chain layer to jointly achieve the waterproof performance. At the same time, in the present invention, ammonium polyphosphate and calcium pyrophosphate are compounded under the action of calcium stearate. Calcium pyrophosphate acts as a heterogeneous nucleating agent during the decomposition of ammonium polyphosphate to promote the densification of the expanded carbon layer. Calcium stearate can accelerate the crystallization of the carbon layer and reduce the porosity, and the flame retardant effect is significant. Melamine cyanurate decomposes when heated to release inert gases, diluting the concentration of combustible gases, and cooperating with the carbon layer to jointly block the heat and oxygen transfer. And in the present invention, thermoplastic polyurethane and SEBS copolymer are compounded, and together with the action of toughening agent and compatibilizer, the mechanical properties of the thermoplastic elastomer material can be significantly improved, making it have good flexibility and elastic properties. Together with the action of the composite flame retardant, the flame retardant properties of the material are significantly improved, and the addition amount of the flame retardant can be reduced, further enhancing the toughness and wear resistance of the material.

[0057] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitution or change, and all should be covered within the protection scope of the present invention.

Claims

1. A wear-resistant thermoplastic elastomer, characterized in that, Its raw materials by mass parts include: 80 - 120 parts of thermoplastic polyurethane, 10 - 30 parts of fluorine-treated mesoporous silica, 1 - 3 parts of graphene oxide, 1 - 2 parts of silane coupling agent, 5 - 15 parts of SEBS copolymer, 5 - 15 parts of toughening agent, 1 - 5 parts of compatibilizer, 5 - 15 parts of ammonium polyphosphate, 1 - 5 parts of calcium pyrophosphate whiskers, 1 - 2 parts of melamine cyanurate, 1 - 3 parts of calcium stearate, 1 - 2 parts of ultraviolet absorber, 1 - 2 parts of light stabilizer, 1 - 2 parts of antioxidant, and 1 - 2 parts of heat-resistant agent.

2. The wear-resistant thermoplastic elastomer according to claim 1, wherein, The hardness of the thermoplastic polyurethane is 65 - 85A.

3. The wear-resistant thermoplastic elastomer according to claim 1, characterized in that, The styrene content of the SEBS copolymer is 30 - 40%.

4. The wear-resistant thermoplastic elastomer according to claim 1, wherein The toughening agent is methyl methacrylate - butadiene - styrene copolymer; the compatibilizer is maleic anhydride grafted SEBS.

5. The wear-resistant thermoplastic elastomer according to claim 1, characterized in that, The ultraviolet absorber is ultraviolet absorber UV - 329; the light stabilizer includes: light stabilizer 944 or / and light stabilizer 622.

6. The wear-resistant thermoplastic elastomer according to claim 1, wherein The heat-resistant agent is N-phenylmaleimide; the antioxidant includes: antioxidant 1010 or / and antioxidant 168.

7. The wear-resistant thermoplastic elastomer according to claim 1, wherein The fluorine-treated mesoporous silica is prepared by the following steps: adding mesoporous silica and perfluoroalkyltrimethoxysilane into an ethanol aqueous solution, ultrasonic treating for 1 - 2 h, filtering, washing, and vacuum drying.

8. The wear-resistant thermoplastic elastomer according to claim 7, characterized in that, The mass ratio of mesoporous silica to perfluoroalkyltrimethoxysilane is 5 - 15:1 - 2.

9. A method for preparing the wear-resistant thermoplastic elastomer according to any one of claims 1-8, characterized in that, It includes the following steps: S1. Mix thermoplastic polyurethane, fluorine-treated mesoporous silica, graphene oxide, silane coupling agent, ultraviolet absorber, light stabilizer, antioxidant, and heat-resistant agent evenly, and carry out internal mixing at 160 - 180 °C for 5 - 15 min to obtain premix a; S2. Mix ammonium polyphosphate, calcium pyrophosphate whiskers, melamine cyanurate, and calcium stearate evenly, extrude, granulate, and vacuum dry to obtain a composite flame retardant; mix the SEBS copolymer, toughening agent, compatibilizer, and composite flame retardant to obtain premix b; S3. Mix premix a and premix b evenly, extrude and mold, and dry.

10. The wear-resistant thermoplastic elastomer according to any one of claims 1 - 8 is used for a cable sheath.

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