High and low temperature resistant and anti-aging composite PVC material for charging pile

Abstract

The invention discloses a high and low temperature resistant and anti-aging composite PVC material for a charging pile, belongs to the technical field of composite materials, and aims to solve the technical problem that the high and low temperature resistance and flame retardance of a composite PVC material in the prior art need to be further improved. The modified polyvinyl chloride comprises the following raw materials in parts by weight: 100-120 parts of modified polyvinyl chloride, 20-30 parts of a modified filler and 13-26 parts of an auxiliary additive, hybrid polyvinyl chloride chain segments and polysiloxane chain segments in the modified polyvinyl chloride prepared by the invention cooperate with the modified filler to significantly enhance the flame retardant property of the material, and a large number of polysiloxane chain segment structures in the modified polyvinyl chloride enable the modified polyvinyl chloride to have high molecular flexibility, so that the modified polyvinyl chloride does not generate brittle fracture at low temperature, and the service life of the modified polyvinyl chloride is prolonged. Good flexibility and anti-cracking performance are maintained, meanwhile, the material is not prone to fracture or decomposition in a high-temperature environment, and the high and low temperature aging resistance of the material is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and particularly to a composite PVC material with high and low temperature resistance and anti-aging for charging piles. Background Art

[0002] The composite PVC materials for charging piles have seen significant development in terms of high and low temperature resistance and flame retardancy. Traditional PVC is prone to softening at high temperatures and brittle cracking at low temperatures, making it difficult to meet the requirements of extreme outdoor environments. By introducing low-temperature plasticizers and heat stabilizers, the temperature resistance range of modified PVC has been increased to -30°C - 90°C, which solves the temperature adaptability problem to a certain extent, but there are still limitations in extreme environments. The latest composite PVC materials use polysiloxane modification and nano-filler reinforcement technologies, enabling them to withstand 150°C at high temperatures and remain flexible below -40°C at low temperatures. In addition, by adding halogen-free flame retardants, the material meets the V-0 grade flame retardancy standard, effectively suppressing combustion and smoke release, and further improving the safety of charging piles.

[0003] For example, the prior art CN114921036B discloses a polyvinyl chloride alloy elastomer polymer with high and low temperature resistance and its preparation method. The polyvinyl chloride alloy elastomer polymer includes the following components in parts by weight: 100 parts of polyvinyl chloride resin, 70 - 90 parts of plasticizer, 5 - 15 parts of stabilizer, 15 - 25 parts of flame retardant, 0.5 - 1.0 part of lubricant, 0.5 - 1.0 part of antioxidant, 20 - 60 parts of toughening agent, 0.2 - 0.8 part of ultraviolet absorber, and 1 - 5 parts of processing aid. In the implementation process of the present invention, a high-polymerization-degree polyvinyl chloride resin and a medium-polymerization-degree polyvinyl chloride resin are mixed. The two resins can cooperate synergistically and be mixed with specific plasticizers, toughening agents, and processing aids, so that the resulting composite material has excellent mechanical properties, good high and low temperature resistance, and excellent weather resistance.

[0004] However, the above patent enhances its high and low temperature resistance and flame retardancy through high-polymerization-degree polyvinyl chloride resin and medium-polymerization-degree polyvinyl chloride resin, and by modifying with processing aids. However, only by using the closely arranged molecular chain structure of high-polymerization-degree polyvinyl chloride resin and coordinating with auxiliary agents such as toughening agents, the high and low temperature resistance of the material is enhanced. The high-polymerization-degree polyvinyl chloride resin has high rigidity, resulting in reduced flexibility of the molecular chain, restricting the mobility of chain segments at low temperatures, making the high-polymerized polyvinyl chloride prone to brittle cracking at low temperatures, showing poor low-temperature brittleness, and the high and low temperature resistance of the material needs to be further improved.

[0005] Moreover, the chlorine group density of polyvinyl chloride molecules with high degree of polymerization is too high, which is prone to thermal decomposition during combustion, releasing hydrogen chloride gas, weakening the carbon skeleton structure of polyvinyl chloride, causing it to further crack and coke, and ultimately promoting the further combustion of the material, resulting in the need to further improve the flame retardancy of the material.

[0006] In view of the technical deficiencies in this regard, a solution is proposed now. Summary of the Invention

[0007] The purpose of the present invention is to provide a composite PVC material for charging piles with high and low temperature resistance and anti-aging properties, which is used to solve the technical problems that the high and low temperature resistance and flame retardancy of the existing composite PVC materials need to be further improved.

[0008] The purpose of the present invention can be achieved through the following technical solutions: A composite PVC material for charging piles with high and low temperature resistance and anti-aging properties, comprising the following raw materials in parts by weight: 100-120 parts of modified polyvinyl chloride, 20-30 parts of modified filler, and 13-26 parts of auxiliary additive;

[0009] The auxiliary additive comprises the following raw materials in parts by weight: 5-10 parts of plasticizer, 1-2 parts of antioxidant, 1-2 parts of light stabilizer, 5-10 parts of heat stabilizer, and 1-2 parts of lubricant.

[0010] Furthermore, the plasticizer is one or both of dioctyl phthalate and dioctyl adipate; the antioxidant is one or both of tris(2,4-di-tert-butylphenyl) phosphate and cetyl 3,5-di-tert-butyl-4-hydroxybenzoate; the light stabilizer is one or both of 2-hydroxy-4-octyloxybenzophenone and bis(2,2,6,6-tetramethylpiperidyl) sebacate; the heat stabilizer is one or more of tribasic lead sulfate, calcium stearate, and dibutyltin dilaurate; the lubricant is one or both of calcium stearate and montan wax.

[0011] Furthermore, the preparation method of the modified polyvinyl chloride is as follows: Add hybrid polyvinyl chloride and N,N-dimethylacetamide into a reaction kettle, raise the temperature of the reaction kettle to 70-80 °C, keep warm and stir for 10-15 minutes, then add a modifier into the reaction kettle, continue to keep warm and stir at 40-60 °C, and perform post-treatment to obtain modified polyvinyl chloride.

[0012] The reaction principle for preparing the modified polyvinyl chloride is as follows: Under the catalysis of alkaline conditions and high temperature, the epoxy group structure on the hybrid polyvinyl chloride undergoes a ring-opening reaction to form a hydroxyl structure, which reacts with the silicon hydroxyl group at the end of the hydroxyl silicone oil to form a cross-linked structure, and finally the modified polyvinyl chloride is prepared.

[0013] Further, the stirring rate of the reaction kettle is 60 - 80 rpm, and the dosage ratio of hybrid polyvinyl chloride, N,N - dimethylacetamide and the modifier is 8 - 10 g:50 - 60 mL:20 - 30 mL. Among them, the modifier is obtained by mixing triethylamine, hydroxy silicone oil and N,N - dimethylacetamide according to the dosage ratio of 2 - 3 g:8 - 10 mL:40 - 60 mL. The post - treatment includes: after the reaction kettle is cooled to room temperature, the reaction solution is added into a rotary evaporator with a water bath temperature of 80 - 100 °C, and vacuum distillation is carried out until no liquid is collected, obtaining modified polyvinyl chloride.

[0014] Further, the preparation method of hybrid polyvinyl chloride is as follows:

[0015] A1. Add polyvinyl chloride powder and N,N - dimethylacetamide into the reaction kettle. Raise the temperature of the reaction kettle to 70 - 80 °C, keep stirring for 1 - 2 h, then add the ammoniating solution dropwise into the reaction kettle, and continue to keep stirring for 3 - 4 h to obtain ammoniated polyvinyl chloride.

[0016] A2. Add ammoniated polyvinyl chloride, triethoxysilyl butyraldehyde, aluminum chloride and N,N - dimethylacetamide into a three - necked flask and stir. Heat the three - necked flask to 60 - 80 °C, keep stirring for 20 - 30 min, then add 2β - acetyl - 3α - methyloxirane into the reaction kettle, continue to keep stirring for 40 - 60 min, and obtain hybrid polyvinyl chloride through post - treatment.

[0017] The reaction equation for preparing hybrid polyvinyl chloride is:

[0018]

[0019] In the formula: “*” represents the active connection site of the organic chain segment.

[0020] The reaction principle for preparing ammoniated polyvinyl chloride is: under high - temperature conditions, the aminating agent undergoes a cross - linking reaction with some chlorine groups on polyvinyl chloride to form a cross - linked structure with secondary amine as the linking hub. Further, under the catalysis of Lewis acid, triethoxysilyl butyraldehyde is protonated, and the secondary amino group attacks the carbonyl carbon of triethoxysilyl butyraldehyde to form an unstable imine structure. Under acidic conditions, the α - hydrogen of 2β - acetyl - 3α - methyloxirane is deprotonated to form an unstable enol or enolate structure, which then attacks the imine structure, and finally hybrid polyvinyl chloride is prepared.

[0021] Further, in step A1, the stirring rate of the reaction kettle is 60 - 80 rpm, and the dosage ratio of polyvinyl chloride powder, N,N-dimethylacetamide, and ammoniating solution is 6 - 8 g:50 mL:10 mL. Among them, the ammoniating solution is obtained by mixing triethylenetetramine and N,N-dimethylacetamide according to the dosage ratio of 8 - 10 g:100 mL. After the reaction kettle is cooled to room temperature, the reaction solution is added into a rotary evaporator with a water bath temperature of 80 - 100 °C, and vacuum distillation is carried out until no liquid is collected, obtaining ammoniated polyvinyl chloride;

[0022] Further, in step A2, the stirring rate of the reaction kettle is 60 - 80 rpm, and the dosage ratio of ammoniated polyvinyl chloride, triethoxysilyl butyraldehyde, aluminum chloride, N,N-dimethylacetamide, and 2β-acetyl-3α-methylepoxyethane is 20 - 24 g:2 - 3 g:0.5 - 0.6 g:100 - 120 mL:1 - 1.6 g. The post-treatment includes: after the reaction kettle is cooled to room temperature, the reaction solution is added into a rotary evaporator with a water bath temperature of 80 - 100 °C, and vacuum distillation is carried out until no liquid is collected, obtaining hybrid polyvinyl chloride.

[0023] Further, the preparation method of the modified filler is as follows: Add the composite particles and dimethyl sulfoxide into the reaction kettle and stir for 5 - 8 min. Then, lower the temperature of the reaction kettle to 0 - 5 °C, and while maintaining the state of heat preservation and stirring, add the oxidizing solution dropwise into the reaction kettle. The dropping operation lasts for 3 - 4 h. After the dropping is completed, stir for 1 h under heat preservation, and then perform post-treatment to obtain the modified filler.

[0024] The reaction principle for preparing the modified filler is: Under the catalysis of Lewis acid, benzoic acid is oxidized by hydrogen peroxide to form peroxybenzoic acid, which oxidizes the double bond groups on the surface of the composite filler to form epoxy groups, thereby preparing the modified filler.

[0025] Further, the stirring rate of the reaction kettle is 60 - 80 rpm, and the dosage ratio of the composite particles, dimethyl sulfoxide, and oxidizing solution is 15 - 20 g:60 - 80 mL:10 - 15 mL. The oxidizing solution is obtained by mixing benzoic acid, aluminum chloride, and saturated hydrogen peroxide solution according to the dosage ratio of 4 - 6 g:0.5 - 0.8 g:10 - 15 mL. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake with anhydrous ethanol and deionized water 3 - 5 times, then transfer the filter cake to a drying oven at 60 °C, and vacuum dry to constant weight to obtain the modified filler.

[0026] Further, the preparation method of the composite particles includes the following steps:

[0027] B1. Add nano-magnesium oxide and tartaric acid aqueous solution into the reaction kettle, raise the temperature of the reaction kettle to 40 - 60 °C, keep stirring for 30 - 40 min under heat preservation, and then perform post-treatment to obtain modified particles;

[0028] B2. Add the modified particles and ethanol into a reaction kettle. After stirring at room temperature for 5 - 8 min, raise the temperature of the reaction kettle to 30 - 40 °C, and add the modification solution into the reaction kettle. Keep stirring for 8 - 12 h under insulation, and then perform post-treatment to obtain the composite particle precursor;

[0029] B3. Add the composite particle precursor and 5 - 6 wt% sodium hydroxide aqueous solution into a reaction kettle and stir. Raise the temperature of the reaction kettle to 60 - 80 °C. After keeping the temperature for reaction for 30 - 40 min, add 3-(methacryloyloxy)propyltrimethoxysilane dropwise into the reaction kettle, and continue to stir under insulation for 1 - 2 h. Then perform post-treatment to obtain the composite particles.

[0030] The reaction principle for preparing the composite particles is as follows: Under the modification of tartaric acid, an acidic structure is formed on the surface of nano-magnesium oxide, enhancing the adhesion of the silica coating layer formed by the hydrolysis of tetraethyl orthosilicate on its surface. Through hydrolysis and coating, an organic chain segment modification structure is finally formed on the surface of the magnesium oxide structure through the modification of the silane coupling agent, and finally the composite particles are prepared.

[0031] Further, in step B1, the dosage ratio of nano-magnesium oxide to the tartaric acid aqueous solution is 2 - 3 g:10 mL, and the concentration of the tartaric acid aqueous solution is 0.02 - 0.04 mol / L; The post-treatment includes: After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 3 - 5 times with absolute ethanol and deionized water, then transfer the filter cake to a drying oven at 60 °C, and dry it under vacuum until constant weight to obtain the modified particles;

[0032] Further, in step B2, the dosage ratio of the modified particles, ethanol and the modification solution is 5 - 6 g:50 - 60 mL:50 mL. The modification solution is obtained by mixing tetraethyl orthosilicate, ethanol and deionized water according to the dosage ratio of 1 - 2 g:5 mL:20 mL, and adjusting the pH to 8 - 10 under the condition of saturated ammonia water; The post-treatment includes: After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 3 - 5 times with absolute ethanol and deionized water, then transfer the filter cake to a drying oven at 60 °C, and dry it under vacuum until constant weight to obtain the composite particle precursor;

[0033] Further, in step B3, the dosage ratio of the composite particle precursor, 5 - 6 wt% sodium hydroxide aqueous solution and 3-(methacryloyloxy)propyltrimethoxysilane is 4 - 6 g:20 - 24 mL:1 - 2 g. The post-treatment includes: After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 3 - 5 times with absolute ethanol and deionized water, then transfer the filter cake to a drying oven at 60 °C, and dry it under vacuum until constant weight to obtain the composite particles.

[0034] Furthermore, the preparation method of the composite PVC material is as follows: Mix modified polyvinyl chloride, modified filler, modified plasticizer, antioxidant, light stabilizer, heat stabilizer and lubricant evenly, and then add them into a twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 200 °C, 215 °C, 215 °C, 220 °C, 220 °C, 230 °C, 230 °C, and 240 °C in sequence. The main machine speed of the twin-screw extruder is 80 - 120 rpm, and the pressure is 100 - 150 bar. Melt and extrude to obtain the composite PVC material.

[0035] The present invention has the following beneficial effects:

[0036] 1. After ammoniating polyvinyl chloride, the present invention enhances the reaction activity and the compatibility with inorganic fillers by modifying active functional groups. Finally, after cross-linking with hydroxy silicone oil, modified polyvinyl chloride is prepared. The ammoniated structure in the modified polyvinyl chloride hybridizes the organic chain segments of polyvinyl chloride, enhancing its wear resistance and tensile resistance. During the combustion process, ammonia gas is released, which neutralizes the hydrogen chloride gas released during the combustion of the polyvinyl chloride chain segments, thereby reducing the damage to the human body during the combustion of the charging pile, and reducing the fire extinguishing risk and difficulty. Moreover, the cross-linked polysiloxane chain segment structure will also decompose to produce a flame retardant layer during the combustion process, further slowing down the spread of the flame. The large number of polysiloxane chain segment structures in the modified polyvinyl chloride endow the modification with high molecular flexibility, enabling it not to undergo brittle fracture at low temperatures, thus maintaining good flexibility and crack resistance. At the same time, it is not easily broken or decomposed in a high-temperature environment, thereby significantly improving the high and low temperature aging resistance of the material.

[0037] 2. The present invention also coats a silica layer on the surface of the magnesium oxide material and modifies it with a silane coupling agent. Finally, through oxyacid oxidation, a surface with a large number of epoxy group structures is obtained. The surface modification of the silica layer inhibits the agglomeration of the magnesium oxide material and enhances the compatibility between the modified filler and the organic matrix. During the processing of polyvinyl chloride, the free radicals generated by pyrolysis react with the epoxy groups modified on the surface of silica, so that the modified filler is evenly and stably dispersed in the material. Finally, the wear resistance and tensile resistance of the material are significantly enhanced. During the combustion process, the surface of the magnesium oxide structure provides active sites to combine with the free radicals generated by the degradation of the polyvinyl chloride material, inhibiting the degradation reaction and thus suppressing combustion. Moreover, the porous structure and hydrophilicity of the silica layer enable water to form a water layer on the surface of the modified filler during the fire extinguishing process, promoting the dissolution of hydrogen chloride gas and making it easier for magnesium oxide to neutralize hydrogen chloride gas, thereby reducing the damage to the human body during the combustion of the charging pile and reducing the fire extinguishing risk and difficulty. Specific Embodiments

[0038] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] The hydroxyl-terminated dimethyl silicone used in the present invention is purchased from Shandong Longhui Chemical Co., Ltd., and the product name is hydroxyl silicone oil.

[0040] The 2β-acetyl-3α-methyloxirane used in the present invention is purchased from Tanmo Quality Inspection Technology Co., Ltd., and the product name is 2β-Acetyl-3α-methyloxirane, and the cas number is 17257-79-3.

[0041] Example 1

[0042] This example provides a preparation method of hybrid polyvinyl chloride for a high and low temperature resistant and anti-aging composite PVC material for charging piles, including the following steps:

[0043] Step ①, prepare ammoniated polyvinyl chloride

[0044] Weigh: 800.0 g of triethylenetetramine and 10000.0 mL of N,N-dimethylacetamide are mixed to obtain an ammoniating solution.

[0045] Weigh: 600.0 g of polyvinyl chloride powder and 5000.0 mL of N,N-dimethylacetamide are added to the reaction kettle. The temperature of the reaction kettle is raised to 70 °C, and the reaction kettle is kept stirring at a stirring rate of 60 rpm for 1 h. Then, 1000.0 mL of the ammoniating solution is added dropwise to the reaction kettle, and stirring is continued for 3 h while keeping the temperature. After the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80 °C, and vacuum distillation is carried out until no liquid is collected, obtaining ammoniated polyvinyl chloride.

[0046] Step ②, prepare hybrid polyvinyl chloride

[0047] Weigh: 2000.0 g of ammoniated polyvinyl chloride, 200.0 g of triethoxysilyl butyraldehyde, 50.0 g of aluminum chloride and 10000.0 mL of N,N-dimethylacetamide are added to a three-necked flask and stirred. The three-necked flask is heated to 60 °C, and the reaction kettle is kept stirring at a stirring rate of 60 rpm for 20 min. Then, 100.0 g of 2β-acetyl-3α-methyloxirane is added to the reaction kettle, and stirring is continued for 40 min while keeping the temperature. After the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80 °C, and vacuum distillation is carried out until no liquid is collected, obtaining hybrid polyvinyl chloride.

[0048] Example 2

[0049] This embodiment provides a preparation method of hybrid polyvinyl chloride for a high and low temperature resistant and anti-aging composite PVC material for charging piles, including the following steps:

[0050] Step ①, prepare ammoniated polyvinyl chloride

[0051] Weigh: 1000.0 g of triethylenetetramine and 10000.0 mL of N,N-dimethylacetamide are mixed to obtain an ammoniating solution;

[0052] Weigh: 800.0 g of polyvinyl chloride powder and 5000.0 mL of N,N-dimethylacetamide are added to a reaction kettle. The temperature of the reaction kettle is raised to 80 °C. After the reaction kettle is kept warm and stirred at a stirring rate of 80 rpm for 2 h, 1000.0 mL of the ammoniating solution is added dropwise to the reaction kettle, and stirring is continued while keeping warm for 4 h. After the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 100 °C, and vacuum distillation is carried out until no liquid is collected, obtaining ammoniated polyvinyl chloride.

[0053] Step ②, prepare hybrid polyvinyl chloride

[0054] Weigh: 2400.0 g of ammoniated polyvinyl chloride, 300.0 g of triethoxysilyl butyraldehyde, 60.0 g of aluminum chloride and 12000.0 mL of N,N-dimethylacetamide are added to a three-necked flask and stirred. The three-necked flask is heated to 80 °C. After the reaction kettle is kept warm and stirred at a stirring rate of 80 rpm for 30 min, 160.0 g of 2β-acetyl-3α-methylepoxyethane is added to the reaction kettle, and stirring is continued while keeping warm for 60 min. After the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 100 °C, and vacuum distillation is carried out until no liquid is collected, obtaining hybrid polyvinyl chloride.

[0055] Example 3

[0056] This embodiment provides a preparation method of hybrid polyvinyl chloride for a high and low temperature resistant and anti-aging composite PVC material for charging piles, including the following steps:

[0057] Step ①, prepare ammoniated polyvinyl chloride

[0058] Weigh: 900.0 g of triethylenetetramine and 10000.0 mL of N,N-dimethylacetamide are mixed to obtain an ammoniating solution;

[0059] Weigh: 700.0 g of polyvinyl chloride powder and 5000.0 mL of N,N-dimethylacetamide are added to a reaction kettle. The temperature of the reaction kettle is raised to 75 °C. After the reaction kettle is kept stirring at a stirring rate of 70 rpm for 2 h, 1000.0 mL of ammoniating solution is added dropwise to the reaction kettle, and stirring is continued while keeping warm for 4 h. After the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 90 °C, and vacuum distillation is carried out until no liquid is collected, obtaining ammoniated polyvinyl chloride.

[0060] Step ②, Preparation of hybrid polyvinyl chloride

[0061] Weigh: 2100.0 g of ammoniated polyvinyl chloride, 250.0 g of triethoxysilyl butyraldehyde, 55.0 g of aluminum chloride and 10000.0 mL of N,N-dimethylacetamide are added to a three-necked flask and stirred. The three-necked flask is heated to 70 °C. After the reaction kettle is kept stirring at a stirring rate of 70 rpm for 24 min, 120.0 g of 2β-acetyl-3α-methyloxirane is added to the reaction kettle, and stirring is continued while keeping warm for 50 min. After the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 90 °C, and vacuum distillation is carried out until no liquid is collected, obtaining hybrid polyvinyl chloride.

[0062] Example 4

[0063] This example provides a preparation method of modified polyvinyl chloride for a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0064] Weigh: 200.0 g of triethylamine, 800.0 mL of hydroxy silicone oil and 4000.0 mL of N,N-dimethylacetamide are mixed to obtain a modifier;

[0065] Weigh: 800.0 g of the hybrid polyvinyl chloride prepared in Example 1 and 5000.0 mL of N,N-dimethylacetamide are added to a reaction kettle. The temperature of the reaction kettle is raised to 70 °C. After the reaction kettle is kept stirring at a stirring rate of 60 rpm for 10 min, 2000.0 mL of the modifier is added to the reaction kettle, and stirring is continued while keeping warm at 40 °C. After the reaction kettle is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80 °C, and vacuum distillation is carried out until no liquid is collected, obtaining modified polyvinyl chloride.

[0066] Example 5

[0067] This example provides a preparation method of modified polyvinyl chloride for a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0068] Weigh: 300.0 g of triethylamine, 1000.0 mL of hydroxy silicone oil and 6000.0 mL of N,N-dimethylacetamide are mixed to obtain a modifier;

[0069] Weigh: 1000.0 g of the hybrid polyvinyl chloride prepared in Example 2 and 6000.0 mL of N,N-dimethylacetamide were added to a reaction kettle. The temperature of the reaction kettle was raised to 80 °C. After the reaction kettle was kept stirring at a stirring rate of 80 rpm for 15 min, 3000.0 mL of a modifier was added to the reaction kettle, and stirring was continued while maintaining the temperature at 60 °C. After the reaction kettle was cooled to room temperature, the reaction solution was added to a rotary evaporator with a water bath temperature of 100 °C, and vacuum distillation was carried out until no liquid was collected, obtaining modified polyvinyl chloride.

[0070] Example 6

[0071] This example provides a method for preparing modified polyvinyl chloride for a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0072] Weigh: 250.0 g of triethylamine, 900.0 mL of hydroxyl silicone oil and 5000.0 mL of N,N-dimethylacetamide were mixed to obtain a modifier;

[0073] Weigh: 900.0 g of the hybrid polyvinyl chloride prepared in Example 3 and 5400.0 mL of N,N-dimethylacetamide were added to a reaction kettle. The temperature of the reaction kettle was raised to 75 °C. After the reaction kettle was kept stirring at a stirring rate of 70 rpm for 12 min, 2500.0 mL of the modifier was added to the reaction kettle, and stirring was continued while maintaining the temperature at 50 °C. After the reaction kettle was cooled to room temperature, the reaction solution was added to a rotary evaporator with a water bath temperature of 90 °C, and vacuum distillation was carried out until no liquid was collected, obtaining modified polyvinyl chloride.

[0074] Example 7

[0075] This example provides a method for preparing modified filler for a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0076] Step I. Prepare modified microparticles

[0077] Weigh: 200.0 g of nano-magnesium oxide and 1000.0 mL of 0.02 mol / L tartaric acid aqueous solution were added to a reaction kettle. The temperature of the reaction kettle was raised to 40 °C, and stirring was carried out while maintaining the temperature for 30 min. After the reaction was completed, when the temperature of the reaction kettle was lowered to room temperature, the reaction solution was filtered by suction to collect the filter cake. After the filter cake was washed 3 times with absolute ethanol and deionized water, the filter cake was transferred to a drying oven at 60 °C and vacuum dried to constant weight, obtaining modified microparticles.

[0078] Step II. Prepare composite microparticle precursors

[0079] Weigh: 100.0 g of tetraethyl orthosilicate, 500.0 mL of ethanol and 2000.0 mL of deionized water were mixed, and the pH was adjusted to 8 using saturated ammonia water to obtain a modified solution;

[0080] Weigh: 500.0 g of modified microparticles and 5000.0 mL of ethanol are added to the reaction kettle. After stirring at room temperature for 5 min, the temperature of the reaction kettle is raised to 30 °C, and 5000.0 mL of modifier solution is added to the reaction kettle. Keep the temperature and stir for 8 h, and then perform post-treatment to obtain the composite microparticle precursor.

[0081] Step III: Prepare composite microparticles

[0082] Weigh: 400.0 g of composite microparticle precursor and 2000.0 mL of 5 wt% sodium hydroxide aqueous solution are added to the reaction kettle and stirred. The temperature of the reaction kettle is raised to 60 °C. After keeping the temperature and reacting for 30 min, 100.0 g of 3-(methacryloyloxy)propyltrimethoxysilane is added dropwise to the reaction kettle, and continue to keep the temperature and stir for 1 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake 3 times with absolute ethanol and deionized water, then transfer the filter cake to a drying oven at 60 °C, and vacuum dry to constant weight to obtain the composite microparticles.

[0083] Step IV: Prepare modified filler

[0084] Weigh: 400.0 g of benzoic acid, 50.0 g of aluminum chloride and 1000.0 mL of saturated hydrogen peroxide solution are mixed to obtain the oxidation solution;

[0085] Weigh: 1500.0 g of composite microparticles and 6000.0 mL of dimethyl sulfoxide are added to the reaction kettle. After the reaction kettle is stirred at a stirring rate of 60 rpm for 5 min, the temperature of the reaction kettle is lowered to 0 °C. While maintaining the temperature and stirring, 1000.0 mL of the oxidation solution is added dropwise to the reaction kettle. The dropping operation lasts for 3 h. After the dropping is completed, keep the temperature and stir for 1 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake 3 times with absolute ethanol and deionized water, then transfer the filter cake to a drying oven at 60 °C, and vacuum dry to constant weight to obtain the modified filler.

[0086] Example 8

[0087] This example provides a preparation method of a modified filler for a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0088] Step I: Prepare modified microparticles

[0089] Weigh: 300.0 g of nano-magnesium oxide and 1000.0 mL of 0.04 mol / L tartaric acid aqueous solution are added to a reaction kettle. The temperature of the reaction kettle is raised to 60 °C, and it is kept warm and stirred for 40 min. After the reaction is completed, when the temperature of the reaction kettle drops to room temperature, the reaction solution is filtered by suction to collect the filter cake. After washing the filter cake 5 times with absolute ethanol and deionized water, the filter cake is transferred to a drying oven at 60 °C and vacuum dried to a constant weight to obtain modified particles.

[0090] Step II: Preparation of composite particle precursor

[0091] Weigh: After mixing 200.0 g of tetraethyl orthosilicate, 500.0 mL of ethanol and 2000.0 mL of deionized water, adjust the pH to 10 with saturated ammonia water to obtain a modification solution.

[0092] Weigh: 600.0 g of modified particles and 6000.0 mL of ethanol are added to a reaction kettle. After stirring at room temperature for 8 min, the temperature of the reaction kettle is raised to 40 °C, and 5000.0 mL of the modification solution is added to the reaction kettle. It is kept warm and stirred for 12 h, and then post-treated to obtain a composite particle precursor.

[0093] Step III: Preparation of composite particles

[0094] Weigh: 600.0 g of the composite particle precursor and 2400.0 mL of 6 wt% sodium hydroxide aqueous solution are added to a reaction kettle and stirred. The temperature of the reaction kettle is raised to 80 °C. After keeping warm and reacting for 40 min, 200.0 g of 3-(methacryloyloxy)propyltrimethoxysilane is added dropwise to the reaction kettle, and it is continuously kept warm and stirred for 2 h. After the reaction is completed, when the temperature of the reaction kettle drops to room temperature, the reaction solution is filtered by suction to collect the filter cake. After washing the filter cake 5 times with absolute ethanol and deionized water, the filter cake is transferred to a drying oven at 60 °C and vacuum dried to a constant weight to obtain composite particles.

[0095] Step IV: Preparation of modified filler

[0096] Weigh: Mix 600.0 g of benzoic acid, 80.0 g of aluminum chloride and 1500.0 mL of saturated hydrogen peroxide solution to obtain an oxidation solution.

[0097] Weigh: 2000.0 g of composite particles and 8000.0 mL of dimethyl sulfoxide are added to a reaction kettle. After the reaction kettle is stirred at a stirring rate of 80 rpm for 8 min, the temperature of the reaction kettle is lowered to 5 °C. While maintaining the state of stirring and keeping warm, 1500.0 mL of the oxidation solution is added dropwise to the reaction kettle. The dropping operation is maintained for 4 h. After the dropping is completed, it is stirred and kept warm for 1 h. After the reaction is completed, when the temperature of the reaction kettle drops to room temperature, the reaction solution is filtered by suction to collect the filter cake. After washing the filter cake 5 times with absolute ethanol and deionized water, the filter cake is transferred to a drying oven at 60 °C and vacuum dried to a constant weight to obtain modified filler.

[0098] Example 9

[0099] This example provides a preparation method of a modified filler for a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0100] Step Ⅰ: Preparation of modified microparticles

[0101] Weigh: 250.0 g of nano-magnesium oxide and 1000.0 mL of 0.03 mol / L tartaric acid aqueous solution are added to the reaction kettle, the temperature of the reaction kettle is raised to 50 °C, and it is kept warm and stirred for 36 min. After the reaction is completed, when the temperature of the reaction kettle drops to room temperature, the reaction solution is filtered to collect the filter cake. After washing the filter cake 4 times with absolute ethanol and deionized water, the filter cake is transferred to a drying oven at 60 °C and vacuum dried to constant weight to obtain modified microparticles.

[0102] Step Ⅱ: Preparation of composite microparticle precursors

[0103] Weigh: After mixing 150.0 g of tetraethyl orthosilicate, 500.0 mL of ethanol and 2000.0 mL of deionized water, the modifier solution is obtained by adjusting the pH to 9 under the condition of saturated ammonia water;

[0104] Weigh: 540.0 g of modified microparticles and 5500.0 mL of ethanol are added to the reaction kettle. After stirring at room temperature for 6 min, the temperature of the reaction kettle is raised to 36 °C, and 5000.0 mL of the modifier solution is added to the reaction kettle. It is kept warm and stirred for 10 h, and the composite microparticle precursors are obtained after post-treatment.

[0105] Step Ⅲ: Preparation of composite microparticles

[0106] Weigh: 500.0 g of composite microparticle precursors and 2100.0 mL of 6 wt% sodium hydroxide aqueous solution are added to the reaction kettle and stirred. The temperature of the reaction kettle is raised to 70 °C. After keeping warm and reacting for 36 min, 160.0 g of 3-(methacryloyloxy)propyltrimethoxysilane is added dropwise to the reaction kettle, and it is continuously kept warm and stirred for 2 h. After the reaction is completed, when the temperature of the reaction kettle drops to room temperature, the reaction solution is filtered to collect the filter cake. After washing the filter cake 4 times with absolute ethanol and deionized water, the filter cake is transferred to a drying oven at 60 °C and vacuum dried to constant weight to obtain composite microparticles.

[0107] Step Ⅳ: Preparation of modified filler

[0108] Weigh: 500.0 g of benzoic acid, 72.0 g of aluminum chloride and 1200.0 mL of saturated hydrogen peroxide solution are mixed to obtain an oxidation solution;

[0109] Weigh: 1800.0 g of composite particles and 7200.0 mL of dimethyl sulfoxide are added to the reaction kettle. After the reaction kettle is stirred at a stirring rate of 70 rpm for 6 min, the temperature of the reaction kettle is reduced to 3 °C. While maintaining the state of heat preservation and stirring, 1200.0 mL of oxidation liquid is added dropwise to the reaction kettle. The dropping operation is maintained for 3 h. After the dropping is completed, it is stirred under heat preservation for 1 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature. Filter the reaction solution by suction to collect the filter cake. After washing the filter cake 4 times with absolute ethanol and deionized water, transfer the filter cake to a drying oven at 60 °C and vacuum dry it to constant weight to obtain the modified filler.

[0110] Example 10

[0111] This example provides a preparation method of a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0112] Weigh: 10000.0 g of the modified polyvinyl chloride prepared in Example 4, 2000.0 g of the modified filler prepared in Example 7, 500.0 g of dioctyl phthalate, 100.0 g of tris(2,4-di-tert-butylphenyl) phosphate, 100.0 g of 2-hydroxy-4-octyloxybenzophenone, 500.0 g of calcium stearate and 100.0 g of montan wax are mixed evenly and then added to a twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 170 °C, 185 °C, 185 °C, 190 °C, 190 °C, 200 °C, 200 °C, and 210 °C in sequence. The main machine speed of the twin-screw extruder is 80 rpm, the pressure is 100 bar, and the composite PVC material is obtained by melt extrusion.

[0113] Example 11

[0114] This example provides a preparation method of a composite PVC material with high and low temperature resistance and anti-aging for charging piles, including the following steps:

[0115] Weigh: 15000.0 g of the modified polyvinyl chloride prepared in Example 5, 3000.0 g of the modified filler prepared in Example 8, 1000.0 g of dioctyl phthalate, 200.0 g of tris(2,4-di-tert-butylphenyl) phosphate, 200.0 g of 2-hydroxy-4-octyloxybenzophenone, 1000.0 g of calcium stearate and 200.0 g of montan wax are mixed evenly and then added to a twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 170 °C, 185 °C, 185 °C, 190 °C, 190 °C, 200 °C, 200 °C, and 210 °C in sequence. The main machine speed of the twin-screw extruder is 120 rpm, the pressure is 150 bar, and the composite PVC material is obtained by melt extrusion.

[0116] Example 12

[0117] This embodiment provides a preparation method of a high and low temperature resistant and anti-aging composite PVC material for charging piles, including the following steps:

[0118] Weigh: 11000.0 g of the modified polyvinyl chloride prepared in Example 6, 2400.0 g of the modified filler prepared in Example 9, 800.0 g of dioctyl phthalate, 160.0 g of tris(2,4-di-tert-butylphenyl) phosphate, 160.0 g of 2-hydroxy-4-octyloxybenzophenone, 800.0 g of calcium stearate, and 160.0 g of montan wax. After mixing evenly, add them to a twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 170 °C, 185 °C, 185 °C, 190 °C, 190 °C, 200 °C, 200 °C, and 210 °C in sequence. The main machine speed of the twin-screw extruder is 100 rpm, and the pressure is 120 bar. Melt extrusion is carried out to obtain the composite PVC material.

[0119] Comparative Example 1

[0120] The difference between this embodiment and Comparative Example 12 is that the use of modified polyvinyl chloride is cancelled, and the hybrid polyvinyl chloride prepared in Example 3 is used to replace the modified polyvinyl chloride in equal amount.

[0121] Comparative Example 3

[0122] The difference between this embodiment and Comparative Example 12 is that the use of modified polyvinyl chloride is cancelled, and the polyvinyl chloride powder of Example 3 is used to replace the modified polyvinyl chloride in equal amount.

[0123] Comparative Example 3

[0124] The difference between this embodiment and Comparative Example 12 is that the use of modified filler is cancelled, and nano-silica is used to replace the modified filler in equal amount.

[0125] Performance test:

[0126] Refer to the standard GB / T 2408-2021 "Plastics - Determination of flammability - Horizontal and vertical methods" to test the vertical burning grade of the composite PVC materials prepared in Examples 10 - 12 and Comparative Examples 1 - 3;

[0127] Refer to the standard GB / T 528-2009 "Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties" to test the tensile strength of the composite PVC materials prepared in Examples 10 - 12 and Comparative Examples 1 - 3;

[0128] Refer to the standard GB / T 9867-2008 "Rubber, vulcanized or thermoplastic - Determination of abrasion resistance (rotary roller type abrader method)" to test the volume abrasion of the composite PVC materials prepared in Examples 10 - 12 and Comparative Examples 1 - 3;

[0129] Referring to the standard GB / T 7141-2008 "Test Method for Thermal Aging of Plastics", the composite PVC materials prepared in Examples 10-12 and Comparative Examples 1-3 were placed in an incubator at a temperature of 150 °C for heat preservation treatment for 500 h. Then, referring to the standard GB / T 2951.14-2008 "General Test Methods for Insulating and Sheathing Materials of Cables and Optical Fibre Cables - Part 14: General Test Methods - Low Temperature Tests", after the composite PVC materials prepared in Examples 10-12 and Comparative Examples 1-3 were subjected to low temperature treatment at -50 °C for 16 h, referring to the standard GB / T 528-2009, the tensile strength of the materials was measured, the tensile strength retention rate was calculated, and referring to the standard GB / T 9867-2008, the change rate of the volume abrasion amount of the materials was calculated. The specific data are shown in Table 1.

[0130] Table 1 - Performance Test Data Sheet of Each Specimen

[0131]

[0132] Data Analysis:

[0133] By comparing and analyzing the data in Table 1 above, the vertical burning grade of the composite PVC material prepared in the present invention is V-0, the tensile strength is 57.6 MPa, and the volume wear amount is 28.5 mm 3 and the change rate of the volume wear amount after high and low temperature treatment is 102.8%, while the tensile strength retention rate is 98.3%;

[0134] It shows that after ammoniating polyvinyl chloride in the present invention, by modifying the active functional groups, the reaction activity and the compatibility with inorganic fillers are enhanced. Finally, after crosslinking with hydroxy silicone oil, modified polyvinyl chloride is finally prepared. The ammoniated structure in the modified polyvinyl chloride hybridizes the organic chain segments of polyvinyl chloride, enhancing its wear resistance and tensile resistance. In addition, ammonia gas is released during the combustion process, thereby neutralizing the hydrogen chloride gas released by the polyvinyl chloride chain segments during the combustion process, thus reducing the damage to the human body during the combustion of the charging pile, reducing the fire extinguishing risk and difficulty. And the crosslinked polysiloxane chain segment structure will also decompose to generate a flame retardant layer during the combustion process, further slowing down the spread of the flame; a large number of polysiloxane chain segment structures in the modified polyvinyl chloride endow the modification with high molecular flexibility, enabling it not to undergo brittle fracture at low temperatures, thus maintaining good flexibility and crack resistance, while not being easily broken or decomposed in a high temperature environment, thus significantly improving the high and low temperature aging resistance of the material;

[0135] It is explained that in the present invention, a silica layer is coated on the surface of the magnesium oxide material and modified with a silane coupling agent. Finally, through oxyacid oxidation, a large number of epoxy group structures are formed on the surface. The surface modification of the silica layer inhibits the agglomeration of the magnesium oxide material, enhances the compatibility between the modified filler and the organic matrix. During the processing of polyvinyl chloride, free radicals generated by pyrolysis react with the epoxy groups modified on the silica surface, so that the modified filler is evenly and stably dispersed in the material, ultimately significantly enhancing the wear resistance and tensile properties of the material. During the combustion process, the surface of the magnesium oxide structure provides active sites to combine with the free radicals generated by the degradation of the polyvinyl chloride material, inhibiting the degradation reaction and thus suppressing combustion. Moreover, the porous structure and hydrophilicity of the silica layer enable water to form a water layer on the surface of the modified filler during the fire extinguishing process, promoting the dissolution of hydrogen chloride gas, making it easier for magnesium oxide to neutralize hydrogen chloride gas, thereby reducing the harm to the human body during the combustion of the charging pile, and reducing the fire extinguishing risk and difficulty.

[0136] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation manners. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A high and low temperature resistant and anti-aging composite PVC material for a charging pile, characterized in that: The invention comprises the following raw materials in parts by weight: 100-120 parts of modified polyvinyl chloride, 20-30 parts of modified filler and 13-26 parts of auxiliary additives; The auxiliary additive comprises the following raw materials in parts by weight: 5-10 parts of modified plasticizer, 1-2 parts of antioxidant, 1-2 parts of light stabilizer, 5-10 parts of heat stabilizer and 1-2 parts of lubricant.

2. The high-low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 1, characterized in that: The preparation method of the modified polyvinyl chloride is as follows: hybrid polyvinyl chloride and N,N-dimethylacetamide are added into a reaction kettle, the temperature of the reaction kettle is increased to 70-80°C, and the reaction kettle is stirred for 10-15 minutes, then a modifier is added into the reaction kettle, and the stirring is continued at 40-60°C, and the modified polyvinyl chloride is obtained by post-treatment.

3. The high and low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 2, characterized in that: The dosage ratio of hybrid polyvinyl chloride, N,N-dimethylacetamide and modifier is 8-10g:50-60mL:20-30mL, wherein the modifier is obtained by mixing triethylamine, hydroxy silicone oil and N,N-dimethylacetamide in a dosage ratio of 2-3g:8-10mL:40-60mL.

4. The high and low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 1, characterized in that: The preparation method of the hybrid polyvinyl chloride is: A1. Add polyvinyl chloride powder and N,N-dimethylacetamide into a reactor, raise the temperature of the reactor to 70-80°C, keep warm and stir for 1-2 hours, then drop ammoniated liquid into the reactor, continue to keep warm and stir for 3-4 hours to obtain aminated polyvinyl chloride; A2. Add ammoniated polyvinyl chloride, triethoxysilyl butyraldehyde, aluminum chloride and N,N-dimethylacetamide into a three-necked flask and stir. Heat the three-necked flask to 60-80°C. Keep warm and stir for 20-30 minutes. Add 2β-acetyl-3α-methyl oxirane into the reactor. Keep warm and stir for 40-60 minutes. Post-treat to obtain hybrid polyvinyl chloride.

5. The high and low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 4, characterized in that: In step A1, the amount ratio of polyvinyl chloride powder, N,N-dimethylacetamide and ammoniated liquid is 6-8g:50mL:10mL, wherein the ammoniated liquid is obtained by mixing triethylenetetramine and N,N-dimethylacetamide in an amount ratio of 8-10g:100mL; in step A2, the amount ratio of ammoniated polyvinyl chloride, triethoxysilylbutyraldehyde, aluminum chloride, N,N-dimethylacetamide and 2β-acetyl-3α-methylethylene oxide is 20-24g:2-3g:0.5-0.6g:100-120mL:1-1.6g.

6. The high-low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 1, characterized in that: The preparation method of the modified filler is as follows: after adding composite particles and dimethyl sulfoxide into a reactor and stirring for 5-8 minutes, the temperature of the reactor is reduced to 0-5°C, and an oxidizing liquid is added dropwise into the reactor under heat preservation and stirring, and the dropping operation is maintained for 3-4 hours. After the dropping is completed, the reaction mixture is kept warm and stirred for 1 hour, and the modified filler is obtained by post-processing.

7. The high and low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 6, characterized in that: The usage ratio of the composite particles, dimethyl sulfoxide and the oxidizing solution is 15-20 g: 60-80 mL: 10-15 mL, and the oxidizing solution is obtained by mixing benzoic acid, aluminum chloride and saturated hydrogen peroxide solution in the usage ratio of 4-6 g: 0.5-0.8 g: 10-15 mL.

8. The high and low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 6, characterized in that: The method for preparing the composite particles comprises the following steps: B1. Add nano magnesium oxide and tartaric acid aqueous solution into a reactor, raise the temperature of the reactor to 40-60°C, keep warm and stir for 30-40 minutes, and post-treat to obtain modified particles; B2, adding the modified microparticles and ethanol into the reactor, stirring at room temperature for 5-8 minutes, raising the temperature of the reactor to 30-40°C, adding the modification liquid into the reactor, keeping the temperature and stirring for 8-12 hours, and post-treating to obtain the composite microparticle precursor; B3. Add the composite particle precursor and 5-6wt% sodium hydroxide aqueous solution into the reactor and stir. Raise the temperature of the reactor to 60-80°C. After keeping warm for 30-40 minutes, add 3-(methacryloyloxy)propyltrimethoxysilane dropwise into the reactor. Continue keeping warm and stirring for 1-2 hours. Post-treat to obtain composite particles.

9. The high-low temperature resistant and anti-aging composite PVC material for a charging pile according to claim 8, characterized in that: In step B1, the dosage ratio of nano-magnesium oxide and tartaric acid aqueous solution is 2-3g:10mL, and the concentration of tartaric acid aqueous solution is 0.02-0.04mol / L; in step B2, the dosage ratio of modified particles, ethanol and modification liquid is 5-6g:50-60mL:50mL, and the modification liquid is a mixture of ethyl orthosilicate, ethanol and deionized water in a dosage ratio of 1-2g:5mL:20mL, and saturated ammonia water is used to adjust the pH to 8-10 to obtain; In step B3, the usage ratio of the composite particle precursor, 5-6 wt % sodium hydroxide aqueous solution and 3-(methacryloyloxy)propyltrimethoxysilane is 4-6 g:20-24 mL:1-2 g.

Images