High-temperature-resistant creep-resistant modified polyvinyl fluoride material

Abstract

The invention relates to the technical field of modified polyvinyl fluoride, and discloses a high-temperature-resistant creep-resistant modified polyvinyl fluoride material, which is prepared from the following raw materials in parts by mass: 100 to 120 parts of polyvinyl fluoride, 15 to 20 parts of reinforcing filler, 2 to 5 parts of heat stabilizer, 3 to 5 parts of antioxidant, 1 to 2 parts of coupling agent and 1 to 2 parts of compatilizer. The distance between polyvinyl fluoride molecular chains can be increased through the reinforcing filler, so that the polyvinyl fluoride molecular chains are entangled through the reinforcing filler, mutual slippage between rubber molecular chains is inhibited, and the creep resistance of the polyvinyl fluoride material is improved; the high temperature resistance and creep resistance of the modified polyvinyl fluoride material can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of modified polyvinyl fluoride, in particular to a high-temperature resistant and creep-resistant modified polyvinyl fluoride material. Background Art

[0002] Cables are made of one or more wires twisted together to form a conductor core, mainly composed of a core, an insulation layer, a shielding layer and a sheath layer. They are widely used in various fields of life and production. The function of the cable sheath layer is to seal and protect the cable from the invasion of external impurities and moisture, and to prevent external forces from directly damaging the cable insulation layer. Polyvinyl fluoride material has good chemical corrosion resistance, electrical insulation, mechanical properties and wear resistance, and is widely used in the field of cable sheath materials.

[0003] Polyvinyl fluoride is composed of a long-chain carbon fluoride structure with high crystallinity, no branches, and weak intermolecular forces. This causes the molecular chain of the polyvinyl fluoride material to slip easily when subjected to long-term stress, resulting in poor creep resistance, affecting the use of polyvinyl fluoride materials in cable sheath materials. In addition, the use of polyvinyl fluoride materials in high-temperature environments will aggravate the creep of the polyvinyl fluoride materials, resulting in poor high-temperature resistance of the polyvinyl fluoride materials, limiting the use of polyvinyl fluoride materials in high-temperature environments. Summary of the Invention

[0004] The present invention provides a high-temperature resistant and creep-resistant modified polyvinyl fluoride material, which solves the problem of poor high-temperature resistance and creep resistance of polyvinyl fluoride materials.

[0005] The technical solution of the present invention:

[0006] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by weight: 100-120 parts of polyvinyl fluoride, 15-20 parts of reinforcing filler, 2-5 parts of thermal stabilizer, 3-5 parts of antioxidant, 1-2 parts of coupling agent, and 1-2 parts of compatibilizer;

[0007] Among them, the reinforcing filler is prepared by synthesizing porous carbon on the surface of alumina fiber, loading heat-resistant monomers with tannic acid, and then reacting with terminal hydroxyl polydimethylsiloxane and carboxyl-polyethylene glycol-carboxyl;

[0008] The heat-resistant monomer is synthesized by the reaction of 4,4'-biphenyl ether tetracarboxylic dianhydride, benzene and hydrazine hydrate;

[0009] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0010] The modified polyvinyl fluoride material is obtained by mixing polyvinyl fluoride, reinforcing filler, heat stabilizer, antioxidant, coupling agent and compatibilizer, stirring and mixing at 800-1000 r / min for 3-5 minutes, and extruding and granulating.

[0011] Furthermore, the extrusion is performed using a twin-screw extruder, with an extrusion temperature of 190-200° C., a screw speed of 180-220 rpm, and a time of 2-4 hours.

[0012] Furthermore, the heat stabilizer is selected from any one of calcium zinc stabilizer CZ-116, calcium zinc stabilizer CZ-108, and calcium zinc stabilizer CZ-113.

[0013] Furthermore, the antioxidant is selected from any one of antioxidant 168, antioxidant 565, antioxidant 1024, antioxidant 1010, and antioxidant BHT.

[0014] Furthermore, the coupling agent is selected from a titanate coupling agent or a silane coupling agent; the titanate coupling agent is isopropyl tris(dioctyl pyrophosphate) titanate; and the silane coupling agent is KH550.

[0015] Furthermore, the compatibilizer is maleic anhydride grafted ethylene-vinyl acetate copolymer.

[0016] Furthermore, the reinforcing filler is specifically prepared by the following steps:

[0017] A1. Benzene, anhydrous aluminum chloride, and 4,4'-biphenyl ether tetracarboxylic dianhydride were uniformly mixed and stirred for reaction. The mixture was then placed in deionized water, hydrochloric acid was added, excess benzene was removed by distillation, and the mixture was filtered and dried to obtain an intermediate acid. The intermediate acid, hydrazine hydrate, and ethanol were uniformly mixed and stirred for reaction. After completion of the reaction, the solid was collected by filtration, washed, and dried to obtain a heat-resistant monomer.

[0018] A2. Alumina fibers, glucose, and citric acid were added to ethanol and stirred uniformly. Hydrochloric acid was added and stirred. After the reaction was complete, the mixture was filtered, washed, and dried. The mixture was placed in a tube furnace, potassium hydroxide solution was added, nitrogen was introduced, and carbonization was performed. The mixture was cooled to room temperature, removed, washed, and dried to obtain porous carbon-loaded alumina fibers.

[0019] A3. The heat-resistant monomer and tannic acid were added to deionized water and stirred, and the porous carbon-loaded alumina fiber was added and stirred, filtered, washed, and dried to obtain modified alumina fiber;

[0020] A4. Add hydroxy-terminated polydimethylsiloxane and carboxyl-polyethylene glycol-carboxyl to ethanol, stir evenly, add hydrochloric acid, and after the stirring reaction is complete, add modified alumina fiber, continue stirring the reaction, cool to room temperature, filter, wash, and dry to obtain a reinforcing filler.

[0021] Furthermore, in the above-mentioned reaction process A1, 4,4'-biphenyl ether tetracarboxylic acid and benzene are used as raw materials, and anhydrous aluminum chloride is used as a catalyst, so that 4,4'-biphenyl ether tetracarboxylic acid and benzene react to form an intermediate acid; ethanol is used as a solvent, so that the intermediate acid and hydrazine hydrate undergo a nucleophilic addition reaction to form an anthracene-type diazinone structure-type bisphenol monomer, that is, a heat-resistant monomer.

[0022] The synthesis steps are as follows:

[0023]

[0024] Furthermore, during the above-mentioned A2 reaction process, the large number of hydroxyl groups contained in citric acid can be chemically bonded to the oxygen-containing functional groups contained on the surface of the alumina fiber, and citric acid can also be chemically bonded to glucose, so that glucose adheres to the surface of the alumina fiber through citric acid. After high-temperature carbonization, the glucose decomposes under heat to form a dense carbon layer. Potassium hydroxide solution, as an activator, can form pores on the surface of the dense carbon layer, thereby realizing the synthesis of a porous carbon structure on the surface of the alumina fiber, and obtaining alumina fiber loaded with porous carbon.

[0025] Furthermore, during the above-mentioned A3 reaction process, tannic acid and a heat-resistant monomer are mixed. Tannic acid contains a large number of phenolic hydroxyl groups and has excellent adhesion. The porous carbon contained in the alumina fiber loaded with porous carbon has high adsorption performance and can adsorb tannic acid and a heat-resistant monomer into the pore structure of the porous carbon to obtain modified alumina fiber.

[0026] Furthermore, during the above-mentioned A4 reaction process, the hydroxyl group contained in the terminal hydroxyl polydimethylsiloxane can react with the carboxyl group of the carboxyl-polyethylene glycol-carboxyl group, and the active functional group phenolic hydroxyl group contained on the surface of the modified alumina fiber can participate in the reaction, so that the terminal hydroxyl polydimethylsiloxane and the carboxyl-polyethylene glycol-carboxyl group form a cross-linked network structure coated on the surface of the modified alumina fiber to obtain a reinforcing filler.

[0027] Furthermore, in step A1, the ratio of benzene, anhydrous aluminum chloride and 4,4'-biphenyl ether tetracarboxylic dianhydride is (45-55) mL: (3-3.6) g: (1-2) g.

[0028] Furthermore, in step A1, the ratio of the intermediate acid, hydrazine hydrate and ethanol is (4-4.4) g: (1.6-2) g: (80-120) mL.

[0029] Furthermore, in step A2, the ratio of the amount of alumina fiber, glucose, citric acid, ethanol, hydrochloric acid and potassium hydroxide solution is (4-5) g: (3-3.4) g: (0.5-0.7) g: (80-120) mL: (0.2-0.6) mL: (3-5) mL.

[0030] Furthermore, in step A3, the ratio of the heat-resistant monomer, tannic acid, deionized water and porous carbon-loaded alumina fiber is (2.1-2.5) g: (1-2) g: (70-90) mL: (5-6) g.

[0031] Furthermore, in step A4, the amount ratio of terminal hydroxyl polydimethylsiloxane, carboxyl-polyethylene glycol-carboxyl, ethanol, hydrochloric acid and modified alumina fiber is (2-2.2) g: (1.1-1.5) g: (75-85) mL: (1-2) mL: (5-6) g.

[0032] Furthermore, the diameter of the alumina fiber is 0.1-0.5 μm and the length is 10-20 μm.

[0033] The present invention has the following beneficial effects:

[0034] (1) In the technical solution of the present invention, 4,4'-biphenyl ether tetracarboxylic dianhydride, benzene and hydrazine hydrate are reacted to synthesize a heat-resistant monomer. The diazinone structure contained in the monomer has high rigidity and shows high heat resistance. When added to the polyvinyl fluoride material, the rigidity of the polyvinyl fluoride material is improved, thereby improving the heat resistance of the polyvinyl fluoride material. The benzene ring structure contained in the heat-resistant monomer is dispersed between the polyvinyl fluoride molecular chains, generating entanglement, hindering the slippage of the polyvinyl fluoride molecular chains, thereby improving the creep resistance of the polyvinyl fluoride material.

[0035] (2) In the technical solution of the present invention, a porous carbon structure is synthesized on the surface of alumina fiber. On the one hand, alumina fiber and porous carbon serve as reinforcing fillers, which can improve the high temperature resistance and creep resistance of polyvinyl fluoride materials, and the synthesized porous carbon can form a rough surface on the surface of alumina fiber, thereby increasing the contact area between alumina fiber and polyvinyl fluoride. Its rough structure can form a mechanical interlock with the polyvinyl fluoride molecular chain, hindering the slip of the polyvinyl fluoride molecular chain, thereby improving the creep resistance and high temperature resistance of the polyvinyl fluoride material. On the other hand, alumina fiber has an excellent aspect ratio and is randomly distributed in the polyvinyl fluoride material, further hindering the slip of the polyvinyl fluoride molecular chain, improving the creep resistance, and forming a network structure that can absorb gravity, thereby improving the mechanical properties of the polyvinyl fluoride material.

[0036] (3) In the technical solution of the present invention, the heat-resistant monomer is adsorbed onto the surface of the alumina fiber loaded with porous carbon through tannic acid. On the one hand, the alumina fiber loaded with porous carbon serves as a carrier of the heat-resistant monomer, so that the heat-resistant monomer is evenly dispersed in the polyvinyl fluoride material, thereby improving the high temperature resistance and creep resistance of the polyvinyl fluoride material. On the other hand, tannic acid has good adhesion properties, which further improves the force of the heat-resistant monomer on the surface of the modified alumina fiber, thereby avoiding the migration and precipitation of the heat-resistant monomer. In addition, tannic acid gives the modified alumina fiber a large number of active functional groups, which is beneficial to the formation of an organic silicon coating on the surface of the modified alumina fiber, thereby improving the mechanical properties of the polyvinyl fluoride material.

[0037] (4) In the technical solution of the present invention, end-hydroxy polydimethylsiloxane and carboxyl-polyethylene glycol-carboxyl form an organic silicone cross-linked network structure coated on the surface of the modified alumina fiber. On the one hand, the formed organic silicone cross-linked network structure can improve the impact resistance of the polyvinyl fluoride material, thereby enhancing the mechanical properties of the polyvinyl fluoride material, and the organic silicone cross-linked network structure increases the distance between the polyvinyl fluoride molecular chains, so that the polyvinyl fluoride molecular chains are entangled through the organic silicone cross-linked network structure, inhibiting the mutual slip between the rubber molecular chains, and improving the creep resistance of the polyvinyl fluoride material. On the other hand, the organic silicone cross-linked network structure is coated on the surface of the modified alumina fiber, further increasing the contact area between the reinforcing filler and the polyvinyl fluoride material, so that the reinforcing filler is evenly dispersed in the polyvinyl fluoride material system, enhancing the mechanical properties, high temperature resistance and creep resistance of the polyvinyl fluoride material. DETAILED DESCRIPTION

[0038] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] The raw materials used in the examples of the present invention are as follows, and all reagents used are of analytical grade.

[0040] Among them, polyvinyl fluoride has a density of 1.75g / min 3 , purchased from Pingxiang Zhongtai Environmental Protection Chemical Packing Co., Ltd.

[0041] The heat stabilizer is calcium zinc stabilizer CZ-116, the antioxidant is antioxidant 168, and the coupling agent is isopropyl tris (dioctyl pyrophosphate) titanate.

[0042] The compatibilizer is maleic anhydride grafted ethylene-vinyl acetate copolymer, brand 3861, purchased from Dongguan Shangyi Plastic Co., Ltd.

[0043] The alumina fibers have a diameter of 0.4 μm and a length of 15 μm.

[0044] Example 1

[0045] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by mass: 100 parts of polyvinyl fluoride, 15 parts of reinforcing filler, 2 parts of calcium zinc stabilizer CZ-116, 3 parts of antioxidant 168, 1 part of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and 1 part of maleic anhydride grafted ethylene-vinyl acetate copolymer;

[0046] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0047] The modified polyvinyl fluoride material was obtained by mixing polyvinyl fluoride, reinforcing filler, calcium zinc stabilizer CZ-116, antioxidant 168, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate and maleic anhydride grafted ethylene-vinyl acetate copolymer, stirring and mixing at 800 r / min for 3 minutes, extruding and granulating.

[0048] A twin-screw extruder was used for extrusion, with an extrusion temperature of 190°C, a screw speed of 180 rpm, and a time of 2 h.

[0049] The reinforcing filler is specifically prepared by the following steps:

[0050] A1. Mix 45 mL of benzene, 3 g of anhydrous aluminum chloride, and 1 g of 4,4'-biphenyl ether tetracarboxylic dianhydride. Stir and react at 30°C for 30 minutes. Place the mixture in 100 mL of deionized water at 0°C, add 10 mL of 36% hydrochloric acid, remove excess benzene by distillation, filter, and dry in a vacuum oven at 30°C for 10 minutes to obtain the intermediate acid.

[0051] 4 g of the intermediate acid, 1.6 g of hydrazine hydrate and 80 mL of ethanol were mixed evenly, stirred and reacted at 50°C for 30 min, and the solid was collected by filtration. The solid was washed twice with ethanol and dried in an oven at 80°C for 10 min to obtain a heat-resistant monomer;

[0052] A2. 4 g of alumina fiber, 3 g of glucose, and 0.5 g of citric acid were added to 80 mL of ethanol and stirred. 0.2 mL of 36% hydrochloric acid was added and stirred at 65°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 3 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded alumina fiber.

[0053] A3. 2.1 g of heat-resistant monomer and 1 g of tannic acid were added to 70 mL of deionized water and stirred. 5 g of porous carbon-loaded alumina fibers were added and stirred at 60°C for 10 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified alumina fibers.

[0054] A4. Add 2 g of hydroxy-terminated polydimethylsiloxane and 1.1 g of carboxyl-polyethylene glycol-carboxyl to 75 mL of ethanol and stir well. Add 1 mL of 36% hydrochloric acid and stir at 70°C for 30 minutes. Add 5 g of modified alumina fiber and continue stirring for 30 minutes. Cool to room temperature, filter, wash three times with deionized water, and dry in a 70°C oven for 10 minutes to obtain a reinforcing filler.

[0055] Example 2

[0056] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by mass: 110 parts of polyvinyl fluoride, 18 parts of reinforcing filler, 3 parts of calcium zinc stabilizer CZ-116, 4 parts of antioxidant 168, 1.5 parts of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and 1.5 parts of maleic anhydride grafted ethylene-vinyl acetate copolymer;

[0057] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0058] Polyvinyl fluoride, reinforcing filler, calcium zinc stabilizer CZ-116, antioxidant 168, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate and maleic anhydride grafted ethylene-vinyl acetate copolymer were mixed, stirred at 900 r / min for 4 minutes, extruded and granulated to obtain a modified polyvinyl fluoride material;

[0059] A twin-screw extruder was used for extrusion, with an extrusion temperature of 195°C, a screw speed of 200 rpm, and a time of 3 h.

[0060] The reinforcing filler is specifically prepared by the following steps:

[0061] A1. Mix 50 mL of benzene, 3.3 g of anhydrous aluminum chloride, and 1.5 g of 4,4'-biphenyl ether tetracarboxylic dianhydride. Stir and react at 30°C for 30 minutes. Place in 100 mL of deionized water at 0°C, add 10 mL of 36% hydrochloric acid, remove excess benzene by distillation, filter, and dry in a vacuum oven at 30°C for 10 minutes to obtain the intermediate acid.

[0062] 4.2 g of the intermediate acid, 1.8 g of hydrazine hydrate and 100 mL of ethanol were mixed evenly, stirred and reacted at 50°C for 30 min, and the solid was collected by filtration. The solid was washed twice with ethanol and dried in an oven at 80°C for 10 min to obtain a heat-resistant monomer;

[0063] A2. 4.5 g of alumina fibers, 3.2 g of glucose, and 0.6 g of citric acid were added to 100 mL of ethanol and stirred. 0.4 mL of 36% hydrochloric acid was added and stirred at 65°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was placed in a tube furnace, and 4 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded alumina fibers.

[0064] A3. 2.3 g of heat-resistant monomer and 1.5 g of tannic acid were added to 80 mL of deionized water and stirred. 5.6 g of porous carbon-loaded alumina fibers were added and stirred at 60°C for 10 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified alumina fibers.

[0065] A4. Add 2.1g of hydroxy-terminated polydimethylsiloxane and 1.3g of carboxyl-polyethylene glycol-carboxyl to 80mL of ethanol and stir well. Add 1.5mL of 36% hydrochloric acid and stir at 70°C for 30 minutes. Add 5.5g of modified alumina fiber and continue stirring for 30 minutes. Cool to room temperature, filter, wash three times with deionized water, and dry in a 70°C oven for 10 minutes to obtain a reinforcing filler.

[0066] Example 3

[0067] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by weight: 120 parts of polyvinyl fluoride, 20 parts of reinforcing filler, 5 parts of calcium zinc stabilizer CZ-116, 5 parts of antioxidant 168, 2 parts of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and 2 parts of maleic anhydride grafted ethylene-vinyl acetate copolymer;

[0068] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0069] The modified polyvinyl fluoride material was obtained by mixing polyvinyl fluoride, reinforcing filler, calcium zinc stabilizer CZ-116, antioxidant 168, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate and maleic anhydride grafted ethylene-vinyl acetate copolymer, stirring and mixing at 1000 r / min for 5 minutes, extruding and granulating.

[0070] A twin-screw extruder was used for extrusion, with an extrusion temperature of 200°C, a screw speed of 220 rpm, and a time of 4 h.

[0071] The reinforcing filler is specifically prepared by the following steps:

[0072] A1. Mix 55 mL of benzene, 3.6 g of anhydrous aluminum chloride, and 2 g of 4,4'-biphenyl ether tetracarboxylic dianhydride. Stir and react at 30°C for 30 minutes. Place the mixture in 100 mL of deionized water at 0°C, add 10 mL of 36% hydrochloric acid, remove excess benzene by distillation, filter, and dry in a vacuum oven at 30°C for 10 minutes to obtain the intermediate acid.

[0073] 4.4 g of the intermediate acid, 2 g of hydrazine hydrate and 120 mL of ethanol were mixed evenly, stirred and reacted at 50°C for 30 min, and the solid was collected by filtration. The solid was washed twice with ethanol and dried in an oven at 80°C for 10 min to obtain a heat-resistant monomer;

[0074] A2. 5 g of alumina fibers, 3.4 g of glucose, and 0.7 g of citric acid were added to 120 mL of ethanol and stirred. 0.6 mL of 36% hydrochloric acid was added and stirred at 65°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded alumina fibers.

[0075] A3. 2.5 g of heat-resistant monomer and 2 g of tannic acid were added to 90 mL of deionized water and stirred. 6 g of porous carbon-loaded alumina fibers were added and stirred at 60°C for 10 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified alumina fibers.

[0076] A4. Add 2.2 g of hydroxy-terminated polydimethylsiloxane and 1.5 g of carboxyl-polyethylene glycol-carboxyl to 85 mL of ethanol and stir well. Add 2 mL of 36% hydrochloric acid and stir at 70°C for 30 minutes. Add 6 g of modified alumina fiber and continue stirring for 30 minutes. Cool to room temperature, filter, wash three times with deionized water, and dry in a 70°C oven for 10 minutes to obtain a reinforcing filler.

[0077] Comparative Example 1

[0078] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by weight: 120 parts of polyvinyl fluoride, 20 parts of reinforcing filler, 5 parts of calcium zinc stabilizer CZ-116, 5 parts of antioxidant 168, 2 parts of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and 2 parts of maleic anhydride grafted ethylene-vinyl acetate copolymer;

[0079] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0080] The modified polyvinyl fluoride material was obtained by mixing polyvinyl fluoride, reinforcing filler, calcium zinc stabilizer CZ-116, antioxidant 168, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate and maleic anhydride grafted ethylene-vinyl acetate copolymer, stirring and mixing at 1000 r / min for 5 minutes, extruding and granulating.

[0081] A twin-screw extruder was used for extrusion, with an extrusion temperature of 200°C, a screw speed of 220 rpm, and a time of 4 h.

[0082] The reinforcing filler is specifically prepared by the following steps:

[0083] A1. Mix 55 mL of benzene, 3.6 g of anhydrous aluminum chloride, and 2 g of 4,4'-biphenyl ether tetracarboxylic dianhydride. Stir and react at 30°C for 30 minutes. Place the mixture in 100 mL of deionized water at 0°C, add 10 mL of 36% hydrochloric acid, remove excess benzene by distillation, filter, and dry in a vacuum oven at 30°C for 10 minutes to obtain the intermediate acid.

[0084] A2. 5 g of alumina fibers, 3.4 g of glucose, and 0.7 g of citric acid were added to 120 mL of ethanol and stirred. 0.6 mL of 36% hydrochloric acid was added and stirred at 65°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded alumina fibers.

[0085] A3. Add 2.5 g of the intermediate acid and 2 g of tannic acid to 90 mL of deionized water and stir until uniform. Then add 6 g of porous carbon-loaded alumina fibers. Stir at 60°C for 10 min, filter, wash three times with deionized water, and dry in a 70°C oven for 10 min to obtain modified alumina fibers.

[0086] A4. Add 2.2 g of hydroxy-terminated polydimethylsiloxane and 1.5 g of carboxyl-polyethylene glycol-carboxyl to 85 mL of ethanol and stir well. Add 2 mL of 36% hydrochloric acid and stir at 70°C for 30 minutes. Add 6 g of modified alumina fiber and continue stirring for 30 minutes. Cool to room temperature, filter, wash three times with deionized water, and dry in a 70°C oven for 10 minutes to obtain a reinforcing filler.

[0087] Comparative Example 2

[0088] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by weight: 120 parts of polyvinyl fluoride, 20 parts of reinforcing filler, 5 parts of calcium zinc stabilizer CZ-116, 5 parts of antioxidant 168, 2 parts of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and 2 parts of maleic anhydride grafted ethylene-vinyl acetate copolymer;

[0089] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0090] The modified polyvinyl fluoride material was obtained by mixing polyvinyl fluoride, reinforcing filler, calcium zinc stabilizer CZ-116, antioxidant 168, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate and maleic anhydride grafted ethylene-vinyl acetate copolymer, stirring and mixing at 1000 r / min for 5 minutes, extruding and granulating.

[0091] A twin-screw extruder was used for extrusion, with an extrusion temperature of 200°C, a screw speed of 220 rpm, and a time of 4 h.

[0092] The reinforcing filler is specifically prepared by the following steps:

[0093] A1. Mix 55 mL of benzene, 3.6 g of anhydrous aluminum chloride, and 2 g of 4,4'-biphenyl ether tetracarboxylic dianhydride. Stir and react at 30°C for 30 minutes. Place the mixture in 100 mL of deionized water at 0°C, add 10 mL of 36% hydrochloric acid, remove excess benzene by distillation, filter, and dry in a vacuum oven at 30°C for 10 minutes to obtain the intermediate acid.

[0094] 4.4 g of the intermediate acid, 2 g of hydrazine hydrate and 120 mL of ethanol were mixed evenly, stirred and reacted at 50°C for 30 min, and the solid was collected by filtration. The solid was washed twice with ethanol and dried in an oven at 80°C for 10 min to obtain a heat-resistant monomer;

[0095] A2. Add 2.5 g of heat-resistant monomer and 2 g of tannic acid to 90 mL of deionized water and stir well. Then add 6 g of alumina fiber and stir at 60°C for 10 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified alumina fiber.

[0096] A3. Add 2.2 g of hydroxy-terminated polydimethylsiloxane and 1.5 g of carboxyl-polyethylene glycol-carboxyl to 85 mL of ethanol and stir well. Add 2 mL of 36% hydrochloric acid and stir at 70°C for 30 minutes. Add 6 g of modified alumina fiber and continue stirring for 30 minutes. Cool to room temperature, filter, wash three times with deionized water, and dry in a 70°C oven for 10 minutes to obtain a reinforcing filler.

[0097] Comparative Example 3

[0098] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by weight: 120 parts of polyvinyl fluoride, 20 parts of reinforcing filler, 5 parts of calcium zinc stabilizer CZ-116, 5 parts of antioxidant 168, 2 parts of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and 2 parts of maleic anhydride grafted ethylene-vinyl acetate copolymer;

[0099] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0100] The modified polyvinyl fluoride material was obtained by mixing polyvinyl fluoride, reinforcing filler, calcium zinc stabilizer CZ-116, antioxidant 168, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate and maleic anhydride grafted ethylene-vinyl acetate copolymer, stirring and mixing at 1000 r / min for 5 minutes, extruding and granulating.

[0101] A twin-screw extruder was used for extrusion, with an extrusion temperature of 200°C, a screw speed of 220 rpm, and a time of 4 h.

[0102] The reinforcing filler is specifically prepared by the following steps:

[0103] A1. Mix 55 mL of benzene, 3.6 g of anhydrous aluminum chloride, and 2 g of 4,4'-biphenyl ether tetracarboxylic dianhydride. Stir and react at 30°C for 30 minutes. Place the mixture in 100 mL of deionized water at 0°C, add 10 mL of 36% hydrochloric acid, remove excess benzene by distillation, filter, and dry in a vacuum oven at 30°C for 10 minutes to obtain the intermediate acid.

[0104] 4.4 g of the intermediate acid, 2 g of hydrazine hydrate and 120 mL of ethanol were mixed evenly, stirred and reacted at 50°C for 30 min, and the solid was collected by filtration. The solid was washed twice with ethanol and dried in an oven at 80°C for 10 min to obtain a heat-resistant monomer;

[0105] A2. 5 g of alumina fibers, 3.4 g of glucose, and 0.7 g of citric acid were added to 120 mL of ethanol and stirred. 0.6 mL of 36% hydrochloric acid was added and stirred at 65°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded alumina fibers.

[0106] A3. 4.5 g of heat-resistant monomer was added to 90 mL of deionized water and stirred. 6 g of porous carbon-loaded alumina fibers were added and stirred at 60 ° C for 10 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 70 ° C for 10 min to obtain modified alumina fibers.

[0107] A4. Add 2.2 g of hydroxy-terminated polydimethylsiloxane and 1.5 g of carboxyl-polyethylene glycol-carboxyl to 85 mL of ethanol and stir well. Add 2 mL of 36% hydrochloric acid and stir at 70°C for 30 minutes. Add 6 g of modified alumina fiber and continue stirring for 30 minutes. Cool to room temperature, filter, wash three times with deionized water, and dry in a 70°C oven for 10 minutes to obtain a reinforcing filler.

[0108] Comparative Example 4

[0109] A high-temperature resistant and creep-resistant modified polyvinyl fluoride material, comprising the following raw materials in parts by weight: 120 parts of polyvinyl fluoride, 20 parts of reinforcing filler, 5 parts of calcium zinc stabilizer CZ-116, 5 parts of antioxidant 168, 2 parts of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and 2 parts of maleic anhydride grafted ethylene-vinyl acetate copolymer;

[0110] A method for preparing a high-temperature resistant and creep-resistant modified polyvinyl fluoride material comprises the following steps:

[0111] The modified polyvinyl fluoride material was obtained by mixing polyvinyl fluoride, reinforcing filler, calcium zinc stabilizer CZ-116, antioxidant 168, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate and maleic anhydride grafted ethylene-vinyl acetate copolymer, stirring and mixing at 1000 r / min for 5 minutes, extruding and granulating.

[0112] A twin-screw extruder was used for extrusion, with an extrusion temperature of 200°C, a screw speed of 220 rpm, and a time of 4 h.

[0113] The reinforcing filler is specifically prepared by the following steps:

[0114] A1. Mix 55 mL of benzene, 3.6 g of anhydrous aluminum chloride, and 2 g of 4,4'-biphenyl ether tetracarboxylic dianhydride. Stir and react at 30°C for 30 minutes. Place the mixture in 100 mL of deionized water at 0°C, add 10 mL of 36% hydrochloric acid, remove excess benzene by distillation, filter, and dry in a vacuum oven at 30°C for 10 minutes to obtain the intermediate acid.

[0115] 4.4 g of the intermediate acid, 2 g of hydrazine hydrate and 120 mL of ethanol were mixed evenly, stirred and reacted at 50°C for 30 min, and the solid was collected by filtration. The solid was washed twice with ethanol and dried in an oven at 80°C for 10 min to obtain a heat-resistant monomer;

[0116] A2. 5 g of alumina fibers, 3.4 g of glucose, and 0.7 g of citric acid were added to 120 mL of ethanol and stirred. 0.6 mL of 36% hydrochloric acid was added and stirred at 65°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded alumina fibers.

[0117] A3. 2.5 g of heat-resistant monomer and 2 g of tannic acid were added to 90 mL of deionized water and stirred. 6 g of porous carbon-loaded alumina fibers were added and stirred at 60°C for 10 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified alumina fibers.

[0118] A4. Add 3.7 g of carboxyl-polyethylene glycol-carboxyl and 6 g of modified alumina fiber to 85 mL of ethanol and stir evenly. Add 2 mL of 36% hydrochloric acid and stir at 70°C for 30 minutes. Cool to room temperature, filter, wash three times with deionized water, and dry in a 70°C oven for 10 minutes to obtain a reinforcing filler.

[0119] The performance of the modified polyvinyl fluoride materials prepared in Examples 1-3 and Comparative Examples 1-4 was tested.

[0120] Creep resistance test: The creep rate of the modified polyvinyl fluoride material prepared above was tested according to ASTM D2990-17 “Standard Test Method for Creep and Creep Rupture of Plastics in Tension, Compression, and Flexure”.

[0121] Temperature resistance test: The thermal shrinkage of the modified polyvinyl fluoride material prepared above was tested according to GB / T 2951.21-2008 standard, with the test temperature being 220° C. and the test time being 8 h.

[0122] Mechanical property testing: The tensile strength and elongation at break of the modified polyvinyl fluoride material prepared above were tested according to GB-T1040-1992 standard.

[0123] As shown in Table 1 below.

[0124] Table 1 Performance test of modified polyvinyl fluoride materials prepared in Examples 1-3 and Comparative Examples 1-4

[0125]

[0126] It can be seen from the data in Table 1 that the modified polyvinyl fluoride materials prepared in Examples 1-3 have relatively high mechanical properties, high temperature resistance and creep resistance.

[0127] In Comparative Example 1, the heat-resistant monomer is replaced with a reinforcing filler prepared from an intermediate acid and added to the modified polyvinyl fluoride material. Its high temperature resistance and creep resistance decrease, proving that the heat-resistant monomer synthesized by reacting 4,4'-diphenyl ether tetracarboxylic dianhydride, benzene and hydrazine hydrate contains a diazinone structure with high rigidity and exhibits high heat resistance. The benzene ring structure contained in the heat-resistant monomer is dispersed between the polyvinyl fluoride molecular chains, generating entanglement, hindering the slip of the polyvinyl fluoride molecular chains, and thereby improving the creep resistance of the polyvinyl fluoride material.

[0128] In Comparative Example 2, the alumina fiber loaded with porous carbon is replaced with a reinforcing filler prepared from alumina fiber and added to the modified polyvinyl fluoride material. Its mechanical properties, high temperature resistance and creep resistance decrease, which proves that the porous carbon structure synthesized on the surface of the alumina fiber can form a rough surface on the surface of the alumina fiber, thereby increasing the contact area between the alumina fiber and polyvinyl fluoride. Its rough structure can form a mechanical interlock with the polyvinyl fluoride molecular chain, hindering the slip of the polyvinyl fluoride molecular chain, thereby improving the creep resistance and high temperature resistance of the polyvinyl fluoride material. In addition, the alumina fiber has an excellent aspect ratio and is randomly distributed in the polyvinyl fluoride material, which can form a network structure that can absorb gravity, thereby improving the mechanical properties of the polyvinyl fluoride material.

[0129] In Comparative Example 3, reinforcing fillers prepared by replacing the mass of tannic acid with heat-resistant monomers were added to the modified polyvinyl fluoride material. Its mechanical properties, high temperature resistance and creep resistance decreased, proving that the heat-resistant monomers were adsorbed to the surface of the alumina fiber loaded with porous carbon through tannic acid. Tannic acid has good adhesion properties, which further improves the force of the heat-resistant monomers on the surface of the modified alumina fiber and avoids the migration and precipitation of the heat-resistant monomers. In addition, tannic acid gives the modified alumina fiber a large number of active functional groups, which is beneficial to the formation of an organic silicon coating on the surface of the modified alumina fiber, thereby improving the mechanical properties of the polyvinyl fluoride material.

[0130] In Comparative Example 4, a reinforcing filler prepared by replacing the end-hydroxy polydimethylsiloxane with carboxyl-polyethylene glycol-carboxyl is added to the modified polyvinyl fluoride material, and its mechanical properties, high temperature resistance and creep resistance decrease, proving that the end-hydroxy polydimethylsiloxane and carboxyl-polyethylene glycol-carboxyl form an organic silicon cross-linked network structure coated on the surface of the modified alumina fiber. The formed organic silicon cross-linked network structure can improve the impact resistance of the polyvinyl fluoride material, thereby enhancing the mechanical properties of the polyvinyl fluoride material, and the organic silicon cross-linked network structure increases the distance between the polyvinyl fluoride molecular chains, so that the polyvinyl fluoride molecular chains are entangled through the organic silicon cross-linked network structure, inhibiting the mutual slippage between the rubber molecular chains, and improving the creep resistance of the polyvinyl fluoride material.

[0131] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0132] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A high temperature resistant and creep resistant modified polyvinyl fluoride material, characterized in that: The invention comprises the following raw materials in parts by weight: 100-120 parts of polyvinyl fluoride, 15-20 parts of reinforcing filler, 2-5 parts of thermal stabilizer, 3-5 parts of antioxidant, 1-2 parts of coupling agent and 1-2 parts of compatibilizer; Among them, the reinforcing filler is prepared by synthesizing porous carbon on the surface of alumina fiber, loading heat-resistant monomers with tannic acid, and then reacting with terminal hydroxyl polydimethylsiloxane and carboxyl-polyethylene glycol-carboxyl; The heat-resistant monomer is synthesized by the reaction of 4,4'-biphenyl ether tetracarboxylic dianhydride, benzene and hydrazine hydrate.

2. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 1, characterized in that: The reinforcing filler is specifically prepared by the following steps: A1. Benzene, anhydrous aluminum chloride, and 4,4'-biphenyl ether tetracarboxylic dianhydride were uniformly mixed and stirred for reaction. The mixture was then placed in deionized water, hydrochloric acid was added, excess benzene was removed by distillation, and the mixture was filtered and dried to obtain an intermediate acid. The intermediate acid, hydrazine hydrate, and ethanol were uniformly mixed and stirred for reaction. After completion of the reaction, the solid was collected by filtration, washed, and dried to obtain a heat-resistant monomer. A2. Alumina fibers, glucose, and citric acid were added to ethanol and stirred uniformly. Hydrochloric acid was added and stirred. After the reaction was complete, the mixture was filtered, washed, and dried. The mixture was placed in a tube furnace, potassium hydroxide solution was added, nitrogen was introduced, and carbonization was performed. The mixture was cooled to room temperature, removed, washed, and dried to obtain porous carbon-loaded alumina fibers. A3. The heat-resistant monomer and tannic acid were added to deionized water and stirred evenly. The porous carbon-loaded alumina fibers were added and stirred evenly. The mixture was filtered, washed, and dried to obtain modified alumina fibers. A4. Add hydroxy-terminated polydimethylsiloxane and carboxyl-polyethylene glycol-carboxyl to ethanol, stir evenly, add hydrochloric acid, and after the stirring reaction is complete, add modified alumina fiber, continue stirring the reaction, cool to room temperature, filter, wash, and dry to obtain a reinforcing filler.

3. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 2, characterized in that: In step A1, the ratio of benzene, anhydrous aluminum chloride and 4,4'-biphenyl ether tetracarboxylic dianhydride is (45-55) mL: (3-3.6) g: (1-2) g; In step A1, the ratio of the intermediate acid, hydrazine hydrate and ethanol is (4-4.4) g: (1.6-2) g: (80-120) mL.

4. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 2, characterized in that: In step A2, the ratio of the amount of alumina fiber, glucose, citric acid, ethanol, hydrochloric acid and potassium hydroxide solution is (4-5) g: (3-3.4) g: (0.5-0.7) g: (80-120) mL: (0.2-0.6) mL: (3-5) mL.

5. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 2, characterized in that: In step A3, the ratio of the heat-resistant monomer, tannic acid, deionized water and porous carbon-loaded alumina fiber is (2.1-2.5) g: (1-2) g: (70-90) mL: (5-6) g.

6. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 2, characterized in that: In step A4, the amount ratio of the hydroxy-terminated polydimethylsiloxane, carboxyl-polyethylene glycol-carboxyl, ethanol, hydrochloric acid and modified alumina fiber is (2-2.2) g: (1.1-1.5) g: (75-85) mL: (1-2) mL: (5-6) g.

7. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 1, characterized in that: The heat stabilizer is selected from any one of calcium zinc stabilizer CZ-116, calcium zinc stabilizer CZ-108, and calcium zinc stabilizer CZ-113.

8. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 1, characterized in that: The antioxidant is selected from any one of antioxidant 168, antioxidant 565, antioxidant 1024, antioxidant 1010, and antioxidant BHT.

9. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 1, characterized in that: The coupling agent is selected from titanate coupling agent or silane coupling agent; The compatibilizer is maleic anhydride grafted ethylene-vinyl acetate copolymer.

10. The high temperature resistant and creep resistant modified polyvinyl fluoride material according to claim 1, characterized in that: The modified polyvinyl fluoride material comprises the following preparation steps: The modified polyvinyl fluoride material is obtained by mixing polyvinyl fluoride, reinforcing filler, heat stabilizer, antioxidant, coupling agent and compatibilizer, stirring and mixing at 800-1000 r / min for 3-5 minutes, and extruding and granulating.

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