A temperature-resistant high-toughness modified polyvinyl chloride particle, a preparation method and application thereof

Abstract

This invention belongs to the field of polyvinyl chloride (PVC) manufacturing technology, specifically relating to a high-temperature resistant and high-toughness modified PVC granules, its preparation method, and applications. This invention uses PVC as a base material, introducing heat-resistant fibers and toughening fibers. The heat-resistant fibers form a continuous high-temperature network, blocking heat transfer and increasing the heat distortion temperature and long-term service temperature of PVC. The toughening fibers can transmit and disperse stress, improving the toughness of PVC. The acrylonitrile-butadiene-styrene copolymer elastomer absorbs impact energy, improving the impact strength of PVC. The modified PVC granules obtained by this invention are uniform, consistent in color, and free of impurities, possessing excellent temperature resistance and mechanical properties, better able to withstand the lateral pressure of freshly poured concrete, and meeting the requirements of building formwork.

Description

Technical Field

[0001] This invention belongs to the field of polyvinyl chloride manufacturing technology, specifically relating to a temperature-resistant and high-toughness modified polyvinyl chloride particle, its preparation method, and its application. Background Technology

[0002] Formwork engineering is an integral part of building construction, fixing the dimensions and position of concrete, ensuring construction safety, and improving pouring quality. Currently, the main formwork used in the construction industry is wooden formwork and aluminum alloy formwork. However, wooden formwork suffers from low reusability, easy wear and tear, and environmental pollution, while aluminum alloy formwork is expensive and lacks flexibility, limiting the continued development of the formwork industry. Polyvinyl chloride (PVC) plastic formwork, as a new type of building formwork material, has advantages such as energy saving, environmental protection, high reusability, and high recycling rate. Because the coefficient of thermal expansion of PVC differs from traditional formwork materials, temperature changes can cause significant changes in the formwork dimensions. Therefore, improving the heat resistance and mechanical strength of PVC to meet construction conditions is currently a research hotspot.

[0003] Chinese invention patent CN111100406B discloses a modified PVC granule and its preparation method, relating to the field of PVC technology. The modified PVC granule comprises the following components by weight: 100 parts PVC; 40-60 parts DOTP; 3-5 parts epoxidized soybean oil; 3-6 parts heat stabilizer; 50-75 parts nano-calcium carbonate; 0.5-1.5 parts lubricant; and 4-8 parts CPE; wherein the nano-calcium carbonate has a particle size of 30-50 nm. When the modified PVC granules of this invention are used to manufacture cable outer sheaths, the outer sheath is less prone to whitening. However, existing technologies have a technical problem: they do not improve the structure and composition of the toughening material to further enhance the temperature resistance and mechanical properties of the PVC granules. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature resistant and high-toughness modified polyvinyl chloride (PVC) particle, its preparation method, and its application, in order to solve the technical problem in the prior art that the temperature resistance and mechanical properties of PVC particles have not been further improved by modifying the structural composition of the toughening material.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A type of temperature-resistant and high-toughness modified polyvinyl chloride granules is prepared from the following raw materials in parts by weight: 100 parts polyvinyl chloride, 1-5 parts heat-resistant fiber, 1-5 parts toughening fiber filament, 0.5-2 parts heat stabilizer, 0.5-2 parts lubricant, 0.5-2 parts antioxidant, 10-15 parts calcium carbonate powder filler and 3-6 parts acrylonitrile-butadiene-styrene copolymer elastomer.

[0006] The lubricant is one or more of stearic acid, polyethylene wax, and epoxidized soybean oil; The heat stabilizer is one or more of zinc stearate, barium stearate, and calcium stearate; The antioxidant is one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076; Preferably, the method for preparing the heat-resistant fiber includes the following steps: S11. Tetraethyl orthosilicate and aluminum nitrate are added to deionized water, aluminum isopropoxide and polyethylene glycol are added dropwise and stirred, oxalic acid is added to catalyze aging to obtain a precursor sol, polyvinyl alcohol and deionized water are mixed to obtain a spinning aid, and the precursor sol and spinning aid are mixed to obtain a spinning solution. S12. Add the spinning solution to the electrospinning machine and spin to obtain precursor fiber. Then, heat the precursor fiber and calcine it to obtain mullite fiber. S13. Add mullite fiber to deionized water, add magnesium nitrate, aluminum nitrate and lanthanum nitrate, add dropwise an alkaline aqueous solution containing 70 g / L sodium hydroxide and 50 g / L sodium carbonate, heat up to modify the reaction, filter to collect the solid, wash and dry to obtain heat-resistant fiber.

[0007] Preferably, in S11, the mass ratio of tetraethyl orthosilicate, aluminum isopropoxide, aluminum nitrate, deionized water, polyethylene glycol, and oxalic acid is 1.5~2.5:3~5:3~4:10~20:0.01~0.05:0.1~0.2, the mass ratio of polyvinyl alcohol and deionized water in the spinning aid is 5~8:100, the amount of spinning aid added is 2~3wt% of the precursor sol mass, and the mixture is aged at 50~60℃ for 18~24h.

[0008] Preferably, the spinning speed in S12 is 1~1.5mL / h and the spinning voltage is 10~15kV.

[0009] Preferably, in step S12, the temperature is raised to 300-500℃ at a heating rate of 1-2℃ / min and calcined for 1-2 hours, and then raised to 1300-1600℃ at a heating rate of 3-5℃ / min and calcined for 30-60 minutes, so that the average diameter of the mullite fiber is 300-500nm.

[0010] Preferably, in S13, the mass ratio of mullite fiber to deionized water is 5~10:30~50, and the mass ratio of magnesium nitrate, aluminum nitrate, lanthanum nitrate, and alkaline aqueous solution is 4~6:2:0.1~0.3:30~50. The mixture is heated to 60~70℃ and reacted for 20~24 hours, washed with deionized water, and dried at 50~60℃.

[0011] Preferably, the method for preparing the toughened fiber includes the following steps: S21. Add chopped hemp fibers to a 5-7 wt% sodium hydroxide aqueous solution for alkali treatment, wash with deionized water until neutral, and dry to obtain alkali-treated hemp fibers. S22. Alkali-treated hemp fibers are added to a 50% ethanol aqueous solution, KH-550 is added, the temperature is raised to react, and the fibers are washed and dried to obtain toughened fiber filaments.

[0012] Preferably, in step S21, the temperature is raised to 70-80°C for alkali treatment for 4-6 hours, and then dried at 50-60°C.

[0013] Preferably, in S22, the mass ratio of alkali-treated hemp fiber, kH-550 and 50% ethanol aqueous solution is 4~6:2~3:20~30, the temperature is raised to 50~60℃ and reacted for 1~2 hours, washed with deionized water and dried at 50~60℃.

[0014] A method for preparing temperature-resistant and high-toughness modified polyvinyl chloride particles includes the following steps: S1. Add the raw materials to the mixer, heat and mix to obtain a mixture; S2. The mixture is added to an extruder, heated and continuously extruded, granulated, and air-cooled to obtain a heat-resistant and high-toughness modified polyvinyl chloride granules.

[0015] Preferably, in step S1, the temperature is raised to 90~105℃ and stirred at a speed of 1000~2000rpm for 30~60min.

[0016] Preferably, the extrusion production parameters in S2 are as follows: barrel temperature is 155~175℃, sprue temperature is 155~170℃, die temperature is 175~205℃, and extrusion rate is 0.5~0.6m / min.

[0017] The application of a high-temperature resistant and high-toughness modified polyvinyl chloride granule involves adding the modified polyvinyl chloride granule into a mold, heating it to 170~190℃, and hot-pressing it at a pressure of 10~15MPa for 10~20min to obtain a plastic building template.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention uses polyvinyl chloride (PVC) as the base material and introduces heat-resistant fibers and toughening fibers. The heat-resistant fibers form a continuous high-temperature resistant network, blocking heat transfer and increasing the heat distortion temperature and long-term service temperature of PVC. The toughening fibers can transmit and disperse stress, improving the toughness of PVC. The acrylonitrile-butadiene-styrene copolymer elastomer absorbs impact energy, improving the impact strength of PVC. The modified PVC particles obtained by this invention are uniform in size, consistent in color, and free of impurities. They possess excellent temperature resistance and mechanical properties, better able to withstand the lateral pressure of freshly poured concrete, and meet the requirements of building formwork.

[0019] 2. This invention obtains mullite fibers through electrospinning, and grows hydrotalcite by co-precipitating magnesium nitrate, aluminum nitrate and lanthanum nitrate on the surface of the mullite fibers to obtain heat-resistant fibers. The hydrotalcite is doped with lanthanum, which can adsorb chlorine gas during heat processing, slow down the thermal decomposition of PVC materials, and decompose and release water vapor when heated and burned to prevent combustion, thereby improving the heat resistance of PVC particles.

[0020] 3. This invention modifies hemp fiber with kH-550, introducing amino groups to improve the compatibility between hemp fiber and polyvinyl chloride. When polyvinyl chloride is subjected to bending stress, stress concentration is reduced by crack deflection, ensuring stable stress transmission and improving the mechanical properties of polyvinyl chloride. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The calcium carbonate powder filler involved in this invention is heavy calcium carbonate with a calcium carbonate content of 98.5 wt% and an average particle size of 5 μm; the acrylonitrile-butadiene-styrene copolymer elastomer is model 0215A.

[0023] Example 1: A temperature-resistant and high-toughness modified polyvinyl chloride particle is prepared from the following raw materials: 100g of polyvinyl chloride, 5g of heat-resistant fiber, 1g of toughening fiber filament, 0.5g of heat stabilizer, 0.5g of lubricant, 0.5g of antioxidant, 10g of calcium carbonate powder filler and 4g of acrylonitrile-butadiene-styrene copolymer elastomer.

[0024] The lubricant is stearic acid; The heat stabilizer is prepared by mixing zinc stearate and calcium stearate in a mass ratio of 1:1. The antioxidant is prepared by mixing antioxidant 1010 and antioxidant 1076 in a mass ratio of 1:3; The method for preparing heat-resistant fibers in this embodiment includes the following steps: S11. Add 1.5g of tetraethyl orthosilicate and 3g of aluminum nitrate to 10g of deionized water, add 3g of aluminum isopropoxide and 0.02g of polyethylene glycol dropwise and stir. Heat to 50℃ and add 0.1g of oxalic acid for catalytic aging for 24h to obtain a precursor sol. Mix 5g of polyvinyl alcohol and 100g of deionized water to obtain a spinning aid. Mix 10g of the precursor sol and 0.2g of the spinning aid to obtain a spinning solution. S12. Add the spinning solution to the electrospinning machine and spin at a spinning speed of 1 mL / h and a spinning voltage of 10 kV to obtain precursor fibers. Heat the precursor fibers to 300℃ at a heating rate of 1℃ / min and calcine for 1 h. Then heat them to 1300℃ at a heating rate of 3℃ / min and calcine for 60 min to obtain mullite fibers. S13. Add 5g of mullite fiber to 30g of deionized water, add 4g of magnesium nitrate, 2g of aluminum nitrate and 0.1g of lanthanum nitrate, add dropwise 30g of an alkaline aqueous solution containing 70g / L sodium hydroxide and 50g / L sodium carbonate, heat to 70℃ and react for 20h, filter to collect the solid, wash with deionized water, and dry at 50℃ to obtain heat-resistant fiber.

[0025] The method for preparing the toughened fiber filament in this embodiment includes the following steps: S21. Add chopped hemp fibers to a 5wt% sodium hydroxide aqueous solution and heat to 70℃ for alkali treatment for 4 hours. Wash with deionized water until neutral and dry at 50℃ to obtain alkali-treated hemp fibers. S22. Add 4g of alkali-treated hemp fiber to 20g of 50% ethanol aqueous solution, add 2g of KH-550, heat to 50℃ and react for 1h, wash with deionized water, and dry at 50℃ to obtain toughened fiber filaments.

[0026] The preparation method of the high-temperature resistant and high-toughness modified polyvinyl chloride particles in this embodiment includes the following steps: S1. Add the raw materials to the mixer, heat to 90°C, and stir at 1000 rpm for 30 minutes to obtain the mixture. S2. The mixture is added to an extruder and heated for continuous extrusion. The barrel temperature is 155℃, the sprue temperature is 155℃, the die temperature is 175℃, the extrusion rate is 0.5m / min, the pellets are cut, and after air cooling, a high-temperature resistant and high-toughness modified polyvinyl chloride granules are obtained.

[0027] This embodiment describes the application of a heat-resistant and high-toughness modified polyvinyl chloride (PVC) granule. The modified PVC granule is added to a mold and heated to 170°C. The mold is then hot-pressed at 10 MPa for 10 minutes to obtain a plastic building template.

[0028] Example 2: A temperature-resistant and high-toughness modified polyvinyl chloride particle, prepared from the following raw materials: 100g of polyvinyl chloride, 1g of heat-resistant fiber, 1g of toughening fiber filament, 1g of heat stabilizer, 1g of lubricant, 1g of antioxidant, 12g of calcium carbonate powder filler and 3.5g of acrylonitrile-butadiene-styrene copolymer elastomer.

[0029] The lubricant is prepared by mixing stearic acid and polyethylene wax in a mass ratio of 1:1. The heat stabilizer is prepared by mixing zinc stearate and barium stearate in a mass ratio of 2:1. The antioxidant is prepared by mixing antioxidant 1010 and antioxidant 1076 in a mass ratio of 1:1; The method for preparing heat-resistant fibers in this embodiment includes the following steps: S11. Add 2g of tetraethyl orthosilicate and 3.5g of aluminum nitrate to 15g of deionized water, add 3.5g of aluminum isopropoxide and 0.03g of polyethylene glycol dropwise and stir. Heat to 55℃ and add 0.1g of oxalic acid for catalytic aging for 18h to obtain a precursor sol. Mix 6g of polyvinyl alcohol and 100g of deionized water to obtain a spinning aid. Mix 10g of the precursor sol and 0.25g of the spinning aid to obtain a spinning solution. S12. Add the spinning solution to the electrospinning machine and spin at a spinning speed of 1.2 mL / h and a spinning voltage of 15 kV to obtain precursor fibers. Heat the precursor fibers to 400℃ at a heating rate of 1.5℃ / min and calcine for 1.5 h. Then heat them to 1350℃ at a heating rate of 4℃ / min and calcine for 30 min to obtain mullite fibers. S13. Add 6g of mullite fiber to 35g of deionized water, add 4.5g of magnesium nitrate, 2g of aluminum nitrate and 0.15g of lanthanum nitrate, and add dropwise 35g of an alkaline aqueous solution containing 70g / L sodium hydroxide and 50g / L sodium carbonate. Heat to 60℃ and react for 20h. Filter to collect the solid, wash with deionized water, and dry at 50℃ to obtain heat-resistant fiber.

[0030] The method for preparing the toughened fiber filament in this embodiment includes the following steps: S21. Add chopped hemp fibers to a 6wt% sodium hydroxide aqueous solution, heat to 70℃ for alkali treatment for 4 hours, wash with deionized water until neutral, and dry at 60℃ to obtain alkali-treated hemp fibers. S22. Add 4.5g of alkali-treated hemp fiber to 25g of 50% ethanol aqueous solution, add 2.5g of KH-550, heat to 60℃ and react for 2h, wash with deionized water, and dry at 60℃ to obtain toughened fiber filaments.

[0031] The preparation method of the high-temperature resistant and high-toughness modified polyvinyl chloride particles in this embodiment includes the following steps: S1. Add the raw materials to the mixer, heat to 100℃, and stir at 1500 rpm for 40 minutes to obtain the mixture. S2. The mixture is added to an extruder and heated for continuous extrusion. The barrel temperature is 160℃, the confluence core temperature is 165℃, the die temperature is 190℃, the extrusion rate is 0.55m / min, the pellets are cut, and after air cooling, a high-temperature resistant and high-toughness modified polyvinyl chloride granules are obtained.

[0032] This embodiment describes the application of a heat-resistant and high-toughness modified polyvinyl chloride (PVC) granule. The modified PVC granule is added to a mold and heated to 180°C. The mold is then hot-pressed at 11 MPa for 15 minutes to obtain a plastic building template.

[0033] Example 3: A temperature-resistant and high-toughness modified polyvinyl chloride particle, prepared from the following raw materials: 100g of polyvinyl chloride, 2g of heat-resistant fiber, 2g of toughening fiber filament, 1.5g of heat stabilizer, 1.5g of lubricant, 1.5g of antioxidant, 13g of calcium carbonate powder filler and 4g of acrylonitrile-butadiene-styrene copolymer elastomer.

[0034] The lubricant is prepared by mixing polyethylene wax and epoxidized soybean oil in a mass ratio of 2:1. The heat stabilizer is prepared by mixing barium stearate and calcium stearate in a mass ratio of 1:3. The antioxidant is prepared by mixing antioxidant 168 and antioxidant 1076 in a mass ratio of 1:1; The method for preparing heat-resistant fibers in this embodiment includes the following steps: S11. Add 2g of tetraethyl orthosilicate and 3.5g of aluminum nitrate to 10g of deionized water, add 4.5g of aluminum isopropoxide and 0.03g of polyethylene glycol dropwise and stir. Heat to 60℃ and add 0.15g of oxalic acid for catalytic aging for 24h to obtain a precursor sol. Mix 5-8g of polyvinyl alcohol and 100g of deionized water to obtain a spinning aid. Mix 100g of the precursor sol and 2-3g of the spinning aid to obtain a spinning solution. S12. Add the spinning solution to the electrospinning machine and spin at a spinning speed of 1.3 mL / h and a spinning voltage of 10~15 kV to obtain precursor fibers. Heat the precursor fibers to 500℃ at a heating rate of 1.5℃ / min and calcine for 1 h, then heat to 1400℃ at a heating rate of 3.5℃ / min and calcine for 40 min to obtain mullite fibers. S13. Add 6g of mullite fiber to 40g of deionized water, add 5g of magnesium nitrate, 2g of aluminum nitrate and 0.2g of lanthanum nitrate, and add dropwise 40g of an alkaline aqueous solution containing 70g / L sodium hydroxide and 50g / L sodium carbonate. Heat to 70℃ and react for 24h. Filter to collect the solid, wash with deionized water, and dry at 60℃ to obtain heat-resistant fiber.

[0035] The method for preparing the toughened fiber filament in this embodiment includes the following steps: S21. Add chopped hemp fibers to a 7wt% sodium hydroxide aqueous solution and heat to 80℃ for alkali treatment for 5 hours. Wash with deionized water until neutral and dry at 60℃ to obtain alkali-treated hemp fibers. S22. Add 5g of alkali-treated hemp fiber to 25g of 50% ethanol aqueous solution, add 2.5g of KH-550, heat to 55℃ and react for 2h, wash with deionized water, and dry at 55℃ to obtain toughened fiber filament.

[0036] The preparation method of the high-temperature resistant and high-toughness modified polyvinyl chloride particles in this embodiment includes the following steps: S1. Add the raw materials to the mixer, heat to 95°C, and stir at 2000 rpm for 50 minutes to obtain the mixture. S2. The mixture is added to an extruder and heated for continuous extrusion. The barrel temperature is 160℃, the sprue temperature is 165℃, the die temperature is 180℃, and the extrusion rate is 0.53m / min. After pelleting and air cooling, a high-temperature resistant and high-toughness modified polyvinyl chloride granules are obtained.

[0037] This embodiment describes the application of a heat-resistant and high-toughness modified polyvinyl chloride (PVC) granule. The modified PVC granule is added to a mold and heated to 180°C. The mold is then hot-pressed at 14 MPa for 15 minutes to obtain a plastic building template.

[0038] Example 4: A temperature-resistant and high-toughness modified polyvinyl chloride particle, prepared from the following raw materials: 100g of polyvinyl chloride, 1g of heat-resistant fiber, 5g of toughening fiber filament, 2g of heat stabilizer, 0.5g of lubricant, 1g of antioxidant, 13g of calcium carbonate powder filler and 5g of acrylonitrile-butadiene-styrene copolymer elastomer.

[0039] The lubricant is epoxidized soybean oil; The heat stabilizer is calcium stearate; The antioxidant is prepared by mixing antioxidant 1010, antioxidant 168 and antioxidant 1076 in a mass ratio of 1:1:1; The method for preparing heat-resistant fibers in this embodiment includes the following steps: S11. Add 2g of tetraethyl orthosilicate and 3.5g of aluminum nitrate to 20g of deionized water, add 4.5g of aluminum isopropoxide and 0.04g of polyethylene glycol dropwise and stir. Heat to 60℃ and add 0.2g of oxalic acid for catalytic aging for 24h to obtain a precursor sol. Mix 7g of polyvinyl alcohol and 100g of deionized water to obtain a spinning aid. Mix 100g of the precursor sol and 3g of the spinning aid to obtain a spinning solution. S12. Add the spinning solution to the electrospinning machine and spin at a spinning speed of 1.4 mL / h and a spinning voltage of 14 kV to obtain precursor fibers. Heat the precursor fibers to 400℃ at a heating rate of 1.5℃ / min for 2 hours, and then heat them to 1500℃ at a heating rate of 4℃ / min for 50 minutes to obtain mullite fibers. S13. Add 8g of mullite fiber to 40g of deionized water, add 6g of magnesium nitrate, 2g of aluminum nitrate and 0.25g of lanthanum nitrate, and add dropwise 40g of an alkaline aqueous solution containing 70g / L sodium hydroxide and 50g / L sodium carbonate. Heat to 65℃ and react for 24h. Filter to collect the solid, wash with deionized water, and dry at 55℃ to obtain heat-resistant fiber.

[0040] The method for preparing the toughened fiber filament in this embodiment includes the following steps: S21. Add chopped hemp fibers to a 6wt% sodium hydroxide aqueous solution and heat to 80℃ for alkali treatment for 5 hours. Wash with deionized water until neutral and dry at 55℃ to obtain alkali-treated hemp fibers. S22. Add 5.5g of alkali-treated hemp fiber to 25g of 50% ethanol aqueous solution, add 2.5g of KH-550, heat to 55℃ and react for 1.5h, wash with deionized water, and dry at 55℃ to obtain toughened fiber filament.

[0041] The preparation method of the high-temperature resistant and high-toughness modified polyvinyl chloride particles in this embodiment includes the following steps: S1. Add the raw materials to the mixer, heat to 100℃, and stir at 1000 rpm for 40 minutes to obtain the mixture. S2. The mixture is added to an extruder and heated for continuous extrusion. The barrel temperature is 165℃, the confluence core temperature is 170℃, the die temperature is 200℃, and the extrusion rate is 0.55m / min. After pelleting and air cooling, a high-temperature resistant and high-toughness modified polyvinyl chloride granules are obtained.

[0042] This embodiment describes the application of a heat-resistant and high-toughness modified polyvinyl chloride (PVC) granule. The modified PVC granule is added to a mold and heated to 175°C. The mold is then hot-pressed at 10 MPa for 10 minutes to obtain a plastic building template.

[0043] Example 5: A temperature-resistant and high-toughness modified polyvinyl chloride particle, prepared from the following raw materials: 100g of polyvinyl chloride, 5g of heat-resistant fiber, 5g of toughening fiber filament, 2g of heat stabilizer, 2g of lubricant, 0.5g of antioxidant, 15g of calcium carbonate powder filler and 6g of acrylonitrile-butadiene-styrene copolymer elastomer.

[0044] The lubricant is epoxidized soybean oil; The heat stabilizer is prepared by mixing zinc stearate and calcium stearate in a mass ratio of 1:3. The antioxidant is antioxidant 1010; The method for preparing heat-resistant fibers in this embodiment includes the following steps: S11. Add 2.5g of tetraethyl orthosilicate and 4g of aluminum nitrate to 20g of deionized water, add 5g of aluminum isopropoxide and 0.05g of polyethylene glycol dropwise and stir. Heat to 60℃ and add 0.2g of oxalic acid for catalytic aging for 24h to obtain a precursor sol. Mix 8g of polyvinyl alcohol and 100g of deionized water to obtain a spinning aid. Mix 10g of the precursor sol and 0.3g of the spinning aid to obtain a spinning solution. S12. Add the spinning solution to the electrospinning machine and spin at a spinning speed of 1.5 mL / h and a spinning voltage of 15 kV to obtain precursor fibers. Heat the precursor fibers to 500℃ at a heating rate of 2℃ / min and calcine for 2 h. Then heat them to 1600℃ at a heating rate of 5℃ / min and calcine for 30 min to obtain mullite fibers. S13. Add 10g of mullite fiber to 50g of deionized water, add 6g of magnesium nitrate, 2g of aluminum nitrate and 0.3g of lanthanum nitrate, and add dropwise 50g of an alkaline aqueous solution containing 70g / L sodium hydroxide and 50g / L sodium carbonate. Heat to 70℃ and react for 24h. Filter to collect the solid, wash with deionized water, and dry at 60℃ to obtain heat-resistant fiber.

[0045] The method for preparing the toughened fiber filament in this embodiment includes the following steps: S21. Add chopped hemp fibers to a 7wt% sodium hydroxide aqueous solution and heat to 80℃ for alkali treatment for 6 hours. Wash with deionized water until neutral and dry at 60℃ to obtain alkali-treated hemp fibers. S22. Add 6g of alkali-treated hemp fiber to 30g of 50% ethanol aqueous solution, add 3g of KH-550, heat to 60℃ and react for 2h, wash with deionized water, and dry at 60℃ to obtain toughened fiber filament.

[0046] The preparation method of the high-temperature resistant and high-toughness modified polyvinyl chloride particles in this embodiment includes the following steps: S1. Add the raw materials to the mixer, heat to 105℃, and stir at 2000 rpm for 30 minutes to obtain the mixture. S2. The mixture is added to an extruder and heated for continuous extrusion. The barrel temperature is 175℃, the sprue temperature is 170℃, the die temperature is 205℃, and the extrusion rate is 0.6m / min. After pelleting and air cooling, a high-temperature resistant and high-toughness modified polyvinyl chloride granule is obtained.

[0047] This embodiment describes the application of a heat-resistant and high-toughness modified polyvinyl chloride (PVC) granule. The modified PVC granule is added to a mold and heated to 190°C. The mold is then hot-pressed at 15 MPa for 20 minutes to obtain a plastic building template.

[0048] Comparative Example 1 differs from Example 1 in that it does not contain heat-resistant toughening fiber filaments.

[0049] Comparative Example 2 differs from Example 1 in that it does not contain toughening fiber filaments.

[0050] Comparative Example 3 differs from Example 1 in that the heat-resistant fiber is replaced with fumed silica with an average particle size of 500 nm.

[0051] Performance testing The flexural strength and flexural modulus of the modified polyvinyl chloride granules prepared in each example and comparative example were tested according to GB / T 9341-2008 "Determination of Flexural Properties of Plastics".

[0052] The Shore hardness of the modified polyvinyl chloride particles prepared in each example and comparative example was tested according to GB / T 2411-2008 "Determination of indentation hardness (Shore hardness) of plastics and hard rubber using a hardness tester".

[0053] The Vicat softening point of the modified polyvinyl chloride particles prepared in each example and comparative example was tested according to GB / T 1633-2000 "Determination of Vicat softening temperature (VST) of thermoplastic plastics".

[0054] The unnotched impact strength of the simply supported beams of the modified polyvinyl chloride granules prepared in each example and comparative example was tested according to GB / T1043.1-2008 "Determination of impact properties of simply supported beams of plastics - Part 1: Non-instrumental impact test".

[0055] The test results are shown in Table 1 below: Table 1 Test Results As shown in Table 1, the modified polyvinyl chloride (PVC) particles prepared in Examples 1-5 have a flexural strength of 66-68 MPa and a flexural modulus of 5019-5043 MPa. Comparative Example 2 lacks toughening fiber filaments and cannot form a network to prevent the propagation of internal cracks in the matrix, resulting in a flexural strength of only 58 MPa and a flexural modulus of 4727 MPa. This indicates that the modified PVC particles prepared in this invention possess excellent toughness. The Shore hardness of the modified PVC particles prepared in Examples 1-5 is 82-85 H. D The Vicat softening point is 82~84℃, and the unnotched impact strength of a simply supported beam is 110~117kJ / m. 2 This demonstrates that the modified polyvinyl chloride particles prepared by this invention have excellent temperature resistance and impact resistance.

[0056] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0057] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A temperature-resistant and high-toughness modified polyvinyl chloride granule, characterized in that, It is prepared from the following parts by weight of raw materials: 100 parts polyvinyl chloride, 1-5 parts heat-resistant fiber, 1-5 parts toughening fiber filament, 0.5-2 parts heat stabilizer, 0.5-2 parts lubricant, 0.5-2 parts antioxidant, 10-15 parts calcium carbonate powder filler and 3-6 parts acrylonitrile-butadiene-styrene copolymer elastomer.

2. The modified polyvinyl chloride granules with high temperature resistance and high toughness according to claim 1, characterized in that, The lubricant is one or more of stearic acid, polyethylene wax, and epoxidized soybean oil; the heat stabilizer is one or more of zinc stearate, barium stearate, and calcium stearate; and the antioxidant is one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076.

3. The modified polyvinyl chloride granules with high temperature resistance and high toughness according to claim 1, characterized in that, The method for preparing the heat-resistant fiber includes the following steps: S11. Tetraethyl orthosilicate and aluminum nitrate are added to deionized water, aluminum isopropoxide and polyethylene glycol are added dropwise and stirred, oxalic acid is added to catalyze aging to obtain a precursor sol, polyvinyl alcohol and deionized water are mixed to obtain a spinning aid, and the precursor sol and spinning aid are mixed to obtain a spinning solution. S12. Add the spinning solution to the electrospinning machine and spin to obtain precursor fiber. Then, heat the precursor fiber and calcine it to obtain mullite fiber. S13. Add mullite fiber to deionized water, add magnesium nitrate, aluminum nitrate and lanthanum nitrate, add dropwise an alkaline aqueous solution containing 70 g / L sodium hydroxide and 50 g / L sodium carbonate, heat up to modify the reaction, filter to collect the solid, wash and dry to obtain heat-resistant fiber.

4. The modified polyvinyl chloride granules with high temperature resistance and high toughness according to claim 3, characterized in that, The mass ratio of tetraethyl orthosilicate, aluminum isopropoxide, aluminum nitrate, deionized water, polyethylene glycol, and oxalic acid in S11 is 1.5~2.5:3~5:3~4:10~20:0.01~0.05:0.1~0.

2. The mass ratio of polyvinyl alcohol and deionized water in the spinning aid is 5~8:

100. The amount of spinning aid added is 2~3wt% of the precursor sol mass. The mixture is heated to 50~60℃ and aged for 18~24h.

5. The modified polyvinyl chloride granules with high temperature resistance and high toughness according to claim 3, characterized in that, In step S12, the temperature is increased to 300-500℃ at a heating rate of 1-2℃ / min and calcined for 1-2 hours, then increased to 1300-1600℃ at a heating rate of 3-5℃ / min and calcined for 30-60 minutes. In step S13, the mass ratio of mullite fiber to deionized water is 5-10:30-50, and the mass ratio of magnesium nitrate, aluminum nitrate, lanthanum nitrate, and alkaline aqueous solution is 4-6:2:0.1-0.3:30-50. The mixture is heated to 60-70℃ and reacted for 20-24 hours. After washing with deionized water, the mixture is dried at 50-60℃.

6. The modified polyvinyl chloride granules with high temperature resistance and high toughness according to claim 1, characterized in that, The method for preparing the toughened fiber includes the following steps: S21. Add chopped hemp fibers to a 5-7 wt% sodium hydroxide aqueous solution for alkali treatment, wash with deionized water until neutral, and dry to obtain alkali-treated hemp fibers. S22. Alkali-treated hemp fibers are added to a 50% ethanol aqueous solution, KH-550 is added, the temperature is raised to react, and the fibers are washed and dried to obtain toughened fiber filaments.

7. The modified polyvinyl chloride granules with high temperature resistance and high toughness according to claim 6, characterized in that, In step S21, the temperature is raised to 70-80℃ for alkali treatment for 4-6 hours, and then dried at 50-60℃. In step S22, the mass ratio of alkali-treated hemp fiber, kH-550 and 50% ethanol aqueous solution is 4-6:2-3:20-30, the temperature is raised to 50-60℃ for 1-2 hours, the mixture is washed with deionized water and dried at 50-60℃.

8. A method for preparing a temperature-resistant and high-toughness modified polyvinyl chloride particle according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Add the raw materials to the mixer, heat and mix to obtain a mixture; S2. The mixture is added to an extruder, heated and continuously extruded, granulated, and air-cooled to obtain a heat-resistant and high-toughness modified polyvinyl chloride granules.

9. The method for preparing a temperature-resistant and high-toughness modified polyvinyl chloride particle according to claim 8, characterized in that, In step S1, the temperature is raised to 90~105℃ and stirred at a speed of 1000~2000rpm for 30~60min; in step S2, the extrusion production parameters are as follows: barrel temperature is 155~175℃, sprue temperature is 155~170℃, die temperature is 175~205℃, and extrusion rate is 0.5~0.6m / min.

10. The application of the temperature-resistant and high-toughness modified polyvinyl chloride granules according to any one of claims 1-7, characterized in that, Modified polyvinyl chloride granules are added to a mold and heated to 170~190℃, then hot-pressed at 10~15MPa for 10~20min to obtain plastic building templates.

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