Self-repairing polyurethane toughened polyvinyl chloride composite material and preparation method thereof

Abstract

The application belongs to the technical field of PVC composite materials, and discloses a self-repairing polyurethane toughened polyvinyl chloride composite material and a preparation method thereof.The composite material is prepared from the following components by weight: 50-70 parts of polyvinyl chloride, 10-40 parts of self-repairing polyurethane elastomer, 3-10 parts of compatibilizer, 2-10 parts of nanomaterial, 0.5-8 parts of coupling agent, 3-10 parts of plasticizer, 1-8 parts of heat stabilizer, 0.5-4 parts of lubricant, 0.5-3 parts of antioxidant, 0.5-2 parts of pigment and 0.5-2 parts of light stabilizer.The application further discloses a preparation method of the composite material.The self-repairing polyurethane elastomer is used for toughening, so that the problems of poor toughness, poor impact strength and short service life of the PVC material are solved.The composite material has good toughness, greatly improved impact strength and tensile strength, and is expected to be applied on a large scale in the field of water supply and drainage.

Description

Technical Field

[0001] This invention belongs to the technical field of polymer materials, specifically relating to a self-healing polyurethane-toughened PVC composite material and its preparation method. Background Technology

[0002] PVC composite materials are widely used polymer materials in the water supply and drainage industry. PVC has advantages such as good water resistance and chemical resistance, fast construction speed, and low construction cost. However, when using PVC materials, due to their poor toughness and low impact strength, they are prone to brittle fracture and cracking, resulting in a significantly reduced service life and increased maintenance and replacement costs. Existing methods to improve the toughness of PVC composite materials include adding toughening agents, blending modification, and changing the material structure. However, some additives may pose environmental pollution problems. Improving the toughness of PVC composite materials often leads to a decrease in hardness, while increasing processing difficulty and cost. Therefore, the preparation and development of PVC composite materials with good toughness, high ring stiffness, and excellent impact resistance are of significant application value in the field of water supply and drainage pipelines. Summary of the Invention

[0003] To address the shortcomings and deficiencies of existing PVC composite materials, the present invention aims to provide a self-healing polyurethane-toughened PVC composite material and its preparation method. In this invention, the polyurethane elastomer is prepared through a one-pot polycondensation reaction using cholic acid molecular derivatives as hard segments and polyethylene glycol (PEG) as soft segments. The dynamic non-covalent interactions of hydrogen bonds, hydrophobic surfaces, and hydroxyl groups on the urethane bonds of the cholic acid units endow the polyurethane elastomer with self-healing properties. This self-healing polyurethane, when combined with PVC as a toughening agent, prepares a high-strength and high-toughness PVC composite material. The rigid framework of cholic acid molecules in the self-healing polyurethane exhibits good compatibility with PVC, improving the mechanical strength of the composite material. The introduction of PEG soft segments significantly improves the toughness of PVC. Furthermore, the strength and toughness of the PVC composite material can be further adjusted by changing the equivalence ratio of hard and soft segments in the molecular chain.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A self-healing polyurethane-toughened PVC composite material is prepared from the following components in parts by weight: 50-70 parts of polyvinyl chloride, 10-40 parts of self-healing polyurethane elastomer, 3-10 parts of compatibilizer, 2-10 parts of nanomaterials, 0.5-8 parts of coupling agent, 3-10 parts of plasticizer, 1-8 parts of heat stabilizer, 0.5-4 parts of lubricant, 0.5-3 parts of antioxidant, 0.5-2 parts of pigment, and 0.5-2 parts of light stabilizer.

[0006] The content of the self-healing polyurethane elastomer is preferably 10-30 parts.

[0007] The polyvinyl chloride has an apparent density ≥0.51g / ml, a viscosity number of 109ml / g, volatile matter ≤0.26%, monomer content ≤0.7μg / g, and impurities ≤24 per kg.

[0008] The polyurethane elastomer has a maximum Young's modulus of 163 MPa, a maximum tensile strength of 6.21 MPa, and a maximum elongation at break of 972%. After complete fracture, the elastomer can be repaired at 90°C for 1.5 hours, and the tensile strength can be restored to 90% of its original value.

[0009] The self-healing polyurethane elastomer is obtained by the following preparation method:

[0010] 1) Lithocholic acid is reacted with ethylene glycol to obtain bile acid diol monomer (LCA-EG);

[0011] 2) Using an organic solvent as the reaction medium, bile acid diol monomer, polyethylene glycol and hexamethylene diisocyanate are reacted under the action of a catalyst to obtain self-healing polyurethane elastomer (LCA-PU).

[0012] The structure of the bile acid diol monomer (LCA-EG) is as follows:

[0013]

[0014] The polyethylene glycol mentioned in step 2) has a molecular weight of 200-800, such as PEG. 200 PEG 400 PEG 600 PEG 800 The molecular weight of the polyethylene glycol is preferably 200-600, more preferably 300-500.

[0015] The organic solvent mentioned in step 2) is one or more of N,N-dimethylformamide (DMF) and xylene. The reaction temperature is 80-100℃, and the reaction time is 3-8 hours; the reaction is carried out under a protective atmosphere.

[0016] In step 2), the molar ratio of bile acid diol monomer, polyethylene glycol, and hexamethylene diisocyanate is (0.7-1.3):(0.7-1.3):(2-3), preferably (0.7-1.3):(0.7-1.3):(2.5-3); the total molar amount of bile acid diol monomer and polyethylene glycol is 2 parts.

[0017] The reaction described in step 1) uses an organic solvent as the reaction medium, and the organic solvent is one or more of dimethyl sulfoxide (DMSO), N,N-dimethylformamide, benzene, xylene, and chloroform.

[0018] The reaction described in step 1) is carried out under the catalysis of a catalyst; the catalyst is an acid, such as hydrochloric acid, sulfuric acid, or p-benzenesulfonic acid; after the acid is added, the pH of the system is 2.5 to 3.5, preferably 3.

[0019] In step 1), the molar ratio of LCA to EG is 1:(50-100), preferably 1:(70-75).

[0020] The reaction temperature in step 1) is 75–85°C, and the reaction time is 3–6 hours.

[0021] After the reaction is complete, a precipitant is used for precipitation, followed by filtration, washing, and drying.

[0022] The specific preparation steps of (LCA-EG) in step 1) are as follows: LCA and ethylene glycol (EG) are mixed in an organic solvent, and then a catalyst is added to react. After precipitation, filtration, washing and drying, LCA-EG is obtained.

[0023] The precipitant is a 5 wt% NaHCO3 solution; the washing involves rinsing the solid multiple times with water; the drying is vacuum drying at a temperature of 30-60℃.

[0024] The catalyst mentioned in step 2) is dibutyltin dilaurate or organic bismuth.

[0025] After the reaction in step 2) is complete, the mixture is poured, dried, reconstituted, and molded.

[0026] The pouring temperature is 80-100℃, and the pouring time is 8-15 hours; the drying is vacuum drying, and the drying temperature is 45-55℃; the resolution refers to dissolving the product with DMF or DMSO.

[0027] The specific preparation steps of LCA-PU are as follows: LCA-EG and PEG are dissolved in an organic solvent, water is removed, hexamethylene diisocyanate is added, then a catalyst is added, and the reaction is carried out under a protective atmosphere. After casting, drying, resolution, molding, and volatilization, LCA-PU elastomer is obtained.

[0028] The conditions for volatilization are: temperature of 60-80℃ and volatilization time of more than 50 hours.

[0029] The reaction equation for the preparation of LCA-EG in step 1) is:

[0030]

[0031] The structure of the self-healing polyurethane elastomer (LCA-PU) is as follows:

[0032]

[0033] In the above-mentioned self-healing polyurethane-toughened PVC composite material, the compatibilizer is at least one of styrene-maleic anhydride copolymer, ethylene-propylene copolymer, chlorinated polyethylene, macromolecular silane coupling agent, and maleic anhydride graft copolymer.

[0034] The macromolecular silane coupling agent is vinyltriethoxysilane or γ-glycidylpropoxytrimethoxysilane; the maleic anhydride graft copolymer is a maleic anhydride graft styrene copolymer.

[0035] In the aforementioned self-healing polyurethane-toughened PVC composite material, the nanomaterial is at least one of wollastonite, calcium carbonate, talc, barium sulfate, titanium dioxide, or whiskers (the purchased nanomaterial itself has undergone activation treatment).

[0036] In the aforementioned self-healing polyurethane-toughened PVC composite material, the coupling agent is at least one of titanate coupling agent, aluminum-titanium coupling agent, aluminate coupling agent, and silane coupling agent.

[0037] In the aforementioned self-healing polyurethane-toughened PVC composite material, the plasticizer is at least one of the following: acrylate polymer copolymer, polyethylene graft chloride, citric acid esters, epoxidized soybean oil, and diisooctyl phthalate.

[0038] The acrylate polymer copolymer is a methyl methacrylate / acrylate copolymer or an acrylate / styrene copolymer; the polyethylene graft chloride is chlorinated polyethylene; the citric acid ester is one or more of tributyl citrate and ethyl tributyl citrate.

[0039] In the above-mentioned self-healing polyurethane-toughened PVC composite material, the heat stabilizer is at least one of organotin compounds (such as tin mercaptoacetate, methyl tin mercaptoacetate), base compounds (such as lead acetate, calcium carbonate), and fatty acid soaps (such as calcium phthalocyanine blue, calcium stearate).

[0040] In the above-mentioned self-healing polyurethane-toughened PVC composite material, the lubricant is at least one of polyethylene wax, paraffin wax, and stearic acid.

[0041] In the above-mentioned self-healing polyurethane-toughened PVC composite material, the antioxidant is at least one of phosphite esters (such as triphenyl phosphite) and hindered phenols (such as bisphenol A, tri-tert-butylhydroxybenzene, and di-tert-butyl-p-cresol).

[0042] In the aforementioned self-healing polyurethane-toughened PVC composite material, the pigment is at least one of iron oxide brown, titanium dioxide, and carbon black.

[0043] In the above-mentioned self-healing polyurethane-toughened PVC composite material, the light stabilizer is at least one of benzotriazole, benzophenone, nickel dithiocarbamate, salicylate, hindered amine, thiobisphenol, and zinc oxide.

[0044] This invention also provides a method for preparing the above-mentioned self-healing polyurethane-toughened PVC composite material, comprising the following steps:

[0045] S1: Mix PVC, self-healing polyurethane elastomer, compatibilizer, lubricant, and coupling agent thoroughly;

[0046] The mixing described in step S1 involves stirring in a pulverizer at 500-1500 r / min for 1-5 minutes;

[0047] S2: Then add plasticizer, heat stabilizer, antioxidant, light stabilizer, nanomaterials, and pigment, mix well, and obtain a mixture;

[0048] In step S2, after each ingredient is added, stir at 500-1500 rpm for 1-5 minutes until the mixture is homogeneous;

[0049] S3: Extrude and granulate the mixture.

[0050] The extrusion process parameters described in step S3 are as follows: a twin-screw extruder is used, with the temperature in zone 1 being 150-160℃, zone 2 being 160-175℃, zone 3 being 175-180℃, and zone 4 being 180-190℃; the residence time is 1-2 min; the pressure is 10-15 MPa; the rotation speed is 70-150 r / min; and the traction speed is 0.1-5 m / min.

[0051] The composite material of this invention is used to manufacture drainage pipes.

[0052] The present invention has the following advantages and beneficial effects:

[0053] (1) The self-healing polyurethane elastomer required by the present invention has a simple synthesis method, other raw materials are cheap and readily available, the process is simple to operate, and it can be prepared in large quantities.

[0054] (2) The self-healing polyurethane toughened PVC composite material prepared by the present invention has excellent toughness, impact strength and tensile strength; the present invention can adjust the strength and toughness of PVC composite material by changing the equivalent ratio of soft and hard segments in the polyurethane elastomer molecular chain, etc., and improve toughness without sacrificing strength.

[0055] (3) The self-healing polyurethane toughened PVC composite material prepared by the present invention has a high cost performance, so the prepared PVC composite material pipe is expected to be used on a large scale in the field of water supply and drainage. Detailed Implementation

[0056] The present invention will be described in further detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0057] In the embodiments of the present invention, the polyurethane elastomer is prepared by the following method:

[0058] (1) Preparation of LCA-EG: Lithocholic acid (4.665 g, 12.39 mmol) was dissolved in 24 mL DMSO, and ethylene glycol (50 mL, 896 mmol) was added. After stirring evenly, 500 μL hydrochloric acid was added to the reaction system and the reaction was carried out at 80 °C for 5 hours. The reaction system was precipitated in 5 wt% NaHCO3 solution. Subsequently, the precipitate was filtered to obtain a white solid. The white solid was washed several times with deionized water to obtain the purified product. Finally, the product was dried under vacuum at 50 °C for 24 hours to obtain LCA-EG.

[0059] (2) Preparation of LCA-PU: LCA-EG (0.75g, 1.783mmol) and PEG were mixed. 400 (1189 mg, 2.971 mmol) was dissolved in 12 mL of DMF. After complete dissolution, the mixture was vacuum-treated at room temperature for 20 min, then vacuum-treated at 90 °C for 20 min. Under a nitrogen atmosphere, hexamethylene diisocyanate (1070 μL, 6.679 mmol) was rapidly added, followed by 25 μL of dibutyltin dilaurate catalyst. The mixture was stirred at 80 °C for 3 h. The reactants were then cast at 80 °C for 12 h and then vacuum-dried at 50 °C for 24 h to obtain LCA-PU.

[0060] Example 1

[0061] Self-healing polyurethane-toughened PVC composite material was prepared using the following weight ratios: 50 parts polyvinyl chloride, 30 parts polyurethane elastomer, 5 parts chlorinated polyethylene, 3 parts nano-calcium carbonate (particle size 10000 mesh, manufactured by Guangshuo Chemical Co., Ltd., model GS-6), 2 parts titanate coupling agent (model NDZ201), 5 parts diisooctyl phthalate, 3 parts methyl mercaptan, 0.5 parts polyethylene wax, 0.5 parts triphenyl phosphite, 0.5 parts iron oxide brown, and 0.5 parts benzophenone.

[0062] The following preparation method is used:

[0063] a. Weigh out each raw material according to the proportion and set aside. Add the five raw materials, namely PVC, polyurethane elastomer, compatibilizer, lubricant and coupling agent, into the multi-functional pulverizer and stir at 700r / min for 2 minutes until they are evenly mixed.

[0064] b. Then add plasticizer, heat stabilizer, antioxidant, light stabilizer, nanomaterials and pigment in sequence. Stir at 700 r / min for 3 minutes after each addition until the mixture is uniform.

[0065] c. Finally, add the mixture to the barrel of the twin-screw extruder, heat and mix, and then extrude and granulate.

[0066] The processing parameters for the twin-screw extruder are as follows:

[0067] The twin-screw extruder has a zone temperature of 155℃, a zone temperature of 165℃, a zone temperature of 180℃, a zone temperature of 185℃, a residence time of 1 minute, a pressure of 10MPa, a rotation speed of 100r / min, and a traction speed of 0.1m / min.

[0068] Example 2

[0069] Self-healing polyurethane-toughened PVC composite material was prepared using the following weight ratios: 60 parts polyvinyl chloride, 20 parts polyurethane elastomer, 5 parts chlorinated polyethylene, 3 parts nano-calcium carbonate, 2 parts titanate coupling agent NDZ201, 5 parts diisooctyl phthalate, 3 parts methyl mercaptan, 0.5 parts polyethylene wax, 0.5 parts triphenyl phosphite, 0.5 parts iron oxide brown, and 0.5 parts benzophenone.

[0070] The preparation method and processing parameters are the same as in Example 1.

[0071] Example 3

[0072] Self-healing polyurethane-toughened PVC composite material was prepared using the following weight ratios: 70 parts polyvinyl chloride, 10 parts polyurethane elastomer, 5 parts chlorinated polyethylene, 3 parts nano-calcium carbonate, 2 parts titanate coupling agent NDZ201, 5 parts diisooctyl phthalate, 3 parts methyl mercaptan, 0.5 parts polyethylene wax, 0.5 parts triphenyl phosphite, 0.5 parts iron oxide brown, and 0.5 parts benzophenone.

[0073] The preparation method and processing parameters are the same as in Example 1.

[0074] Comparative Example 1

[0075] Toughened PVC composite material of methyl methacrylate-butadiene-styrene copolymer (MBS) was prepared using the following weight ratio: 60 parts polyvinyl chloride, 20 parts MBS, 5 parts chlorinated polyethylene, 3 parts nano-calcium carbonate, 12 parts titanate coupling agent NDZ201, 5 parts diisooctyl phthalate, 3 parts methyl mercaptan, 0.5 parts polyethylene wax, 0.5 parts triphenyl phosphite, 0.5 parts iron oxide brown, and 0.5 parts benzophenone.

[0076] The comparative example replaced the polyurethane elastomer with MBS, a common PVC toughening agent.

[0077] The preparation method and processing parameters are the same as in Example 1.

[0078] Comparative Example 2

[0079] The following weight ratio was used to prepare a PVC composite material toughened with polyurethane elastomer: 60 parts polyvinyl chloride, 20 parts polyurethane elastomer, 5 parts chlorinated polyethylene, 3 parts nano calcium carbonate, 2 parts titanate coupling agent NDZ201, 5 parts diisooctyl phthalate, 3 parts methyl mercaptan, 0.5 parts polyethylene wax, 0.5 parts triphenyl phosphite, 0.5 parts iron oxide brown, and 0.5 parts benzophenone.

[0080] The preparation method of the polyurethane elastomer in this comparative example:

[0081] PEG 400 (1189 mg, 2.971 mmol) was dissolved in 10 mL of DMF. After complete dissolution, the mixture was vacuum-treated at room temperature for 20 min, then vacuum-treated at 90 °C for 20 min. Under a nitrogen atmosphere, hexamethylene diisocyanate (535 μL, 3.340 mmol) was rapidly added, followed by 15 μL of dibutyltin dilaurate catalyst. The mixture was stirred at 80 °C for 3 h. The reactants were then cast at 80 °C for 12 h, and then vacuum-dried at 50 °C for 24 h to obtain PU.

[0082] The preparation method and processing parameters are the same as in Example 1.

[0083] The performance test results of the composite materials prepared in Examples 1-3 and Comparative Examples 1-2 are shown in Table 1.

[0084] Table 1 Performance Tests of PVC Composite Materials

[0085] Test Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tensile strength (MPa) 34.21 36.04 37.15 31.34 36.86 Flexural modulus of elasticity (MPa) 1597 1872 2196 1342 1643 <![CDATA[Falling weight impact test (kJ / m 2 )]]> 7.90 8.40 10.42 6.78 9.12

[0086] The self-healing polyurethane-toughened PVC composite material provided by this invention has excellent toughness, impact strength, and tensile strength, comparable to MBS-toughened PVC composite materials. While PVC materials toughened with diisocyanate as the hard segment of polyurethane elastomer have high hardness and strength, they have poor flexibility.

Claims

1. A self-healing polyurethane-toughened polyvinyl chloride composite material, characterized in that: It is prepared from the following components in parts by weight: 50-70 parts polyvinyl chloride, 10-40 parts self-healing polyurethane elastomer, 3-10 parts compatibilizer, 2-10 parts nanomaterials, 0.5-8 parts coupling agent, 3-10 parts plasticizer, 1-8 parts heat stabilizer, 0.5-4 parts lubricant, 0.5-3 parts antioxidant, 0.5-2 parts pigment, and 0.5-2 parts light stabilizer; The self-healing polyurethane elastomer is prepared by the following method: 1) Lithocholic acid is reacted with ethylene glycol to obtain bile acid diol monomer; 2) Using an organic solvent as the reaction medium, bile acid diol monomer, polyethylene glycol and hexamethylene diisocyanate are reacted under the action of a catalyst to obtain a self-healing polyurethane elastomer. The structure of the bile acid diol monomer is as follows: ； The molecular weight of the polyethylene glycol mentioned in step 2) is 200-600; The organic solvent mentioned in step 2) is one or more of N,N-dimethylformamide and xylene; the reaction temperature is 80-100℃, the reaction time is 3-8 hours; the reaction is carried out under a protective atmosphere. In step 2), the molar ratio of bile acid diol monomer, polyethylene glycol, and hexamethylene diisocyanate is (0.7~1.3):(0.7~1.3):(2-3); when the molar amount of bile acid diol monomer is 0.7~1.3 parts and the molar amount of polyethylene glycol is 0.7~1.3 parts, the total molar amount of bile acid diol monomer and polyethylene glycol is 2 parts.

2. The self-healing polyurethane-toughened polyvinyl chloride composite material according to claim 1, characterized in that: The content of the self-healing polyurethane elastomer is 10-30 parts; In the preparation of self-healing polyurethane elastomer, the molecular weight of the polyethylene glycol mentioned in step 2) is 300~500; The molar ratio of bile acid diol monomer, polyethylene glycol and hexamethylene diisocyanate in step 2) is (0.7~1.3):(0.7~1.3):(2.5-3). The catalyst mentioned in step 2) is dibutyltin dilaurate or organic bismuth; After the reaction in step 2) is completed, the mixture is poured, dried, reconstituted, and molded; the pouring temperature is 80-100℃, and the pouring time is 8-15 hours; the drying is vacuum drying.

3. The self-healing polyurethane-toughened polyvinyl chloride composite material according to claim 1, characterized in that: In the preparation of self-healing polyurethane elastomer, the reaction in step 1) uses an organic solvent as the reaction medium, wherein the organic solvent is one or more of dimethyl sulfoxide, N,N-dimethylformamide, benzene, xylene, and chloroform; the reaction in step 1) is carried out under the catalysis of a catalyst; the catalyst is an acid, and after the acid is added, the pH of the system is 2.5~3.5; the molar ratio of lithocholic acid to ethylene glycol in step 1) is 1:(50-100); the reaction temperature in step 1) is 75~85℃, and the reaction time is 3~6h; after the reaction is complete, precipitation is carried out using a precipitant, followed by filtration, washing, and drying; In the self-healing polyurethane-toughened polyvinyl chloride composite material, the compatibilizer is at least one of styrene-maleic anhydride copolymer, ethylene-propylene copolymer, chlorinated polyethylene, silane coupling agent, and maleic anhydride graft copolymer; the silane coupling agent is vinyltriethoxysilane or γ-glycidylpropoxytrimethoxysilane; and the maleic anhydride graft copolymer is maleic anhydride-grafted styrene copolymer. The nanomaterial is at least one of wollastonite, calcium carbonate, talc, barium sulfate, titanium dioxide, or whiskers.

4. The self-healing polyurethane-toughened polyvinyl chloride composite material according to claim 1, characterized in that: In self-healing polyurethane-toughened polyvinyl chloride composites, The coupling agent is at least one of titanate coupling agents, aluminum-titanium coupling agents, aluminate coupling agents, and silane coupling agents; The plasticizer is at least one of the following: acrylate polymer copolymer, polyethylene graft chloride, citric acid esters, epoxidized soybean oil, and diisooctyl phthalate.

5. The self-healing polyurethane-toughened polyvinyl chloride composite material according to claim 4, characterized in that: The acrylate polymer copolymer is a methyl methacrylate / acrylate copolymer or an acrylate / styrene copolymer; the polyethylene graft chloride is chlorinated polyethylene; the citric acid ester is one or more of tributyl citrate and ethyl tributyl citrate.

6. The self-healing polyurethane-toughened polyvinyl chloride composite material according to claim 1, characterized in that: The heat stabilizer is at least one of organotin stabilizers, bases, and fatty acid soaps; The lubricant is at least one of polyethylene wax, paraffin wax, and stearic acid; The antioxidant is at least one of phosphites and hindered phenols; The pigment is at least one of iron oxide brown, titanium dioxide, and carbon black; The light stabilizer is at least one of benzotriazole, benzophenone, nickel dithiocarbamate, salicylate, hindered amine, thiobisphenol, and zinc oxide.

7. The method for preparing the self-healing polyurethane-toughened polyvinyl chloride composite material according to any one of claims 1 to 6, characterized in that: Includes the following steps: S1: Mix polyvinyl chloride, self-healing polyurethane elastomer, compatibilizer, lubricant, and coupling agent evenly; S2: Then add plasticizer, heat stabilizer, antioxidant, light stabilizer, nanomaterials, and pigment, mix well, and obtain a mixture; S3: Extrude and granulate the mixture.

8. The method for preparing the self-healing polyurethane-toughened polyvinyl chloride composite material according to claim 7, characterized in that: The mixing described in step S1 involves stirring in a pulverizer at 500-1500 r / min for 1-5 minutes; In step S2, after each ingredient is added, stir at 500-1500 r / min for 1-5 minutes until the mixture is homogeneous; The extrusion process parameters described in step S3 are as follows: a twin-screw extruder is used, with the temperature in zone 1 being 150-160℃, zone 2 being 160-175℃, zone 3 being 175-180℃, and zone 4 being 180-190℃; the residence time is 1-2 min; the pressure is 10-15 MPa; the rotation speed is 70-150 r / min; and the traction speed is 0.1-5 m / min.

9. The application of the self-healing polyurethane-toughened polyvinyl chloride composite material according to any one of claims 1 to 6, characterized in that: The self-healing polyurethane-toughened polyvinyl chloride composite material is used to manufacture drainage pipes.

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