PVC composite material with antibacterial effect and preparation method thereof

Abstract

The invention relates to the technical field of composite materials, and discloses a PVC composite material with an antibacterial effect and a preparation method thereof.The PVC composite material is prepared from PVC, a plasticizer, a calcium-zinc stabilizer, filler, a lubricant, an antibacterial additive and a composite functional component, and the antibacterial additive is added in the preparation process of the PVC composite material, so that the antibacterial effect is achieved; the antibacterial PVC composite material has the advantages that the antibacterial PVC composite material has excellent mechanical properties and long-term and efficient antibacterial properties by adding the composite functional components in the preparation process of the PVC composite material, interaction with molecular chains of the PVC matrix can be generated, external impact energy can be absorbed and dispersed, crack propagation can be slowed down or prevented, the toughness of the PVC composite material can be effectively enhanced, and the service life of the PVC composite material can be prolonged. And the PVC composite material contains flavonoid molecules which can be synergistically antibacterial with antibacterial additives, and can effectively inhibit the oxidation process, so that the oxidation resistance of the PVC composite material is improved, and the service life of the PVC composite material is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a PVC composite material with antibacterial effect and a preparation method thereof. Background Art

[0002] PVC material, also known as polyvinyl chloride material, is a widely used plastic material with many advantages. For example, PVC material is affordable and suitable for large-scale production. PVC material has excellent tolerance to chemical substances and can resist corrosion from acid, alkali and other chemical substances. PVC material has excellent electrical insulation and flame retardancy, which can reduce the risk of fire to a certain extent. At the same time, PVC material has good processing performance and can be processed into products of various sizes and shapes through various processing methods such as extrusion, injection molding, blow molding, etc. Therefore, it is widely used in construction, automobiles, electronics, packaging, medical care, agriculture and other fields. However, the antibacterial and antioxidant properties of PVC materials are insufficient, which limits the application of PVC materials in some fields. Therefore, it is necessary to modify PVC materials.

[0003] The patent with the publication number of CN116496587B discloses a method for preparing an enhanced antibacterial PVC composite material. The method comprises the following steps: mixing a solution formed by mixing clove essential oil, tea polyphenols and Span80 with a chitosan solution and adding a sodium tripolyphosphate solution to obtain microcapsules; reacting carboxylated carbon nanotubes, oxalyl chloride, DMF, pyridine and hyperbranched polyamide HyperN102 to obtain hyperbranched polyamide grafted modified carbon nanotubes; modifying the hyperbranched polyamide grafted modified carbon nanotubes to obtain hyperbranched polyamide-nickel co-modified carbon nanotubes; finally, mixing the microcapsules, the hyperbranched polyamide-nickel co-modified carbon nanotubes and PVC particles, and melt-blending the mixture in a mixer to obtain a PVC composite material. The PVC composite material has excellent mechanical properties while ensuring antibacterial properties. However, the patent does not take into account the poor antioxidant properties of the PVC material, which limits the application of the PVC material. Therefore, the present invention provides a PVC composite material with antibacterial effect. The PVC composite material has excellent mechanical properties and toughness while maintaining excellent antibacterial and antioxidant properties, and has broad application prospects. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the object of the present invention is to provide a PVC composite material with antibacterial effect and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A PVC composite material with antibacterial effect comprises the following raw materials in parts by weight: 75-90 parts of PVC, 20-35 parts of plasticizer, 2-5 parts of calcium zinc stabilizer, 5-10 parts of filler, 0.5-2 parts of lubricant, 3-5 parts of antibacterial additives and 4-6 parts of composite functional components.

[0007] Furthermore, the plasticizer is any one of butyl benzyl phthalate, dialkyl adipate, dioctyl adipate, tri-n-ethyl butyryl citrate or dicyclohexyl phthalate; the filler is calcium carbonate or talc; and the lubricant is any one of polyethylene wax, paraffin or paraffin oil.

[0008] Furthermore, the preparation method of the antibacterial additive comprises the following steps:

[0009] Step T1, adding acrylic fiber to a sodium hydroxide solution, stirring evenly, raising the temperature to 85-95° C., treating for 25-45 minutes, filtering, washing, and drying to obtain pretreated acrylic fiber;

[0010] Step T2, disodium hydrogen phosphate dodecahydrate and sodium dihydrogen phosphate are configured into a phosphate buffer with a pH of 5.6-5.8, and then the pretreated acrylic fiber is added to the phosphate buffer, and then the composite catalyst and dopamine are added, stirred for 8-10 hours, and the solid product is separated, washed, and dried to obtain the modified acrylic fiber;

[0011] Step T3, adding the modified acrylic fiber to the copper salt solution, stirring for 2-4 hours at room temperature, filtering, washing, and drying to obtain an antibacterial additive.

[0012] By adopting the above technical scheme, after the acrylic fiber is treated with an alkaline solution, carboxyl active groups appear in the molecular chain of the acrylic fiber, thereby obtaining a pretreated acrylic fiber. Under the action of a composite catalyst, the active carboxyl groups in the pretreated acrylic fiber can react with the amino groups in the dopamine structure, thereby introducing phenolic hydroxyl groups into the acrylic fiber, thereby obtaining a modified acrylic fiber. The amino groups and phenolic hydroxyl groups contained in the modified acrylic fiber can form a coordination effect with the copper ions in the copper salt solution, thereby loading the copper ions on the surface of the acrylic fiber, thereby obtaining an antibacterial additive. The antibacterial additive prepared by the present invention uses acrylic fiber as a matrix. The acrylic fiber is an organic fiber with high strength, has good interface bonding force with a PVC matrix material, can be evenly dispersed in the PVC material, increases the surface roughness of the fiber after being combined with dopamine, and dopamine has an adhesion effect, so that the interface bonding with the PVC matrix material is more firm. When subjected to external force, it can ensure that effective load transfer can be achieved between the acrylic fiber and the matrix material, thereby enhancing the mechanical properties of the composite material. At the same time, the coordination effect of dopamine and copper ions is utilized to load copper ions on the surface of the acrylic fiber, thereby avoiding a large amount of copper ions from being lost, and further utilizing the high-efficiency antibacterial ability of copper ions to endow the PVC composite material with excellent and long-lasting antibacterial properties.

[0013] Furthermore, in step T1, the mass fraction of the sodium hydroxide solution is 5-7%.

[0014] Furthermore, in step T2, the composite catalyst is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and N-hydroxysuccinimide in a mass ratio of 0.8-1:0.2-0.4.

[0015] Furthermore, in step T3, the copper salt solution is a copper sulfate solution or a copper chloride solution.

[0016] Furthermore, the preparation method of the composite functional component comprises the following steps:

[0017] Step A, adding hydroxy-terminated polypropylene carbonate to tetrahydrofuran, mixing evenly, adding 3-chloropropyl isocyanate and a tin catalyst, raising the temperature to 55-60° C., reacting for 2-4 hours, precipitating, washing, and vacuum drying to obtain an intermediate material;

[0018] Step B, adding the intermediate material into dimethyl sulfoxide, mixing evenly, introducing nitrogen, adding genistein and alkaline catalyst, raising the temperature to 65-80°C, stirring the reaction for 4-6 hours, cooling the material, washing, and drying to obtain a composite functional component.

[0019] By adopting the above technical scheme, the terminal hydroxyl group in the terminal hydroxyl polypropylene carbonate structure can react with the isocyanate group in the 3-chloropropyl isocyanate structure under the action of a tin catalyst, thereby introducing a chlorine substituent to obtain an intermediate material. Under the action of an alkaline catalyst, the chlorine substituent in the intermediate material structure can react with the hydroxyl group in the genistein structure to obtain a composite functional component. The composite functional component prepared by the present invention contains genistein with antioxidant and antibacterial effects, which is introduced into the terminal hydroxy polypropylene carbonate in a chemical bonding manner, can effectively exist in the PVC matrix material for a long time, will not easily migrate, remove free radicals and terminate the chain reaction of free radicals, inhibit the oxidation process, delay the aging process, and extend the service life of the PVC composite material. At the same time, a synergistic antibacterial effect is formed with the antibacterial composite material. In addition, the terminal hydroxy polypropylene carbonate in the composite functional component can serve as a stress concentration point, absorb and disperse external impact energy, slow down or prevent the expansion of cracks, and effectively enhance the toughness of the PVC composite material. At the same time, the carbamate in the structure of the composite functional component can interact with the PVC matrix molecular chain, thereby improving the interface bonding force. When subjected to external force, it is more difficult for the molecular chains to slide and separate relative to each other, and the toughness of the PVC composite material can be further enhanced.

[0020] Furthermore, in step A, the tin catalyst is dibutyltin dilaurate or stannous octoate.

[0021] Furthermore, in step B, the alkaline catalyst is anhydrous potassium carbonate or anhydrous sodium carbonate.

[0022] A method for preparing a PVC composite material with antibacterial effect comprises the following steps:

[0023] Step 1: Add PVC, plasticizer, calcium zinc stabilizer, filler, lubricant, antibacterial additive and composite functional component into a mixer, stir and mix them evenly at a speed of 400-600 r / min and 125-140° C. to obtain a mixed material;

[0024] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 180-200° C. to obtain a PVC composite material.

[0025] Beneficial effects of the present invention:

[0026] The present invention prepares antibacterial additives and composite functional components and adds them into the preparation process of PVC composite materials, so that the prepared PVC composite materials have excellent mechanical properties, antibacterial properties, toughness and antioxidant properties, the tensile strength can reach up to 26.3MPa, the antibacterial rate can reach up to 99.9%, the elongation at break can reach up to 313.8%, and the tensile strength retention rate of the PVC composite materials after aging can reach up to 98.6%. The PVC composite materials have a long service life and broad application prospects.

[0027] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 This is the infrared spectrum of the composite functional component prepared by the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0031] The preparation methods of the antibacterial additives and composite functional components in the following examples and comparative examples are as follows:

[0032] 1. Preparation of antibacterial additives

[0033] Step T1, adding 3 g of acrylic fiber into a 6% sodium hydroxide solution by mass, stirring evenly, raising the temperature to 90° C., treating for 35 min, filtering, washing, and drying to obtain pretreated acrylic fiber;

[0034] Step T2, 2 mol / L of disodium hydrogen phosphate dodecahydrate and 2 mol / L of sodium dihydrogen phosphate are configured into a phosphate buffer with a pH of 5.7, 3 g of pretreated acrylic fiber is added to the phosphate buffer, and then 0.4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, 0.1 g of N-hydroxysuccinimide and 2 g of dopamine are added, stirred for 8 h, the solid product is separated, washed, and dried to obtain modified acrylic fiber;

[0035] Step T3, add 2.8 g of modified acrylic fiber into 10 mL of 0.06 g / mL copper sulfate solution, stir for 3 h at room temperature, filter, wash, and dry to obtain an antibacterial additive.

[0036] 1 g of the antibacterial additive was taken and the copper content of the antibacterial additive was tested using a WFX-910 atomic absorption spectrometer. The mass fraction of copper in the antibacterial additive was found to be 6.68% by weight.

[0037] 2. Preparation of composite functional components

[0038] Step A, add 3.8 g of terminal hydroxyl polypropylene carbonate to tetrahydrofuran, mix well, add 2 g of 3-chloropropyl isocyanate and 0.2 g of dibutyltin dilaurate, raise the temperature to 58° C., react for 3 h, precipitate, wash, and vacuum dry to obtain an intermediate material;

[0039] Step B: Add 3.5 g of the intermediate material to dimethyl sulfoxide, mix well, introduce nitrogen, add 1.8 g of genistein and 0.4 g of anhydrous potassium carbonate, raise the temperature to 75°C, stir and react for 5 hours, cool and discharge, wash and dry to obtain a composite functional component.

[0040] Infrared testing of composite functional components, such as Figure 1 As shown, analysis shows that 3075cm -1 The absorption peak of carbon and hydrogen in the benzene ring appeared at 1708cm -1 The absorption peak of the carbon-oxygen double bond in carbamate appeared at 1540 cm -1 The absorption peak of nitrogen-hydrogen bond appeared at 1089cm -1 The absorption peak of ether bond appeared at

[0041] Example 1

[0042] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 75g of PVC, 20g of dicyclohexyl phthalate, 2g of calcium zinc stabilizer, 5g of calcium carbonate, 0.5g of polyethylene wax, 3g of antibacterial additive, and 4g of composite functional components;

[0043] The preparation method of the PVC composite material comprises the following steps:

[0044] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax, antibacterial additives and composite functional components into a mixer, stirring and mixing at a speed of 400 r / min and 125° C. to obtain a mixed material;

[0045] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 180° C. to obtain a PVC composite material.

[0046] Example 2

[0047] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 80g of PVC, 25g of dicyclohexyl phthalate, 3g of calcium zinc stabilizer, 6g of calcium carbonate, 1g of polyethylene wax, 3.5g of antibacterial additive, and 4.5g of composite functional components;

[0048] The preparation method of the PVC composite material comprises the following steps:

[0049] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax, antibacterial additives and composite functional components into a mixer, stirring and mixing at a speed of 450 r / min and 130° C. to obtain a mixed material;

[0050] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 190° C. to obtain a PVC composite material.

[0051] Example 3

[0052] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 85g of PVC, 30g of dicyclohexyl phthalate, 4g of calcium zinc stabilizer, 7g of calcium carbonate, 1.5g of polyethylene wax, 4.5g of antibacterial additive, and 5.5g of composite functional components;

[0053] The preparation method of the PVC composite material comprises the following steps:

[0054] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax, antibacterial additives and composite functional components into a mixer, stirring and mixing at a speed of 500 r / min and 135° C. to obtain a mixed material;

[0055] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 190° C. to obtain a PVC composite material.

[0056] Example 4

[0057] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 90g of PVC, 35g of dicyclohexyl phthalate, 5g of calcium zinc stabilizer, 10g of calcium carbonate, 2g of polyethylene wax, 5g of antibacterial additive, and 6g of composite functional components;

[0058] The preparation method of the PVC composite material comprises the following steps:

[0059] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax, antibacterial additives and composite functional components into a mixer, stirring and mixing at a speed of 600 r / min and 140° C. to obtain a mixed material;

[0060] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 200° C. to obtain a PVC composite material.

[0061] Comparative Example 1

[0062] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 85g of PVC, 30g of dicyclohexyl phthalate, 4g of calcium zinc stabilizer, 7g of calcium carbonate, 1.5g of polyethylene wax, and 4.5g of antibacterial additive;

[0063] The preparation method of the PVC composite material comprises the following steps:

[0064] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax and antibacterial additives into a mixer, stirring and mixing at a speed of 500 r / min and 135° C. to obtain a mixed material;

[0065] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 190° C. to obtain a PVC composite material.

[0066] Comparative Example 2

[0067] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 85g of PVC, 30g of dicyclohexyl phthalate, 4g of calcium zinc stabilizer, 7g of calcium carbonate, 1.5g of polyethylene wax, and 5.5g of composite functional components;

[0068] The preparation method of the PVC composite material comprises the following steps:

[0069] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax and composite functional components into a mixer, stirring and mixing at a speed of 500 r / min and 135° C. to obtain a mixed material;

[0070] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 190° C. to obtain a PVC composite material.

[0071] Comparative Example 3

[0072] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 85g of PVC, 30g of dicyclohexyl phthalate, 4g of calcium zinc stabilizer, 7g of calcium carbonate, 1.5g of polyethylene wax, 4.5g of acrylic fiber, and 5.5g of composite functional components;

[0073] The preparation method of the PVC composite material comprises the following steps:

[0074] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax, acrylic fiber and composite functional components into a mixer, stirring and mixing at a speed of 500 r / min and 135° C. to obtain a mixed material;

[0075] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 190° C. to obtain a PVC composite material.

[0076] Comparative Example 4

[0077] A PVC composite material with antibacterial effect, comprising the following raw materials in parts by weight: 85g of PVC, 30g of dicyclohexyl phthalate, 4g of calcium zinc stabilizer, 7g of calcium carbonate, 1.5g of polyethylene wax, 4.5g of antibacterial additive, and 5.5g of terminal hydroxyl polypropylene carbonate;

[0078] The preparation method of the PVC composite material comprises the following steps:

[0079] Step 1, adding PVC, dicyclohexyl phthalate, calcium zinc stabilizer, calcium carbonate, polyethylene wax, antibacterial additive and terminal hydroxy polypropylene carbonate into a mixer, stirring and mixing at a speed of 500 r / min and 135° C. to obtain a mixed material;

[0080] Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 190° C. to obtain a PVC composite material.

[0081] Performance Testing

[0082] The PVC composite materials prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were prepared into samples that met the test specifications. The tensile strength and elongation at break of the samples were tested according to GB / T 1040.3-2006, so as to judge the mechanical properties and toughness of the samples. After the samples were aged at 100°C for 12 hours, the tensile strength after aging was tested again, and the tensile strength retention rate was calculated according to the formula of tensile strength retention rate (%) = (tensile strength after aging / initial tensile strength) × 100%, so as to judge the antioxidant properties of the samples. According to GB / T31402-2023 standard, Staphylococcus aureus was used as the test strain, and the antibacterial rate was calculated according to the formula of antibacterial rate (%) = [(number of live bacteria in the blank control group - number of live bacteria in the sample group) / number of live bacteria in the blank control group] × 100%, so as to judge the antibacterial properties of the samples. The test results are shown in the following table:

[0083]

[0084]

[0085] It can be seen from the above table that the PVC composite materials prepared by Examples 1 to 4 of the present invention have excellent mechanical properties, antibacterial properties, toughness and antioxidant properties. Comparative Example 1 adds antibacterial additives but does not add composite functional components, and has excellent mechanical properties and antibacterial properties, but poor toughness and antioxidant properties; Comparative Example 2 adds composite functional components but does not add antibacterial additives, and has excellent toughness and antioxidant properties, but poor mechanical properties and antibacterial properties; Comparative Example 3 adds acrylic fiber and composite functional components, and copper ions cannot be used for efficient antibacterial, so the mechanical properties are good but the antibacterial properties are poor, and the toughness and antioxidant properties are excellent; Comparative Example 4 adds antibacterial additives and terminal hydroxy polypropylene carbonate, and has excellent mechanical properties and antibacterial properties, but poor antioxidant properties.

[0086] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A PVC composite material with antibacterial effect, characterized in that: The invention comprises the following raw materials in parts by weight: 75-90 parts of PVC, 20-35 parts of plasticizer, 2-5 parts of calcium zinc stabilizer, 5-10 parts of filler, 0.5-2 parts of lubricant, 3-5 parts of antibacterial additive and 4-6 parts of composite functional components.

2. The PVC composite material with antibacterial effect according to claim 1, characterized in that: The plasticizer is any one of butyl benzyl phthalate, dialkyl adipate, dioctyl adipate, tri-n-ethyl butyryl citrate or dicyclohexyl phthalate; the filler is calcium carbonate or talc; and the lubricant is any one of polyethylene wax, paraffin or paraffin oil.

3. The PVC composite material with antibacterial effect according to claim 1, characterized in that: The preparation method of the antibacterial additive comprises the following steps: Step T1, adding acrylic fiber to a sodium hydroxide solution, stirring evenly, raising the temperature to 85-95° C., treating for 25-45 minutes, filtering, washing, and drying to obtain pretreated acrylic fiber; Step T2, disodium hydrogen phosphate dodecahydrate and sodium dihydrogen phosphate are configured into a phosphate buffer with a pH of 5.6-5.8, and then the pretreated acrylic fiber is added to the phosphate buffer, and then the composite catalyst and dopamine are added, stirred for 8-10 hours, and the solid product is separated, washed, and dried to obtain the modified acrylic fiber; Step T3, adding the modified acrylic fiber to the copper salt solution, stirring for 2-4 hours at room temperature, filtering, washing, and drying to obtain an antibacterial additive.

4. The PVC composite material with antibacterial effect according to claim 3, characterized in that: In step T1, the mass fraction of the sodium hydroxide solution is 5-7%.

5. The PVC composite material with antibacterial effect according to claim 3, characterized in that: In step T2, the composite catalyst is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and N-hydroxysuccinimide in a mass ratio of 0.8-1:0.2-0.

4.

6. The PVC composite material with antibacterial effect according to claim 3, characterized in that: In step T3, the copper salt solution is a copper sulfate solution or a copper chloride solution.

7. The PVC composite material with antibacterial effect according to claim 1, characterized in that: The preparation method of the composite functional component comprises the following steps: Step A, adding hydroxy-terminated polypropylene carbonate to tetrahydrofuran, mixing evenly, adding 3-chloropropyl isocyanate and a tin catalyst, raising the temperature to 55-60° C., reacting for 2-4 hours, precipitating, washing, and vacuum drying to obtain an intermediate material; Step B, adding the intermediate material into dimethyl sulfoxide, mixing evenly, introducing nitrogen, adding genistein and alkaline catalyst, raising the temperature to 65-80°C, stirring the reaction for 4-6 hours, cooling the material, washing, and drying to obtain a composite functional component.

8. The PVC composite material with antibacterial effect according to claim 7, characterized in that: In step A, the tin catalyst is dibutyltin dilaurate or stannous octoate.

9. The PVC composite material with antibacterial effect according to claim 7, characterized in that: In step B, the alkaline catalyst is anhydrous potassium carbonate or anhydrous sodium carbonate.

10. A method for preparing a PVC composite material with antibacterial effect as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Add PVC, plasticizer, calcium zinc stabilizer, filler, lubricant, antibacterial additive and composite functional component into a mixer, stir and mix them evenly at a speed of 400-600 r / min and 125-140° C. to obtain a mixed material; Step 2: Add the mixed material into a twin-screw extruder, melt-extrude and granulate at 180-200° C. to obtain a PVC composite material.

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