Method for modifying the surface of polyvinyl chloride material with functional isocyanate crosslinking agent

Abstract

The present invention provides a method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent. The functional isocyanate crosslinking agent has a polyether chain in its molecular structure, and the two ends of the polyether chain are respectively connected to sulfobetaine and isocyanate groups. The isocyanate group can chemically crosslink and modify the polyvinyl chloride material whose surface has been activated; at the same time, the isocyanate group is used as a spacer arm to bond the sulfobetaine unit to the surface of the polyvinyl chloride material in a "prone" and "attached" manner through the polyether chain, thereby giving the polyvinyl chloride surface strong hydrophilicity, smoothness after being wetted with water, conductivity, antibacterial properties, antifogging and anti-fouling, anti-coagulation and enhanced mechanical properties.

Description

Technical Field

[0001] The invention relates to a method for modifying the surface of a polyvinyl chloride material with an isocyanate crosslinking agent, and in particular to a method for crosslinking and modifying the surface of polyvinyl chloride using a functional isocyanate crosslinking agent containing disulfobetaine and a polyether chain in a molecular structure to make the surface hydrophilic, antibacterial, anticoagulant and biocompatibility enhanced, belonging to the field of functional polymer materials. Technical Background

[0002] Polyvinyl chloride is a general-purpose plastic. Due to its excellent mechanical properties, low cytotoxicity and low price, it is often used as a raw material for the production of medical catheters, hemodialysis tubing, blood storage bags, urine storage bags or marine aquaculture cages. However, the surface of polyvinyl chloride materials is hydrophobic and has no antibacterial and antimicrobial properties. It cannot be directly used in medical treatment or marine aquaculture. For this reason, people have been tirelessly researching and developing the hydrophilicity, antibacterial properties, or biocompatibility and anticoagulant properties of the surface of polyvinyl chloride materials. The main method to improve the hydrophilicity, antibacterial properties, anticoagulant properties and biocompatibility of the surface of polyvinyl chloride materials is to graft three major types of hydrophilic substances such as polyethylene glycol, carboxybetaine / sulfobetaine / phosphorylcholine, or heparin on its surface. Polyethylene glycol is a hydrophilic polymer. Because of its good anti-biological adhesion properties, it is widely used in the anti-bacterial adhesion of the surface of polyvinyl chloride materials. The principle is that it can form a hydration layer on the surface of polyvinyl chloride material by hydrogen bonding with a large number of water molecules. Compared with protein and microbial adhesion, the hydration layer is a physical barrier, which can effectively prevent bacteria from adhering, colonizing and growing on the surface of polyvinyl chloride material. Zwitterions containing units such as carboxybetaine, sulfobetaine or phosphorylcholine have higher hydrophilicity and biocompatibility. They interact strongly with water molecules through ion solvation to produce a hydration layer, rather than the hydrogen bonded water molecules used by polyethylene glycol. At the same time, the exposure of its negative charge also shows the same-sex repulsion of negatively charged proteins and bacteria, so these zwitterionic units are grafted on the surface of polyvinyl chloride, making it show significant anti-fouling function. Heparin is a type of polysaccharide molecule containing a large number of sulfonic acid groups and carboxyl groups and unevenly distributed. Its molecular weight is about 20,000, and its sulfur content is about 9-12.9%, which is acidic. At the same time, heparin is easy to absorb moisture and dissolve in water, and it has excellent anti-coagulation properties.

[0003] So far, many reports have confirmed that chemical modification after surface activation treatment of polyvinyl chloride materials is the preferred method for the durable and firm surface modification of polyvinyl chloride materials. The so-called surface activation treatment of polyvinyl chloride materials mainly includes ① plasma treatment of polyvinyl chloride materials in a mixed atmosphere of O2, NH3, air, helium / oxygen or argon / oxygen to obtain the activation effect of surface hydroxylation, amination or carboxylation; ② immersion of polyvinyl chloride materials in dilute alkali solution for alkaline hydrolysis treatment to obtain the activation effect of surface hydroxylation; ③ the surface of polyvinyl chloride after activation treatment is treated with silane coupling agent to introduce functional groups such as OH, NH2, epoxy, NCO, C=C double bond on its surface, and then connect the hydrophilic substance by covalent bonding or graft polymerization.

[0004] Accordingly, according to the principle of molecular design, the inventors combined the structural characteristics of the activated polyvinyl chloride surface, the structural characteristics and functional applications of polyethylene glycol and sulfobetaine to design a method for modifying the surface of polyvinyl chloride materials using a functional isocyanate crosslinker. The functional isocyanate crosslinker refers to a functional isocyanate crosslinker containing disulfobetaine and a polyether chain in the molecular structure, wherein the two ends of the polyether chain are connected to sulfobetaine and isocyanate groups respectively. The isocyanate group can covalently bond to the polyvinyl chloride material whose surface has been activated; at the same time, the isocyanate group is used as a spacer arm, and the polyether chain is "flat" bonded to the hydroxyl or amino group after activation on the surface of the polyvinyl chloride material, so as to "attach" the sulfobetaine to the surface of the polyvinyl chloride material, thereby giving the polyvinyl chloride surface strong hydrophilicity, smoothness after water wetting, conductivity, antibacterial, antifogging and antifouling, anticoagulation and mechanical property enhancement effects. The functional isocyanate crosslinker of the present invention is used for surface modification of polyvinyl chloride materials, which is simple, convenient and easy to implement, and has a significant modification effect. Summary of the invention

[0005] The present invention provides a functional isocyanate cross-linking agent containing bissulfobetaine in the molecular structure for hydrophilic, antibacterial and anticoagulant modification of the surface of polyvinyl chloride materials, which comprises the following steps:

[0006] Preparation of functional isocyanate crosslinking agent: at room temperature, dissolve the general formula (B) in an organic solvent, start stirring, slowly add acrylate, the amount of acrylate is 2.0 to 2.2 times the molar amount of the general formula (B); after the acrylate is added, increase the reaction temperature to 50 to 70°C, continue to react for 2 to 20 hours, maintain the reaction temperature, add γ-propane sultone to the reaction system, the amount of γ-propane sultone is 1.8 to 2.2 times the molar amount of the general formula (B), after reacting for 2 to 20 hours, add a catalyst, a diluent and a polyisocyanate to the reaction system in sequence, continue stirring and heat-insulating the reaction, detect whether the NCO content in the material in the reactor is consistent with the predetermined value, and reduce the temperature of the reaction product system to room temperature to obtain a solution of a functional isocyanate crosslinking agent containing bissulfobetaine in the molecular structure.

[0007] The functional isocyanate crosslinking agent containing bissulfobetaine has a structure shown in general formula (A):

[0008]

[0009] Wherein R in the general formula (A) is selected from H or methyl, R1 and R2 are selected from C1 to C 18 Hydrocarbon, Selected from C1~C 18 Hydrocarbylene, wherein n is selected from a natural number between 1 and 2000, Selected from C1~C 18 Alkylene or One of the above, wherein q is selected from a natural number between 1 and 2000.

[0010] The general formula (B) has the following structure:

[0011]

[0012] Wherein R1 and R2 in the general formula (B) are selected from C1 to C 18 Hydrocarbon, Selected from C1~C 18 Alkylene or One of the above, wherein q is selected from a natural number between 1 and 2000.

[0013] The acrylate has a structure shown in general formula (C):

[0014]

[0015] Wherein R in the general formula (C) is selected from H or methyl, and n is selected from a natural number between 1 and 2000.

[0016] The organic solvent refers to one or more of tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, N,N-diethylformamide or hexamethylphosphoramide; the amount of the organic solvent used is 1 to 10 times the mass of the diamine of general formula (B).

[0017] The catalyst refers to a composite of organic tin and organic amine; wherein the organic tin refers to one of dibutyltin dilaurate, stannous octoate, stannous oxalate, dibutyltin dimaleate, di(dodecylsulfide) dibutyltin or dibutyltin diacetate; the organic amine refers to one of triethylamine, p-dimethylaminopyridine, N,N-dimethylformamide, triethylenediamine, dialkylpiperazine, alkylimidazole, 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylenediamine carboxylate, dialkylpiperazine carboxylate or alkylimidazole carboxylate; the mass ratio of the organic tin to the organic amine is 1:0-1.5; the amount of the catalyst is 0.05-5% of the mass of the polyisocyanate of general formula (D).

[0018] The polyisocyanate has a structure shown in general formula (D):

[0019]

[0020] Wherein p in the general formula (D) is selected from a positive integer of 1 to 5, Selected from C1~C 18 alkylene;

[0021] The amount of the polyisocyanate used is 2.02 to 2.25 times the molar amount of the general formula (B).

[0022] The diluent refers to one or more of acetone, butanone, cyclohexanone, methyl acetate, ethyl acetate, ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, toluene, xylene, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, N,N-diethylformamide or hexamethylphosphoramide; the amount of the diluent is 1 to 10 times the mass of the general formula (B).

[0023] Surface modification of polyvinyl chloride materials: at room temperature, immerse the surface activated polyvinyl chloride material in the functional isocyanate crosslinking agent solution containing bissulfobetaine until it is evenly filled; or spray, roll or brush the functional isocyanate crosslinking agent solution containing bissulfobetaine on the surface activated polyvinyl chloride material, and then place it in a reactor at 60 to 130° C. for heat treatment for 0.2 to 20 hours, then take it out and cool it down to obtain a polyvinyl chloride material with bissulfobetaine and polyether chains bonded to the surface, which is called a surface modified polyvinyl chloride material.

[0024] The surface activated polyvinyl chloride material refers to a surface clean polyvinyl chloride material that is subjected to plasma treatment in a plasma chamber with an oxygen, ammonia or air atmosphere, with a gas pressure of 30 to 50 Pa in the chamber, a temperature of 10 to 40° C. in the chamber, a radio frequency power of 50 to 500 watts, and an irradiation time of 50 to 5000 seconds. OH groups or NH2 groups are generated on the surface of the clean polyvinyl chloride material, which is called a surface activated polyvinyl chloride material; or the clean polyvinyl chloride material is immersed in an alkali solution with a mass percentage concentration of 0.01 to 10%, ultrasonically hydrolyzed at room temperature for 2 to 200 minutes, taken out and washed with deionizer until neutral, and vacuum dried at 60° C., OH groups are generated on the surface of the clean polyvinyl chloride material, which is called a surface activated polyvinyl chloride material.

[0025] The clean polyvinyl chloride material refers to the polyvinyl chloride raw material that is washed with ethanol and deionized water in sequence, and then dried under vacuum at 60°C to obtain the surface clean polyvinyl chloride material;

[0026] The polyvinyl chloride raw material specifically includes one of polyvinyl chloride artificial organs, polyvinyl chloride catheters, polyvinyl chloride blood storage bags, polyvinyl chloride containers, polyvinyl chloride foams, polyvinyl chloride films, polyvinyl chloride filters, polyvinyl chloride filter membranes, polyvinyl chloride nonwoven fabrics or polyvinyl chloride fibers that have not undergone any surface treatment;

[0027] The alkaline solution refers to an aqueous solution of potassium hydroxide, sodium hydroxide, N,N,N-trimethyl-N-benzylammonium hydroxide, N,N,N-triethyl-N-benzylammonium hydroxide or N,N,N,N-tetrabutylammonium hydroxide.

[0028] The mass percentage concentration of the functional isocyanate crosslinking agent containing bissulfobetaine in the functional isocyanate crosslinking agent solution containing bissulfobetaine is 0.5-50%, and the dosage of the functional isocyanate crosslinking agent solution containing bissulfobetaine is 5-500% of the mass of the surface activated polyvinyl chloride material.

[0029] The N in the molecular structure of the functional isocyanate cross-linking agent containing bissulfobetaine provided by the present invention is + R1 and R2 can be selected from C1 to C2 according to the actual needs of functional modification of polyvinyl chloride materials and their performance changes. 18 Hydrocarbon; Secondly, if the main purpose is to enhance the tensile strength of polyvinyl chloride materials through cross-linking, The polyether chain in the acrylate of general formula (C) can be selected to be shorter; if the modification is mainly for hydrophilicity, antifouling, biocompatibility, etc., The polyether chain in the acrylate of general formula (C) can be selected to be longer; the concentration of the functional isocyanate crosslinking agent solution containing bissulfobetaine when surface-modifying the polyvinyl chloride material can be adjusted, and the number of surface modification treatments can be increased or decreased. In summary, the functional isocyanate crosslinking agent containing bissulfobetaine provided by the present invention is a flexible and effective preferred method for surface modification of polyvinyl chloride materials. DETAILED DESCRIPTION

[0030] In order to further understand the present invention, it is specifically described by way of examples, the purpose of which is to better understand the content of the present invention. Therefore, the method for surface modification of polyvinyl chloride material by functional isocyanate crosslinking agent not listed in the examples should not be regarded as limiting the scope of protection of the present invention.

[0031] Example 1 Modified polyvinyl chloride membrane (I)

[0032] Preparation and activation of polyvinyl chloride diaphragm: Dissolve 5 grams of SH-200 polyvinyl chloride powder produced by Shanghai Chlor-Alkali Chemical Co., Ltd. in 55 grams of tetrahydrofuran to prepare a solution, pour the polyvinyl chloride solution into a flat plate mold, and after the solvent evaporates naturally, make a film with a thickness of 0.2 mm, cut into 80*80 mm diaphragms, use ethanol and deionized water for ultrasonic washing in turn, and vacuum dry at 60°C for 10 hours to obtain a polyvinyl chloride diaphragm with a clean surface.

[0033] The surface-cleaned polyvinyl chloride film is placed in a plasma chamber, the O2 pressure in the chamber is 30 Pa, the temperature in the chamber is 35° C., the radio frequency power is 100 W, and the irradiation time is 100 seconds to obtain a surface-activated polyvinyl chloride film.

[0034] Preparation of isocyanate crosslinking agent solution containing bissulfobetaine of formula (1): 25 g of N,N'-dibenzylethylenediamine is dissolved in 80 g of tetrahydrofuran and added into a reaction kettle, stirring is started, 30 g of hydroxyethyl methacrylate is slowly added at room temperature, after the addition of hydroxyethyl methacrylate is completed, the reaction temperature is increased to 55-60°C, and the reaction is continued for 4 hours, 26 g of γ-propane sultone is added into the reaction kettle, and after the reaction is continued for 6 hours, 0.22 g of dibutyltin dilaurate, 0.15 g of triethylenediamine, 120 g of toluene and 40 g of toluene diisocyanate are added into the reaction kettle, the reaction is continued with heat preservation and stirring, and the NCO value in the reaction product system is detected to be within the range of 2.55-2.88%, the reaction is stopped and the temperature is lowered to obtain a solution of isocyanate crosslinking agent containing bissulfobetaine of the structure shown in formula (1).

[0035]

[0036] After infrared spectroscopy testing, a strong peak of NCO appeared near 2270nm in the IR spectrum, a characteristic absorption peak belonging to carbamate NH appeared at 3482nm, and a characteristic peak of carbamate C=O appeared at 1726nm, which was consistent with the structural characteristics of formula (1), confirming that the chemical structure of the product was consistent with the theoretical design of formula (1). The isocyanate group percentage in the isocyanate crosslinker solution containing bissulfobetaine in the structure shown in formula (1) was detected by the method specified in GB / T 29493.6-2013, and was 3.78%.

[0037] Surface modification of polyvinyl chloride membrane: At room temperature, the surface activated polyvinyl chloride membrane is immersed in an isocyanate crosslinker solution containing disulfobetaine having a structure shown in formula (1). After being evenly dipped, it is sent into a reactor at 80-90°C for a residence time of 6 hours. Thereafter, it is taken out and cooled to obtain a modified polyvinyl chloride membrane Ⅰ-1.

[0038] After the isocyanate crosslinking agent solution containing bissulfobetaine of the structure shown in formula (1) was diluted by 1 time with ethylene glycol dimethyl ether, the polyvinyl chloride film to be modified was treated in the same manner to obtain modified polyvinyl chloride film I-2.

[0039] After the isocyanate crosslinking agent solution containing bissulfobetaine having the structure shown in formula (1) was diluted by 1 time with ethylene glycol dimethyl ether, the modified polyvinyl chloride film I-2 was repeatedly treated with the same method to obtain a secondary modified polyvinyl chloride film I-3.

[0040] Example 2 Modified polyvinyl chloride membrane (II)

[0041] Preparation of isocyanate crosslinking agent containing bissulfobetaine of formula (2): According to the method and operation steps of Example 1, N,N'-dibenzylethylenediamine in Example 1 is replaced by α,ω-bisbenzylaminopolyethylene oxide-2000, hydroxyethyl methacrylate is replaced by polyethylene glycol-2000 monomethacrylate, and toluene diisocyanate is replaced by diphenylmethane diisocyanate to prepare a solution of isocyanate crosslinking agent containing bissulfobetaine of the structure shown in formula (2).

[0042]

[0043] After infrared spectroscopy testing, a strong peak of NCO appeared near 2271nm in the IR spectrum of formula (2), a characteristic absorption peak belonging to carbamate NH appeared at 3487nm, and a characteristic peak of carbamate C=O appeared at 1728nm, which was consistent with the structural characteristics of formula (2), confirming that the chemical structure of the product was consistent with the theoretical design of formula (2). The isocyanate group percentage in the isocyanate crosslinker solution containing bissulfobetaine in the structure shown in formula (2) was detected by the method specified in GB / T 29493.6-2013, and was 0.32%.

[0044] Surface modification of polyvinyl chloride membrane: At room temperature, the surface activated polyvinyl chloride membrane is immersed in an isocyanate crosslinking agent solution containing disulfobetaine of formula (2), and after being evenly soaked and allowed to stand for 3 minutes, it is sent to a reactor at 80-90°C for a residence time of 10 hours, and then taken out and cooled to obtain a modified polyvinyl chloride membrane II-1.

[0045] Example 3 Modified polyvinyl chloride urinary catheter (I)

[0046] According to the method and steps of Example 1, the polyvinyl chloride catheter produced by Jiangsu Jiadingcheng Medical Instrument Co., Ltd. was ultrasonically cleaned with ethanol and deionized water in sequence, and vacuum dried at 60° C. for 10 hours to obtain a surface-cleaned polyvinyl chloride catheter.

[0047] The surface-cleaned polyvinyl chloride catheter is placed in a plasma chamber, the O2 pressure in the chamber is 40 Pa, the temperature in the chamber is 25° C., the radio frequency power is 100 W, and the irradiation time is 100 seconds, so as to obtain a surface-activated polyvinyl chloride catheter.

[0048] At room temperature, the surface activated polyvinyl chloride catheter is immersed in the functional isocyanate crosslinking agent solution of formula (1). After being evenly dipped, it is sent to a reactor at 80-90°C for a residence time of 10 hours, and then taken out and cooled to obtain a modified polyvinyl chloride catheter I-1.

[0049] Example 4 Modified polyvinyl chloride urinary catheter (II)

[0050] According to the method and steps of Example 1, the polyvinyl chloride catheter produced by Jiangsu Jiadingcheng Medical Instrument Co., Ltd. was ultrasonically cleaned with ethanol and deionized water in sequence, and vacuum dried at 60° C. for 10 hours to obtain a surface-cleaned polyvinyl chloride catheter.

[0051] The surface-cleaned polyvinyl chloride catheter is placed in a plasma chamber, the O2 pressure in the chamber is 40 Pa, the temperature in the chamber is 25° C., the radio frequency power is 100 W, and the irradiation time is 150 seconds to obtain a surface-activated polyvinyl chloride catheter.

[0052] At room temperature, the surface activated polyvinyl chloride catheter is immersed in the functional isocyanate crosslinking agent solution of formula (2). After being evenly dipped, it is sent to a reactor at 80-90°C for a residence time of 10 hours, and then taken out and cooled to obtain a modified polyvinyl chloride catheter II-1.

[0053] Example 5 Modified polyvinyl chloride fishing net (I)

[0054] According to the method and steps of Example 1, the polyvinyl chloride fishing net produced by Lianyungang Xingqiu Plastic Co., Ltd. was ultrasonically cleaned with ethanol and deionized water in sequence, and then vacuum dried at 60° C. for 10 hours to obtain a surface-cleaned polyvinyl chloride fishing net.

[0055] The surface-cleaned polyvinyl chloride fishing net is placed in a plasma chamber, the O2 pressure in the chamber is 30 Pa, the temperature in the chamber is 25° C., the radio frequency power is 100 W, and the irradiation time is 80 seconds to obtain a surface-activated polyvinyl chloride fishing net.

[0056] At room temperature, the surface activated polyvinyl chloride fishing net is immersed in the functional isocyanate crosslinking agent solution of formula (1). After being evenly dipped, it is sent to a reactor at 80-90°C for a residence time of 10 hours, and then taken out and cooled to obtain modified polyvinyl chloride fishing net I-1.

[0057] Example 6 Modified polyvinyl chloride fishing net (II)

[0058] According to the method and steps of Example 1, the polyvinyl chloride fishing net produced by Lianyungang Xingqiu Plastic Co., Ltd. was ultrasonically cleaned with ethanol and deionized water in sequence, and then vacuum dried at 60° C. for 10 hours to obtain a surface-cleaned polyvinyl chloride fishing net.

[0059] The surface-cleaned polyvinyl chloride fishing net is placed in a plasma chamber, the O2 pressure in the chamber is 30 Pa, the temperature in the chamber is 25° C., the radio frequency power is 100 W, and the irradiation time is 100 seconds to obtain a surface-activated polyvinyl chloride fishing net.

[0060] At room temperature, the surface activated polyvinyl chloride fishing net is immersed in the functional isocyanate crosslinking agent solution of formula (2). After being evenly dipped, it is sent to a reactor at 80-90°C for a residence time of 10 hours, and then taken out and cooled to obtain modified polyvinyl chloride fishing net II-1.

[0061] Example 7 Changes in properties of polyvinyl chloride materials before and after modification of Examples 1 to 6

[0062] The polyvinyl chloride materials before and after modification of Examples 1 to 6 were respectively taken, placed in ethanol for ultrasonic washing, and then vacuum dried at 60° C. to constant weight, and the weight gain and water contact angle were measured. The results are shown in Table 1.

[0063] Table 1 Properties of polyvinyl chloride materials before and after modification

[0064]

[0065] From the data in Table 1, it can be seen that the weight of the polyvinyl chloride material increased after being modified by the functional isocyanate crosslinker. The water contact angle on the surface of the polyvinyl chloride membrane decreased. Repeated treatment of the polyvinyl chloride membrane with a functional isocyanate crosslinker can also achieve similar modification effects. Under the same conditions, the weight gain rate of the polyvinyl chloride fishing net after treatment with a functional isocyanate crosslinker is significantly higher than that of the polyvinyl chloride catheter and the polyvinyl chloride membrane, indicating that the larger the specific surface area of ​​the material to be modified, the better the surface grafting modification effect.

Claims

1. A method for modifying the surface of a polyvinyl chloride material using a functional isocyanate crosslinking agent, characterized in that The following steps are involved: At room temperature, immersing the surface activated polyvinyl chloride material in a functional isocyanate crosslinking agent solution and evenly immersing it; or spraying, rolling or brushing the surface activated polyvinyl chloride material with the functional isocyanate crosslinking agent solution, and then putting it into a reactor at 60 to 130° C. for heat treatment for 0.2 to 20 hours, and then taking it out and cooling it to obtain a surface modified polyvinyl chloride material; The functional isocyanate crosslinking agent containing bissulfobetaine has a structure shown in general formula (A): Wherein R in the general formula (A) is selected from H or methyl, R1 and R2 are selected from C1 to C 18 The hydrocarbon group, Selected from C1~C 18 Hydrocarbylene, wherein n is selected from a natural number between 1 and 2000, Selected from C1~C 18 Alkylene or One of the following, wherein q is selected from a natural number between 1 and 2000; The surface activated polyvinyl chloride material refers to a surface clean polyvinyl chloride material which is subjected to plasma treatment in a plasma chamber with an oxygen, ammonia or air atmosphere, with a gas pressure of 30 to 50 Pa in the chamber, a temperature of 10 to 40° C. in the chamber, a radio frequency power of 50 to 500 W, and an irradiation time of 50 to 5000 seconds, and OH groups or NH2 groups are generated on the surface of the clean polyvinyl chloride material, which is called a surface activated polyvinyl chloride material; or the surface clean polyvinyl chloride material is immersed in an alkali solution with a mass percentage concentration of 0.01 to 10%, ultrasonically hydrolyzed at room temperature for 2 to 200 minutes, and then taken out and washed with deionizer until neutral, and vacuum dried at 60° C., and OH groups are generated on the surface of the clean polyvinyl chloride material, which is called a surface activated polyvinyl chloride material; The mass percentage concentration of the functional isocyanate crosslinking agent in the functional isocyanate crosslinking agent solution is 0.5-50%, and the usage of the functional isocyanate crosslinking agent solution is 5-500% of the mass of the surface activated polyvinyl chloride material.

2. A method for modifying the surface of a polyvinyl chloride material using a functional isocyanate crosslinking agent according to claim 1, characterized in that The surface clean polyvinyl chloride material refers to the polyvinyl chloride raw material that is washed with ethanol and deionized water in sequence, and then dried under vacuum at 60°C to obtain the surface clean polyvinyl chloride material; The polyvinyl chloride raw material refers to one of polyvinyl chloride artificial organs, polyvinyl chloride catheters, polyvinyl chloride blood storage bags, polyvinyl chloride containers, polyvinyl chloride foams, polyvinyl chloride films, polyvinyl chloride filters, polyvinyl chloride filter membranes, polyvinyl chloride nonwoven fabrics or polyvinyl chloride fibers that have not undergone any surface treatment.

3. A method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent according to claim 1, characterized in that The alkaline solution refers to one of potassium hydroxide, sodium hydroxide, N,N,N-trimethyl-N-benzylammonium hydroxide, N,N,N-triethyl-N-benzylammonium hydroxide or N,N,N,N-tetrabutylammonium hydroxide aqueous solution.

4. A method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent according to claim 1, characterized in that The preparation method of the functional isocyanate crosslinking agent is as follows: at room temperature, dissolving the general formula (B) in an organic solvent, stirring is started, and acrylate is slowly added, wherein the amount of acrylate is 2.0 to 2.2 times the molar amount of the general formula (B); after the acrylate is added, the reaction temperature is increased to 50 to 70° C., and the reaction is continued for 2 to 20 hours, and then the reaction temperature is maintained, and γ-propane sultone is added to the reaction system, wherein the amount of γ-propane sultone is 1.8 to 2.2 times the molar amount of the general formula (B). After the reaction is continued for 2 to 20 hours, a catalyst, a diluent and a polyisocyanate are sequentially added to the reaction system, and the stirring and heat preservation reaction is continued. When the NCO content in the material in the reactor is detected to be consistent with the predetermined value, the temperature of the reaction product system is reduced to room temperature, and a solution of a functional isocyanate crosslinking agent containing bissulfobetaine in the molecular structure is obtained; The general formula (B) has the following structure: Wherein R1 and R2 in the general formula (B) are selected from hydrocarbon groups, Selected from C1~C 18 Alkylene or One of the above, wherein q is selected from a natural number between 1 and 2000.

5. A method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent according to claim 4, characterized in that The organic solvent refers to one or more of tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, N,N-diethylformamide or hexamethylphosphoramide; the amount of the organic solvent used is 1 to 10 times the mass of the diamine of general formula (B).

6. A method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent according to claim 4, characterized in that The acrylate has a structure shown in general formula (C): Wherein R in the general formula (C) is selected from H or methyl, and n is selected from a natural number between 1 and 2000.

7. A method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent according to claim 4, characterized in that The catalyst refers to a composite of organic tin and organic amine; wherein the organic tin refers to one of dibutyltin dilaurate, stannous octoate, stannous oxalate, dibutyltin dimaleate, di(dodecylsulfide) dibutyltin or dibutyltin diacetate; the organic amine refers to one of triethylamine, p-dimethylaminopyridine, N,N-dimethylformamide, triethylenediamine, dialkylpiperazine, alkylimidazole, 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylenediamine carboxylate, dialkylpiperazine carboxylate or alkylimidazole carboxylate; the mass ratio of the organic tin to the organic amine is 1:0-1.5; the amount of the catalyst used is 0.05-5% of the mass of the polyisocyanate of general formula (D).

8. A method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent according to claim 4, characterized in that The polyisocyanate has a structure shown in general formula (D): Wherein p in the general formula (D) is selected from a positive integer of 1 to 5, Selected from C1~C 18 alkylene; The amount of the polyisocyanate used is 2.02 to 2.25 times the molar amount of the general formula (B).

9. A method for modifying the surface of a polyvinyl chloride material with a functional isocyanate crosslinking agent according to claim 4, characterized in that The diluent refers to one or more of acetone, butanone, cyclohexanone, methyl acetate, ethyl acetate, ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, toluene, xylene, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, N,N-diethylformamide or hexamethylphosphoramide; the amount of the diluent is 1 to 10 times the mass of the general formula (B).

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