Preparation process of antibacterial modified silicone rubber composite material

Abstract

The invention relates to the technical field of silicone rubber, and discloses a preparation process of an antibacterial modified silicone rubber composite material, which comprises the following steps: mixing methyl vinyl silicone rubber, organosilicon quaternary ammonium salt polyimide, a reinforcing agent, an accelerant, an anti-aging agent, a cross-linking agent, a vulcanizing agent and the like in an open mill, and finally carrying out two-stage vulcanization in a press vulcanizer to obtain the antibacterial modified silicone rubber composite material. The antibacterial modified silicone rubber composite material is obtained. The organosilicon quaternary ammonium salt polyimide provided by the invention has very strong high temperature resistance and thermal decomposition resistance, can improve the thermal decomposition mass loss temperature of the silicone rubber material, and improves the high temperature resistance. Meanwhile, the organosilicon quaternary ammonium salt polyimide contains quaternary ammonium salt antibacterial groups and can generate electrostatic interaction with cell membranes, with negative charges, of bacteria, so that the permeability of the cell membranes is changed, substances in the cell membranes flow out, the bacteria are inhibited and killed, and the antibacterial performance of the silicone rubber material is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of silicone rubber, in particular to a preparation process of an antibacterial modified silicone rubber composite material. Background Art

[0002] Silicone rubber has excellent properties such as high and low temperature resistance, solvent resistance, elasticity, and air permeability, and is widely used in the fields of wires and cables, automobile manufacturing, electronic appliances, etc. Due to its physiological inertness and biocompatibility, silicone rubber also has important applications in surgical instruments, medical catheters and other medical supplies. Improving the antibacterial and bactericidal properties of silicone rubber is conducive to the practical application of silicone rubber in the medical field. Polyimide is a polymer material with high strength, good high temperature resistance and excellent insulation properties. It can be used as a structural material or functional material and has important applications in rubber, plastics, fibers, etc. Chinese patent CN106118065B discloses an intumescent flame retardant silicone rubber and a preparation method thereof. The intumescent flame retardant is composed of ammonium polyphosphate, pentaerythritol esters, and melamine-polyimide supramolecular network composite materials, which improves the mechanical, thermal stability and flame retardant properties of silicone rubber. However, the patent does not improve the antibacterial and bactericidal properties of silicone rubber, which is not conducive to its practical application in the fields of antibacterial medical supplies. Summary of the Invention

[0003] (1) Technical problems to be solved: The present invention provides a preparation process for an antibacterial modified silicone rubber composite material, which solves the problem of poor antibacterial properties of silicone rubber and enhances the high temperature resistance and other properties of silicone rubber.

[0004] (II) Technical Solution: A process for preparing an antibacterial modified silicone rubber composite material comprises the following steps:

[0005] Step A: Add N,N-dimethylformamide, dianhydride compound, aromatic diamine compound, and silicon-containing diamine compound to a reaction vessel, stir and react at room temperature in a nitrogen atmosphere for 18-24 hours, then add bromoalkane, heat to 120-140°C, react for 36-48 hours, pour the solution on the surface of a glass mold, place it in a heating box, heat to 150-160°C for 1.5-2 hours, 200-220°C for 1-1.5 hours, 250-260°C for 1-1.5 hours, and 280-300°C for 1-1.5 hours, and cool to obtain an organosilicon quaternary ammonium salt polyimide. The reaction formula is:

[0006]

[0007] Step B, placing methyl vinyl silicone rubber and organosilicon quaternary ammonium salt polyimide in an open mill for plasticizing, then adding a reinforcing agent, an accelerator, an antioxidant, and a cross-linking agent, mixing, then adding a vulcanizing agent, mixing, and finally vulcanizing the material in a flat vulcanizing press, first at 160-170° C. and 10-12 MPa pressure for 20-40 minutes, and then at normal pressure at 170-175° C. for 2-3 hours, cooling and discharging to obtain an antibacterial modified silicone rubber composite material.

[0008] Furthermore, in step B, the molar ratio of the dianhydride compound, the aromatic diamine compound, the silicon-containing diamine compound, and the brominated alkane is 100:(75-90):(10-25):(24-56).

[0009] Furthermore, the dianhydride compound is pyromellitic anhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride or 4,4'-biphenyl ether dianhydride, and the aromatic diamine compound is p-phenylenediamine, 4,4-biphenyl ether diamine or 4,4'-diaminodiphenylmethane.

[0010] Furthermore, the brominated alkane is 1-bromododecane, 1-bromodridecane, 1-bromodotetradecane, 1-bromodopentadecane or 1-bromodhexadecane.

[0011] Furthermore, the preparation process of the silicon-containing diamine compound is as follows:

[0012] (1) Tetrahydrofuran, 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane in a molar ratio of 1:(2.4-3):(2-2.4), N-methyl-p-nitroaniline, and sodium hydroxide are added to a reaction vessel, heated to 60-65° C., condensed and refluxed for 8-12 hours, cooled and filtered, the filtrate is distilled under reduced pressure, washed with water, and the product is recrystallized from ethanol to obtain a silicon-containing dinitro compound.

[0013] (2) Add ethanol to the reaction vessel, introduce nitrogen, add a silicon-containing dinitro compound, a palladium carbon catalyst, and hydrazine hydrate in a mass ratio of 100:(7.2-8.4):(40-52), heat to 70-80°C, reflux under condensation for 5-8 hours, filter, and distill the filtrate under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain a silicon-containing diamine compound. The reaction formula is:

[0014]

[0015] Furthermore, in step B, the mass ratio of methyl vinyl silicone rubber to organosilicon quaternary ammonium salt polyimide is 100:(10-30).

[0016] Furthermore, in step B, the reinforcing agent is white carbon black, the accelerator is 2-mercaptobenzothiazole, the antioxidant is N-phenyl-2-naphthylamine, the crosslinking agent is dicumyl peroxide, and the vulcanizing agent is sulfur.

[0017] (III) Technical Effects of the Invention: 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane and N-methyl-p-nitroaniline are used as reactants to obtain a silicon-containing dinitro compound having a tertiary amine structure through substitution and reduction reactions. This is then subjected to an amidation polymerization reaction with a dianhydride compound and an aromatic diamine compound, and then to a quaternization reaction with a brominated alkane. Finally, a high-temperature thermal imidization reaction is performed to obtain an organosilicon quaternary ammonium salt polyimide.

[0018] The present invention uses methyl vinyl silicone rubber as a matrix and organosilicon quaternary ammonium salt polyimide as a modifier. The materials are mixed with white carbon black as a reinforcing agent, dicumyl peroxide as a crosslinking agent, and sulfur as a vulcanizing agent, and then subjected to high-temperature vulcanization to obtain an antibacterial modified silicone rubber composite material. The organosilicon quaternary ammonium salt polyimide contains the same siloxane structure as the methyl vinyl silicone rubber, thereby improving the compatibility between the polyimide and the silicone rubber, resulting in a good reinforcing effect of the polyimide, and increasing the Shore A hardness and tear strength of the silicone rubber material.

[0019] The organosilicon quaternary ammonium salt polyimide of the present invention has strong resistance to high temperatures and thermal decomposition, can increase the thermal decomposition mass loss temperature of silicone rubber materials, and improve high-temperature resistance. Furthermore, the organosilicon quaternary ammonium salt polyimide contains quaternary ammonium salt antibacterial groups, which can electrostatically interact with the negatively charged bacterial cell membranes, changing the permeability of the cell membranes and allowing substances within the cell membranes to flow out, thereby inhibiting and killing bacteria and significantly improving the antibacterial properties of the silicone rubber material. DETAILED DESCRIPTION

[0020] To more clearly illustrate the present invention and provide a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below. However, this should not be construed as limiting the scope of the present invention. Palladium-carbon catalyst: Product No. YB54681, CAS No.: 7440-05-3, Hunan Yunbang Biotechnology Co., Ltd.

[0021] Example 1 (1) Add 120 mL of tetrahydrofuran, 20 mmol of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, 56 mmol of N-methyl-p-nitroaniline, and 40 mmol of sodium hydroxide to a reaction vessel, heat to 60°C, condense and reflux for 12 hours, cool and filter, distill the filtrate under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain a silicon-containing dinitro compound.

[0022] (2) Add 150 mL of ethanol to the reaction vessel, introduce nitrogen, add 10 g of a silicon-containing dinitro compound, 0.84 g of a palladium-carbon catalyst, and 5.2 g of an 80% by mass hydrazine hydrate solution, heat to 70° C., condense and reflux to react for 8 h, filter, and distill the filtrate under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain a silicon-containing diamine compound.

[0023] (3) Add 250 mL of N,N-dimethylformamide, 100 mmol of pyromellitic anhydride, 90 mmol of 4,4-biphenyl ether diamine, and 10 mmol of a silicon-containing diamine compound to a reaction vessel, stir and react at room temperature in a nitrogen atmosphere for 18 hours, then add 24 mmol of 1-bromohexadecane, heat to 120°C, and react for 48 hours. Pour the solution on the surface of a glass mold, place it in a heating box, and heat it to 160°C for 1.5 hours, 220°C for 1 hour, 260°C for 1.5 hours, and 280°C for 1.5 hours in sequence, and cool to obtain an organosilicon quaternary ammonium salt polyimide.

[0024] (4) Place 1 kg of methyl vinyl silicone rubber and 100 g of silicone quaternary ammonium salt polyimide in an open mill and plasticize for 20 minutes. Then add 80 g of reinforcing agent white carbon black, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of cross-linking agent diisopropyl peroxide, mix for 40 minutes, then add 12 g of vulcanizing agent sulfur, mix for 5 minutes, and finally vulcanize the material in a flat vulcanizer at 165 ° C and 10 MPa pressure for 40 minutes, and then vulcanize at 175 ° C at normal pressure for 2 hours. Cool and discharge the material to obtain an antibacterial modified silicone rubber composite material.

[0025] Example 2 (1) Add 120 mL of tetrahydrofuran, 20 mmol of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, 60 mmol of N-methyl-p-nitroaniline, and 40 mmol of sodium hydroxide to a reaction vessel, heat to 65°C, condense and reflux for 8 hours, cool and filter, distill the filtrate under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain a silicon-containing dinitro compound.

[0026] (2) Add 120 mL of ethanol to the reaction vessel, introduce nitrogen, add 10 g of a silicon-containing dinitro compound, 0.72 g of a palladium-carbon catalyst, and 4 g of an 80% by mass hydrazine hydrate solution, heat to 80° C., condense and reflux to react for 8 h, filter, and distill the filtrate under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain a silicon-containing diamine compound.

[0027] (3) Add 300 mL of N,N-dimethylformamide, 100 mmol of 4,4'-biphenyl ether dianhydride, 85 mmol of p-phenylenediamine, and 15 mmol of a silicon-containing diamine compound into a reaction vessel, stir and react at room temperature in a nitrogen atmosphere for 24 hours, then add 36 mmol of 1-bromododecane, heat to 125°C, and react for 36 hours. Pour the solution onto the surface of a glass mold, place it in a heating box, and heat it to 150°C for 2 hours, 200°C for 2 hours, 260°C for 1 hour, and 300°C for 1 hour in sequence, and cool to obtain an organosilicon quaternary ammonium salt polyimide.

[0028] (4) Place 1 kg of methyl vinyl silicone rubber and 200 g of silicone quaternary ammonium salt polyimide in an open mill and plasticize for 20 minutes. Then add 60 g of reinforcing agent white carbon black, 23 g of accelerator 2-mercaptobenzothiazole, 18 g of antioxidant N-phenyl-2-naphthylamine, and 24 g of cross-linking agent diisopropyl peroxide, mix for 40 minutes, then add 9 g of vulcanizing agent sulfur, mix for 5 minutes, and finally vulcanize the material in a flat vulcanizer at 160 ° C and 10 MPa pressure for 40 minutes, and then vulcanize at 170 ° C at normal pressure for 3 hours. Cool and discharge the material to obtain an antibacterial modified silicone rubber composite material.

[0029] Example 3 (1) Add 100 mL of tetrahydrofuran, 20 mmol of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, 48 mmol of N-methyl-p-nitroaniline, and 48 mmol of sodium hydroxide to a reaction vessel, heat to 60°C, reflux under condensation for 12 hours, cool and filter, distill the filtrate under reduced pressure, wash with water, and recrystallize the product from ethanol to obtain a silicon-containing dinitro compound.

[0030] (2) Add 120 mL of ethanol to the reaction vessel, introduce nitrogen, add 10 g of a silicon-containing dinitro compound, 0.78 g of a palladium-carbon catalyst, and 4 g of an 80% by mass hydrazine hydrate solution, heat to 70-80 ° C, condense and reflux for 5 hours, filter, and distill the filtrate under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain a silicon-containing diamine compound.

[0031] (3) Add 250 mL of N,N-dimethylformamide, 100 mmol of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 75 mmol of 4,4'-diaminodiphenylmethane, and 25 mmol of a silicon-containing diamine compound into a reaction vessel, stir and react at room temperature in a nitrogen atmosphere for 24 hours, then add 56 mmol of 1-bromotetradecane, heat to 140°C, and react for 36 hours. Pour the solution onto the surface of a glass mold, place it in a heating box, heat to 160°C for 1.5 hours, 220°C for 1 hour, 250°C for 1.5 hours, and 300°C for 1 hour, and cool to obtain an organosilicon quaternary ammonium salt polyimide.

[0032] (4) Place 1 kg of methyl vinyl silicone rubber and 300 g of silicone quaternary ammonium salt polyimide in an open mill and plasticize for 20 minutes. Then add 50 g of reinforcing agent white carbon black, 18 g of accelerator 2-mercaptobenzothiazole, 12 g of antioxidant N-phenyl-2-naphthylamine, and 21 g of cross-linking agent diisopropyl peroxide, mix for 40 minutes, then add 10 g of vulcanizing agent sulfur, mix for 5 minutes, and finally vulcanize the material in a flat vulcanizer at 160 ° C and 12 MPa pressure for 20 minutes, and then vulcanize at 175 ° C under normal pressure for 2 hours. Cool and discharge the material to obtain an antibacterial modified silicone rubber composite material.

[0033] The difference between Comparative Example 1 and Example 1 is that the organosilicon quaternary ammonium salt polyimide is not added.

[0034] (1) Place 1 kg of methyl vinyl silicone rubber in an open mill and plasticize for 20 minutes. Then add 80 g of reinforcing agent white carbon black, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of cross-linking agent diisopropyl peroxide, mix for 40 minutes, then add 12 g of vulcanizing agent sulfur, mix for 5 minutes, and finally vulcanize the material in a flat vulcanizer at 165 ° C and 10 MPa pressure for 40 minutes, then vulcanize at 175 ° C under normal pressure for 2 hours, cool and discharge to obtain a silicone rubber composite material.

[0035] The difference between Comparative Example 2 and Example 1 is that the silicon-containing diamine compound and 1-bromohexadecane are not added during the preparation of the polyimide.

[0036] (1) Add 250 mL of N,N-dimethylformamide, 100 mmol of pyromellitic anhydride, and 100 mmol of 4,4-diphenyl ether diamine to a reaction vessel, stir and react at room temperature in a nitrogen atmosphere for 18 hours, pour the solution on the surface of a glass mold, place it in a heating box, heat it to 160°C for 1.5 hours, 220°C for 1 hour, 260°C for 1.5 hours, and 280°C for 1.5 hours, and cool it to obtain polyimide.

[0037] (2) Place 1 kg of methyl vinyl silicone rubber and 100 g of polyimide in an open mill and plasticize for 20 minutes. Then add 80 g of reinforcing agent white carbon black, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of cross-linking agent diisopropyl peroxide, mix for 40 minutes, then add 12 g of vulcanizing agent sulfur, mix for 5 minutes, and finally vulcanize the material in a flat vulcanizer at 165 ° C and 10 MPa pressure for 40 minutes, and then vulcanize at 175 ° C at normal pressure for 2 hours. Cool and discharge the material to obtain a modified silicone rubber composite material.

[0038] The difference between Comparative Example 3 and Example 1 is that 1-bromohexadecane is not added during the preparation of the polyimide.

[0039] (1) Add 250 mL of N,N-dimethylformamide, 100 mmol of pyromellitic anhydride, 90 mmol of 4,4-biphenyl ether diamine, and 10 mmol of a silicon-containing diamine compound into a reaction vessel, stir and react at room temperature in a nitrogen atmosphere for 18 hours, pour the solution on the surface of a glass mold, place it in a heating box, heat it to 160°C for 1.5 hours, 220°C for 1 hour, 260°C for 1.5 hours, and 280°C for 1.5 hours, and cool it to obtain a silicone polyimide.

[0040] (2) Place 1 kg of methyl vinyl silicone rubber and 100 g of silicone polyimide in an open mill and plasticize for 20 minutes. Then add 80 g of reinforcing agent white carbon black, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of cross-linking agent diisopropyl peroxide, mix for 40 minutes, then add 12 g of vulcanizing agent sulfur, mix for 5 minutes, and finally vulcanize the material in a flat vulcanizer at 165 ° C and 10 MPa pressure for 40 minutes, and then vulcanize at 175 ° C at normal pressure for 2 hours. Cool and discharge the material to obtain a modified silicone rubber composite material.

[0041] The main difference between Comparative Example 4 and Example 1 is that 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane is used instead of the silicon-containing diamine compound when preparing the polyimide.

[0042] (1) Add 250 mL of N,N-dimethylformamide, 100 mmol of pyromellitic anhydride, 90 mmol of 4,4-diphenyl ether diamine, and 10 mmol of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to a reaction vessel, stir and react at room temperature in a nitrogen atmosphere for 18 hours, then add 24 mmol of 1-bromohexadecane, heat to 120°C, mix for 48 hours, pour the solution on the surface of a glass mold, place it in a heating box, heat to 160°C for 1.5 hours, 220°C for 1 hour, 260°C for 1.5 hours, and 280°C for 1.5 hours, cool, and obtain silicone polyimide.

[0043] (2) Place 1 kg of methyl vinyl silicone rubber and 100 g of silicone polyimide in an open mill and plasticize for 20 minutes. Then add 80 g of reinforcing agent white carbon black, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of cross-linking agent diisopropyl peroxide, mix for 40 minutes, then add 12 g of vulcanizing agent sulfur, mix for 5 minutes, and finally vulcanize the material in a flat vulcanizer at 165 ° C and 10 MPa pressure for 40 minutes, and then vulcanize at 175 ° C at normal pressure for 2 hours. Cool and discharge the material to obtain a modified silicone rubber composite material.

[0044] The Shore A hardness of silicone rubber composites was tested according to GB / T 531.1-2008. The tear resistance was tested according to GB / T529-2008.

[0045] 5 mg of the modified silicone rubber composite material was weighed and placed in a thermogravimetric analyzer for thermogravimetric performance analysis in a nitrogen atmosphere at a heating rate of 10°C / min.

[0046] Antibacterial performance test: The modified silicone rubber composite material was molded into a film with a thickness of 1 mm, and the comparative example was used as a blank group, and Examples 1-3 and Comparative Examples 2-4 were used as experimental groups; then 0.2 mL of Escherichia coli or Staphylococcus aureus suspension (both at a concentration of 10 5 cfu / mL) was dropped on the surface of the silicone rubber membrane, which was then covered with a sterilized polyethylene film and cultured in a constant temperature and humidity incubator at 37°C for 24 h. The silicone rubber membrane and polyethylene film were washed with physiological saline, and then 0.1 mL of the solution was inoculated into an agar medium and cultured at 37°C for 24 h. The colonies were counted and the inhibition rate was calculated.

[0047] Bacterial inhibition rate R = (BC) / B × 100%. B is the average number of colonies recovered in the blank group. C is the average number of colonies recovered in the experimental group.

[0048] Table 1 Performance test of silicone rubber composite materials

[0049]

[0050] After testing, compared with Comparative Example 1, Comparative Example 2 added polyimide to the silicone rubber. Due to the poor compatibility between the two, the tear strength of the silicone rubber material was reduced, and the increase in Shore A hardness was low. In addition, it did not contain quaternary ammonium salt antibacterial groups, resulting in the silicone rubber having no antibacterial properties.

[0051] Examples 1-3 incorporate organosilicon quaternary ammonium salt polyimide, which contains the same siloxane structure as methyl vinyl silicone rubber, thereby improving the compatibility between polyimide and silicone rubber, allowing the polyimide to have a good reinforcing effect, improving the Shore A hardness and tear strength of the silicone rubber material, and the polyimide has strong high temperature resistance and thermal decomposition resistance, which can increase the thermal decomposition mass loss temperature of the silicone rubber material and improve high temperature resistance. At the same time, the organosilicon quaternary ammonium salt polyimide contains a quaternary ammonium salt antibacterial group, which can electrostatically interact with the negatively charged cell membrane of bacteria, changing the permeability of the cell membrane and causing the outflow of substances within the cell membrane, thereby inhibiting and killing bacteria, and significantly improving the antibacterial properties of the silicone rubber material.

[0052] The organosilicone polyimide of Comparative Example 3 contains an organosiloxane structure and exhibits excellent compatibility with methyl vinyl silicone rubber. The silicone rubber material exhibits increased Shore A hardness, tear strength, and thermal decomposition mass loss temperature, improving its mechanical properties and high-temperature resistance. However, without the addition of 1-bromohexadecane, no quaternization reaction occurs, resulting in the organosilicone polyimide containing no quaternary ammonium salt antimicrobial groups and virtually no antimicrobial properties.

[0053] Comparative Example 4 utilizes conventional 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to undergo polymerization with pyromellitic anhydride and 4,4-diphenyl ether diamine to obtain an organosilicon polyimide. This contains an organosiloxane structure and has good compatibility with methyl vinyl silicone rubber. The Shore A hardness, tear strength, and thermal decomposition mass loss temperature of the silicone rubber material increase, and the mechanical properties and high temperature resistance improve. However, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane does not contain a tertiary amine group and cannot undergo a quaternization reaction with 1-bromohexadecane, resulting in the organosilicon polyimide not containing a quaternary ammonium salt antibacterial group, and the silicone rubber material has almost no antibacterial properties.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A process for preparing an antibacterial modified silicone rubber composite material, characterized in that: The preparation process comprises the following steps: Step A, adding N,N-dimethylformamide, dianhydride compound, aromatic diamine compound, and the structural formula The silicon-containing diamine compound is stirred and reacted at room temperature for 18-24 hours in a nitrogen atmosphere, and then a brominated alkane is added, heated to 120-140° C., and reacted for 36-48 hours. The solution is poured on the surface of a glass mold, placed in a heating box, and heated to 150-160° C. for 1.5-2 hours, 200-220° C. for 1-1.5 hours, 250-260° C. for 1-1.5 hours, and 280-300° C. for 1-1.5 hours in sequence, and cooled to obtain an organosilicon quaternary ammonium salt polyimide; Step B, placing methyl vinyl silicone rubber and silicone quaternary ammonium salt polyimide in an open mill for plasticizing, then adding a reinforcing agent, an accelerator, an antioxidant, and a cross-linking agent for mixing, then adding a vulcanizing agent for mixing, and finally performing a two-stage vulcanization of the material in a flat vulcanizer, cooling and discharging the material to obtain an antibacterial modified silicone rubber composite material.

2. The preparation process of the antibacterial modified silicone rubber composite material according to claim 1, characterized in that: In the step B, the molar ratio of the dianhydride compound, the aromatic diamine compound, the silicon-containing diamine compound, and the brominated alkane is 100:(75-90):(10-25):(24-56).

3. The preparation process of the antibacterial modified silicone rubber composite material according to claim 2, characterized in that: The dianhydride compound is pyromellitic anhydride, 3,3',4,4'-biphenyltetracarboxylic anhydride or 4,4'-biphenyl ether dianhydride, and the aromatic diamine compound is p-phenylenediamine, 4,4-biphenyl ether diamine or 4,4'-diaminodiphenylmethane.

4. The preparation process of the antibacterial modified silicone rubber composite material according to claim 2, characterized in that: The brominated alkane is 1-bromododecane, 1-bromodridecane, 1-bromodotetradecane, 1-bromodopentadecane or 1-bromodhexadecane.

5. The preparation process of the antibacterial modified silicone rubber composite material according to claim 2, characterized in that: The preparation process of the silicon-containing diamine compound is: (1) Add tetrahydrofuran, 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, N-methyl-p-nitroaniline and sodium hydroxide to a reaction vessel, heat to 60-65° C., condense and reflux for 8-12 hours, cool and filter, distill the filtrate under reduced pressure, wash and recrystallize to obtain a silicon-containing dinitro compound; (2) Add ethanol to the reaction vessel, introduce nitrogen, add the silicon-containing dinitro compound, palladium carbon catalyst, and hydrazine hydrate, heat to 70-80° C., condense and reflux for 5-8 hours, filter, distill the filtrate under reduced pressure, wash, and recrystallize to obtain a silicon-containing diamine compound.

6. The preparation process of the antibacterial modified silicone rubber composite material according to claim 5, characterized in that: The molar ratio of 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane, N-methyl-p-nitroaniline and sodium hydroxide in (1) is 1:(2.4-3):(2-2.4).

7. The preparation process of the antibacterial modified silicone rubber composite material according to claim 5, characterized in that: The mass ratio of the silicon-containing dinitro compound, palladium-carbon catalyst and hydrazine hydrate in (2) is 100:(7.2-8.4):(40-52).

8. The preparation process of the antibacterial modified silicone rubber composite material according to claim 1, characterized in that: The two-stage vulcanization in step B is first vulcanization at 160-170° C. and 10-12 MPa pressure for 20-40 minutes, and then vulcanization at 170-175° C. under normal pressure for 2-3 hours.

9. The preparation process of the antibacterial modified silicone rubber composite material according to claim 1, characterized in that: In the step B, the mass ratio of methyl vinyl silicone rubber to organosilicon quaternary ammonium salt polyimide is 100:(10-30).

10. The preparation process of the antibacterial modified silicone rubber composite material according to claim 1, characterized in that: In the step B, the reinforcing agent is white carbon black, the accelerator is 2-mercaptobenzothiazole, the antioxidant is N-phenyl-2-naphthylamine, the crosslinking agent is diisopropylbenzene peroxide, and the vulcanizing agent is sulfur.

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