A preparation process for an antibacterial modified silicone rubber composite material

Abstract

This invention relates to the field of silicone rubber technology and discloses a preparation process for an antibacterial modified silicone rubber composite material. The invention involves mixing methyl vinyl silicone rubber, organosilicon quaternary ammonium salt polyimide, reinforcing agents, accelerators, antioxidants, crosslinking agents, and vulcanizing agents in an open mill, followed by two-stage vulcanization in a flat vulcanizing mill to obtain the antibacterial modified silicone rubber composite material. The organosilicon quaternary ammonium salt polyimide of this invention exhibits strong high-temperature resistance and resistance to thermal decomposition, which can increase the thermal decomposition mass loss temperature of silicone rubber materials and improve their high-temperature resistance. Simultaneously, the organosilicon quaternary ammonium salt polyimide contains quaternary ammonium salt antibacterial groups, which can interact electrostatically with the negatively charged cell membranes of bacteria, altering cell membrane permeability and allowing substances within the cell membrane to flow out, thereby inhibiting and killing bacteria and significantly improving the antibacterial properties of the silicone rubber material.

Description

Technical Field

[0001] This invention relates to the field of silicone rubber technology, specifically to a preparation process for an antibacterial modified silicone rubber composite material. Background Technology

[0002] Silicone rubber possesses excellent high and low temperature resistance, solvent resistance, elasticity, and air permeability, making it widely used in wire and cable, automotive manufacturing, and electronics industries. 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 would benefit its practical application in the medical field. Polyimide is a high-strength, high-temperature resistant, and excellent insulating polymer material, which can be used as a structural or functional material and has important applications in rubber, plastics, and fibers. Chinese patent CN106118065B discloses an intumescent flame-retardant silicone rubber and its preparation method, which uses an intumescent flame retardant composed of ammonium polyphosphate, pentaerythritol esters, and a melamine-polyimide supramolecular network composite material. This improves the mechanical, thermal stability, and flame-retardant properties of silicone rubber; however, this patent does not improve the antibacterial and bactericidal properties of silicone rubber, which is detrimental to its practical application in antibacterial medical supplies and other fields. Summary of the Invention

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

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

[0005] Step A: Add N,N-dimethylformamide, dianhydride compound, aromatic diamine compound, and silane-containing diamine compound to the reaction vessel. Stir and react at room temperature under a nitrogen atmosphere for 18-24 hours. Then add bromoalkanes and heat to 120-140℃, reacting for 36-48 hours. Pour the solution onto the surface of a glass mold and place it in a heating chamber. Heat sequentially to 150-160℃ for 1.5-2 hours, 200-220℃ for 1-1.5 hours, 250-260℃ for 1-1.5 hours, and 280-300℃ for 1-1.5 hours. Cool to obtain organosilicon quaternary ammonium salt polyimide. The reaction formula is:

[0006]

[0007] Step B: Place methyl vinyl silicone rubber and organosilicon quaternary ammonium salt polyimide in a two-roll mill for plasticizing, then add reinforcing agent, accelerator, antioxidant, and crosslinking agent for mixing, then add vulcanizing agent for mixing, and finally place the material in a flat vulcanizing machine. First, vulcanize at 160-170℃ and 10-12MPa pressure for 20-40 minutes, then vulcanize at 170-175℃ under normal pressure for 2-3 hours. Cool and discharge to obtain antibacterial modified silicone rubber composite material.

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

[0009] Furthermore, the dianhydride compound is pyromellitic dianhydride, 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 bromoalkane is 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecanane, or 1-bromohexadecane.

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

[0012] (1) Add 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 to a reaction vessel. Heat to 60-65℃ and reflux for 8-12 hours. After cooling, filter, distill under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain a silicon-containing dinitro compound.

[0013] (2) Add ethanol to the reaction vessel, purge with nitrogen, and add a silicon-containing dinitro compound, palladium on carbon catalyst, and hydrazine hydrate in a mass ratio of 100:(7.2-8.4):(40-52). Heat to 70-80℃, reflux for 5-8 hours, filter, distill 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 silica, 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: Using 1,3-bis(3-chloropropyl)-1,1,3,3-tetramethyldisiloxane and N-methyl-p-nitroaniline as reactants, a silicon-containing dinitro compound with a tertiary amine structure is obtained through substitution and reduction reactions. Then, it undergoes an amidation polymerization reaction with a dianhydride compound and an aromatic diamine compound, followed by a quaternization reaction with a brominated alkane, and finally high-temperature thermal imidization to obtain an organosilicon quaternary ammonium salt polyimide.

[0018] This invention uses methyl vinyl silicone rubber as the matrix and organosilicon quaternary ammonium salt polyimide as the modifier. It is then mixed and vulcanized at high temperature with reinforcing agents such as silica, crosslinking agents such as dicumyl peroxide, and vulcanizing agents such as sulfur to obtain an antibacterial modified silicone rubber composite material. This organosilicon quaternary ammonium salt polyimide contains the same siloxane structure as methyl vinyl silicone rubber, thereby improving the compatibility between polyimide and silicone rubber. This improved compatibility results in better reinforcing properties of the polyimide, increasing the Shore A hardness and tear strength of the silicone rubber material.

[0019] The organosilicon quaternary ammonium salt polyimide of this invention exhibits strong high-temperature resistance and resistance to thermal decomposition, which can increase the thermal decomposition mass loss temperature of silicone rubber materials and improve their high-temperature resistance. Simultaneously, the organosilicon quaternary ammonium salt polyimide contains quaternary ammonium salt antibacterial groups, which can interact electrostatically with the negatively charged cell membranes of bacteria, altering cell membrane permeability and causing substances within the cell membrane to flow out, thereby inhibiting and killing bacteria and significantly improving the antibacterial properties of silicone rubber materials. Detailed Implementation

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

[0021] Example 1 (1): 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 were added to the reaction vessel. The mixture was heated to 60 °C and refluxed for 12 h. After cooling, the mixture was filtered, the filtrate was distilled under reduced pressure, washed with water, and the product was recrystallized from ethanol to obtain a silicon-containing dinitro compound.

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

[0023] (3) Add 250 mL of N,N-dimethylformamide, 100 mmol of pyromellitic anhydride, 90 mmol of 4,4-diphenyl ether diamine, and 10 mmol of silane-containing diamine compound to the reaction vessel. Stir the reaction at room temperature under a nitrogen atmosphere for 18 h. Then add 24 mmol of 1-bromohexadecane, heat to 120 °C, and react for 48 h. Pour the solution onto the surface of a glass mold, place it in a heating box, and heat it sequentially to 160 °C for 1.5 h, 220 °C for 1 h, 260 °C for 1.5 h, and 280 °C for 1.5 h. Cool to obtain organosilicon quaternary ammonium salt polyimide.

[0024] (4) Place 1 kg of methyl vinyl silicone rubber and 100 g of organosilicon quaternary ammonium salt polyimide in a two-roll mill and plasticize for 20 min. Then add 80 g of reinforcing agent silica, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of crosslinking agent diisopropylbenzene peroxide and mix for 40 min. Then add 12 g of vulcanizing agent sulfur and mix for 5 min. Finally, put the material in a flat vulcanizing machine and vulcanize it at 165 °C and 10 MPa for 40 min. Then vulcanize it at 175 °C for 2 h under normal pressure. Cool and discharge the material to obtain antibacterial modified silicone rubber composite material.

[0025] Example 2 (1): 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 were added to the reaction vessel. The mixture was heated to 65 °C and refluxed for 8 h. After cooling, the mixture was filtered, the filtrate was distilled under reduced pressure, washed with water, and the product was recrystallized from ethanol to obtain a silicon-containing dinitro compound.

[0026] (2) Add 120 mL of ethanol to the reaction vessel, introduce nitrogen gas, add 10 g of silicon-containing dinitro compound, 0.72 g of palladium on carbon catalyst, and 4 g of hydrazine hydrate solution with a mass fraction of 80%. Heat to 80 °C, reflux and react for 8 h. After filtration, distill the filtrate under reduced pressure, wash with water, and recrystallize the product with ethanol to obtain 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 silanediamine compound to the reaction vessel. Stir the mixture at room temperature under a nitrogen atmosphere for 24 h. Then add 36 mmol of 1-bromododecane and heat to 125 °C. React for 36 h. Pour the solution onto the surface of a glass mold and place it in a heating box. Heat the mold to 150 °C for 2 h, 200 °C for 2 h, 260 °C for 1 h, and 300 °C for 1 h in sequence. Cool the mold to obtain organosilicon quaternary ammonium salt polyimide.

[0028] (4) Place 1 kg of methyl vinyl silicone rubber and 200 g of organosilicon quaternary ammonium salt polyimide in a two-roll mill and plasticize for 20 min. Then add 60 g of reinforcing agent silica, 23 g of accelerator 2-mercaptobenzothiazole, 18 g of antioxidant N-phenyl-2-naphthylamine, and 24 g of crosslinking agent diisopropylbenzene peroxide and mix for 40 min. Then add 9 g of vulcanizing agent sulfur and mix for 5 min. Finally, put the material in a flat vulcanizing machine and vulcanize it at 160°C and 10 MPa for 40 min. Then vulcanize it at 170°C for 3 h under normal pressure. Cool and discharge the material to obtain antibacterial modified silicone rubber composite material.

[0029] Example 3 (1): 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 were added to the reaction vessel. The mixture was heated to 60 °C and refluxed for 12 h. After cooling, the mixture was filtered, and the filtrate was distilled under reduced pressure and washed with water. The product was recrystallized from ethanol to obtain a silicon-containing dinitro compound.

[0030] (2) Add 120 mL of ethanol to the reaction vessel, introduce nitrogen gas, add 10 g of silicon-containing dinitro compound, 0.78 g of palladium on carbon catalyst, and 4 g of hydrazine hydrate solution with a mass fraction of 80%. Heat to 70-80 °C, reflux for 5 h, filter, distill under reduced pressure, wash with water, recrystallize the product with ethanol to obtain 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 silanediamine compound to a reaction vessel. Stir the mixture at room temperature under a nitrogen atmosphere for 24 h. Then add 56 mmol of 1-bromotetradecane, heat to 140 °C, and react for 36 h. Pour the solution onto the surface of a glass mold, place it in a heating box, and heat it sequentially to 160 °C for 1.5 h, 220 °C for 1 h, 250 °C for 1.5 h, and 300 °C for 1 h. Cool the mixture to obtain organosilicon quaternary ammonium salt polyimide.

[0032] (4) Place 1 kg of methyl vinyl silicone rubber and 300 g of organosilicon quaternary ammonium salt polyimide in a two-roll mill and plasticize for 20 min. Then add 50 g of reinforcing agent silica, 18 g of accelerator 2-mercaptobenzothiazole, 12 g of antioxidant N-phenyl-2-naphthylamine, and 21 g of crosslinking agent diisopropylbenzene peroxide and mix for 40 min. Then add 10 g of vulcanizing agent sulfur and mix for 5 min. Finally, put the material in a flat vulcanizing machine and vulcanize it at 160°C and 12 MPa for 20 min. Then vulcanize it at 175°C for 2 h under normal pressure. Cool and discharge the material to obtain antibacterial modified silicone rubber composite material.

[0033] The difference between Comparative Example 1 and Example 1 is that no organosilicon quaternary ammonium salt polyimide is added.

[0034] (1) Place 1 kg of methyl vinyl silicone rubber in a two-roll mill and plasticize for 20 min. Then add 80 g of reinforcing agent silica, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of crosslinking agent dicumyl peroxide. Mix for 40 min. Then add 12 g of vulcanizing agent sulfur and mix for 5 min. Finally, put the material in a flat vulcanizing machine. First, vulcanize at 165°C and 10 MPa pressure for 40 min. Then, vulcanize at 175°C under normal pressure for 2 h. Cool and discharge the material to obtain silicone rubber composite material.

[0035] The difference between Comparative Example 2 and Example 1 is that no silane diamine compound and 1-bromohexadecane were 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 the reaction vessel. Stir the reaction at room temperature under a nitrogen atmosphere for 18 h. Pour the solution onto the surface of a glass mold and place it in a heating box. Heat the mold to 160 °C for 1.5 h, 220 °C for 1 h, 260 °C for 1.5 h, and 280 °C for 1.5 h in sequence. Cool the mold to obtain polyimide.

[0037] (2) Place 1 kg of methyl vinyl silicone rubber and 100 g of polyimide in a two-roll mill and plasticize for 20 min. Then add 80 g of reinforcing agent silica, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of crosslinking agent diisopropylbenzene peroxide and mix for 40 min. Then add 12 g of vulcanizing agent sulfur and mix for 5 min. Finally, put the material in a flat vulcanizing machine and vulcanize it at 165 °C and 10 MPa for 40 min. Then vulcanize it at 175 °C for 2 h under normal pressure. Cool and discharge the material to obtain the modified silicone rubber composite material.

[0038] The difference between Comparative Example 3 and Example 1 is that 1-bromohexadecane was not added when preparing the polyimide.

[0039] (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 a silicon-containing diamine compound to a reaction vessel. Stir the reaction at room temperature under a nitrogen atmosphere for 18 h. Pour the solution onto the surface of a glass mold and place it in a heating box. Heat the mold to 160 °C for 1.5 h, 220 °C for 1 h, 260 °C for 1.5 h, and 280 °C for 1.5 h in sequence. Cool the mold to obtain organosilicon polyimide.

[0040] (2) Place 1 kg of methyl vinyl silicone rubber and 100 g of organosilicon polyimide in a two-roll mill and plasticize for 20 min. Then add 80 g of reinforcing agent silica, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of crosslinking agent diisopropylbenzene peroxide and mix for 40 min. Then add 12 g of vulcanizing agent sulfur and mix for 5 min. Finally, put the material in a flat vulcanizing machine and vulcanize it at 165 °C and 10 MPa for 40 min. Then vulcanize it at 175 °C for 2 h under normal pressure. Cool and discharge the material to obtain the modified silicone rubber composite material.

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

[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 the reaction vessel. Stir the mixture at room temperature under a nitrogen atmosphere for 18 h. Then add 24 mmol of 1-bromohexadecane, heat to 120 °C, and mix for 48 h. Pour the solution onto the surface of a glass mold, place it in a heating oven, and heat it sequentially to 160 °C for 1.5 h, 220 °C for 1 h, 260 °C for 1.5 h, and 280 °C for 1.5 h. Cool the mixture to obtain organosilicon polyimide.

[0043] (2) Place 1 kg of methyl vinyl silicone rubber and 100 g of organosilicon polyimide in a two-roll mill and plasticize for 20 min. Then add 80 g of reinforcing agent silica, 22 g of accelerator 2-mercaptobenzothiazole, 16 g of antioxidant N-phenyl-2-naphthylamine, and 20 g of crosslinking agent diisopropylbenzene peroxide and mix for 40 min. Then add 12 g of vulcanizing agent sulfur and mix for 5 min. Finally, put the material in a flat vulcanizing machine and vulcanize it at 165 °C and 10 MPa for 40 min. Then vulcanize it at 175 °C for 2 h under normal pressure. Cool and discharge the material to obtain the modified silicone rubber composite material.

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

[0045] 5 mg of the modified silicone rubber composite material was weighed and placed in a thermogravimetric analyzer. The thermogravimetric properties were analyzed under a nitrogen atmosphere at a heating rate of 10 °C / min.

[0046] Antibacterial performance test: Modified silicone rubber composite material was molded into a film with a thickness of 1 mm. The comparative example served as the blank group, and Examples 1-3 and Comparative Examples 2-4 served as the experimental groups, respectively. Then, 0.2 mL of bacterial suspension of Escherichia coli or Staphylococcus aureus (concentration of 10) was transferred to each group. 5 A solution (cfu / mL) was dropped onto the surface of a silicone rubber membrane, then covered with a sterile polyethylene membrane. The membrane was incubated at 37°C for 24 hours in a constant temperature and humidity incubator. The silicone rubber membrane and polyethylene membrane were washed with physiological saline. Then, 0.1 mL of the solution was taken and inoculated into agar medium. The culture was incubated at 37°C for 24 hours, and colony counts were performed to calculate the inhibition rate.

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

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

[0049]

[0050] After testing, compared with Comparative Example 1, Comparative Example 2 added polyimide to silicone rubber. Due to the poor compatibility between the two, the tear strength of the silicone rubber material was reduced, the increase in Shore A hardness was smaller, and it did not contain quaternary ammonium salt antibacterial groups, resulting in the silicone rubber not having antibacterial properties.

[0051] Examples 1-3 incorporated organosilicon quaternary ammonium salt polyimide, which contains the same siloxane structure as methyl vinyl silicone rubber. This improved the compatibility between polyimide and silicone rubber, giving the polyimide a good reinforcing effect, increasing the Shore A hardness and tear strength of the silicone rubber material. Furthermore, the polyimide exhibits strong high-temperature resistance and resistance to thermal decomposition, raising the thermal decomposition mass loss temperature of the silicone rubber material and improving its high-temperature performance. Simultaneously, the organosilicon quaternary ammonium salt polyimide contains quaternary ammonium salt antibacterial groups, which can interact electrostatically with the negatively charged cell membranes of bacteria, altering cell membrane permeability and allowing intracellular substances to flow out, thereby inhibiting and killing bacteria and significantly improving the antibacterial properties of the silicone rubber material.

[0052] Comparative Example 3's organosilicon polyimide contains an organosiloxane structure, exhibiting excellent compatibility with methyl vinyl silicone rubber. This results in increased Shore A hardness, tear strength, and thermal decomposition mass loss temperature of the silicone rubber material, along with improved mechanical properties and high-temperature resistance. However, the absence of 1-bromohexadecane prevents quaternization, resulting in the organosilicon polyimide lacking quaternary ammonium salt antibacterial groups, and thus the silicone rubber material exhibits almost no antibacterial properties.

[0053] Comparative Example 4 utilized conventional 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, which underwent polymerization with pyromellitic tetracarboxylic anhydride and 4,4-diphenyl ether diamine to obtain an organosilicon polyimide. This organosilicon polyimide contained an organosilicon structure and exhibited excellent compatibility with methyl vinyl silicone rubber. The resulting silicone rubber material showed increased Shore A hardness, tear strength, and thermal decomposition mass loss temperature, as well as improved mechanical properties and high-temperature resistance. However, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane lacks a tertiary amine group and cannot undergo quaternization with 1-bromohexadecane. Consequently, the organosilicon polyimide lacked quaternary ammonium salt antibacterial groups, and the silicone rubber material possessed 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, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A preparation process for an antibacterial modified silicone rubber composite material, characterized in that, The preparation process includes the following steps: Step A: Add N,N-dimethylformamide, dianhydride compound, and aromatic diamine compound (with the following structural formula) to the reaction vessel. The silicon-containing diamine compound was reacted with stirring at room temperature under a nitrogen atmosphere for 18-24 hours. Then, bromoalkanes were added, and the mixture was heated to 120-140℃ for 36-48 hours. The solution was poured onto the surface of a glass mold and placed in a heating chamber. The mold was heated sequentially to 150-160℃ for 1.5-2 hours, 200-220℃ for 1-1.5 hours, 250-260℃ for 1-1.5 hours, and 280-300℃ for 1-1.5 hours. After cooling, organosilicon quaternary ammonium salt polyimide was obtained. Step B: Methyl vinyl silicone rubber and organosilicon quaternary ammonium salt polyimide are placed in an open mill for plasticizing. Then, reinforcing agent, accelerator, antioxidant and crosslinking agent are added and mixed. Then, vulcanizing agent is added and mixed. Finally, the material is vulcanized in a flat vulcanizing machine in two stages, cooled and discharged to obtain antibacterial modified silicone rubber composite material. In step A, the molar ratio of the dianhydride compound, the aromatic diamine compound, the silane-containing diamine compound, and the bromoalkane is 100:(75-90):(10-25):(24-56).

2. The preparation process of the antibacterial modified silicone rubber composite material according to claim 1, characterized in that, The dianhydride compound is pyromellitic dianhydride, 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.

3. The preparation process of the antibacterial modified silicone rubber composite material according to claim 1, characterized in that, The bromoalkane is 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecanane, or 1-bromohexadecane.

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

5. The preparation process of the antibacterial modified silicone rubber composite material according to claim 4, 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).

6. The preparation process of the antibacterial modified silicone rubber composite material according to claim 4, characterized in that, The mass ratio of silicon dinitro compound, palladium on carbon catalyst, and hydrazine hydrate in (2) is 100:(7.2-8.4):(40-52).

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

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

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

Images