Intrinsic antibacterial silicone rubber and surgical catheter and method of making same

Abstract

The application belongs to the technical field of silicone rubber, and particularly relates to intrinsic antibacterial silicone rubber and a surgical catheter and a preparation method thereof. The application designs acryl grafted nano zinc oxide, isobornyl acrylate terminated dimethyl siloxane, acryl terminated polydimethyl siloxane, and carries out a Michael addition reaction curing with amino terminated polydimethyl siloxane under the condition of no additional catalyst, thereby obtaining intrinsic antibacterial silicone rubber, which has long-term and high-efficiency antibacterial effect, and by adjusting the segment length of the amino terminated polydimethyl siloxane, high-rigidity and high-flexibility silicone rubber can be prepared, so as to adapt to application scenarios requiring high flexibility, high adhesion, or high support, high dimensional stability.

Description

Technical Field

[0001] This application belongs to the field of silicone rubber technology, and specifically relates to an intrinsic antibacterial silicone rubber, its preparation method and application, and a surgical catheter using the silicone rubber as a material. Background Technology

[0002] Silicone rubber, due to the high bond energy and long bond length of the Si-O bonds in its molecular chain, possesses excellent high and low temperature resistance, with a service temperature range of -60 to 200℃. It also exhibits inherent advantages such as high weather resistance, aging resistance, electrical insulation, excellent biocompatibility, and low surface energy. Furthermore, it is odorless and non-toxic, making it an irreplaceable material in aerospace, automotive manufacturing, medical devices, food, and electronics industries. However, the single basic properties of traditional general-purpose silicone rubber can no longer meet the demands of refined and demanding applications. For silicone rubber materials in the medical device field, long-term and highly effective antibacterial effects are the core requirement.

[0003] Current modification methods for antibacterial silicone rubber mainly involve physical mixing, adding common antibacterial fillers such as silver ions, quaternary ammonium salts, and nano-metal oxides. However, this type of modification has significant drawbacks: short-lasting and unstable antibacterial effects; the antibacterial fillers are prone to dissolution and migration, leading to a decline in antibacterial efficacy or even loss of antibacterial ability after long-term use. Furthermore, the fillers themselves are highly polar, resulting in poor compatibility with the non-polar silicone rubber matrix and a tendency to aggregate, leading to decreased tensile / tear strength and toughness. Moreover, their use in the medical field poses safety risks, such as the cumulative toxicity and sensitization risks of free silver ions or quaternary ammonium salt compounds. Therefore, grafting antibacterial groups into the silicone rubber molecular chain and cross-linking network through chemical bonding to create intrinsic antibacterial silicone rubber has become the mainstream research direction for antibacterial silicone rubber materials, fundamentally solving the problems of easy dissolution of antibacterial fillers and poor compatibility with silicone rubber.

[0004] On the other hand, silicone rubber itself is divided into addition-type and condensation-type silicone rubber. Condensation-type silicone rubber is cured based on a condensation reaction, producing small molecule byproducts such as methanol, water, and ethanol. These small molecule products are difficult to completely expel and easily form micropores and bubbles inside the material, becoming stress concentration points. Under external force, they are prone to fracture at the defects, resulting in low mechanical properties. Furthermore, their use in medical devices can pose health risks. Traditional hydrosilylation addition-type silicone rubber uses platinum catalysts that are prone to poisoning, especially compounds containing heteroatoms such as N, S, P, Sn, and Hg, which are strong poisoning sources for platinum catalysts. Even concentrations as low as ppm can lead to catalyst failure and incomplete vulcanization of the addition-type silicone rubber. Therefore, designing platinum-free Michael addition-type silicone rubber can avoid vulcanization failure due to catalyst poisoning. Moreover, the formulation design of silicone rubber is more flexible, allowing for the easy introduction of N-containing antibacterial agents and amino-containing polysiloxane segments, as well as the adjustment of the mechanical properties of silicone rubber according to the needs of different application scenarios. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this application designs acryloyl-grafted nano-zinc oxide, isobornyl methacrylate-terminated dimethylsiloxane, and acryloyl-terminated polydimethylsiloxane, which undergo Michael addition with amino-terminated polydimethylsiloxane without the need for external catalysts, thereby preparing intrinsic antibacterial silicone rubber with long-term and high-efficiency antibacterial effects. Furthermore, by adjusting the chain length of amino-terminated polydimethylsiloxane, silicone rubber with high rigidity and high flexibility can be prepared.

[0006] To achieve the above technical objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, an intrinsically antibacterial silicone rubber, the raw materials of which include: amino-terminated polydimethylsiloxane, acryloyl-terminated polydimethylsiloxane, isoborneol-terminated polydimethylsiloxane, and acryloyl-grafted nano zinc oxide.

[0008] The general structural formula of the amino-terminated polydimethylsiloxane is:

[0009] ; where R1 is selected from hydrocarbon groups with 1 to 6 carbon atoms; n is a positive integer greater than 10;

[0010] Preferably, the amino-terminated polydimethylsiloxane is selected from bis(3-aminopropyl)-terminated polydimethylsiloxane;

[0011] The acryloyl-terminated polydimethylsiloxane is a polydimethylsiloxane with at least one acryloyl group at each end;

[0012] Preferably, the acryloyl-terminated polydimethylsiloxane is a polydimethylsiloxane with 1-3 acryloyl groups at each end, and its general structural formula includes:

[0013] , , Wherein, R2 is selected from alkyl, alkoxy, alkylamine or alkylamino ester groups having 1 to 20 carbon atoms; R3 is selected from alkyl, alkoxy or alkylamine groups having 1 to 10 carbon atoms; m is a positive integer greater than or equal to 1;

[0014] Preferably, the acryloyl-terminated polydimethylsiloxane is obtained by reacting isocyanate-terminated polydimethylsiloxane with hydroxyl-containing acrylates or hydroxyl-containing methacrylates.

[0015] The structural formula of the isoborneol-terminated polydimethylsiloxane is:

[0016] Where a is a positive integer greater than or equal to 1, and R4 is selected from hydrogen atoms or methyl groups;

[0017] Preferably, the isoborneol-terminated polydimethylsiloxane shown is an isoborneol-terminated dimethylsiloxane with a degree of polymerization of 1.

[0018] Preferably, the isoborneol-terminated dimethylsiloxane is obtained by Michael addition reaction of isoborneol acrylate or isoborneol methacrylate with 1,3-bis(aminopropyl)tetramethyldisiloxane.

[0019] Preferably, the Michael addition reaction is carried out at a temperature of 40-80°C;

[0020] Acryloyl-grafted nano-zinc oxide is obtained by surface modification of nano-zinc oxide with a silane coupling agent containing at least one acryloyl group;

[0021] Preferably, the average particle size of the nano-zinc oxide does not exceed 100 nm;

[0022] Preferably, the silane coupling agent containing at least one acryloyl group is selected from γ-methacryloyloxypropyltrimethoxysilane;

[0023] Preferably, the surface modification method includes: dispersing nano zinc oxide in water and an alcohol solvent, adding a silane coupling agent containing at least one acryloyl group, heating to 40-60°C and reacting for 1-8 hours, and then allowing it to stand at room temperature for 12-60 hours to mature.

[0024] Preferably, the alcohol solvent is selected from fatty alcohols with 1-4 carbon atoms;

[0025] Preferably, the mass ratio of the silane coupling agent containing at least one acryloyl group is 10-30 wt% of the nano zinc oxide.

[0026] Furthermore, the intrinsic antibacterial silicone rubber includes fillers selected from one or more of silica, quartz powder, wollastonite, barium sulfate, diatomaceous earth, kaolin, and calcium carbonate;

[0027] Preferably, the filler is selected from silica.

[0028] Furthermore, the intrinsic antibacterial silicone rubber contains hydroxyl silicone oil or methyl silicone oil;

[0029] Preferably, the intrinsic antibacterial silicone rubber contains hydroxyl silicone oil.

[0030] Furthermore, the intrinsic antibacterial silicone rubber also contains amino-terminated polydimethylsiloxane with a low degree of polymerization of 1-10.

[0031] Preferably, the low-polymerization-degree amino-terminated polydimethylsiloxane is 1,3-bis(aminopropyl)tetramethyldisiloxane.

[0032] Furthermore, an intrinsically antibacterial silicone rubber, by weight, comprises: 90-110 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane, 1-5 parts by weight of acryloyl-terminated polydimethylsiloxane, 1-10 parts by weight of isoborneol-terminated dimethylsiloxane, 0.1-1 parts by weight of acryloyl-grafted nano zinc oxide, 1-10 parts by weight of filler, and 0.5-2 parts by weight of hydroxyl silicone oil or methyl silicone oil;

[0033] Preferably, an intrinsic antibacterial silicone rubber comprises, by weight, 90-110 parts of bis(3-aminopropyl)-terminated polydimethylsiloxane, 1-5 parts of acryloyl-terminated polydimethylsiloxane, 1-10 parts of isoborneol-terminated dimethylsiloxane, 1-10 parts of low-polymerization-degree amino-terminated polydimethylsiloxane, 0.1-1 parts of acryloyl-grafted nano zinc oxide, 1-10 parts of filler, and 0.5-2 parts of hydroxyl silicone oil or methyl silicone oil;

[0034] Secondly, the preparation method of the intrinsic antibacterial silicone rubber described above is obtained by mixing and thermosetting the raw materials of the antibacterial silicone rubber components described above.

[0035] Preferably, the components of the intrinsic antibacterial silicone rubber described above are mixed and then cured at 100-220°C and 5-15 MPa.

[0036] Preferably, the components of the intrinsic antibacterial silicone rubber described above are first cured at 100-150℃ and 5-15MPa pressure, and finally cured at 150-200℃ and normal pressure.

[0037] Thirdly, the application of the intrinsic antibacterial silicone rubber described above in the field of medical devices.

[0038] Fourthly, a surgical catheter using the aforementioned intrinsic antibacterial silicone rubber as a material.

[0039] The beneficial effects of the technical solution proposed above in this application are as follows: Acryloyl-grafted nano-zinc oxide, isoborneol-terminated dimethylsiloxane (meth)acrylate, and acryloyl-terminated polydimethylsiloxane are designed and cured via a Michael addition reaction with amino-terminated polydimethylsiloxane without the need for an external catalyst, thereby obtaining an intrinsic antibacterial silicone rubber. The introduction of the isoborneol structure directly disrupts the lipid bilayer of the bacterial cell membrane through steric hindrance and hydrophobic interactions. Combined with nano-zinc oxide, it releases Zn through adsorption onto the cell wall. 2+By disrupting the bacterial membrane structure and combining two different antibacterial mechanisms, silicone rubber with broad-spectrum antibacterial, long-term, and highly effective antibacterial effects can be obtained.

[0040] On the other hand, by adjusting the amount of amino-terminated polydimethylsiloxane with different chain segment lengths, silicone rubbers with high rigidity and high elongation at break can be prepared respectively, thereby adapting to application scenarios that require high flexibility, high fit or high support and high dimensional stability. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the acryloyl-grafted nano-zinc oxide structure prepared in Example 1. Detailed Implementation

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention. It should be noted that the terminology used herein is only for describing specific implementation methods and is not intended to limit the exemplary implementation methods according to the present invention.

[0044] Unless otherwise specified, the experimental conditions used in the examples are generally in accordance with conventional conditions in the art or the conditions recommended by the reagent company. Unless otherwise specified, the materials and reagents used in the examples can be purchased commercially.

[0045] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0046] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0047] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0048] In this application, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions composed of the listed features.

[0049] Example 1

[0050] Preparation of acryloyl-grafted nano zinc oxide: 125.5g of nano-sized zinc oxide (Jiangsu Xianfeng Nano) with an average particle size of (50±20)nm was dispersed in a mixed solution of 15.8g water and 50.6g ethanol using a disperser. Acetic acid was added to adjust the pH of the mixed solution to 4-4.5. After stirring at 600 rpm and room temperature for 1 hour, 26g of coupling agent γ-methacryloyloxypropyltrimethoxysilane (KH570) was added. The mixture was heated to 50℃ and reacted for 2 hours. Then, it was cooled to room temperature and allowed to stand for 48 hours for aging. Finally, it was vacuum dried at 80℃ for 12 hours to obtain the reacted acryloyl-grafted nano zinc oxide.

[0051] Example 2

[0052] Preparation of isoborneol acrylate-terminated dimethylsiloxane: isoborneol acrylate was subjected to a Michael addition reaction with 1,3-bis(aminopropyl)tetramethyldisiloxane.

[0053] 74.6 g of 1,3-bis(aminopropyl)tetramethyldisiloxane, 125 g of isobornyl acrylate, and 0.6 g of the polymerization inhibitor p-hydroxybenzophenol were added to a reaction vessel. The mixture was heated to 60 °C with stirring and nitrogen gas was introduced while stirring for 3 hours. The reaction was then tested by sampling. 1 The disappearance of the H-NMR absorption peak at 5.8-6.5 ppm indicates that the reaction is complete, thus yielding isobornyl acrylate-terminated dimethylsiloxane.

[0054] The structure of the product, isobornyl acrylate-terminated dimethylsiloxane, is characterized as follows:

[0055] 1H-NMR (CDCl3): δ 0.08 (12H, s), 0.68 (4H, dd, J = 7.55, 7.55 Hz), 0.84-0.96 (15H, m), 1.04 (3H, s), 1.25-2.05 (16H, m), 2.20 (1H, dddd, J = 4.86,4.86, 1.43, 1.43 Hz), 2.31-2.60 (9H, m), 2.81 (4H, dd, J = 6.62, 6.62 Hz), 5.02 (1H,dd, J = 8.06, 4.20 Hz), 5.14 (1H,ddd, J = 8.06, 4.86, 4.20 Hz).

[0056] 13 C-NMR (CDCl3): δ 0.2 (4C), 13.5, 15.0, 17.6 (2C), 18.9, 19.8, 20.1,21.1, 27.2, 27.9, 28.2, 29.5 (2C), 33.9, 34.6 (2C), 36.9, 40.9, 44.3 (2C), 45.2, 47.9, 48.0, 48.8 (2C), 49.7 (2C), 53.6, 76.2, 79.7, 174.7(2C).

[0057] Therefore, the structural formula of isoborneol acrylate-terminated dimethylsiloxane is confirmed as follows:

[0058] .

[0059] Example 3

[0060] Preparation of acryloyl-terminated polydimethylsiloxane: Silmer NCO Di-50, which isocyanate-terminated, was reacted with 4-hydroxybutyl acrylate. The number-average molecular weight of Silmer NCO Di-50 was 4300 g / mol.

[0061] 430g Silmer NCO Di-50, 43.3g 4-hydroxybutyl acrylate, 0.4g dibutyltin dilaurate, and 1.5g p-hydroxybenzophenol (polymerization inhibitor) were added to a reaction vessel. The mixture was heated to 85℃ and stirred under nitrogen for 8 hours. The infrared spectrum was measured at 2250 cm⁻¹. -1 The disappearance of the nearby absorption peak indicates that the reaction is complete. After removing unreacted monomers by vacuum distillation at 85°C, hydroxybutyl acrylate-terminated polydimethylsiloxane is obtained.

[0062] Example 4

[0063] Preparation of acryloyl-terminated polydimethylsiloxane: Silmer NCO Di-50, which isocyanate-terminated, was reacted with glyceryl dimethacrylate. The number-average molecular weight of Silmer NCO Di-50 was 4300 g / mol.

[0064] 430g Silmer NCO Di-50, 68.5g glyceryl dimethacrylate, 0.5g dibutyltin dilaurate, and 1.8g p-hydroxybenzophenol (polymerization inhibitor) were added to a reaction vessel. The mixture was heated to 85℃ and stirred under nitrogen for 8 hours. The infrared spectrum was measured at 2250 cm⁻¹. -1 The disappearance of the nearby absorption peak indicates that the reaction is complete. Unreacted monomers were removed by vacuum distillation at 85°C to obtain glyceryl dimethacrylate-terminated polydimethylsiloxane.

[0065] Example 5

[0066] Preparation of acryloyl-terminated polydimethylsiloxane: Silmer NCO Di-50, which isocyanate-terminated, was reacted with trimethylolpropane diacrylate. The number-average molecular weight of Silmer NCO Di-50 was 4300 g / mol.

[0067] 430g Silmer NCO Di-50, 72.7g trimethylolpropane diacrylate, 0.5g dibutyltin dilaurate, and 1.8g p-hydroxybenzophenol (polymerization inhibitor) were added to a reaction vessel. The mixture was heated to 85℃ and stirred under nitrogen for 8 hours. The infrared spectrum was measured at 2250 cm⁻¹. -1 The disappearance of the nearby absorption peak indicates that the reaction is complete. After removing unreacted monomers by vacuum distillation at 85°C, trimethylolpropane diacrylate-terminated polydimethylsiloxane is obtained.

[0068] Example 6

[0069] Preparation of acryloyl-terminated polydimethylsiloxane: Silmer NCO Di-50, which isocyanate-terminated, was reacted with pentaerythritol triacrylate. The number-average molecular weight of Silmer NCO Di-50 was 4300 g / mol.

[0070] 430g of Silmer NCO Di-50, 89.5g of pentaerythritol triacrylate, 0.5g of dibutyltin dilaurate, and 2.2g of the polymerization inhibitor p-hydroxybenzophenol were added to a reaction vessel. The mixture was heated to 90℃ and stirred under nitrogen for 12 hours. The infrared spectrum was measured at 2250 cm⁻¹. -1The disappearance of the nearby absorption peak indicates that the reaction is complete. After removing unreacted monomers by vacuum distillation at 90°C, pentaerythritol triacrylate-terminated polydimethylsiloxane is obtained.

[0071] Example 7

[0072] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32 (Gelest, number average molecular weight of 30,000, kinematic viscosity of 2200 cSt at 25°C), 8 parts by weight of isobornyl acrylate-terminated dimethylsiloxane prepared in Example 2, 2.5 parts by weight of hydroxybutyl acrylate-terminated polydimethylsiloxane, 0.3 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 6 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0073] Example 8

[0074] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32 (Gelest, number-average molecular weight of 30,000, kinematic viscosity of 2200 cSt at 25°C), 8 parts by weight of isobornyl acrylate-terminated dimethylsiloxane prepared in Example 2, 2 parts by weight of dimethacrylate-terminated polydimethylsiloxane, 0.3 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 6 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0075] Example 9

[0076] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32, 8 parts by weight of isoborneol acrylate-terminated dimethylsiloxane prepared in Example 2, 2 parts by weight of trimethylolpropane diacrylate-terminated polydimethylsiloxane, 0.3 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 6 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0077] Example 10

[0078] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32, 8 parts by weight of isobornyl acrylate-terminated dimethylsiloxane prepared in Example 2, 1.5 parts by weight of pentaerythritol triacrylate polydimethylsiloxane, 0.3 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 6 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0079] Example 11

[0080] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32, 6 parts by weight of isoborneol-terminated dimethylsiloxane prepared in Example 2, 6 parts by weight of 1,3-bis(aminopropyl)tetramethyldisiloxane, 3.6 parts by weight of hydroxybutyl acrylate-terminated polydimethylsiloxane, 0.5 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 5 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0081] Example 12

[0082] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32, 6 parts by weight of isoborneol-terminated dimethylsiloxane prepared in Example 2, 6 parts by weight of 1,3-bis(aminopropyl)tetramethyldisiloxane, 3 parts by weight of dimethacrylate-terminated polydimethylsiloxane, 0.5 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 5 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0083] Example 13

[0084] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32, 6 parts by weight of isoborneol acrylate-terminated dimethylsiloxane prepared in Example 2, 6 parts by weight of 1,3-bis(aminopropyl)tetramethyldisiloxane, 3 parts by weight of trimethylolpropane diacrylate-terminated polydimethylsiloxane, 0.5 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 5 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0085] Example 14

[0086] The intrinsic antibacterial silicone rubber, by weight, comprises: 100 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32, 6 parts by weight of isoborneol-terminated dimethylsiloxane prepared in Example 2, 6 parts by weight of 1,3-bis(aminopropyl)tetramethyldisiloxane, 2.4 parts by weight of pentaerythritol triacrylate polydimethylsiloxane, 0.5 parts by weight of acryloyl-grafted nano zinc oxide prepared in Example 1, 5 parts by weight of fumed silica, and 1 part by weight of hydroxyl-terminated polydimethylsiloxane (107 silicone rubber, Zhejiang Rongli).

[0087] The processing and molding methods of the intrinsic antibacterial silicone rubber in Examples 7-14 above are as follows:

[0088] S1. First, acryloyl-terminated polydimethylsiloxane, isobornyl acrylate-terminated dimethylsiloxane, fumed silica and acryloyl-grafted nano zinc oxide (in Examples 11-14, the amount of 1,3-di(aminopropyl)tetramethyldisiloxane was added in the formulation) were premixed at room temperature for 30 minutes using a high-speed dispersant.

[0089] S2. Add bis(3-aminopropyl)-terminated polydimethylsiloxane DMS-A32 and 107 silicone rubber to the mixer and mix with the premixed materials for 60 minutes.

[0090] S3. Place the mixed rubber compound into the mold, set the pre-curing conditions to 125℃, 10MPa, and 20 minutes, and perform pre-curing molding.

[0091] S4. After pre-curing, the silicone rubber is placed in a high-temperature oven and cured at 185°C for 2 hours to complete deep curing and obtain intrinsic antibacterial silicone rubber.

[0092] Performance testing

[0093] The intrinsic antibacterial silicone rubber samples prepared in Examples 7-14 above were cured and molded, and then subjected to relevant performance tests after being placed at room temperature for 48 hours.

[0094] Tensile breaking strength, elongation at break, and 100% modulus of constant tensile strength were tested by preparing dumbbell-shaped specimens from silicone rubber according to ASTM D 412 method, with a tensile rate of 300 mm / min.

[0095] Tear resistance test: Following ASTM D 624, right-angled specimens were prepared from silicone rubber and the tear strength (kN·m) of the silicone rubber samples was tested. -1 ).

[0096] Antibacterial performance test: According to the standard GB / T31402-2023, Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus were used as test strains, and the antibacterial activity value R was tested after 2 hours and 24 hours of contact with silicone rubber.

[0097] Long-lasting antibacterial test: The silicone rubber was immersed in deionized water at a controlled temperature of (37±1)℃ for 30 days, and then the antibacterial activity value R was tested according to the above method.

[0098] The test results are recorded in Table 1.

[0099] Analysis of the data in Table 1 shows that the intrinsic antibacterial silicone rubbers prepared in Examples 7-14 exhibit significant differences in mechanical properties. Adjusting the formulation according to the specific application requirements can produce silicone rubber materials with high flexibility, high adhesion, or high support and high dimensional stability. Among these, 1,3-bis(aminopropyl)tetramethyldisiloxane and acryloyl-grafted nano-zinc oxide, as short-chain crosslinking agents, are key components for improving the modulus and strength of silicone rubber. These short-chain crosslinking agents, after curing, reduce the movement space of silicone rubber molecular chains, improving rigidity and dimensional stability, but also leading to a decrease in flexibility. Furthermore, the functionality of the acryloyl end-capping agent is also a key factor in regulating the crosslinking density and mechanical properties of silicone rubber. Using trifunctional end-capping agents such as pentaerythritol triacrylate, compared to monofunctional 4-hydroxybutyl acrylate, difunctional dimethacrylate, and trimethylolpropane diacrylate, can yield silicone rubber materials with higher rigidity, lower deformation, and lower flexibility, and vice versa. The type of acryloyl end-capping agent can be flexibly selected according to the needs to obtain intrinsic antibacterial silicone rubber with different mechanical properties.

[0100] Table 1

[0101]

[0102] Antibacterial tests revealed that the intrinsic antibacterial silicone rubbers of Examples 7-14 exhibited excellent antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. After 2 hours of contact with the silicone rubber, the antibacterial activity R-value was not lower than 1.70, equivalent to an antibacterial rate of ≥98.0%, indicating that the intrinsic antibacterial silicone rubber possesses highly efficient antibacterial properties. After 24 hours of contact, the antibacterial activity R-value was not lower than 2.25, equivalent to an antibacterial rate of ≥99.4%. After 30 days of immersion in water, further antibacterial testing showed no significant decrease in the antibacterial activity R-value, indicating that the intrinsic antibacterial silicone rubber has the advantage of long-lasting antibacterial activity, with the antibacterial agent unlikely to migrate or dissolve. Therefore, the intrinsic antibacterial silicone rubber solves the problems of easy dissolution and diminished antibacterial effect associated with physically mixed or coated antibacterial silicone rubbers. The antibacterial groups (nano-zinc oxide and isoborneol groups) are chemically bonded to the molecular chains or cross-linking points of the silicone rubber, thus maintaining a long-term, highly efficient antibacterial effect.

[0103] Finally, it should be noted that the above-described embodiments are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Furthermore, it should be understood that after reading the above teachings of this application, those skilled in the art can make various alterations or modifications to this application, and the equivalent forms obtained also fall within the scope of protection of this application. It should also be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. An intrinsically antibacterial silicone rubber, characterized in that, The raw materials include: amino-terminated polydimethylsiloxane, acryloyl-terminated polydimethylsiloxane, isobornyl methacrylate-terminated dimethylsiloxane, and acryloyl-grafted nano zinc oxide. The general structural formula of the amino-terminated polydimethylsiloxane is: ; where R1 is selected from hydrocarbon groups with 1 to 6 carbon atoms; n is a positive integer greater than 10; The acryloyl-terminated polydimethylsiloxane is a polydimethylsiloxane with at least one acryloyl group at each end; The structural formula of the isoborneol-terminated polydimethylsiloxane is: ； Where a is a positive integer greater than or equal to 1, and R4 is selected from hydrogen atoms or methyl groups; Acryloyl-grafted nano-zinc oxide is obtained by surface modification of nano-zinc oxide with a silane coupling agent containing at least one acryloyl group.

2. The intrinsic antibacterial silicone rubber according to claim 1, characterized in that, The acryloyl-terminated polydimethylsiloxane is obtained by reacting isocyanate-terminated polydimethylsiloxane with hydroxyl-containing acrylates or hydroxyl-containing methacrylates. The isoborneol-terminated dimethylsiloxane is obtained by Michael addition reaction of isoborneol methacrylate and 1,3-bis(aminopropyl)tetramethyldisiloxane.

3. The intrinsic antibacterial silicone rubber according to claim 2, characterized in that, The Michael addition reaction is carried out at a temperature of 40-80°C.

4. The intrinsic antibacterial silicone rubber according to claim 1, characterized in that, Intrinsic antibacterial silicone rubber contains fillers selected from one or more of silica, quartz powder, wollastonite, barium sulfate, diatomaceous earth, kaolin, and calcium carbonate.

5. The intrinsic antibacterial silicone rubber according to claim 1, characterized in that, Intrinsic antibacterial silicone rubber includes hydroxyl silicone oil or methyl silicone oil; The intrinsic antimicrobial silicone rubber also contains low-polymerization-degree amino-terminated polydimethylsiloxane with a polymerization degree of 1-10.

6. The intrinsic antibacterial silicone rubber according to claim 1, characterized in that, The raw materials of the intrinsic antibacterial silicone rubber include: 90-110 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane, 1-5 parts by weight of acryloyl-terminated polydimethylsiloxane, 1-10 parts by weight of isobornyl methacrylate-terminated dimethylsiloxane, 0.1-1 parts by weight of acryloyl-grafted nano zinc oxide, 1-10 parts by weight of filler, and 0.5-2 parts by weight of hydroxyl silicone oil or methyl silicone oil.

7. The intrinsic antibacterial silicone rubber according to claim 1, characterized in that, The raw materials of the intrinsic antibacterial silicone rubber include: 90-110 parts by weight of bis(3-aminopropyl)-terminated polydimethylsiloxane, 1-5 parts by weight of acryloyl-terminated polydimethylsiloxane, 1-10 parts by weight of isobornyl methacrylate-terminated dimethylsiloxane, 1-10 parts by weight of low-polymerization-degree amino-terminated polydimethylsiloxane, 0.1-1 parts by weight of acryloyl-grafted nano zinc oxide, 1-10 parts by weight of filler, and 0.5-2 parts by weight of hydroxyl silicone oil or methyl silicone oil.

8. A method for preparing intrinsic antibacterial silicone rubber as described in any one of claims 1-7, characterized in that, It is obtained by mixing and thermosetting the various components of antibacterial silicone rubber.

9. The application of the intrinsic antibacterial silicone rubber as described in any one of claims 1-7 in the field of medical devices.

10. A surgical catheter using the intrinsic antimicrobial silicone rubber as described in any one of claims 1-7 as a material.

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