Fluororubber composite material with antibacterial property and preparation method thereof
By adding cold-resistant modifiers and antibacterial agents to fluororubber composites, covalent bonds and flexible segments are formed, solving the problems of traditional fluororubber being prone to bacterial growth and low-temperature brittle fracture in humid environments. This achieves excellent tensile and antibacterial properties, expanding its application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SINOMIN RUBBER GRP CO LTD
- Filing Date
- 2025-09-03
- Publication Date
- 2026-06-16
AI Technical Summary
Traditional fluororubber composites are prone to bacterial growth in humid environments and are brittle and fracture at low temperatures. Their antibacterial and cold-resistant properties are insufficient, limiting their application in medical devices and food processing equipment.
By adding cold-resistant modifiers and antibacterial agents, a composite material containing fluororubber, carbon black, lubricant, calcium carbonate, magnesium oxide, anti-scorching agent and crosslinking agent is prepared. Covalent bonds and flexible segments are formed through specific reaction steps, which enhances interfacial bonding and antibacterial properties.
Excellent tensile properties, cold resistance and antibacterial properties of fluororubber composites have been achieved, making them suitable for humid and low-temperature environments and improving the application range and safety of the materials.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of fluororubber materials technology, specifically to a fluororubber composite material with antibacterial properties and its preparation method. Background Technology
[0002] Fluororubber (FKM) is a synthetic polymer elastomer with fluorine atoms attached to the carbon atoms of its main chain or side chains. It possesses excellent heat resistance, oil resistance, solvent resistance, corrosion resistance, strong oxidation resistance, and good physical and mechanical properties, making it widely used in the automotive, machinery, aerospace, and chemical industries. However, with technological advancements and the continuous expansion and deepening of end-use applications, traditional fluororubber composites face challenges such as insufficient antibacterial properties and poor low-temperature elasticity. In applications involving medical devices (such as respirator seals) and food processing equipment (such as conveyor belts), which are exposed to humid, nutrient-rich environments for extended periods, bacteria can easily adhere to and proliferate, impacting health. Furthermore, at low temperatures, the molecular chain movement of fluororubber freezes, making the material hard and brittle, prone to brittle fracture under external force, thus limiting its application in low-temperature environments.
[0003] Chinese invention patent application CN117186572A discloses a fluororubber composite material for antibacterial wearable devices and its preparation method. The raw materials include amine compounds, vulcanizing agents, epoxy resins, fluororubber, and composite antibacterial fillers. This invention effectively enhances the antibacterial effect and self-cleaning properties of fluororubber composite materials. Sodium borohydride reduces silver nitrate to form silver nanoparticles, which are then blended with waterborne polyurethane to incorporate the silver nanoparticles, facilitating uniform dispersion of the silver nanoparticles in the composite antibacterial filler. This forms a nano-copper-nano zinc oxide composite antibacterial material. Polydimethylsiloxane hydrophobically modifies the surfaces of the polyurethane and polyacrylonitrile. This improves the antibacterial and hydrophobic properties of the fluororubber composite material, but its low-temperature resistance is poor. Summary of the Invention
[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a fluororubber composite material with antibacterial properties.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] A fluororubber composite material with antibacterial properties comprises the following raw materials in parts by weight:
[0007] Fluororubber 75-80 parts, EPDM rubber 5-8 parts, cold-resistant modifier 10-15 parts, carbon black 15-20 parts, antibacterial agent 3-5 parts, lubricant 0.8-1.2 parts, calcium carbonate 3-5 parts, magnesium oxide 6-8 parts, scorching inhibitor 0.1-0.3 parts, crosslinking agent 2.5-3.5 parts;
[0008] The cold-resistant modifier is prepared by the following method:
[0009] S1: 3-Amino-1,2-propanediol reacts with 1,4-phenylenediboronic acid to form intermediate 1, and the reaction equation is shown below:
[0010] .
[0011] S2: Acrylic acid and polyethylene glycol react to form intermediate 2, and the reaction equation is shown below:
[0012] .
[0013] S3: Intermediate 1 and Intermediate 2 react to generate a cold-resistant modifier, and the reaction equation is shown below:
[0014] .
[0015] Where —R— is .
[0016] In step S1, the molar ratio of 3-amino-1,2-propanediol to 1,4-phenylenediboronic acid is (2.1-2.3):1.
[0017] In step S2, the mass ratio of acrylic acid to polyethylene glycol is (0.28-0.32):1.
[0018] In step S3, the mass ratio of intermediate 1 to intermediate 2 is 1:(3-3.3).
[0019] The antibacterial agent is prepared by the following method:
[0020] N1: 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tris[benzaldehyde] reacts with 6-amino-1H-indole-4-carboxylic acid to form compound 1, and the reaction equation is shown below:
[0021] .
[0022] N2: Compound 1 reacts with choline chloride to produce an antibacterial agent. The reaction equation is shown below:
[0023] .
[0024] In step N1, the molar ratio of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tri[benzaldehyde] to 6-amino-1H-indole-4-carboxylic acid is 1:3.1; in step N2, the molar ratio of compound 1 to choline chloride is 1:3.2.
[0025] The lubricant is stearic acid.
[0026] The crosslinking agent is a mixture of hexafluorobisphenol AF and benzyltriphenylphosphine chloride in a mass ratio of 4:1.
[0027] The scorching inhibitor is N-cyclohexylthiophthalimide.
[0028] A method for preparing a fluororubber composite material with antibacterial properties includes the following steps:
[0029] (1) Weigh out the following by weight: 75-80 parts of fluororubber, 5-8 parts of EPDM rubber, 10-15 parts of cold-resistant modifier, 15-20 parts of carbon black, 3-5 parts of antibacterial agent, 0.8-1.2 parts of lubricant, 3-5 parts of calcium carbonate, 6-8 parts of magnesium oxide, 0.1-0.3 parts of anti-scorching agent, and 2.5-3.5 parts of crosslinking agent;
[0030] (2) Add fluororubber and EPDM rubber to a mixer and mix at 50-60℃. Add cold-resistant modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide and anti-scorching agent and mix. Add crosslinking agent and mix. Put it in a flat vulcanizing agent and hot press at 150-170℃ and 12-15MPa for 10-15min. Put it in an oven at 200-220℃ and keep it warm for 2-3h to obtain a fluororubber composite material with antibacterial properties.
[0031] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:
[0032] The fluororubber composite material prepared by this invention exhibits excellent tensile properties, cold resistance, and antibacterial properties. The cold-resistant modifier added to the composite material enhances interfacial bonding by forming covalent bonds with the fluororubber matrix, and improves the tensile properties and cold resistance of the fluororubber composite material by introducing flexible polyethylene glycol segments and dynamic borate ester bonds; the antibacterial agent disrupts the cell membrane and interferes with the reproduction process, thereby enhancing the antibacterial properties of the composite material. Detailed Implementation
[0033] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.
[0034] Example 1: Preparation of cold-resistant modifier:
[0035] S1: 150 ml of anhydrous DMF, 0.5 g of deionized water, and 0.21 mol of 3-amino-1,2-propanediol were added to a reaction vessel and stirred until homogeneous. Then, 0.1 mol of 1,4-phenylenediboric acid was added in 5 batches, with an interval of 15 min between each batch. The mixture was stirred at room temperature for 20 h. The reaction solution was slowly poured into 300 ml of diethyl ether, and the precipitate was stirred to form. The precipitate was filtered, washed twice with 50 ml of diethyl ether each time, and dried under vacuum at 50 °C for 12 h to obtain intermediate 1. Its 1H NMR data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 7.70(s, 4H), 4.50 - 4.11 (m, 6H), 3.07 - 2.64 (m, 4H), 1.08 (t, J = 5.7 Hz, 4H);
[0036] S2: Under nitrogen protection, 800 ml toluene, 28 g acrylic acid, 100 g polyethylene glycol (PEG600), 3 g p-toluenesulfonic acid, and 1 g hydroquinone were added to a reaction vessel, stirred and mixed, heated to 90 °C, and reacted for 15 h. During this period, the water produced in the reaction was separated by a water separator. The mixture was cooled to room temperature, and the pH was adjusted to 7 using saturated sodium bicarbonate. The mixture was separated into liquid and liquid phases. The organic phase was washed three times with deionized water (200 ml each time), dried with 20 g anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 70 °C for 2 h to obtain intermediate 2.
[0037] S3: Under nitrogen protection, 100 ml of methanol and 10 g of intermediate 1 were added to the reaction vessel and stirred until well mixed. 200 ml of methanol solution containing 30 g of intermediate 2 was added dropwise at room temperature. The addition was completed in 1 h. The temperature was raised to 45 °C and the reaction was carried out for 24 h. The mixture was then cooled to room temperature, distilled under reduced pressure at 40 °C for 3 h, and dried under vacuum at 50 °C for 10 h to obtain the cold-resistant modifier.
[0038] Example 2: Preparation of cold-resistant modifier:
[0039] S1: Add 150 ml of anhydrous DMF, 0.5 g of deionized water, and 0.22 mol of 3-amino-1,2-propanediol to a reaction vessel and stir until well mixed. Add 0.1 mol of 1,4-phenylenediboric acid in 5 batches (15 min apart) and stir at room temperature for 24 h. Slowly pour the reaction solution into 300 ml of diethyl ether and stir to precipitate. Filter, wash twice with diethyl ether (50 ml each time), and dry under vacuum at 50 °C for 12 h to obtain intermediate 1.
[0040] S2: Under nitrogen protection, 800 ml toluene, 30 g acrylic acid, 100 g polyethylene glycol (PEG600), 3 g p-toluenesulfonic acid, and 1 g hydroquinone were added to a reaction vessel, stirred and mixed, heated to 100 °C, and reacted for 12 h. During this period, the water produced in the reaction was separated by a water separator. The mixture was cooled to room temperature, and the pH was adjusted to 7 using saturated sodium bicarbonate. The mixture was separated into liquid and liquid phases. The organic phase was washed three times with deionized water (200 ml each time), dried with 20 g anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 70 °C for 2 h to obtain intermediate 2.
[0041] S3: Under nitrogen protection, 100 ml of methanol and 10 g of intermediate 1 were added to the reaction vessel and stirred until well mixed. 200 ml of methanol solution containing 32 g of intermediate 2 was added dropwise at room temperature. The addition was completed in 1 h. The temperature was raised to 50 °C and the reaction was carried out for 22 h. The mixture was then cooled to room temperature, distilled under reduced pressure at 40 °C for 3 h, and dried under vacuum at 50 °C for 10 h to obtain the cold-resistant modifier.
[0042] Example 3: Preparation of cold-resistant modifier:
[0043] S1: Add 150 ml of anhydrous DMF, 0.5 g of deionized water, and 0.23 mol of 3-amino-1,2-propanediol to a reaction vessel and stir until well mixed. Add 0.1 mol of 1,4-phenylenediboric acid in 5 batches (15 min apart) and stir at room temperature for 26 h. Slowly pour the reaction solution into 300 ml of diethyl ether and stir to precipitate. Filter, wash twice with diethyl ether (50 ml each time), and dry under vacuum at 50 °C for 12 h to obtain intermediate 1.
[0044] S2: Under nitrogen protection, 800 ml toluene, 32 g acrylic acid, 100 g polyethylene glycol (PEG600), 3 g p-toluenesulfonic acid, and 1 g hydroquinone were added to a reaction vessel, stirred and mixed, heated to 110 °C, and reacted for 10 h. During this period, the water produced in the reaction was separated by a water separator. The mixture was cooled to room temperature, and the pH was adjusted to 7 using saturated sodium bicarbonate. The mixture was separated into liquid and liquid phases. The organic phase was washed three times with deionized water (200 ml each time), dried with 20 g anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 70 °C for 2 h to obtain intermediate 2.
[0045] S3: Under nitrogen protection, 100 ml of methanol and 10 g of intermediate 1 were added to the reaction vessel and stirred until well mixed. 200 ml of methanol solution containing 33 g of intermediate 2 was added dropwise at room temperature. The addition was completed in 1 h. The temperature was raised to 55 °C and the reaction was carried out for 20 h. The mixture was then cooled to room temperature, distilled under reduced pressure at 40 °C for 3 h, and dried under vacuum at 50 °C for 10 h to obtain the cold-resistant modifier.
[0046] Example 4: Preparation of antibacterial agent:
[0047] N1: 400 ml of anhydrous ethanol and 0.31 mol of 6-amino-1H-indole-4-carboxylic acid were added to a reaction vessel and stirred until well mixed. 2 g of 4A molecular sieve (sodium-A type molecular sieve) was added, and 150 ml of anhydrous ethanol solution containing 0.1 mol of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tris[benzaldehyde] was added dropwise over 1 hour. The mixture was then heated to reflux and reacted for 6 hours. After cooling to room temperature, the reaction solution was slowly poured into 800 ml of deionized water, stirred, and a solid precipitated. The solid was filtered and dried under vacuum at 60 °C for 24 hours to obtain compound 1. Its 1H NMR spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 12.96 (s, 3H), 10.09 (d, J =6.6 Hz, 3H), 8.75 (d, J = 0.6 Hz, 3H), 8.14 - 8.08 (m, 6H), 7.86 - 7.80 (m,6H), 7.76 - 7.72 (m, 3H), 7.34 (dd, J = 6.6, 3.8 Hz, 3H), 7.28 (dd, J = 2.2,0.5 Hz, 3H), 7.09 - 7.04 (m, 3H);
[0048] N2: Add 600 ml of anhydrous acetonitrile and 0.1 mol of compound 1 to a reaction vessel, stir and mix well. Then add 0.36 mol of N,N'-dicyclohexylcarboimide, 0.06 mol of 4-dimethylaminopyridine, and 0.32 mol of choline chloride sequentially. Stir at room temperature for 24 h, filter, and slowly pour the filtrate into 1000 ml of deionized water. Stir to precipitate the solid, filter, and dry under vacuum at 60 °C for 24 h to obtain the antibacterial agent. Its 1H NMR data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 10.02 (d, J = 6.6Hz, 3H), 8.76 (d, J = 0.6 Hz, 3H), 8.14 - 8.08 (m, 6H), 7.89 - 7.86 (m, 3H), 7.83 (dd, J = 8.5, 0.5 Hz, 6H), 7.34 (dd, J = 6.6, 3.8 Hz, 3H), 7.27 (dd, J =2.2, 0.5 Hz, 3H), 7.17 - 7.10 (m, 3H), 4.61 (t, J = 5.2 Hz, 6H), 3.88 (t, J =5.2 Hz, 6H), 3.21 (s, 27H).
[0049] Example 5: Preparation of fluororubber composite material:
[0050] (1) Weigh out: 75g of fluororubber, 5g of EPDM rubber, 10g of cold-resistant modifier (prepared in Example 1), 15g of carbon black, 3g of antibacterial agent (prepared in Example 4), 0.8g of lubricant (stearic acid), 3g of calcium carbonate, 6g of magnesium oxide, 0.1g of anti-scorching agent (N-cyclohexylthiophthalimide), and 2g of crosslinking agent (hexafluorobisphenol AF, 0.5g of benzyltriphenylphosphine chloride);
[0051] (2) Add fluororubber and EPDM rubber to a mixer at 50°C and 60 rpm for 5 min, add cold-resistant modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide and anti-scorching agent, adjust the speed to 120 rpm and mix for 10 min; add hexafluorobisphenol AF and benzyltriphenylphosphine chloride, mix at 60 rpm for 20 min; put it in a flat vulcanizing agent, hot press at 150°C and 15 MPa for 15 min, put it in a 220°C oven, keep it warm for 2 h, and cool it naturally to room temperature to obtain a fluororubber composite material with antibacterial properties.
[0052] Example 6: Preparation of fluororubber composite material:
[0053] (1) Weigh out: 78g of fluororubber, 6g of EPDM rubber, 12g of cold-resistant modifier (prepared in Example 2), 18g of carbon black, 4g of antibacterial agent (prepared in Example 4), 1g of lubricant (stearic acid), 4g of calcium carbonate, 7g of magnesium oxide, 0.2g of anti-scorching agent (N-cyclohexylthiophthalimide), and 2.4g of crosslinking agent (bisphenol A hexafluorophosphate AF and 0.6g of benzyltriphenylphosphine chloride);
[0054] (2) Add fluororubber and EPDM rubber to a mixer at 55°C and 60 rpm for 4 min, add cold-resistant modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide and anti-scorching agent, adjust the speed to 120 rpm and mix for 10 min; add hexafluorobisphenol AF and benzyltriphenylphosphine chloride, mix at 60 rpm for 20 min; put it in a flat vulcanizing agent, hot press at 160°C and 14 MPa for 12 min, put it in a 210°C oven, keep it warm for 2.5 h, and cool it naturally to room temperature to obtain a fluororubber composite material with antibacterial properties.
[0055] Example 7 Preparation of fluororubber composite material:
[0056] (1) Weigh out: 80g of fluororubber, 8g of EPDM rubber, 15g of cold-resistant modifier (prepared in Example 3), 20g of carbon black, 5g of antibacterial agent (prepared in Example 4), 1.2g of lubricant (stearic acid), 5g of calcium carbonate, 8g of magnesium oxide, 0.3g of anti-scorching agent (N-cyclohexylthiophthalimide), and 2.8g of crosslinking agent (bisphenol A hexafluorophosphate AF, 0.7g of benzyltriphenylphosphine chloride);
[0057] (2) Add fluororubber and EPDM rubber to a mixer at 60°C and 60 rpm for 3 min, add cold-resistant modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide and anti-scorching agent, adjust the speed to 120 rpm and mix for 10 min; add hexafluorobisphenol AF and benzyltriphenylphosphine chloride, mix at 60 rpm for 20 min; put it in a flat vulcanizing agent, hot press at 170°C and 12 MPa for 10 min, put it in a 200°C oven, keep it warm for 3 h, and cool it naturally to room temperature to obtain a fluororubber composite material with antibacterial properties.
[0058] Comparative Example 1
[0059] The raw material ratio and preparation method of the fluororubber composite material are basically the same as those in Example 6, except that the cold-resistant modifier (prepared in Example 2) is replaced with an equal mass of the cold-resistant modifier prepared by the following method:
[0060] S1: Under nitrogen protection, 800 ml toluene, 30 g acrylic acid, 100 g polyethylene glycol (PEG600), 3 g p-toluenesulfonic acid, and 1 g hydroquinone were added to a reaction vessel, stirred and mixed, heated to 100 °C, and reacted for 12 h. During this period, the water produced in the reaction was separated by a water separator. The mixture was cooled to room temperature, and the pH was adjusted to 7 using saturated sodium bicarbonate. The mixture was separated into liquid and liquid phases. The organic phase was washed three times with deionized water (200 ml each time), dried with 20 g anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 70 °C for 2 h to obtain intermediate 2.
[0061] S2: Under nitrogen protection, 100 ml of methanol and 10 g of p-phenylenediamine were added to the reaction vessel and stirred until well mixed. 200 ml of methanol solution containing 32 g of intermediate 2 was added dropwise at room temperature. The addition was completed in 1 h. The temperature was raised to 50 °C and the reaction was carried out for 22 h. The mixture was then cooled to room temperature, distilled under reduced pressure at 40 °C for 3 h, and dried under vacuum at 50 °C for 10 h to obtain the cold-resistant modifier.
[0062] Comparative Example 2
[0063] The raw material ratio and preparation method of the fluororubber composite material are basically the same as those in Example 6, except that the cold-resistant modifier (prepared in Example 2) is replaced with an equal mass of the cold-resistant modifier prepared by the following method:
[0064] The preparation method of the cold-resistant modifier is basically the same as that in Example 2, except that the amount of intermediate 2 added in step S3 is replaced with 21g.
[0065] Comparative Example 3
[0066] The raw material ratio and preparation method of the fluororubber composite material are basically the same as those in Example 6, except that the cold-resistant modifier (prepared in Example 2) is replaced with an equal mass of the cold-resistant modifier prepared in the following steps:
[0067] The preparation method of the cold-resistant modifier is basically the same as that in Example 2, except that the polyethylene glycol (PEG600) in step S2 is replaced with 33g of polyethylene glycol (PEG200).
[0068] Comparative Example 4
[0069] The raw material ratio and preparation method of the fluororubber composite material are basically the same as those in Example 6, except that the cold-resistant modifier (prepared in Example 2) is replaced with an equal mass of the cold-resistant modifier prepared in the following steps:
[0070] The preparation method of the cold-resistant modifier is basically the same as that in Example 2, except that the polyethylene glycol (PEG600) in step S2 is replaced with 166g of polyethylene glycol (PEG1000).
[0071] Comparative Example 5
[0072] The raw material ratio and preparation method of the fluororubber composite material are basically the same as those in Example 6. The difference is that the antibacterial agent (prepared in Example 4) is replaced with an equal mass of compound 1 (prepared in step N1 of Example 4).
[0073] Comparative Example 6
[0074] The raw material ratio and preparation method of the fluororubber composite material are basically the same as those in Example 6, except that the antibacterial agent (prepared in Example 4) is replaced with an equal mass of the antibacterial agent prepared by the following method:
[0075] The preparation method of the antibacterial agent is basically the same as that in Example 4, except that 6-amino-1H-indole-4-carboxylic acid in step N1 is replaced with an equimolar amount of 5-aminoindole-2-carboxylic acid.
[0076] Comparative Example 7
[0077] The raw material ratio and preparation method of the fluororubber composite material are basically the same as those in Example 6, except that the antibacterial agent (prepared in Example 4) is replaced with an equal mass of the antibacterial agent prepared by the following method:
[0078] The preparation method of the antibacterial agent is basically the same as that in Example 4, except that 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tri[benzaldehyde] in step N1 is replaced with an equimolar amount of 4-[3,5-bis(4-formylphenyl)phenyl]benzaldehyde.
[0079] The raw materials used in the embodiments and comparative examples of this application are: fluororubber of type FKM 2601, produced by Chenguang Chemours Fluorine Materials (Shanghai) Co., Ltd.; ethylene propylene diene monomer (EPDM) rubber of type NORDEL™ IP 3722P; and carbon black of type N330, produced by Jineng Technology Co., Ltd.
[0080] The fluororubber composite materials of Examples 5-7 and Comparative Examples 1-7 of this application were subjected to tensile property, low-temperature brittleness and antibacterial property tests. The test results are shown in Table 1.
[0081] The fluororubber composite material was cut into dumbbell-shaped specimens of type 1A and tensile properties were tested according to GB / T 528-2009 at a constant rate of 500 mm / min at 23℃. The fluororubber composite material was cut into specimens of 25 mm × 6 mm × 2 mm and low-temperature brittleness was tested according to GB / T 1682-2014.
[0082] Fluororubber composite materials were cut into φ6×2mm samples for antibacterial performance testing. The bacterial strains used were Staphylococcus aureus (ATCC 6538P) and Escherichia coli (ATCC 8739). The samples were placed in petri dishes, and the bacterial concentration was diluted to 5×10⁻⁶. 5 CFU / mL, add 200 μL to the sample, cover with polyethylene film, and carefully press the film to evenly disperse the bacterial solution. Cover with the petri dish lid. Incubate the petri dishes containing the inoculated bacterial solution and the control sample (fluororubber composite material sample without added antibacterial agent) in a 37℃ incubator for 24 h. Aseptically place the covering film and sample into a sterile plastic bag using tweezers, then add 10 mL of phosphate buffer solution and sonicate (50 Hz) for 10 min to wash off the bacteria. Take 100 μL of the washed bacterial solution, detect the number of bacterial colonies, and calculate the inhibition rate r = (R0 - R) / R0 × 100%, where R0 is the control sample and R is the example and comparative sample.
[0083]
[0084] As can be seen from Examples 5, 6 and 7 in Table 1, the fluororubber composite material of the present invention has excellent tensile properties, low-temperature resistance and antibacterial properties.
[0085] The fluororubber composite material prepared by this invention exhibits excellent tensile properties and low-temperature resistance. This is attributed to the presence of carbon-carbon double bonds, polyethylene glycol segments, and borate ester bonds in the cold-resistant modifier added to the composite material. The cold-resistant modifier forms covalent bonds with the fluororubber matrix through carbon-carbon double bonds, enhancing interfacial bonding. The ether bonds (-O-) of the polyethylene glycol segments in the cold-resistant modifier form weak hydrogen bonds or dipole interactions with the CF bonds of the fluororubber, reducing phase separation and ensuring uniform stress transmission. The flexible polyethylene glycol segments can insert into the fluororubber molecular chains, increasing the spacing between chains and thus improving the material's ductility. Furthermore, they can absorb energy, reducing the risk of brittle fracture. The borate ester bonds in the cold-resistant modifier can break and recombine, dispersing external forces through molecular chain slippage and rearrangement, preventing localized crack propagation. In Comparative Example 2, the amount of intermediate 2 containing double bonds added during the preparation of the cold-resistant modifier was relatively small, which could not guarantee that both ends of it contained carbon-carbon double bonds, resulting in fewer covalent bonds formed with fluororubber and reduced interfacial bonding. In Comparative Example 3, the polyethylene glycol cold-resistant modifier had shorter chain segments and insufficient flexibility, leading to a decrease in tensile and mechanical properties. In Comparative Example 4, the polyethylene glycol cold-resistant modifier had longer chain segments, which slowed down the reversible recombination rate of borate ester bonds and resulted in sluggish network response at low temperatures.
[0086] The fluororubber composite material prepared by this invention exhibits excellent antibacterial properties because the antibacterial agent added to the composite material contains quaternary ammonium salt groups, indole rings, triazine ring structures, and Schiff base structures. The positively charged quaternary ammonium salt in the antibacterial agent electrostatically attracts the bacterial cell membrane (a negatively charged phospholipid bilayer), causing cell membrane dysfunction, leakage of contents, and ultimately bacterial death. The indole ring structure in the antibacterial agent can embed into bacterial DNA and, by inhibiting the activity of topoisomerases, interfere with the replication process and inhibit bacterial reproduction. The Schiff base in the antibacterial agent can bind to key bacterial enzymes, inhibiting enzyme activity and thus interfering with bacterial metabolic processes. The triazine ring in the antibacterial agent has a highly symmetrical six-membered nitrogen heterocycle structure. Its electron-rich nitrogen atoms can form multiple hydrogen bonds, and its planar rigid configuration facilitates binding with bacterial surface biomolecules (such as peptidoglycan or lipopolysaccharides), allowing the antibacterial agent to adhere more firmly to the bacterial surface. This synergistic effect with the quaternary ammonium salt, indole ring, and Schiff base enhances the antibacterial performance. In Comparative Example 6, the ester group in the antibacterial agent was linked to the indole ring, which reduced its ability to intercalate into DNA, resulting in a decrease in its antibacterial properties.
[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.
Claims
1. A fluororubber composite material with antibacterial properties, characterized in that, The ingredients include the following parts by weight: Fluororubber 75-80 parts, EPDM rubber 5-8 parts, cold-resistant modifier 10-15 parts, carbon black 15-20 parts, antibacterial agent 3-5 parts, lubricant 0.8-1.2 parts, calcium carbonate 3-5 parts, magnesium oxide 6-8 parts, scorching inhibitor 0.1-0.3 parts, crosslinking agent 2.5-3.5 parts; The cold-resistant modifier is prepared by the following method: S1: 3-Amino-1,2-propanediol reacts with 1,4-phenylenediboric acid to form intermediate 1. S2: Acrylic acid and polyethylene glycol react to form intermediate 2. S3: Intermediate 1 and Intermediate 2 react to generate a cold-resistant modifier; In step S1, the molar ratio of 3-amino-1,2-propanediol to 1,4-phenylenediboronic acid is (2.1-2.3):1; in step S2, the mass ratio of acrylic acid to polyethylene glycol is (0.28-0.32):1; in step S3, the mass ratio of intermediate 1 to intermediate 2 is 1:(3-3.3). In step S2, the polyethylene glycol is PEG600; The structural formula of the antibacterial agent is as follows: 。 2. The fluororubber composite material with antibacterial properties according to claim 1, characterized in that, The antibacterial agent is prepared by the following method: N1: 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tris[benzaldehyde] reacts with 6-amino-1H-indole-4-carboxylic acid to form compound 1. N2: Compound 1 reacts with choline chloride to produce an antibacterial agent.
3. The fluororubber composite material with antibacterial properties according to claim 2, characterized in that, In step N1, the molar ratio of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tri[benzaldehyde] to 6-amino-1H-indole-4-carboxylic acid is 1:3.1; in step N2, the molar ratio of compound 1 to choline chloride is 1:3.
2.
4. The fluororubber composite material with antibacterial properties according to claim 1, characterized in that, The lubricant is stearic acid.
5. The fluororubber composite material with antibacterial properties according to claim 1, characterized in that, The crosslinking agent is a mixture of hexafluorobisphenol AF and benzyltriphenylphosphine chloride in a mass ratio of 4:
1.
6. The fluororubber composite material with antibacterial properties according to claim 1, characterized in that, The scorching inhibitor is N-cyclohexylthiophthalimide.
7. A method for preparing a fluororubber composite material with antibacterial properties according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Weigh out the following by weight: 75-80 parts of fluororubber, 5-8 parts of EPDM rubber, 10-15 parts of cold-resistant modifier, 15-20 parts of carbon black, 3-5 parts of antibacterial agent, 0.8-1.2 parts of lubricant, 3-5 parts of calcium carbonate, 6-8 parts of magnesium oxide, 0.1-0.3 parts of anti-scorching agent, and 2.5-3.5 parts of crosslinking agent; (2) Add fluororubber and EPDM rubber to a mixer and mix at 50-60℃. Add cold-resistant modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide and anti-scorching agent and mix. Add crosslinking agent and mix. Put it in a flat vulcanizing agent and hot press at 150-170℃ and 12-15MPa for 10-15min. Put it in an oven at 200-220℃ and keep it warm for 2-3h to obtain a fluororubber composite material with antibacterial properties.