Fluororubber composite material with antibacterial property and preparation method thereof

Abstract

The invention discloses a fluororubber composite material with antibacterial performance and a preparation method thereof, and relates to the technical field of fluororubber materials. The fluororubber composite material comprises the following raw materials in parts by weight: 75-80 parts of fluororubber, 5-8 parts of ethylene propylene diene monomer, 10-15 parts of a cold-resistant modifier, 15-20 parts of carbon black, 3-5 parts of an antibacterial agent, 0.8-1.2 parts of a lubricant, 3-5 parts of calcium carbonate, 6-8 parts of magnesium oxide, 0.1-0.3 part of a scorch retarder and 2.5-3.5 parts of a cross-linking agent. The cold-resistant modifier is prepared by the following steps: reacting 3-amino-1, 2-propylene glycol with 1, 4-benzene diboronic acid to generate an intermediate 1, reacting acrylic acid with polyethylene glycol to generate an intermediate 2, and reacting the intermediate 1 with the intermediate 2. The fluororubber composite material prepared by the invention has excellent tensile property, low temperature resistance and antibacterial property.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluororubber materials, in particular to a fluororubber composite material with antibacterial performance and a preparation method thereof. BACKGROUND

[0002] Fluororubber (FKM) is a synthetic high polymer elastomer with fluorine atoms connected to the main chain or side chain carbon atoms, which has heat resistance, oil resistance, solvent resistance, corrosion resistance, strong oxidation resistance and good physical and mechanical properties, and is widely used in automobiles, machinery, aviation, aerospace, chemical industry and other fields. With the progress of science and technology and the continuous expansion and deepening of terminal application scenarios, traditional fluororubber composites face the challenges of lack of antibacterial performance and poor low-temperature elasticity. In applications such as medical devices (such as breathing mask sealing rings) and food processing equipment (such as conveyor belts) that are in a humid and nutrient-rich environment for a long time, bacteria are easy to attach and breed, affecting human health; the molecular chain segment movement of fluororubber is frozen at low temperature, the material becomes hard and brittle, and brittle fracture easily occurs when external force is applied, limiting its application in low-temperature environments.

[0003] A fluororubber composite material for an antibacterial wearable device and a preparation method thereof are disclosed in Chinese patent application publication No. CN117186572A. The raw materials include amine compounds, vulcanizing agents, epoxy resins, fluororubber, and composite antibacterial fillers. The invention can effectively enhance the antibacterial effect of the fluororubber composite material and effectively enhance the self-cleaning performance of the fluororubber composite material; sodium borohydride is used to reduce silver nitrate to form nano-silver particles, and the nano-silver particles are blended with water-based polyurethane to make the polyurethane include nano-silver particles, which facilitates the uniform dispersion of the nano-silver particles in the composite antibacterial filler; a nano-copper-nano-zinc oxide composite antibacterial material is formed; polydimethylsiloxane is used for hydrophobic modification treatment of the surfaces of polyurethane and polyacrylonitrile; the antibacterial performance and hydrophobic performance of the fluororubber composite material are improved, but its low-temperature resistance is poor. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a fluororubber composite material with antibacterial performance.

[0005] To achieve the above-mentioned purpose, the present application realizes the following technical solutions: A fluororubber composite material with antibacterial performance comprises the following raw materials by weight: fluororubber 75-80 parts, ternary ethylene propylene 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, scorch retardant 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-benzenediboronic acid to generate intermediate 1, and the reaction equation is as follows: .

[0006] S2: acrylic acid and polyethylene glycol react to generate intermediate 2, and the reaction equation is as follows: .

[0007] S3: intermediate 1 and intermediate 2 react to generate a cold-resistant modifier, and the reaction equation is as follows: .

[0008] wherein, --R-- is .

[0009] In step S1, the molar ratio of 3-amino-1,2-propanediol to 1,4-benzenediboronic acid is (2.1-2.3):1.

[0010] In step S2, the mass ratio of acrylic acid to polyethylene glycol is (0.28-0.32):1.

[0011] In step S3, the mass ratio of intermediate 1 to intermediate 2 is 1:(3-3.3).

[0012] 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 generate compound 1, and the reaction equation is as follows: .

[0013] N2: compound 1 reacts with choline chloride to generate an antibacterial agent. The reaction equation is as follows: .

[0014] In step N1, the molar ratio of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tris[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.

[0015] The lubricant is stearic acid.

[0016] The crosslinking agent is a mixture of hexafluorobisphenol AF and benzyltriphenylphosphonium chloride, and the mass ratio of the mixture is 4:1.

[0017] The scorch retarder is N-cyclohexylthiophthalimide.

[0018] A method for preparing a fluororubber composite material with antibacterial properties, comprising the following steps: (1) Take by weight parts: fluororubber 75-80 parts, ethylene-propylene-diene rubber 5-8 parts, cold resistance 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, anti-scorching agent 0.1-0.3 parts, crosslinking agent 2.5-3.5 parts; (2) Add fluororubber and ethylene-propylene-diene rubber to the internal mixer at 50-60°C, and add cold resistance modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide, and anti-scorching agent for internal mixing; add the crosslinking agent for internal mixing; place it in a flat plate vulcanizing agent, heat it at 150-170°C and 12-15MPa for 10-15min, and then place it in a 200-220°C oven for 2-3h to obtain a fluororubber composite material with antibacterial properties.

[0019] Due to the adoption of the above technical solutions, the present application has the following advantages: The fluororubber composite material prepared by the present application has excellent tensile properties, cold resistance, and antibacterial properties. The cold resistance modifier added in the composite material forms covalent bonds with the fluororubber matrix, enhances the interfacial bonding force, 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 destroys the cell membrane and interferes with the reproduction process, thereby enhancing the antibacterial properties of the composite material. DETAILED DESCRIPTION

[0020] The present application will be further described below with reference to the examples, but the present application is not limited to these examples.

[0021] Example 1: Preparation of a cold resistance modifier: S1: Add 150ml of anhydrous DMF, 0.5g of deionized water, and 0.21mol of 3-amino-1,2-propanediol to a reaction kettle, stir and mix well, add 0.1mol of 1,4-benzene-diboronic acid in batches (5 batches, 15min interval between each batch), stir at room temperature for 20h, slowly pour the reaction liquid into 300ml of ether, stir to precipitate, filter, wash twice with ether (50ml each time), and vacuum dry at 50°C for 12h to obtain intermediate 1; the nuclear magnetic resonance hydrogen spectrum data is 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); S2: 800 ml of toluene, 28 g of acrylic acid, 100 g of polyethylene glycol (PEG600), 3 g of p-toluenesulfonic acid, 1 g of hydroquinone were added into a reaction kettle under nitrogen protection, stirred and mixed uniformly, heated to 90°C, reacted for 15 h, and the water produced during the reaction was separated out through a water trap during the reaction. After cooling to room temperature, the pH was adjusted to 7 using saturated sodium bicarbonate, the liquid was separated, the organic phase was washed with deionated water three times (200 ml each time), dried with 20 g of anhydrous magnesium sulfate, filtered, and distilled at 70°C under reduced pressure for 2 h to obtain intermediate 2; S3: 100 ml of methanol and 10 g of intermediate 1 were added into a reaction kettle under nitrogen protection, stirred and mixed uniformly, 200 ml of a methanol solution containing 30 g of intermediate 2 was added dropwise at room temperature, 1 h after the dropwise addition was completed, the temperature was increased to 45°C, and reacted for 24 h. After cooling to room temperature, the product was distilled at 40°C under reduced pressure for 3 h, and dried at 50°C under vacuum for 10 h to obtain the cold-resistant modifier.

[0022] Example 2: Preparation of a cold-resistant modifier S1: 150 ml of anhydrous DMF, 0.5 g of deionized water, and 0.22 mol of 3-amino-1,2-propanediol were added into a reaction kettle, stirred and mixed uniformly, 0.1 mol of 1,4-benzene-diboronic acid was added in batches (5 batches, 15 min interval between each batch), and stirred at room temperature for 24 h. The reaction solution was slowly poured into 300 ml of ether, and the precipitate was stirred and separated, filtered, washed twice with ether (50 ml each time), and dried at 50°C under vacuum for 12 h to obtain intermediate 1; S2: 800 ml of toluene, 30 g of acrylic acid, 100 g of polyethylene glycol (PEG600), 3 g of p-toluenesulfonic acid, and 1 g of hydroquinone were added into a reaction kettle under nitrogen protection, stirred and mixed uniformly, heated to 100°C, and reacted for 12 h. The water produced during the reaction was separated out through a water trap during the reaction. After cooling to room temperature, the pH was adjusted to 7 using saturated sodium bicarbonate, the liquid was separated, the organic phase was washed with deionized water three times (200 ml each time), dried with 20 g of anhydrous magnesium sulfate, filtered, and distilled at 70°C under reduced pressure for 2 h to obtain intermediate 2; S3: 100 ml of methanol and 10 g of intermediate 1 were added into a reaction kettle under nitrogen protection, stirred and mixed uniformly, 200 ml of a methanol solution containing 32 g of intermediate 2 was added dropwise at room temperature, 1 h after the dropwise addition was completed, the temperature was increased to 50°C, and reacted for 22 h. After cooling to room temperature, the product was distilled at 40°C under reduced pressure for 3 h, and dried at 50°C under vacuum for 10 h to obtain the cold-resistant modifier.

[0023] Example 3: Preparation of a cold-resistant modifier S1: 150 ml of anhydrous DMF, 0.5 g of deionized water, 0.23 mol of 3-amino-1,2-propanediol were added into the reaction kettle, stirred and mixed uniformly, 0.1 mol of 1,4-benzenediboronic acid was added in batches (in 5 batches, with an interval of 15 min), stirred at room temperature for 26 h, the reaction liquid was slowly poured into 300 ml of ether, the precipitate was stirred and precipitated, filtered, washed twice with ether (50 ml each time), and vacuum dried at 50°C for 12 h to obtain intermediate 1; S2: Under nitrogen protection, 800 ml of toluene, 32 g of acrylic acid, 100 g of polyethylene glycol (PEG600), 3 g of p-toluenesulfonic acid, and 1 g of hydroquinone were added into the reaction kettle, stirred and mixed uniformly, heated to 110°C, reacted for 10 h, and the water produced during the reaction was separated out through a water trap during the reaction. Cool to room temperature, adjust the pH to 7 with saturated sodium bicarbonate, separate the liquid, wash the organic phase with deionized water three times (200 ml each time), dry with 20 g of anhydrous magnesium sulfate, filter, and distill at 70°C under reduced pressure for 2 h to obtain intermediate 2. S3: Under nitrogen protection, 100 ml of methanol and 10 g of intermediate 1 were added into the reaction kettle, stirred and mixed uniformly, 200 ml of a methanol solution containing 33 g of intermediate 2 was added dropwise at room temperature, 1 h after the dropwise addition was completed, the temperature was raised to 55°C, and the reaction was carried out for 20 h. Cool to room temperature, distill at 40°C under reduced pressure for 3 h, and vacuum dry at 50°C for 10 h to obtain the cold-resistant modifier.

[0024] Example 4 Preparation of antibacterial agent: N1: 400 ml of anhydrous ethanol, 0.31 mol of 6-amino-1H-indole-4-carboxylic acid was added into the reaction kettle, stirred and mixed uniformly, 2 g of 4A molecular sieve (sodium-A type molecular sieve) was added, 150 ml of anhydrous ethanol containing 0.1 mol of 4,4',4''-(1,3,5-triazine-2,4,6-triazyl) tris[benzaldehyde] was added dropwise, 1 h after the dropwise addition was completed, the temperature was raised to reflux, and the reaction was carried out for 6 h. Cool to room temperature, slowly pour the reaction liquid into 800 ml of deionized water, stir to precipitate the solid, filter, and vacuum dry at 60°C for 24 h to obtain compound 1, whose nuclear magnetic resonance hydrogen 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); N2: 600 ml of anhydrous acetonitrile, 0.1 mol of compound 1 were added into the reaction kettle, stirred and mixed, 0.36 mol of N,N'-dicyclohexylcarbodiimide and 0.06 mol of 4-dimethylaminopyridine, 0.32 mol of choline chloride were added in turn, stirred at room temperature for 24 h, filtered, the filtrate was slowly poured into 1000 ml of deionized water, stirred to precipitate the solid, filtered, vacuum dried at 60°C for 24 h to obtain the antibacterial agent; its nuclear magnetic resonance hydrogen spectrum 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)。

[0025] Example 5 Preparation of fluoro rubber composite material: (1) Take: fluoro rubber 75 g, ethylene propylene diene rubber 5 g, cold resistance modifier (prepared in example 1) 10 g, carbon black 15 g, antibacterial agent (prepared in example 4) 3 g, lubricant (stearic acid) 0.8 g, calcium carbonate 3 g, magnesium oxide 6 g, anti-scorching agent (N-cyclohexyl thio phthalimide) 0.1 g, crosslinking agent (hexafluoro bisphenol AF 2 g, benzyl triphenyl phosphonium chloride 0.5 g); (2) Fluororubber, EPDM rubber were added into 50℃, 60rpm internal mixer, mixing for 5min, then added cold resistance modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide, scorch retarder, mixing for 10min at 120rpm, then added hexafluorobisphenol AF and benzyltriphenyl phosphonium chloride, mixing for 20min at 60rpm, then put into flat vulcanizing agent, hot pressed for 15min at 150℃, 15MPa, then put into 220℃ oven, heat preservation for 2h, natural cooling to room temperature, obtained fluororubber composite material with antibacterial property.

[0026] Example 6 Preparation of fluororubber composite material: (1) Fluororubber 78g, EPDM rubber 6g, cold resistance modifier (prepared in example 2) 12g, carbon black 18g, antibacterial agent (prepared in example 4) 4g, lubricant (stearic acid) 1g, calcium carbonate 4g, magnesium oxide 7g, scorch retarder (N-cyclohexyl thio phthalimide) 0.2g, crosslinking agent (hexafluorobisphenol AF 2.4g, benzyltriphenyl phosphonium chloride 0.6g) were weighed; (2) Fluororubber, EPDM rubber were added into 55℃, 60rpm internal mixer, mixing for 4min, then added cold resistance modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide, scorch retarder, mixing for 10min at 120rpm, then added hexafluorobisphenol AF and benzyltriphenyl phosphonium chloride, mixing for 20min at 60rpm, then put into flat vulcanizing agent, hot pressed for 12min at 160℃, 14MPa, then put into 210℃ oven, heat preservation for 2.5h, natural cooling to room temperature, obtained fluororubber composite material with antibacterial property.

[0027] Example 7 Preparation of fluororubber composite material: (1) Fluororubber 80g, EPDM rubber 8g, cold resistance modifier (prepared in example 3) 15g, carbon black 20g, antibacterial agent (prepared in example 4) 5g, lubricant (stearic acid) 1.2g, calcium carbonate 5g, magnesium oxide 8g, scorch retarder (N-cyclohexyl thio phthalimide) 0.3g, crosslinking agent (hexafluorobisphenol AF 2.8g, benzyltriphenyl phosphonium chloride 0.7g) were weighed; (2) Fluororubber, EPDM rubber were added into 60℃, 60rpm internal mixer, mixing for 3min, then added cold resistance modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide, scorch retarder, mixing for 10min at 120rpm, then added hexafluorobisphenol AF and benzyltriphenyl phosphonium chloride, mixing for 20min at 60rpm, then put into flat vulcanizing agent, hot pressed for 10min at 170℃, 12MPa, then put into 200℃ oven, heat preservation for 3h, natural cooling to room temperature, obtained fluororubber composite material with antibacterial property.

[0028] Comparative example 1 The raw material ratio and preparation method of the fluoroelastomer 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 amount of a cold-resistant modifier prepared by the following method: S1: Under nitrogen protection, 800 ml of toluene, 30 g of acrylic acid, 100 g of polyethylene glycol (PEG600), 3 g of p-toluenesulfonic acid, and 1 g of hydroquinone were added into a reaction kettle, stirred and uniformly mixed, heated to 100°C, reacted for 12 h, during which the water produced in the reaction was separated through a water trap, cooled to room temperature, the pH was adjusted to 7 using saturated sodium bicarbonate, the organic phase was washed with deionized water three times (200 ml each time), dried with 20 g of anhydrous magnesium sulfate, filtered, and distilled at 70°C under reduced pressure for 2 h to obtain intermediate 2; S2: Under nitrogen protection, 100 ml of methanol and 10 g of p-xylylamine were added into a reaction kettle, stirred and uniformly mixed, 200 ml of a methanol solution containing 32 g of intermediate 2 was added dropwise at room temperature, 1 h after the dropwise addition was completed, the temperature was raised to 50°C, and the reaction was carried out for 22 h, then the mixture was cooled to room temperature, distilled at 40°C under reduced pressure for 3 h, and dried at 50°C under vacuum for 10 h to obtain the cold-resistant modifier.

[0029] Comparative Example 2 The raw material ratio and preparation method of the fluoroelastomer 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 amount of a cold-resistant modifier prepared by the following method: The preparation method of the cold-resistant modifier is basically the same as that in Example 2, except that the amount of intermediate 2 in step S3 is replaced with 21 g.

[0030] Comparative Example 3 The raw material ratio and preparation method of the fluoroelastomer 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 amount of a cold-resistant modifier prepared by the following method: 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 33 g of polyethylene glycol (PEG200).

[0031] Comparative Example 4 The raw material ratio and preparation method of the fluoroelastomer 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 amount of a cold-resistant modifier prepared by the following method: 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 166 g of polyethylene glycol (PEG1000).

[0032] Comparative Example 5 The raw material ratio and preparation method of the fluoroelastomer 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 in the following method.

[0033] Comparative Example 6 The raw material ratio and preparation method of the fluoroelastomer 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 in the following method: The preparation method of the antibacterial agent is basically the same as that in Example 4, except that the 6-amino-1H-indole-4-carboxylic acid in step N1 is replaced with an equal molar amount of 5-aminoindole-2-carboxylic acid.

[0034] Comparative Example 7 The raw material ratio and preparation method of the fluoroelastomer 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 in the following method: The preparation method of the antibacterial agent is basically the same as that in Example 4, except that the 4,4',4''-(1,3,5-triazine-2,4,6-triyl) tris[benzaldehyde] in step N1 is replaced with an equal molar amount of 4-[3,5-bis(4-formylphenyl)phenyl] benzaldehyde.

[0035] The raw materials used in the examples and comparative examples of the present application: the model of fluoroelastomer is FKM 2601, which is produced by Chengguo Komo Fluorine Material (Shanghai) Co., Ltd.; the brand of ethylene propylene diene rubber is NORDEL™ IP 3722P; the model of carbon black is N330, which is produced by Jineng Technology Co., Ltd.

[0036] The fluoroelastomer composite materials in Examples 5-7 and Comparative Examples 1-7 of the present application were subjected to tensile property, low temperature brittleness and antibacterial property tests, and the test results are shown in Table 1.

[0037] The fluoroelastomer composite material was cut into a 1A dumbbell-shaped sample, and the tensile property was tested according to GB / T 528-2009 at a constant rate of 500 mm / min at 23°C; the fluoroelastomer composite material was cut into a sample with a size of 25 mm x 6 mm x 2 mm, and the low temperature brittleness test was performed according to GB / T 1682-2014.

[0038] The fluoroelastomer composite material was cut into a sample with a size of φ6 x 2 mm for antibacterial property testing: the bacteria were Staphylococcus aureus (ATCC 6538P) and Escherichia coli (ATCC 8739), the sample was placed in a culture dish, and the bacterial solution was diluted to 5 x 10 5CFU / mL, 200 μL was added to the sample, polyethylene film was covered, and the film was carefully pressed to evenly disperse the bacterial solution, and a flat plate cover was covered. The inoculated bacterial solution and the control sample (fluorine rubber composite material sample without adding antibacterial agent in the component) were cultured in a 37℃ constant temperature incubator for 24h, and the covering film and sample were placed in a sterile plastic bag with sterile operation, then 10mL of phosphate buffered saline solution was added, and ultrasonic (50Hz) was performed for 10min, and the bacteria were washed off. 100 μL of the washed bacterial solution was taken, the number of bacterial colonies was detected, and the antibacterial rate r= (R0-R) / R0x100% was calculated, wherein R0 is the control sample, and R is the sample of the examples and the comparative examples.

[0039]

[0040] As can be seen from Table 1 Examples 5, 6 and 7, the fluorine rubber composite material of the application has excellent tensile properties, low temperature resistance and antibacterial properties.

[0041] The fluorine rubber composite material prepared by the application has good tensile properties and low temperature resistance, because the cold resistance modifier added in the composite material contains carbon-carbon double bond, polyethylene glycol segment and borate ester bond. The cold resistance modifier forms a covalent bond with the fluorine rubber matrix through the carbon-carbon double bond, enhancing the interfacial bonding force. The ether bond (-O-) of the polyethylene glycol segment in the cold resistance modifier forms a weak hydrogen bond or dipole interaction with the C-F bond of the fluorine rubber, reducing phase separation and ensuring uniform stress transmission; the flexible polyethylene glycol segment can insert between the fluorine rubber molecular chains, increasing the spacing between the molecular chains, thereby improving the ductility of the material and reducing the risk of brittle fracture by absorbing energy. The borate ester bond in the cold resistance modifier can be broken and reorganized to disperse external force through molecular chain slipping and rearrangement to prevent local crack propagation. The amount of double bond-containing intermediate 2 added during the preparation of the cold resistance modifier used in Comparative Example 2 is small, which cannot ensure that both ends contain carbon-carbon double bonds, and the covalent bond formed with the fluorine rubber is less, reducing the interfacial bonding force; the polyethylene glycol segment of the cold resistance modifier used in Comparative Example 3 is short, which is not flexible enough, resulting in a decrease in tensile properties and mechanical properties; the polyethylene glycol segment of the cold resistance modifier used in Comparative Example 4 is long, and the reversible reorganization rate of the borate ester bond is slow, and the network response is sluggish at low temperature.

[0042] The fluororubber composite prepared by the application has good antibacterial performance, because the antibacterial agent added in the composite contains quaternary ammonium salt groups, indole rings, triazine ring structures and Schiff base structures. The positively charged quaternary ammonium salt in the antibacterial agent is electrostatically attracted to the bacterial cell membrane (negatively charged phospholipid bilayer), causing the cell membrane to function disorderly and the contents to leak, resulting in the death of bacteria. The indole ring structure in the antibacterial agent can embed into bacterial DNA and interfere with the replication process by inhibiting the activity of topoisomerase, thereby inhibiting bacterial reproduction. The Schiff base in the antibacterial agent can bind to key enzymes of bacteria and inhibit the activity of the enzymes, thereby interfering with the metabolic process of bacteria. The triazine ring in the antibacterial agent is a highly symmetrical six-membered nitrogen heterocyclic structure, and its electron-rich nitrogen atom can form multiple hydrogen bonds, and at the same time has a planar rigid configuration, which is conducive to binding to the surface biomacromolecules (such as peptidoglycan or lipopolysaccharide) of bacteria, so that the antibacterial agent can be more firmly attached to the surface of bacteria, and synergistically act with the quaternary ammonium salt, indole ring and Schiff base to improve the antibacterial performance. The antibacterial agent used in Comparative Example 6 has an ester group connected to the indole ring, which reduces its DNA embedding ability, resulting in a decrease in antibacterial performance.

[0043] The above is only the preferred embodiment of the application and is not used to limit the application; but for ordinary skilled persons in the art, some minor changes, modifications and equivalent changes made by using the above disclosed technical content without departing from the scope of the technical scheme of the application are equivalent embodiments of the application; at the same time, any equivalent changes, modifications and evolution made to the above embodiments according to the essential technology of the application are still within the protection scope of the technical scheme of the application.

Claims

1. A fluoroelastomer composite material having antibacterial properties, characterized in that, The raw materials include the following components by weight: fluorine rubber 75-80 parts, ethylene-propylene-diene rubber 5-8 parts, cold resistance 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, scorch retarder 0.1-0.3 parts, crosslinking agent 2.5-3.5 parts; The cold resistance modifier is prepared by the following method: S1: 3-amino-1,2-propanediol reacts with 1,4-benzenediboronic acid to form intermediate 1, S2: acrylic acid and polyethylene glycol react to form intermediate 2, S3: intermediate 1 and intermediate 2 react to form the cold resistance modifier.

2. The fluoroelastomer composite having antibacterial properties according to claim 1, characterized in that, In step S1, the molar ratio of 3-amino-1,2-propanediol to 1,4-benzenediboronic acid is (2.1-2.3):

1.

3. The fluoroelastomer composite having antibacterial properties according to claim 1, characterized in that, In step S2, the mass ratio of acrylic acid to polyethylene glycol is (0.28-0.32):

1.

4. The fluoroelastomer composite having antibacterial properties according to claim 1, characterized in that, In step S3, the mass ratio of intermediate 1 to intermediate 2 is 1:(3-3.3).

5. The fluoroelastomer composite having 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 form the antibacterial agent.

6. The fluoroelastomer composite having antibacterial properties according to claim 5, characterized in that, In step N1, the molar ratio of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tris[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.

7. The fluororubber composite material with antibacterial properties according to claim 1, characterized in that, The lubricant is stearic acid.

8. The fluoroelastomer composite having antibacterial properties according to claim 1, characterized in that, The crosslinking agent is a mixture of hexafluorobisphenol AF and benzyltriphenylphosphonium chloride, and the mass ratio of the mixture is 4:

1.

9. The fluororubber composite material having an antibacterial property according to claim 1, characterized by, The scorch retarder is N-cyclohexylthiophthalimide.

10. A process for the preparation of a fluoroelastomer composite material having antibacterial properties according to any one of claims 1 to 9, characterized in that, The method includes the following steps: (1) weighing by weight parts: fluorine rubber 75-80 parts, ethylene-propylene-diene rubber 5-8 parts, cold resistance 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, scorch retarder 0.1-0.3 parts, crosslinking agent 2.5-3.5 parts; (2) adding fluorine rubber and ethylene-propylene-diene rubber into an internal mixer and mixing at 50-60℃, adding cold resistance modifier, carbon black, antibacterial agent, lubricant, calcium carbonate, magnesium oxide, scorch retarder and mixing, adding crosslinking agent and mixing, putting into a flat vulcanizing agent, hot pressing at 150-170℃ and 12-15MPa for 10-15min, putting into a 200-220℃ oven and keeping for 2-3h, to obtain a fluorine rubber composite material with antibacterial property.

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