An antibacterial modified graphene polyamide 6 composite material and preparation method thereof

Abstract

The present invention belongs to the field of polyamide 6 materials, and specifically relates to an antibacterial modified graphene polyamide 6 composite material and a preparation method thereof. The present invention first prepolymerizes part of caprolactam to obtain a prepolymer, then adds polyvinyl alcohol sulfonate and functionalized graphene into a dispersion to mix, and obtains a graphene dispersion; then, a perfluoroalkyl quaternary ammonium salt, an amino silicone quaternary ammonium salt, a graphene dispersion, a prepolymer and the remaining caprolactam are mixed, and ring opening, polymerization reaction, slicing, extraction, and drying are performed to obtain an antibacterial modified graphene polyamide 6. Through the synergistic coordination of the amino silicone quaternary ammonium salt and the perfluoroalkyl quaternary ammonium salt, the antibacterial modified graphene polyamide 6 composite material has stronger sterilization durability and excellent mechanical properties.

Description

Technical Field

[0001] The invention belongs to the field of polyamide 6 materials, and specifically relates to an antibacterial modified graphene polyamide 6 composite material and a preparation method thereof. Background Art

[0002] Polyamide (PA for short) refers to a class of compounds containing amide groups (-CO-NH-) on the main chain of the molecule, commonly known as nylon, and is also called nylon when prepared into fibers. PA6 fiber has the common advantages of all synthetic fibers, such as corrosion resistance, insect resistance, mildew resistance, high wet strength, low moisture absorption rate, etc. In addition, PA6 fiber also has excellent wear resistance, fatigue resistance, alkali resistance, and can be colored under acidic conditions. Therefore, it can be used in clothing, curtains, automotive interiors, conveyor belts, cords, etc. Its disadvantages are small initial modulus, easy deformation during use, poor heat resistance and light resistance, easy yellowing under sunlight or ultraviolet light, and no functionality. Graphene not only has good mechanical properties, but also can bring many functional properties to composite materials, such as good antibacterial and antimicrobial properties, excellent UV resistance, etc. In order to improve the performance of polyamide 6 materials and broaden its application areas, the modification of PA6 using graphene has attracted widespread attention from researchers.

[0003] A Chinese patent with publication number CN113122954A discloses a sports fabric based on graphene polyamide 6 fiber and a preparation method thereof. The method first utilizes modified graphene oxide and polyamide 6 to prepare graphene polyamide 6 fiber by spinning, and then utilizes graphene polyamide 6 fiber, cotton nylon fiber, and an antibacterial agent to prepare a sports fabric of graphene polyamide 6 fiber. The sports fabric prepared by the above method has good mechanical strength and skin-friendliness, and at the same time has a certain antibacterial property. However, in actual applications, it is found that the durability of its antibacterial performance is not satisfactory. Summary of the invention

[0004] In view of the above problems existing in the prior art, the object of the present invention is to provide an antibacterial modified graphene polyamide 6 composite material and a preparation method thereof.

[0005] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing an antibacterial modified graphene polyamide 6 composite material comprises the following steps:

[0007] S1: prepolymerizing part of caprolactam to obtain a prepolymer;

[0008] S2: adding polyvinyl alcohol sulfonate and functionalized graphene into the dispersion to obtain a graphene dispersion;

[0009] S3: mixing perfluoroalkyl quaternary ammonium salt, amino silicone quaternary ammonium salt, graphene dispersion, prepolymer and remaining caprolactam, performing ring opening, polymerization reaction, slicing, extraction and drying to obtain antibacterial modified graphene polyamide 6.

[0010] Optionally, the mass ratio of the polyvinyl alcohol sulfonate, perfluoroalkyl quaternary ammonium salt, amino silicone quaternary ammonium salt and functionalized graphene in S3 is (5-15):(3-8):(10-30):15.

[0011] Optionally, the total mass ratio of the functionalized graphene to the caprolactam is (3-5):100.

[0012] Optionally, the amount of caprolactam in S1 accounts for (30-55)% of the total amount of caprolactam.

[0013] Optionally, the prepolymerization reaction temperature is 260-280° C., the pressure is 1-1.2 MPa, and the prepolymerization time is 1.5-2.5 h.

[0014] Optionally, the dispersion is deionized water.

[0015] Optionally, the ring-opening reaction conditions are temperature 255~275°C, pressure 0.15~0.85 MPa, and reaction time 1.5~4 h; the polymerization reaction conditions are temperature 240~255°C, pressure -0.05~-0.20 MPa, and reaction time 3~10 h.

[0016] Optionally, the mixing method adopts an integrated ultrasonic shearing method.

[0017] Optionally, the functionalized graphene is carboxylated graphene.

[0018] The antibacterial modified graphene polyamide 6 composite material is prepared according to the above preparation method.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) In the present invention, graphene, amino-organic silicon quaternary ammonium salt and perfluoroalkyl quaternary ammonium salt all have strong bactericidal ability. Two specific quaternary ammonium salts are selected to be combined with carboxylated graphene, and the skeletons of perfluoroalkyl quaternary ammonium salt and amino-organic silicon quaternary ammonium salt are intertwined with each other. Through synergistic effect, the bactericidal effect is stronger and more durable;

[0021] (2) The present invention controls the dosage ratio of polyvinyl alcohol sulfonate, perfluoroalkyl quaternary ammonium salt, aminated organosilicon quaternary ammonium salt and graphene. By limiting the amount of polyvinyl alcohol sulfonate added, on the one hand, the graphene is uniformly dispersed in the dispersion, and on the other hand, the dispersibility of the perfluoroalkyl quaternary ammonium salt and the aminated organosilicon quaternary ammonium salt on the graphene sheet is improved, so that the stability of the perfluoroalkyl quaternary ammonium salt and the aminated organosilicon quaternary ammonium salt is improved;

[0022] (3) Aminated organosilicon quaternary ammonium salts contain two active functional groups, secondary amine and silaneoxy. The secondary amine can form covalent bonds or hydrogen bonds with the carboxyl groups on the surface of graphene, and can also form hydrogen bonds with the amide groups in polyamide 6, thereby coupling the graphene and polyamide 6 matrix together. The bond is more firmly combined, ensuring the material's long-lasting bactericidal effect, while giving the antibacterial modified graphene polyamide 6 composite fiber good mechanical properties. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments.

[0024] Source of raw materials:

[0025] Polyvinyl alcohol sulfonate: 22g of polyvinyl alcohol was dissolved in 200mL of dimethylformamide, 5.7g of metallic sodium was chopped and added, and mixed at room temperature for 0.5h; then a dimethylformamide solution of 1,3-propane sultone with a mass fraction of 10% was added dropwise, and the weight ratio of polyvinyl alcohol to 1,3-propane sultone was 0.72:1, and the temperature was raised to 80°C for reaction for 3h; the reaction product was dried to obtain sodium polyvinyl alcohol sulfonate; wherein the polyvinyl alcohol was purchased from PVA 1799 of Ningxia Dadi Chemical Co., Ltd., with a degree of polymerization of 1700 and a degree of alcoholysis of 99%;

[0026] Aminated organosilicon quaternary ammonium salt: by mass, add 1.2 parts of 3-aminopropyltriethoxysilane, 1 part of 3-chloro-2-hydroxypropyltrimethylammonium chloride, 0.03 parts of formic acid, 0.02 parts of dibutyltin dilaurate and an appropriate amount of ethanol solvent, stir under N2 atmosphere, heat to boiling of the solvent, stir and reflux for 15 hours, cool and distill to remove the solvent under reduced pressure, and dry in vacuo.

[0027] Perfluoroalkyl quaternary ammonium salt: perfluorohexyltrimethylammonium bromide is used.

[0028] Carboxylated graphene: purchased from Aladdin, CAS No. 7782-42-5.

[0029] Example 1

[0030] Step 1: 11 kg of caprolactam was added into a prepolymerization reactor and reacted at a temperature of 270° C. and 1 MPa for 2 h to obtain a prepolymer;

[0031] Step 2: 0.8 kg of polyvinyl alcohol sulfonate and 1 kg of carboxylated graphene were mixed, and 100 kg of deionized water was added to obtain a graphene dispersion;

[0032] Step 3: The graphene dispersion, prepolymer, 0.4 kg perfluoroalkyl quaternary ammonium salt, 1.2 kg amino silicone quaternary ammonium salt and 17 kg caprolactam are mixed by ultrasonic shearing integrated dispersion, and the ring-opening reaction is carried out at 265°C and 0.5 MPa for 1.5 hours, and then polymerized at 255°C and -0.15 MPa for 3 hours. The polymer is passed into a pelletizer for slicing, and then the slices are placed in an extraction tower and extracted with deionized water at 90°C. The extracted slices are dried in a drying tank filled with hot nitrogen to obtain an antibacterial modified graphene polyamide 6 composite material.

[0033] Example 2

[0034] Step 1: Add 16 kg of caprolactam into a prepolymerization reactor and react at a temperature of 270° C. and 1 MPa for 2 hours to obtain a prepolymer;

[0035] Step 2: 0.8 kg of polyvinyl alcohol sulfonate and 1 kg of carboxylated graphene were mixed, and 100 kg of deionized water was added to obtain a graphene dispersion;

[0036] Step 3: The graphene dispersion, prepolymer, 0.4 kg perfluoroalkyl quaternary ammonium salt, 1.2 kg amino silicone quaternary ammonium salt and 17 kg caprolactam are mixed by ultrasonic shearing integrated dispersion, and the ring-opening reaction is carried out at 265°C and 0.5 MPa for 1.5 hours, and then polymerized at 255°C and -0.15 MPa for 3 hours. The polymer is passed into a pelletizer for slicing, and then the slices are placed in an extraction tower and extracted with deionized water at 90°C. The extracted slices are dried in a drying tank filled with hot nitrogen to obtain an antibacterial modified graphene polyamide 6 composite material.

[0037] Example 3

[0038] Step 1: Add 6 kg of caprolactam into a prepolymerization reactor and react at a temperature of 270° C. and 1 MPa for 2 h to obtain a prepolymer;

[0039] Step 2: 0.8 kg of polyvinyl alcohol sulfonate and 1 kg of carboxylated graphene were mixed, and 100 kg of deionized water was added to obtain a graphene dispersion;

[0040] Step 3: The graphene dispersion, prepolymer, 0.4 kg perfluoroalkyl quaternary ammonium salt, 1.2 kg amino silicone quaternary ammonium salt and 14 kg caprolactam are mixed by ultrasonic shearing integrated dispersion, and the ring-opening reaction is carried out at 265°C and 0.5 MPa for 1.5 hours, and then polymerized at 255°C and -0.15 MPa for 3 hours. The polymer is passed into a pelletizer for slicing, and then the slices are placed in an extraction tower and extracted with deionized water at 90°C. The extracted slices are dried in a drying tank filled with hot nitrogen to obtain an antibacterial modified graphene polyamide 6 composite material.

[0041] Example 4

[0042] Step 1: 11 kg of caprolactam was added into a prepolymerization reactor and reacted at a temperature of 270° C. and 1 MPa for 2 h to obtain a prepolymer;

[0043] Step 2: 0.8 kg of polyvinyl alcohol sulfonate and 1 kg of carboxylated graphene were mixed, and 100 kg of deionized water was added to obtain a graphene dispersion;

[0044] Step 3: The graphene dispersion, prepolymer, 1.6 kg perfluoroalkyl quaternary ammonium salt and 17 kg caprolactam are mixed by ultrasonic shearing integrated dispersion, and the ring-opening reaction is carried out at 265°C and 0.5 MPa for 1.5 hours, and then polymerized at 255°C and -0.15 MPa for 3 hours. The polymer is passed into a pelletizer for slicing, and then the slices are placed in an extraction tower and extracted with deionized water at 90°C. The extracted slices are dried in a drying tank filled with hot nitrogen to obtain an antibacterial modified graphene polyamide 6 composite material.

[0045] Example 5

[0046] Step 1: 11 kg of caprolactam was added into a prepolymerization reactor and reacted at a temperature of 270° C. and 1 MPa for 2 h to obtain a prepolymer;

[0047] Step 2: 0.8 kg of polyvinyl alcohol sulfonate and 1 kg of carboxylated graphene were mixed, and 100 kg of deionized water was added to obtain a graphene dispersion;

[0048] Step 3: The graphene dispersion, prepolymer, 1.6 kg of amino silicone quaternary ammonium salt and 17 kg of caprolactam are mixed by ultrasonic shearing integrated dispersion, and the ring-opening reaction is carried out at 265°C and 0.5 MPa for 1.5 hours, and then polymerized at 255°C and -0.15 MPa for 3 hours. The polymer is passed into a pelletizer for slicing, and then the slices are placed in an extraction tower and extracted with deionized water at 90°C. The extracted slices are dried in a drying tank filled with hot nitrogen to obtain an antibacterial modified graphene polyamide 6 composite material.

[0049] Example 6

[0050] Step 1: 11 kg of caprolactam was added into a prepolymerization reactor and reacted at a temperature of 270° C. and 1 MPa for 2 h to obtain a prepolymer;

[0051] Step 2: adding 1 kg of carboxylated graphene to 100 kg of deionized water and mixing to obtain a graphene dispersion;

[0052] Step 3: The graphene dispersion, prepolymer, 0.4 kg perfluoroalkyl quaternary ammonium salt, 1.2 kg amino silicone quaternary ammonium salt and 17 kg caprolactam are mixed by ultrasonic shearing integrated dispersion, and the ring-opening reaction is carried out at 265°C and 0.5 MPa for 1.5 hours, and then polymerized at 255°C and -0.15 MPa for 3 hours. The polymer is passed into a pelletizer for slicing, and then the slices are placed in an extraction tower and extracted with deionized water at 90°C. The extracted slices are dried in a drying tank filled with hot nitrogen to obtain an antibacterial modified graphene polyamide 6 composite material.

[0053] The antibacterial performance of the slices of the antibacterial modified graphene polyamide 6 composite material obtained in Examples 1-6 was tested. The results are shown in Table 1. The antibacterial performance test method refers to GB / T 2591-2003.

[0054] Table 1 Test results of antibacterial properties of antibacterial modified graphene polyamide 6 composites

[0055]

[0056] The antibacterial modified graphene polyamide 6 composite materials obtained in Examples 1-6 were melt-spun to obtain antibacterial modified graphene polyamide 6 fibers. The mechanical properties of the antibacterial modified graphene polyamide 6 fibers were tested, and the test results are shown in Table 2.

[0057] Table 2 Mechanical properties test results of antibacterial modified graphene polyamide 6 composite fibers

[0058]

[0059] It can be seen from Table 1 and Table 2 that the antibacterial modified graphene polyamide 6 composite material prepared by the method of the present invention has excellent antibacterial properties and mechanical properties, and its antibacterial rate after 12 months is still maintained at more than 96%, and the antibacterial effect is more lasting.

[0060] Compared with Example 6, the antibacterial modified graphene polyamide 6 composite materials obtained in Examples 1-3 have more lasting antibacterial efficacy and better mechanical properties, indicating that the addition of polyvinyl alcohol sulfonate is beneficial to the dispersion of perfluoroalkyl quaternary ammonium salts and amino silicone quaternary ammonium salts on the graphene sheets, making the composite material more uniform and stable, and having better mechanical properties.

[0061] Compared with Example 4 and Example 5, the antibacterial properties of the antibacterial modified graphene composite fibers obtained in Examples 1-3 are more durable, indicating that the synergistic combination of perfluoroalkyl quaternary ammonium salt and amino silicone quaternary ammonium salt can achieve better stability of the antibacterial modified graphene polyamide 6 composite material, thereby making the antibacterial property more durable.

[0062] The above specific implementation methods are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing an antibacterial modified graphene polyamide 6 composite material, characterized in that: The following steps are involved: S1: prepolymerizing part of caprolactam to obtain a prepolymer; S2: adding polyvinyl alcohol sulfonate and functionalized graphene into the dispersion to obtain a graphene dispersion; S3: mixing perfluoroalkyl quaternary ammonium salt, amino silicone quaternary ammonium salt, graphene dispersion, prepolymer and remaining caprolactam, performing ring opening, polymerization reaction, slicing, extraction and drying to obtain antibacterial modified graphene polyamide 6; The mass ratio of the polyvinyl alcohol sulfonate, perfluoroalkyl quaternary ammonium salt, amino silicone quaternary ammonium salt and functionalized graphene in S3 is (5-15):(3-8):(10-30):15; The total mass ratio of the functionalized graphene to the caprolactam is (3-5):100; The amount of caprolactam in S1 accounts for (30-55)% of the total amount of caprolactam; The functionalized graphene is carboxylated graphene; The preparation method of polyvinyl alcohol sulfonate is as follows: 22g of polyvinyl alcohol is dissolved in 200mL of dimethylformamide, 5.7g of metallic sodium is chopped and added, and mixed at room temperature for 0.5h; then a dimethylformamide solution of 1,3-propane sultone with a mass fraction of 10% is added dropwise, and the weight ratio of polyvinyl alcohol to 1,3-propane sultone is 0.72:1, and the temperature is raised to 80°C for reaction for 3h; the reaction product is dried to obtain sodium polyvinyl alcohol sulfonate; The preparation method of the amino-organic silicon quaternary ammonium salt is as follows: by weight, 1.2 parts of 3-aminopropyltriethoxysilane, 1 part of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 0.03 parts of formic acid, 0.02 parts of dibutyltin dilaurate and an appropriate amount of solvent ethanol are stirred under a N2 atmosphere, the temperature is raised to boiling of the solvent, the stirring is refluxed for 15 hours, the solvent is removed by distillation under reduced pressure, and vacuum drying is performed; The perfluoroalkyl quaternary ammonium salt uses perfluorohexyltrimethylammonium bromide.

2. The method for preparing an antibacterial modified graphene polyamide 6 composite material according to claim 1, characterized in that: The prepolymerization reaction temperature is 260-280°C, the pressure is 1-1.2MPa, and the prepolymerization time is 1.5-2.5 hours.

3. The method for preparing an antibacterial modified graphene polyamide 6 composite material according to claim 1, characterized in that: The dispersion liquid is deionized water.

4. The method for preparing an antibacterial modified graphene polyamide 6 composite material according to claim 1, characterized in that: The ring-opening reaction conditions are as follows: temperature 255-275°C, pressure 0.15-0.85 MPa, and reaction time 1.5-4 h; the polymerization reaction conditions are as follows: temperature 240-255°C, pressure -0.05-0.20 MPa, and reaction time 3-10 h.

5. The method for preparing an antibacterial modified graphene polyamide 6 composite material according to claim 1, characterized in that: The mixing method adopts an ultrasonic shearing integration method.

6. An antibacterial modified graphene polyamide 6 composite material obtained according to any one of the preparation methods of claims 1-5.

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