High-wear-resistant heat-resistant nylon 66 composite material and preparation method thereof

Abstract

The invention relates to a high wear-resistant heat-resistant nylon 66 composite material and a preparation method thereof, and the method comprises the following steps: uniformly mixing a phenyl methyl siloxane copolymer and a reaction initiator according to a mass ratio of (8-10): (0.3-0.5) to obtain a mixed solution, and then carrying out a grafting reaction on nylon 66 resin and the mixed solution according to a mass ratio of (80-100): (0.8-1.2) at 228-237 DEG C to obtain the nylon 66 composite material. The phenyl methylsiloxane copolymer and nylon 66 macromolecular chains are subjected to grafting reaction in the presence of the initiator to prepare a macromolecular polymer with a rigid side group structure, so that the molecular chains of the whole macromolecular polymer have the performance of liquid crystal polymers, and the mechanical property and heat resistance of the material are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials, specifically relating to a high wear-resistant and heat-resistant nylon 66 composite material and its preparation method. Background Technology

[0002] Nylon 66 is a general-purpose engineering plastic with high cost-effectiveness, wide application, and environmental friendliness and recyclability, leading to its widespread use. It possesses excellent mechanical strength, toughness, stress cracking resistance, wear resistance, corrosion resistance, and good moldability. However, in practical applications, its performance is significantly inferior to high-performance engineering plastics such as liquid crystal polymers, polyetheretherketone (PEEK), and fluoroplastics. In applications requiring continuous high-temperature and wear resistance, such as automotive gearbox shift forks, high-temperature plastic parts for oil fields, bearing cages, high-temperature gears, bushings, friction-reducing rings, friction-reducing pads, conveyor belts, hot water pipe fittings, and clutch components, higher demands are placed on nylon's high-temperature resistance and wear resistance. Ordinary nylon materials wear very quickly at high temperatures, are easily deformed, and lack sufficient strength and heat resistance.

[0003] Therefore, in order to broaden the application areas of nylon, maximize its overall performance, and expand its application scenarios, it is necessary to modify it to adapt to the aforementioned harsh operating environments. Currently, high-temperature and wear-resistant nylons on the market are mainly modified with fillers such as glass fiber, polytetrafluoroethylene powder, and molybdenum disulfide. These are all physical modifications, which are difficult to disperse evenly, resulting in low modification effects. Glass fiber can easily reduce the performance of nylon, making processing difficult, and the improvement in high-temperature wear resistance is not significant. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the existing technology by providing a farmland drainage diversion, regulation, utilization, and purification system with functional division, and its operation method.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention proposes a method for preparing a high wear-resistant and heat-resistant nylon 66 composite material, comprising:

[0007] S1. The phenylmethylsiloxane copolymer and the reaction initiator are mixed evenly at a mass ratio of 8-10:0.3-0.5 to obtain a mixture, wherein the structural formula of the phenylmethylsiloxane copolymer is:

[0008] ;

[0009] S2. Grafting reaction of nylon 66 resin and mixture at a mass ratio of 80-100:0.8-1.2 at 228-237℃ to obtain nylon 66 composite material.

[0010] S2 includes:

[0011] First, Nylon 66 resin, modified carbon fiber, and modified molybdenum disulfide are mixed evenly at a mass ratio of 80-100:3-5:2-4, and then the mixture is added to carry out the grafting reaction.

[0012] The preparation of the modified carbon fiber includes:

[0013] Modified carbon fiber is obtained by adding carbon fiber prepreg to a phenylmethylsiloxane copolymer solution for modification.

[0014] The preparation of the modified molybdenum disulfide includes:

[0015] Molybdenum disulfide was modified by adding it to a solution of phenylmethylsiloxane copolymer to obtain modified molybdenum disulfide.

[0016] The carbon fiber is modified at a temperature of 75-85℃ for a duration of 0.5-1.5 hours.

[0017] The modification temperature of the molybdenum disulfide is 75-85℃, and the modification time is 10-20 minutes.

[0018] The phenylmethylsiloxane copolymer solution is obtained by mixing anhydrous ethanol, distilled water, and phenylmethylsiloxane copolymer in a mass ratio of 9-12:1-1.3:0.152-0.2.

[0019] The mass ratio of the carbon fiber prepreg to the phenylmethylsiloxane copolymer solution is 10-15:20-30, and the mass ratio of molybdenum disulfide to the phenylmethylsiloxane copolymer solution is 2-5:12-20.

[0020] The reaction initiator is dicumyl peroxide.

[0021] Secondly, the present invention proposes a high wear-resistant and heat-resistant nylon 66 composite material. The raw material composition of the material includes nylon 66 resin, phenylmethylsiloxane copolymer and reaction initiator. The nylon 66 composite material can be obtained by preparing each raw material according to the aforementioned preparation method.

[0022] The composite material also contains modified carbon fiber and modified molybdenum disulfide, and the mass ratio of the amount of modified carbon fiber and modified molybdenum disulfide added to nylon 66 resin is 3-5:2-4:80-100.

[0023] The raw material composition of the modified carbon fiber includes carbon fiber prepreg and phenylmethylsiloxane copolymer solution;

[0024] The raw material composition of the modified molybdenum disulfide includes a solution of molybdenum disulfide and phenylmethylsiloxane copolymer.

[0025] The raw material composition of the phenylmethylsiloxane copolymer solution includes 9-12 parts anhydrous ethanol, 1-1.3 parts distilled water, and 0.152-0.2 parts phenylmethylsiloxane copolymer;

[0026] The mass ratio of the carbon fiber prepreg to the phenylmethylsiloxane copolymer solution is 10-15:20-30, and the mass ratio of molybdenum disulfide to the phenylmethylsiloxane copolymer solution is 2-5:12-20.

[0027] The reaction initiator is dicumyl peroxide.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. The method for preparing the high wear-resistant and heat-resistant nylon 66 composite material proposed in this invention involves first mixing a phenylmethylsiloxane copolymer and a reaction initiator at a mass ratio of 8-10:0.3-0.5 to obtain a uniform mixture. Then, nylon 66 resin and the mixture are grafted at a mass ratio of 80-100:0.8-1.2 at 228-237℃ to obtain the nylon 66 composite material. This method modifies nylon 66 with a phenylmethylsiloxane copolymer. By grafting the phenylmethylsiloxane copolymer onto the nylon 66 macromolecular chain in the presence of an initiator, a polymer with rigid side groups is prepared, giving the entire macromolecular polymer the properties of a liquid crystal polymer, significantly improving the material's mechanical properties and heat resistance.

[0030] 2. The high wear-resistant and heat-resistant nylon 66 composite material proposed in this invention not only improves the wear resistance of the material by adding carbon fiber and molybdenum disulfide, but also uses phenylmethylsiloxane copolymer to coat and modify the carbon fiber and molybdenum disulfide, so that the carbon fiber and molybdenum disulfide can be uniformly dispersed inside the nylon 66 material to ensure that the other properties of the material are not affected. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the composite material described in this invention.

[0032] Figure 2 This is a schematic diagram of the structure of modified carbon fiber and modified molybdenum disulfide.

[0033] Figure 3 This is a schematic diagram showing the formation of active free radicals in dicumyl peroxide under heating conditions.

[0034] Figure 4 This is a schematic diagram illustrating the interaction between active free radicals and nylon 66.

[0035] Figure 5 This is a schematic diagram of the grafting reaction of nylon 66 with active free radicals and phenylmethylsiloxane copolymer. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0037] This invention proposes a method for preparing a high-wear-resistant and heat-resistant nylon 66 composite material. The method first modifies carbon fibers and molybdenum disulfide by coating them with a phenylmethylsiloxane copolymer. Then, the phenylmethylsiloxane copolymer undergoes a grafting reaction with the nylon 66 macromolecular chain in the presence of dicumyl peroxide (DCP) as an initiator, preparing a polymer with a rigid side group structure (the side group being a rigid unit containing five benzene rings). This gives the entire macromolecular polymer the properties of a liquid crystal polymer. The structure of the composite material is as follows: Figure 1 As shown. Modified carbon fiber and modified molybdenum disulfide structures are as follows. Figure 2 As shown, carbon fibers, molybdenum disulfide, and phenylmethylsiloxane copolymers form hydrogen bonds.

[0038] The grafting reaction between phenylmethylsiloxane copolymer and nylon 66 in the presence of dicumyl peroxide (DCP) initiator is as follows: DCP initiator forms active free radicals under heating conditions. These active free radicals react with nylon 66 to form nylon 66 with active free radicals. The nylon 66 with active free radicals then grafts with the phenylmethylsiloxane copolymer to form a polymer with rigid side groups. Figures 3-5 As shown.

[0039] The raw materials used in this invention are described below:

[0040] Anhydrous ethanol: dispersant;

[0041] Phenylmethylsiloxane copolymer: a colorless to pale yellow liquid, a reactive monomer, and a modifier;

[0042] Dicumyl peroxide (DCP): White crystalline powder, reaction initiator;

[0043] Carbon fiber prepreg: Carbon fiber is treated by acid hydrolysis. The carbon fiber is short-cut fiber with a length of 0.5-1 mm and a diameter of 5-10 micrometers.

[0044] Molybdenum disulfide: Powdered form, wear-resistant agent;

[0045] Nylon resin: Nylon 66 pure resin, DuPont E51HSB NC010, melt flow rate 8-12 g / 10 min (270℃, 2.16 Kg).

[0046] Antioxidant 1010: Anti-heat aging agent, white crystalline powder;

[0047] Antioxidant 168: Auxiliary antioxidant, white crystalline powder.

[0048] 10# White Oil: A transparent liquid, used in the mixing of additives.

[0049] Example 1:

[0050] A high wear-resistant and heat-resistant nylon 66 composite material, the raw material composition of which includes nylon 66 resin, phenylmethylsiloxane copolymer, reaction initiator dicumyl peroxide, antioxidant 1010, antioxidant 168, and 10# white oil, and the structural formula of the phenylmethylsiloxane copolymer is as follows:

[0051] .

[0052] The preparation method of the above composite material is as follows:

[0053] The first step involves adding phenylmethylsiloxane copolymer and dicumyl peroxide (DCP) to a container at a mass ratio of 8:0.3. The container is then heated to 50°C and maintained at that temperature to ensure complete and uniform mixing, resulting in a mixture.

[0054] The second step involves sequentially adding nylon 66 resin, 10# white oil, antioxidant 1010, and antioxidant 168 to a high-speed mixer and mixing thoroughly at room temperature. The mixed material is then fed into the hopper of a twin-screw extruder granulator for extrusion granulation. The twin-screw extruder is equipped with a liquid metering scale in the center. The mixture is added to the scale and maintained at 50°C. The scale dispenses the mixture into the mixing zone of the twin-screw extruder according to the extrusion speed. The mass ratio of nylon 66 resin, antioxidant 1010, antioxidant 168, 10# white oil, and the mixture is 80:0.3:0.3:0.05:0.8. The process temperatures of the twin-screw extruder granulator are: Zone 1 210±2°C, Zone 2 215±2°C, Zone 3 220±2°C, Zone 4 225±2°C, Zone 5 230±2°C, Zone 6 235±2°C, and the die head 240±2°C. The injection area of ​​the mixture is divided into three zones: zones one, two, and three are the transport zones; zone four is the initiation zone; zones five and six are the reaction zones; and the die head is the extrusion granulation zone.

[0055] Example 2:

[0056] The difference from Example 1 is as follows:

[0057] The raw material composition of the composite material also includes modified carbon fiber and modified molybdenum disulfide, and the mass ratio of the added amount of modified carbon fiber and modified molybdenum disulfide to nylon 66 resin is 3:2:80.

[0058] The modified carbon fiber was prepared using the following steps:

[0059] A1. Add anhydrous ethanol, distilled water, and phenylmethylsiloxane copolymer in a ratio of 9:1.0:0.152 to a container, and ultrasonically disperse for 10 minutes to completely dissolve the phenylmethylsiloxane copolymer, thus obtaining a phenylmethylsiloxane copolymer solution.

[0060] A2. Add the carbon fiber prepreg to the phenylmethylsiloxane copolymer solution, ultrasonically disperse at 70°C for 30 minutes, then let stand and filter. Take the filter material and react at 80°C for 1 hour, then wash with deionized water to remove unreacted phenylmethylsiloxane copolymer, and finally dry at 80°C to obtain modified carbon fiber. The mass ratio of carbon fiber prepreg to phenylmethylsiloxane copolymer solution is 1:2.

[0061] The modified molybdenum disulfide was prepared by the following method:

[0062] First, molybdenum disulfide was added to a phenylmethylsiloxane copolymer solution and ultrasonically dispersed for 30 minutes. Then, the temperature was raised to 80°C, and the mixture was stirred at a uniform speed for 15 minutes. After cooling to room temperature, the mixture was filtered, and the filter cake was vacuum dried and pulverized to obtain modified molybdenum disulfide. The mass ratio of molybdenum disulfide to the phenylmethylsiloxane copolymer solution was 1:6.

[0063] In the second step, the modified carbon fiber, modified molybdenum disulfide, nylon 66 resin, 10# white oil, antioxidant 1010, and antioxidant 168 are added to a high-speed mixer and mixed thoroughly at room temperature. The order of addition is as follows: nylon 66 resin, 10# white oil, antioxidant 1010, antioxidant 168, modified carbon fiber, and modified molybdenum disulfide.

[0064] Example 3:

[0065] The difference from Example 2 is that:

[0066] The raw material composition and mass fraction of the composite material are as follows: 90 parts of nylon 66 resin, 1.0 part of mixed liquid, 0.4 parts of antioxidant 1010, 0.4 parts of antioxidant 168, 0.07 parts of 10# white oil, 4 parts of modified carbon fiber, and 3 parts of modified molybdenum disulfide. The mass ratio of phenylmethylsiloxane copolymer to dicumyl peroxide in the mixed liquid is 9:0.4.

[0067] When preparing modified carbon fibers, the mass ratio of carbon fiber prepreg to phenylmethylsiloxane copolymer solution is 12:25.

[0068] When preparing modified molybdenum disulfide, the mass ratio of molybdenum disulfide to phenylmethylsiloxane copolymer solution is 3:16.

[0069] In the phenylmethylsiloxane copolymer solution, the mass ratio of anhydrous ethanol, distilled water, and phenylmethylsiloxane copolymer is 10:1.1:0.18.

[0070] Example 4:

[0071] The difference from Example 2 is that:

[0072] The raw material composition and mass fraction of the composite material are as follows: 100 parts of nylon 66 resin, 0.8 parts of mixed liquid, 0.5 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 0.08 parts of 10# white oil, 5 parts of modified carbon fiber, and 4 parts of modified molybdenum disulfide. The mass ratio of phenylmethylsiloxane copolymer to dicumyl peroxide in the mixed liquid is 20:1.

[0073] When preparing modified carbon fibers, the mass ratio of carbon fiber prepreg to phenylmethylsiloxane copolymer solution is 14:30.

[0074] When preparing modified molybdenum disulfide, the mass ratio of molybdenum disulfide to phenylmethylsiloxane copolymer solution is 1:4.

[0075] In the phenylmethylsiloxane copolymer solution, the mass ratio of anhydrous ethanol, distilled water, and phenylmethylsiloxane copolymer is 12:1.3:0.2.

[0076] Comparative example:

[0077] The difference from Example 1 is as follows:

[0078] The raw material composition of the composite material also includes carbon fiber and molybdenum disulfide, and the mass ratio of the amount of carbon fiber and molybdenum disulfide added to nylon 66 resin is 3:2:80.

[0079] In the second step, carbon fiber, molybdenum disulfide, nylon 66 resin, 10# white oil, antioxidant 1010, and antioxidant 168 are added to a high-speed mixer and mixed thoroughly at room temperature. The order of addition is as follows: nylon 66 resin, 10# white oil, antioxidant 1010, antioxidant 168, carbon fiber, and molybdenum disulfide.

[0080] To examine the performance of the product of this invention, the performance of Example 1, Example 2, the comparative product, and the conventional nylon 66 product (DuPont E51HSB NC010) were tested respectively. The results are shown in Table 1:

[0081] Table 1 Performance Comparison Results

[0082]

[0083] As shown in Table 1, grafting nylon 66 resin with phenylmethylsiloxane copolymer (Example 1) significantly improves the material properties, approaching those of liquid crystal polymers, but its wear resistance is insufficient. While adding carbon fiber and molybdenum dioxide (comparative example) improves wear resistance, the interfacial bonding strength between the carbon fiber / molybdenum dioxide and the resin matrix is ​​low, preventing uniform distribution within the matrix, and resulting in a significant decrease in tensile strength, flexural strength, and other properties. However, adding carbon fiber and modified molybdenum dioxide modified with phenylmethylsiloxane copolymer (Example 2) allows the carbon fiber and molybdenum dioxide to maintain their wear resistance without affecting other material properties. Therefore, this invention significantly improves the overall performance of nylon 66 materials.

Claims

1. A method for preparing a high wear-resistant and heat-resistant nylon 66 composite material, characterized in that: The preparation method includes: S1. The phenylmethylsiloxane copolymer and the reaction initiator are mixed evenly at a mass ratio of 8-10:0.3-0.5 to obtain a mixture, wherein the structural formula of the phenylmethylsiloxane copolymer is: ； S2. Grafting reaction of nylon 66 resin and mixture at a mass ratio of 80-100:0.8-1.2 at 228-237℃ to obtain nylon 66 composite material.

2. The high wear-resistant and heat-resistant nylon 66 composite material according to claim 1, characterized in that: S2 includes: First, Nylon 66 resin, modified carbon fiber, and modified molybdenum disulfide are mixed evenly at a mass ratio of 80-100:3-5:2-4, and then the mixture is added to carry out the grafting reaction.

3. The method for preparing a high wear-resistant and heat-resistant nylon 66 composite material according to claim 2, characterized in that: The preparation of the modified carbon fiber includes: Modified carbon fiber is obtained by adding carbon fiber prepreg to a phenylmethylsiloxane copolymer solution for modification. The preparation of the modified molybdenum disulfide includes: Molybdenum disulfide was modified by adding it to a solution of phenylmethylsiloxane copolymer to obtain modified molybdenum disulfide.

4. The method for preparing a high wear-resistant and heat-resistant nylon 66 composite material according to claim 3, characterized in that: The carbon fiber is modified at a temperature of 75-85℃ for a duration of 0.5-1.5 hours. The modification temperature of the molybdenum disulfide is 75-85℃, and the modification time is 10-20 minutes.

5. The method for preparing a high wear-resistant and heat-resistant nylon 66 composite material according to claim 3, characterized in that: The phenylmethylsiloxane copolymer solution is obtained by mixing anhydrous ethanol, distilled water, and phenylmethylsiloxane copolymer in a mass ratio of 9-12:1-1.3:0.152-0.2; The mass ratio of the carbon fiber prepreg to the phenylmethylsiloxane copolymer solution is 10-15:20-30, and the mass ratio of molybdenum disulfide to the phenylmethylsiloxane copolymer solution is 2-5:12-20. The reaction initiator is dicumyl peroxide.

6. A high wear-resistant and heat-resistant nylon 66 composite material prepared by the method of claim 1.

7. The high wear-resistant and heat-resistant nylon 66 composite material according to claim 6, characterized in that: The composite material also contains modified carbon fiber and modified molybdenum disulfide, and the mass ratio of the amount of modified carbon fiber and modified molybdenum disulfide added to nylon 66 resin is 3-5:2-4:80-100.

8. The high wear-resistant and heat-resistant nylon 66 composite material according to claim 7, characterized in that: The raw material composition of the modified carbon fiber includes carbon fiber prepreg and phenylmethylsiloxane copolymer solution; The raw material composition of the modified molybdenum disulfide includes a solution of molybdenum disulfide and phenylmethylsiloxane copolymer.

9. The high wear-resistant and heat-resistant nylon 66 composite material according to claim 8, characterized in that: The raw material composition of the phenylmethylsiloxane copolymer solution includes 9-12 parts anhydrous ethanol, 1-1.3 parts distilled water, and 0.152-0.2 parts phenylmethylsiloxane copolymer; The mass ratio of the carbon fiber prepreg to the phenylmethylsiloxane copolymer solution is 10-15:20-30, and the mass ratio of molybdenum disulfide to the phenylmethylsiloxane copolymer solution is 2-5:12-20.

10. The high wear-resistant and heat-resistant nylon 66 composite material according to claim 6, characterized in that: The reaction initiator is dicumyl peroxide.

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