Oxidation-resistant antistatic PA plastic and preparation method thereof

Abstract

The invention relates to an oxidation-resistant antistatic PA plastic and a preparation method thereof, and belongs to the technical field of high polymer materials. The oxidation-resistant antistatic PA plastic comprises the following components in parts by weight: 70-90 parts of PA resin, 25-35 parts of glass fiber, 1-5 parts of a modified antistatic agent, 1-5 parts of a modified antioxidant, 1-3 parts of a compatilizer, 5-10 parts of a flexibilizer and 1-3 parts of a lubricant, positive ions of a quaternary ammonium salt compound in the modified antistatic agent are neutralized with negative charges on the surface of the material, the quaternary ammonium salt compound also serves as a conducting medium and adsorbs negatively charged bacteria, epoxy groups of glycidyl methacrylate react with PA hydroxyl groups, and the toughness of the material is improved; nitrogen atoms in the modified antioxidant capture free radicals and terminate chain reaction through lone pair electrons, carbonyl in hydroxybenzophenone and benzene rings form hydrogen bonds, and ultraviolet rays are absorbed; the antioxidant antistatic PA plastic prepared by the invention not only has a good antistatic effect, but also has excellent antioxidant and antibacterial effects.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to an oxidation-resistant and antistatic PA plastic and a preparation method thereof. Background Art

[0002] PA (polyamide) is a high-performance engineering plastic composed of repeating amide groups. Its molecular structure and crystallization characteristics give it excellent high strength, wear resistance and chemical resistance. It is widely used in many fields such as automobiles, aircraft, electronics, petrochemicals, medical treatment, textiles, packaging and transportation.

[0003] However, PA plastics tend to accumulate static electricity during use, which is difficult to eliminate. This not only attracts dust from the air, affecting its appearance, but can also damage sensitive components of electronic devices during the plastic manufacturing process. Furthermore, the accumulation of static electricity can cause safety hazards such as electric shock, equipment failure, and even fire. Furthermore, high temperatures accelerate the oxidation reaction of PA plastics, causing the material to turn yellow and become brittle. Meanwhile, ultraviolet radiation can cause molecular chain breakage, activate oxidation chain reactions, further accelerate aging, and shorten the material's service life. Therefore, the development of excellent oxidation-resistant and antistatic PA plastics has important practical significance and application value. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an oxidation-resistant and antistatic PA plastic and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: An oxidation-resistant and antistatic PA plastic and a preparation method thereof, comprising the following raw materials in parts by weight: 70-90 parts of PA resin, 25-35 parts of glass fiber, 1-5 parts of a modified antistatic agent, 1-5 parts of a modified antioxidant, 1-3 parts of a compatibilizer, 5-10 parts of a toughening agent, and 1-3 parts of a lubricant; The compatibilizer is EVA-g-MAH; The toughening agent is maleic anhydride grafted POE; The lubricant is paraffin.

[0006] The modified antistatic agent is prepared by the following method: Step A1: Mix anhydrous ethanol and 2,4,6-tris(dimethylaminomethyl)phenol, stir in a water bath for 5 minutes, react at 25°C for 30 minutes, then heat to 45°C, adjust the pH to 7.5-8, slowly add 1-chlorohexane and methanol, react at 45°C for 8-12 hours, and evaporate under reduced pressure to obtain the compound; Furthermore, the usage ratio of anhydrous ethanol, 2,4,6-tris(dimethylaminomethyl)phenol, 1-chlorohexane, and methanol is 50 mL: 0.01-0.03 mol: 0.03-0.09 mol: 2 mL; First, the amino group of 2,4,6-tris(dimethylaminomethyl)phenol reacts with the chlorine atom of 1-chlorohexane to prepare the compound; Step A2: Acryloyl chloride and N,N-dimethylformamide were mixed evenly, reacted at 60°C for 3 hours, and then the compound and triethylamine were added, and the reaction was continued at 60°C for 3 hours. After the reaction, the mixture was filtered, washed, and vacuum dried for 12 hours to obtain a pre-product; Furthermore, the usage ratio of acryloyl chloride, N,N-dimethylformamide, compound, and triethylamine is 0.01-0.03 mol: 13-15 mL: 0.01-0.03 mol: 2-6 mL; Secondly, the chlorine atom of acryloyl chloride reacts with the phenolic hydroxyl group of the compound to prepare a pre-product; Step A3: The pre-product, glycidyl methacrylate and acetonitrile were mixed uniformly and stirred for 10 minutes. Under nitrogen protection, azobisisobutyronitrile was added and stirred for 30 minutes. The mixture was reacted at 70°C for 3 hours. After the reaction was completed, the mixture was rotary evaporated and vacuum dried at 50°C for 12 hours to obtain a modified antistatic agent. Furthermore, the ratio of the pre-product, glycidyl methacrylate, acetonitrile, and azobisisobutyronitrile is 0.01-0.03 mol: 0.01-0.03 mol: 2 mL: 0.25-0.35 g; Finally, the modified antistatic agent is prepared by copolymerizing the pre-product with the carbon-carbon double bond of glycidyl methacrylate.

[0007] The modified antioxidant is prepared by the following method: Step B1: Add maleic anhydride to a four-necked flask equipped with a thermometer, a condenser, and a mechanical stirrer, and heat it to gradually liquefy it. After the reaction temperature reaches 90°C, add 6-amino-1,3-dimethyluracil and tetrahydrofuran, mix well, and continue the reaction under mechanical stirring for 5 hours. After the reaction is completed, rotary evaporate and dry to obtain an intermediate; Furthermore, the usage ratio of maleic anhydride, 6-amino-1,3-dimethyluracil, and tetrahydrofuran is 0.01-0.03 mol: 0.01-0.03 mol: 40-60 mL; First, the amino group of 6-amino-1,3-dimethyluracil is reacted with maleic anhydride to prepare an intermediate; Step B2: uniformly mix oxybenzone, the intermediate, and N,N-dimethylformamide, and react at 80-100° C. under nitrogen protection with stirring for 3 hours. After the reaction is completed, cool to room temperature, wash, filter, and dry to obtain a modified antioxidant; Furthermore, the usage ratio of oxybenzone, intermediate, and N,N-dimethylformamide is 0.01-0.03 mol: 0.01-0.03 mol: 10-20 mL; Finally, the carboxyl group of the intermediate reacts with the hydroxyl group of oxybenzone to prepare a modified antioxidant.

[0008] A method for preparing oxidation-resistant and antistatic PA plastics specifically comprises the following steps: S1. Evenly mix PA resin, glass fiber, modified antistatic agent, modified antioxidant, compatibilizer, toughening agent and lubricant to prepare a mixed material; S2. Add the mixed material into a twin-screw extruder, melt and extrude at an extrusion temperature of 220-260°C, granulate and dry to obtain oxidation-resistant and antistatic PA plastic.

[0009] Beneficial effects of the present invention: The oxidation-resistant and antistatic PA plastic of the present invention has good antistatic effect, and also has excellent antioxidant and antibacterial effects, further extending the service life.

[0010] The modified antistatic agent prepared by the present invention exhibits antistatic properties that surpass those of traditional small-molecule antistatic agents due to its advantages as a macromolecular polymer. The cationic groups of the quaternary ammonium salt compound in the modified antistatic agent can neutralize the negative charge on the surface of the PA material, reducing static electricity accumulation. The modified antistatic agent can also enhance the hydrophilicity of the material and promote moisture absorption. The ions in the water film formed after moisture absorption act as a conductive medium, accelerating the transfer and dissipation of charge, and preventing the negative impact of static electricity on production and product quality. Simultaneously, the cationic groups of the quaternary ammonium salt compound can adsorb negatively charged bacteria, penetrate the bacterial cell wall, react with proteins on the bacterial cell membrane, destroy the cell membrane structure, cause protein leakage in the bacteria, and accelerate bacterial death, thereby improving the antibacterial effect. In addition, the epoxy groups in the polymerized glycidyl methacrylate can react with the hydroxyl groups in the PA, enhancing intermolecular forces, improving the material toughness, and forming a conductive network, further reducing the surface resistivity. The quaternary ammonium salt synergistically enhances the conductive efficiency of the material surface ions and reduces static electricity accumulation.

[0011] The nitrogen atom in 6-amino-1,3-dimethyluracil in the modified antioxidant prepared by the present invention captures alkyl free radicals and peroxy free radicals generated by thermal degradation of PA materials through lone pairs of electrons, terminates the chain reaction, delays the process of thermal oxidative aging, and effectively improves the thermal stability and aging resistance of the material. In addition, the carbonyl group in oxybenzone forms an intramolecular hydrogen bond with the benzene ring, efficiently absorbs ultraviolet rays, and releases the excited electrons in a weak long-wave form after transitioning to a higher energy level through molecular vibration, thereby reducing material aging caused by ultraviolet rays. In addition, the amide group in the modified antioxidant strengthens the bonding between PA molecular chains by forming hydrogen bonds and intermolecular forces, thereby improving the crystallinity of the material, inhibiting segment movement at high temperatures, reducing material aging caused by high temperatures, and extending the service life. DETAILED DESCRIPTION

[0012] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0013] Example 1: A method for preparing oxidation-resistant and antistatic PA plastic, comprising the following steps: S1. Weigh the raw materials by weight: 70 parts of PA resin, 25 parts of glass fiber, 1 part of modified antistatic agent (prepared in this example), 1 part of modified antioxidant (prepared in this example), 1 part of compatibilizer, 5 parts of toughening agent, and 1 part of lubricant; uniformly mix the PA resin, glass fiber, modified antistatic agent, modified antioxidant, EVA-g-MAH, maleic anhydride grafted POE, and paraffin to obtain a mixed material; S2, adding the mixed material into a twin-screw extruder, melting and extruding at an extrusion temperature of 220° C., granulating, and drying to obtain an oxidation-resistant and antistatic PA plastic; The modified antistatic agent is prepared by the following method: Step A1: Mix 50 mL of anhydrous ethanol and 0.01 mol of 2,4,6-tris(dimethylaminomethyl)phenol, stir in a water bath for 5 min, react at 25°C for 30 min, then heat to 45°C and adjust the pH to 7.5. Slowly add 0.03 mol of 1-chlorohexane and 2 mL of methanol, react at 45°C for 8 h, and evaporate under reduced pressure to obtain the compound. Step A2: Mix 0.01 mol of acryloyl chloride and 13 mL of N,N-dimethylformamide, react at 60°C for 3 h, then add 0.01 mol of the compound and 2 mL of triethylamine, and continue to react at 60°C for 3 h. After the reaction, filter, wash, and vacuum dry for 12 h to obtain a pre-product; Step A3: 0.01 mol of the pre-product, 0.01 mol of glycidyl methacrylate, and 2 mL of acetonitrile were mixed uniformly and stirred for 10 min. Under nitrogen protection, 0.25 g of azobisisobutyronitrile was added and the mixture was stirred for 30 min. The mixture was reacted at 70°C for 3 h. After the reaction was completed, the mixture was rotary evaporated and dried in vacuum at 50°C for 12 h to obtain a modified antistatic agent. The modified antioxidant is prepared by the following method: Step B1: Add 0.01 mol of maleic anhydride to a four-necked flask equipped with a thermometer, a condenser, and a mechanical stirrer, and heat it to gradually liquefy it. After the reaction temperature rises to 90°C, add 0.01 mol of 6-amino-1,3-dimethyluracil and 40 mL of tetrahydrofuran, mix well, and continue the reaction under mechanical stirring for 5 hours. After the reaction is completed, rotary evaporate and dry to obtain an intermediate; Step B2: 0.01 mol of hydroxybenzoate, 0.01 mol of the intermediate and 10 mL of N,N-dimethylformamide were mixed evenly, and stirred at 80°C for 3 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, washed, filtered, and dried to obtain a modified antioxidant.

[0014] Example 2: A method for preparing oxidation-resistant and antistatic PA plastic, comprising the following steps: S1. Weigh the raw materials by weight: 80 parts of PA resin, 30 parts of glass fiber, 3 parts of modified antistatic agent (prepared in this example), 3 parts of modified antioxidant (prepared in this example), 2 parts of compatibilizer, 7.5 parts of toughening agent, and 2 parts of lubricant; uniformly mix the PA resin, glass fiber, modified antistatic agent, modified antioxidant, EVA-g-MAH, maleic anhydride grafted POE, and paraffin to obtain a mixed material; S2, adding the mixed material into a twin-screw extruder, melting and extruding at an extrusion temperature of 240° C., granulating, and drying to obtain an oxidation-resistant and antistatic PA plastic; The modified antistatic agent is prepared by the following method: Step A1: Mix 50 mL of anhydrous ethanol and 0.02 mol of 2,4,6-tris(dimethylaminomethyl)phenol, stir in a water bath for 5 min, react at 25°C for 30 min, then heat to 45°C and adjust the pH to 7.7. Slowly add 0.06 mol of 1-chlorohexane and 2 mL of methanol, react at 45°C for 10 h, and evaporate under reduced pressure to obtain the compound. Step A2: 0.02 mol of acryloyl chloride and 14 mL of N,N-dimethylformamide were mixed evenly, reacted at 60°C for 3 h, and then 0.02 mol of the compound and 4 mL of triethylamine were added, and the reaction was continued at 60°C for 3 h. After the reaction, the mixture was filtered, washed, and vacuum dried for 12 h to obtain a pre-product; Step A3: 0.02 mol of the pre-product, 0.02 mol of glycidyl methacrylate, and 2 mL of acetonitrile were mixed uniformly and stirred for 10 min. Under nitrogen protection, 0.3 g of azobisisobutyronitrile was added and the mixture was stirred for 30 min. The mixture was reacted at 70°C for 3 h. After the reaction was completed, the mixture was rotary evaporated and dried in vacuum at 50°C for 12 h to obtain a modified antistatic agent. The modified antioxidant is prepared by the following method: Step B1: Add 0.02 mol of maleic anhydride to a four-necked flask equipped with a thermometer, a condenser, and a mechanical stirrer, and heat it to gradually liquefy it. After the reaction temperature rises to 90°C, add 0.02 mol of 6-amino-1,3-dimethyluracil and 50 mL of tetrahydrofuran, mix well, and continue the reaction under mechanical stirring for 5 hours. After the reaction is completed, rotary evaporate and dry to obtain an intermediate; Step B2: 0.02 mol of hydroxybenzophenone, 0.02 mol of the intermediate and 15 mL of N,N-dimethylformamide were mixed evenly, and stirred at 90°C for 3 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, washed, filtered, and dried to obtain a modified antioxidant.

[0015] Example 3: A method for preparing oxidation-resistant and antistatic PA plastic, comprising the following steps: S1. Weigh the raw materials by weight: 90 parts of PA resin, 35 parts of glass fiber, 5 parts of modified antistatic agent (prepared in this example), 5 parts of modified antioxidant (prepared in this example), 3 parts of compatibilizer, 10 parts of toughening agent, and 3 parts of lubricant; uniformly mix the PA resin, glass fiber, modified antistatic agent, modified antioxidant, EVA-g-MAH, maleic anhydride grafted POE, and paraffin to obtain a mixed material; S2, adding the mixed material into a twin-screw extruder, melting and extruding at an extrusion temperature of 260° C., granulating, and drying to obtain an oxidation-resistant and antistatic PA plastic; The modified antistatic agent is prepared by the following method: Step A1: Mix 50 mL of anhydrous ethanol and 0.03 mol of 2,4,6-tris(dimethylaminomethyl)phenol, stir in a water bath for 5 min, react at 25°C for 30 min, then heat to 45°C and adjust the pH to 8. Slowly add 0.09 mol of 1-chlorohexane and 2 mL of methanol, react at 45°C for 12 h, and evaporate under reduced pressure to obtain the compound. Step A2: Mix 0.03 mol of acryloyl chloride and 15 mL of N,N-dimethylformamide, react at 60°C for 3 h, then add 0.03 mol of the compound and 6 mL of triethylamine, and continue to react at 60°C for 3 h. After the reaction, filter, wash, and vacuum dry for 12 h to obtain a pre-product; Step A3: 0.03 mol of the pre-product, 0.03 mol of glycidyl methacrylate, and 2 mL of acetonitrile were mixed uniformly and stirred for 10 min. Under nitrogen protection, 0.35 g of azobisisobutyronitrile was added and the mixture was stirred for 30 min. The mixture was reacted at 70°C for 3 h. After the reaction was completed, the mixture was rotary evaporated and dried in vacuum at 50°C for 12 h to obtain a modified antistatic agent. The modified antioxidant is prepared by the following method: Step B1: Add 0.03 mol of maleic anhydride to a four-necked flask equipped with a thermometer, a condenser, and a mechanical stirrer, and heat it to gradually liquefy it. After the reaction temperature rises to 90°C, add 0.03 mol of 6-amino-1,3-dimethyluracil and 60 mL of tetrahydrofuran, mix well, and continue the reaction under mechanical stirring for 5 hours. After the reaction is completed, rotary evaporate and dry to obtain an intermediate; Step B2: 0.03 mol of hydroxybenzophenone, 0.03 mol of the intermediate and 20 mL of N,N-dimethylformamide were mixed evenly, and stirred at 100°C for 3 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, washed, filtered, and dried to obtain a modified antioxidant.

[0016] Comparative Example 1: This comparative example is an oxidation-resistant antistatic PA plastic. The difference from Example 3 is that an equal amount of carbon black is used to replace the modified antistatic agent prepared in Example 3. All other aspects are the same.

[0017] Comparative Example 2: This comparative example is an oxidation-resistant and antistatic PA plastic. The difference from Example 3 is that an equal amount of antioxidant 1010 is used to replace the modified antioxidant prepared in Example 3, and the rest are the same.

[0018] Performance testing: The oxidation-resistant and antistatic PA plastics prepared in Examples 1-3 and Comparative Examples 1-2 were cut into standard test sizes and tested for surface resistivity according to GB / T 1410-2006; oxidation induction time according to GB / T 19466.6-2009; antibacterial testing according to QB / T 2591-2003; and tensile strength according to GB / T 1040-2018. The test results are shown in Table 1 below: Table 1

[0019] It can be seen from the test data in Table 1 that the oxidation-resistant and antistatic PA plastic prepared by the present invention has a good antioxidant effect. It can also be seen from Table 1 that the oxidation-resistant and antistatic PA plastic prepared by the present invention has good antistatic and antibacterial effects, and extends the service life.

[0020] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing oxidation-resistant and antistatic PA plastic, characterized in that: The specific steps include: S1. Weigh the raw materials by weight: 70-90 parts of PA resin, 25-35 parts of glass fiber, 1-5 parts of modified antistatic agent, 1-5 parts of modified antioxidant, 1-3 parts of compatibilizer, 5-10 parts of toughening agent, and 1-3 parts of lubricant; uniformly mix the PA resin, glass fiber, modified antistatic agent, modified antioxidant, compatibilizer, toughening agent, and lubricant to obtain a mixed material; S2, adding the mixed material into a twin-screw extruder, melting and extruding at an extrusion temperature of 220-260°C, granulating, and drying to obtain an oxidation-resistant and antistatic PA plastic; The modified antistatic agent is prepared by the following method: Step A1: Mix anhydrous ethanol and 2,4,6-tris(dimethylaminomethyl)phenol, stir in a water bath for 5 minutes, react at 25°C for 30 minutes, then heat to 45°C, adjust the pH to 7.5-8, slowly add 1-chlorohexane and methanol, react at 45°C for 8-12 hours, and evaporate under reduced pressure to obtain the compound; Step A2: Acryloyl chloride and N,N-dimethylformamide were mixed evenly, reacted at 60°C for 3 hours, and then the compound and triethylamine were added, and the reaction was continued at 60°C for 3 hours. After the reaction, the mixture was filtered, washed, and vacuum dried for 12 hours to obtain a pre-product; Step A3: The pre-product, glycidyl methacrylate and acetonitrile were mixed evenly, stirred for 10 minutes, and azobisisobutyronitrile was added under nitrogen protection. The mixture was stirred for 30 minutes and reacted at 70°C for 3 hours. After the reaction was completed, the mixture was rotary evaporated and vacuum dried at 50°C for 12 hours to obtain a modified antistatic agent.

2. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 1, characterized in that: In step A1, the usage ratio of anhydrous ethanol, 2,4,6-tris(dimethylaminomethyl)phenol, 1-chlorohexane, and methanol is 50 mL: 0.01-0.03 mol: 0.03-0.09 mol: 2 mL.

3. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 1, characterized in that: In step A2, the usage ratio of acryloyl chloride, N,N-dimethylformamide, compound, and triethylamine is 0.01-0.03 mol: 13-15 mL: 0.01-0.03 mol: 2-6 mL.

4. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 1, characterized in that: In step A3, the usage ratio of the pre-product, glycidyl methacrylate, acetonitrile, and azobisisobutyronitrile is 0.01-0.03 mol: 0.01-0.03 mol: 2 mL: 0.25-0.35 g.

5. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 1, characterized in that: The modified antioxidant is prepared by the following method: Step B1: Add maleic anhydride to a four-necked flask equipped with a thermometer, a condenser, and a mechanical stirrer, and heat it to gradually liquefy it. After the reaction temperature reaches 90°C, add 6-amino-1,3-dimethyluracil and tetrahydrofuran, mix well, and continue the reaction under mechanical stirring for 5 hours. After the reaction is completed, rotary evaporate and dry to obtain an intermediate; Step B2: uniformly mix oxybenzone, the intermediate and N,N-dimethylformamide, and stir the mixture at 80-100° C. for 3 h under nitrogen protection. After the reaction is completed, cool the mixture to room temperature, wash, filter, and dry to obtain a modified antioxidant.

6. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 5, characterized in that: In step B1, the usage ratio of maleic anhydride, 6-amino-1,3-dimethyluracil, and tetrahydrofuran is 0.01-0.03 mol: 0.01-0.03 mol: 40-60 mL.

7. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 5, characterized in that: In step B2, the usage ratio of oxybenzone, intermediate, and N,N-dimethylformamide is 0.01-0.03 mol: 0.01-0.03 mol: 10-20 mL.

8. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 1, characterized in that: The compatibilizer is EVA-g-MAH, the toughening agent is maleic anhydride grafted POE, and the lubricant is paraffin.

9. An oxidation-resistant and antistatic PA plastic, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 8.

Images