Oxidation-resistant antistatic PA plastic and preparation method thereof

Abstract

The application 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: PA resin 70-90 parts, glass fiber 25-35 parts, modified antistatic agent 1-5 parts, modified antioxidant 1-5 parts, compatible agent 1-3 parts, toughening agent 5-10 parts and lubricant 1-3 parts. The cation of a quaternary ammonium salt compound in the modified antistatic agent is neutralized with the negative charge on the surface of the material, also serves as a conductive medium, and simultaneously adsorbs negative bacteria. The epoxy group of glycidyl methacrylate reacts with the hydroxyl group of PA, so as to improve the toughness of the material. The nitrogen atom in the modified antioxidant captures free radicals through a lone pair of electrons, terminates chain reactions, the carbonyl group in hydroxybenzophenone forms a hydrogen bond with a benzene ring, and absorbs ultraviolet rays. The oxidation-resistant antistatic PA plastic prepared by the application not only has good antistatic effect, but also has excellent antioxidant and antibacterial effects.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to an oxidation-resistant and antistatic PA plastic and its preparation method. Background Technology

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

[0003] However, PA plastics are prone to accumulating static electricity during use, which is difficult to eliminate. This not only attracts dust from the air, affecting the appearance, but may also damage sensitive components of electronic devices during the plastic manufacturing process. In addition, the accumulation of static electricity may cause electric shock, equipment malfunction, and even fire hazards. Furthermore, high temperatures accelerate the oxidation reaction of PA plastics, causing the material to yellow and become brittle. At the same time, 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 oxidation-resistant and antistatic PA plastics with excellent properties has significant practical significance and application value. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an oxidation-resistant and antistatic PA plastic and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An oxidation-resistant and antistatic PA plastic and its preparation method, comprising the following raw materials in parts by weight: 70-90 parts PA resin, 25-35 parts glass fiber, 1-5 parts modified antistatic agent, 1-5 parts modified antioxidant, 1-3 parts compatibilizer, 5-10 parts toughening agent, and 1-3 parts lubricant.

[0007] The compatibilizer is EVA-g-MAH;

[0008] The toughening agent is maleic anhydride-grafted POE;

[0009] The lubricant mentioned is paraffin wax.

[0010] The modified antistatic agent is prepared by the following method:

[0011] Step A1: Mix anhydrous ethanol and 2,4,6-tris(dimethylaminomethyl)phenol evenly, stir in a water bath for 5 min, react at 25℃ for 30 min, then raise the temperature to 45℃, adjust the pH to 7.5-8, then slowly add 1-chlorohexane and methanol, react at 45℃ for 8-12 h, and evaporate under reduced pressure to obtain compound a.

[0012] Furthermore, the 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;

[0013] Compound a was prepared by reacting the amino group of 2,4,6-tris(dimethylaminomethyl)phenol with the chlorine atom of 1-chlorohexane.

[0014] Step A2: Acryloyl chloride and N,N-dimethylformamide are mixed evenly and reacted at 60°C for 3 hours. Then, compound a and triethylamine are added and the reaction is continued at 60°C for 3 hours. After the reaction is completed, the mixture is filtered, washed, and vacuum dried for 12 hours to obtain the preproduct.

[0015] Furthermore, the ratio of acryloyl chloride, N,N-dimethylformamide, compound a, and triethylamine is 0.01-0.03 mol: 13-15 mL: 0.01-0.03 mol: 2-6 mL;

[0016] Secondly, the preproduct was prepared by reacting the chlorine atom of acryloyl chloride with the phenolic hydroxyl group of compound a.

[0017] Step A3: Mix the preproduct, glycidyl methacrylate and acetonitrile evenly, stir for 10 min, add azobisisobutyronitrile under nitrogen protection, continue stirring for 30 min, react at 70℃ for 3 h, after the reaction is completed, rotary evaporate, vacuum dry at 50℃ for 12 h to obtain the modified antistatic agent.

[0018] Furthermore, the ratio of the preproduct, glycidyl methacrylate, acetonitrile, and azobisisobutyronitrile is 0.01-0.03 mol: 0.01-0.03 mol: 2 mL: 0.25-0.35 g;

[0019] Finally, a modified antistatic agent was prepared by copolymerizing the preproduct with the carbon-carbon double bond of glycidyl methacrylate.

[0020] The modified antioxidant is prepared by the following method:

[0021] Step B1: Add maleic anhydride to a four-necked flask equipped with a thermometer, condenser and mechanical stirrer, and heat it to gradually liquefy it. When the reaction temperature reaches 90°C, add 6-amino-1,3-dimethyluridine and tetrahydrofuran and mix well. Continue to react under mechanical stirring for 5 hours. After the reaction is completed, evaporate by rotary evaporation and dry to obtain the intermediate.

[0022] Furthermore, the 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;

[0023] The intermediate was prepared by reacting the amino group of 6-amino-1,3-dimethyluracil with maleic anhydride.

[0024] Step B2: Mix hydroxybenzophenone, intermediate and N,N-dimethylformamide evenly, stir and react at 80-100℃ for 3h under nitrogen protection. After the reaction is completed, cool to room temperature, wash, filter and dry to obtain modified antioxidant.

[0025] Furthermore, the ratio of hydroxybenzophenone, the intermediate, and N,N-dimethylformamide is 0.01-0.03 mol: 0.01-0.03 mol: 10-20 mL;

[0026] Finally, the modified antioxidant was prepared by reacting the carboxyl group of the intermediate with the hydroxyl group of hydroxybenzophenone.

[0027] A method for preparing an oxidation-resistant and antistatic PA plastic specifically includes the following steps:

[0028] S1. PA resin, glass fiber, modified antistatic agent, modified antioxidant, compatibilizer, toughening agent and lubricant are mixed evenly to obtain a mixture.

[0029] S2. Add the mixture to a twin-screw extruder, melt extrude at an extrusion temperature of 220-260℃, granulate, and dry to obtain oxidation-resistant and antistatic PA plastic.

[0030] The beneficial effects of this invention are:

[0031] The oxidation-resistant and antistatic PA plastic of the present invention has good antistatic effect, and at the same time, it also has excellent anti-oxidation and antibacterial effects, further extending its service life.

[0032] The modified antistatic agent prepared by this invention exhibits superior antistatic performance compared to traditional small-molecule antistatic agents due to the advantages of its macromolecular polymer. The cationic groups of the quaternary ammonium salt compound in this modified antistatic agent can neutralize the negative charge on the surface of PA materials, reducing static electricity accumulation. It also enhances the hydrophilicity of the material, promoting moisture absorption. The ions in the water film formed after moisture absorption act as a conductive medium, accelerating charge transfer and dissipation, thus preventing static electricity from negatively impacting production and product quality. Simultaneously, the cationic groups of the quaternary ammonium salt compound can adsorb negatively charged bacteria, penetrating bacterial cell walls and reacting with proteins on the bacterial cell membrane, disrupting the cell membrane structure, causing protein leakage, and accelerating bacterial death, thereby improving the antibacterial effect. Furthermore, the epoxy groups in the polymerized glycidyl methacrylate can react with the hydroxyl groups in PA, enhancing intermolecular forces, improving material toughness, and forming a conductive network, further reducing surface resistivity. This synergistic effect with the quaternary ammonium salt enhances the conductivity of ions on the material surface, reducing static electricity accumulation.

[0033] In the modified antioxidant prepared by this invention, the nitrogen atom in 6-amino-1,3-dimethyluracil captures alkyl and peroxy radicals generated by the thermal degradation of PA materials through lone pair electrons, terminating the chain reaction, delaying the thermo-oxidative aging process, and effectively improving the thermal stability and aging resistance of the material. In addition, the carbonyl group in hydroxybenzophenone forms an intramolecular hydrogen bond with the benzene ring, efficiently absorbing ultraviolet light, and releasing the excited state electrons in a weak long-wavelength form after transitioning to a higher energy level through molecular vibration, reducing material aging caused by ultraviolet light. Furthermore, the amide group in this modified antioxidant enhances the bonding between PA molecular chains by forming hydrogen bonds and intermolecular forces, improving the crystallinity of the material, inhibiting chain segment movement at high temperatures, reducing material aging caused by high temperatures, and extending service life. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1: A method for preparing an oxidation-resistant and antistatic PA plastic, specifically including the following steps:

[0036] S1. Weigh the raw materials according to the following parts by weight: 70 parts PA resin, 25 parts glass fiber, 1 part modified antistatic agent (prepared in this embodiment), 1 part modified antioxidant (prepared in this embodiment), 1 part compatibilizer, 5 parts toughening agent, and 1 part lubricant; mix the PA resin, glass fiber, modified antistatic agent, modified antioxidant, EVA-g-MAH, maleic anhydride grafted POE, and paraffin wax evenly to obtain a mixture.

[0037] S2. Add the mixture to a twin-screw extruder, melt extrude at an extrusion temperature of 220℃, granulate, and dry to obtain oxidation-resistant and antistatic PA plastic;

[0038] The modified antistatic agent is prepared by the following method:

[0039] Step A1: Mix 50 mL of anhydrous ethanol and 0.01 mol of 2,4,6-tris(dimethylaminomethyl)phenol evenly, stir in a water bath for 5 min, react at 25 °C for 30 min, then raise the temperature to 45 °C, adjust the pH to 7.5, then 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 compound a;

[0040] Step A2: Mix 0.01 mol acryloyl chloride and 13 mL N,N-dimethylformamide evenly, react at 60 °C for 3 h, then add 0.01 mol compound a and 2 mL triethylamine, and continue to react at 60 °C for 3 h. After the reaction is completed, filter, wash, and vacuum dry for 12 h to obtain the preproduct.

[0041] Step A3: Mix 0.01 mol of preproduct, 0.01 mol of glycidyl methacrylate and 2 mL of acetonitrile evenly, stir for 10 min, add 0.25 g of azobisisobutyronitrile under nitrogen protection, continue stirring for 30 min, react at 70 °C for 3 h, after the reaction is completed, rotary evaporate, vacuum dry at 50 °C for 12 h to obtain the modified antistatic agent.

[0042] The modified antioxidant is prepared by the following method:

[0043] Step B1: Add 0.01 mol of maleic anhydride to a four-necked flask equipped with a thermometer, condenser and mechanical stirrer, and heat it to gradually liquefy it. When the reaction temperature reaches 90℃, add 0.01 mol of 6-amino-1,3-dimethyluracil and 40 mL of tetrahydrofuran and mix well. Continue to react under mechanical stirring for 5 h. After the reaction is completed, evaporate by rotary evaporation and dry to obtain the intermediate.

[0044] Step B2: Mix 0.01 mol hydroxybenzophenone, 0.01 mol intermediate and 10 mL N,N-dimethylformamide evenly, stir and react at 80 °C for 3 h under nitrogen protection. After the reaction is completed, cool to room temperature, wash, filter and dry to obtain modified antioxidant.

[0045] Example 2: A method for preparing an oxidation-resistant and antistatic PA plastic, specifically including the following steps:

[0046] S1. Weigh the raw materials according to the following parts by weight: 80 parts PA resin, 30 parts glass fiber, 3 parts modified antistatic agent (prepared in this embodiment), 3 parts modified antioxidant (prepared in this embodiment), 2 parts compatibilizer, 7.5 parts toughening agent, and 2 parts lubricant; mix the PA resin, glass fiber, modified antistatic agent, modified antioxidant, EVA-g-MAH, maleic anhydride grafted POE, and paraffin wax evenly to obtain a mixture.

[0047] S2. Add the mixture to a twin-screw extruder, melt extrude at an extrusion temperature of 240℃, granulate, and dry to obtain oxidation-resistant and antistatic PA plastic.

[0048] The modified antistatic agent is prepared by the following method:

[0049] Step A1: Mix 50 mL of anhydrous ethanol and 0.02 mol of 2,4,6-tris(dimethylaminomethyl)phenol evenly, stir in a water bath for 5 min, react at 25 °C for 30 min, then raise the temperature to 45 °C, adjust the pH to 7.7, then 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 compound a;

[0050] Step A2: Mix 0.02 mol acryloyl chloride and 14 mL N,N-dimethylformamide evenly, react at 60 °C for 3 h, then add 0.02 mol compound a and 4 mL triethylamine, and continue to react at 60 °C for 3 h. After the reaction is completed, filter, wash, and vacuum dry for 12 h to obtain the preproduct.

[0051] Step A3: Mix 0.02 mol of preproduct, 0.02 mol of glycidyl methacrylate and 2 mL of acetonitrile evenly, stir for 10 min, add 0.3 g of azobisisobutyronitrile under nitrogen protection, continue stirring for 30 min, react at 70 °C for 3 h, after the reaction is completed, rotary evaporate, vacuum dry at 50 °C for 12 h to obtain the modified antistatic agent.

[0052] The modified antioxidant is prepared by the following method:

[0053] Step B1: Add 0.02 mol of maleic anhydride to a four-necked flask equipped with a thermometer, condenser and mechanical stirrer, and heat it to gradually liquefy it. When the reaction temperature reaches 90℃, add 0.02 mol of 6-amino-1,3-dimethyluracil and 50 mL of tetrahydrofuran and mix well. Continue to react under mechanical stirring for 5 h. After the reaction is completed, evaporate by rotary evaporation and dry to obtain the intermediate.

[0054] Step B2: Mix 0.02 mol hydroxybenzophenone, 0.02 mol intermediate and 15 mL N,N-dimethylformamide evenly, stir and react at 90 °C for 3 h under nitrogen protection. After the reaction is completed, cool to room temperature, wash, filter and dry to obtain modified antioxidant.

[0055] Example 3: A method for preparing an oxidation-resistant and antistatic PA plastic, specifically including the following steps:

[0056] S1. Weigh the raw materials according to the following parts by weight: 90 parts PA resin, 35 parts glass fiber, 5 parts modified antistatic agent (prepared in this embodiment), 5 parts modified antioxidant (prepared in this embodiment), 3 parts compatibilizer, 10 parts toughening agent, and 3 parts lubricant; mix the PA resin, glass fiber, modified antistatic agent, modified antioxidant, EVA-g-MAH, maleic anhydride grafted POE, and paraffin wax evenly to obtain a mixture.

[0057] S2. Add the mixture to a twin-screw extruder, melt extrude at an extrusion temperature of 260℃, granulate, and dry to obtain oxidation-resistant and antistatic PA plastic.

[0058] The modified antistatic agent is prepared by the following method:

[0059] Step A1: Mix 50 mL of anhydrous ethanol and 0.03 mol of 2,4,6-tris(dimethylaminomethyl)phenol evenly, stir in a water bath for 5 min, react at 25 °C for 30 min, then raise the temperature to 45 °C, adjust the pH to 8, and 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 compound a;

[0060] Step A2: Mix 0.03 mol acryloyl chloride and 15 mL N,N-dimethylformamide evenly, react at 60 °C for 3 h, then add 0.03 mol compound a and 6 mL triethylamine, and continue to react at 60 °C for 3 h. After the reaction is completed, filter, wash, and vacuum dry for 12 h to obtain the preproduct.

[0061] Step A3: Mix 0.03 mol of preproduct, 0.03 mol of glycidyl methacrylate and 2 mL of acetonitrile evenly, stir for 10 min, add 0.35 g of azobisisobutyronitrile under nitrogen protection, continue stirring for 30 min, react at 70 °C for 3 h, after the reaction is completed, rotary evaporate, vacuum dry at 50 °C for 12 h to obtain the modified antistatic agent;

[0062] The modified antioxidant is prepared by the following method:

[0063] Step B1: Add 0.03 mol of maleic anhydride to a four-necked flask equipped with a thermometer, condenser and mechanical stirrer, and heat it to gradually liquefy it. When the reaction temperature reaches 90℃, add 0.03 mol of 6-amino-1,3-dimethyluracil and 60 mL of tetrahydrofuran and mix well. Continue to react under mechanical stirring for 5 h. After the reaction is completed, evaporate by rotary evaporation and dry to obtain the intermediate.

[0064] Step B2: Mix 0.03 mol hydroxybenzophenone, 0.03 mol intermediate and 20 mL N,N-dimethylformamide evenly, stir and react at 100 °C for 3 h under nitrogen protection. After the reaction is completed, cool to room temperature, wash, filter and dry to obtain the modified antioxidant.

[0065] Comparative Example 1: This comparative example is an oxidation-resistant and antistatic PA plastic. The difference between this example and Example 3 is that an equal amount of carbon black is used instead of the modified antistatic agent prepared in Example 3. All other aspects are the same.

[0066] Comparative Example 2: This comparative example is an oxidation-resistant and antistatic PA plastic. The difference between this example and Example 3 is that an equal amount of antioxidant 1010 is used instead of the modified antioxidant prepared in Example 3. All other aspects are the same.

[0067] Performance testing: The oxidation-resistant and antistatic PA plastics obtained in Examples 1-3 and Comparative Examples 1-2 were cut into standard test sizes. Surface resistivity was tested according to GB / T 1410-2006; oxidation induction time was tested according to GB / T 19466.6-2009; antibacterial properties were tested according to QB / T 2591-2003; and tensile strength was tested according to GB / T 1040-2018. The test results are shown in Table 1 below.

[0068] Table 1

[0069]

[0070] As can be seen from the test data in Table 1, the oxidation-resistant and antistatic PA plastic prepared by the present invention has a good anti-oxidation effect. Table 1 also shows that the oxidation-resistant and antistatic PA plastic prepared by the present invention has a good antistatic and antibacterial effect, extending its service life.

[0071] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A process for the preparation of an oxidation resistant antistatic PA plastic, characterized in that, Specifically comprising the following steps: S1, the raw materials are weighed according to the weight parts, PA resin 70-90 parts, glass fiber 25-35 parts, modified antistatic agent 1-5 parts, modified antioxidant 1-5 parts, compatible agent 1-3 parts, toughening agent 5-10 parts, lubricant 1-3 parts; the PA resin, glass fiber, modified antistatic agent, modified antioxidant, compatible agent, toughening agent and lubricant are mixed uniformly to prepare a mixture; S2, the mixture is added into a double screw extruder, melted and extruded, the extrusion temperature is 220-260 DEG C, granulated and dried to prepare the oxidation-resistant antistatic PA plastic; The modified antistatic agent is prepared by the following method: Step A1: anhydrous ethanol and 2, 4, 6-tri (dimethylaminomethyl) phenol are mixed uniformly, stirred in a water bath for 5 min, reacted at 25 DEG C for 30 min, then heated to 45 DEG C, the pH is adjusted to 7.5-8, then 1-chlorohexane and methanol are slowly added, reacted at 45 DEG C for 8-12 h, rotary evaporation under reduced pressure to prepare compound a; Step A2: acryloyl chloride and N, N-dimethylformamide are mixed uniformly, reacted at 60 DEG C for 3 h, then compound a and triethylamine are added, reacted at 60 DEG C for another 3 h, after the reaction, filtered, washed and vacuum dried for 12 h to prepare a pre-product; Step A3: the pre-product, glycidyl methacrylate and acetonitrile are mixed uniformly, stirred for 10 min, then azobisisobutyronitrile is added under nitrogen protection, continues to stir for 30 min, reacted at 70 DEG C for 3 h, after the reaction, rotary evaporation, vacuum dried at 50 DEG C for 12 h to prepare the modified antistatic agent; The modified antioxidant is prepared by the following method: Step B1: maleic anhydride is added into a four-necked flask equipped with a thermometer, a condenser and a mechanical stirring device, heated to gradually liquefy, when the reaction temperature is increased to 90 DEG C, 6-amino-1, 3-dimethyluracil and tetrahydrofuran are mixed uniformly, continuously reacted for 5 h under mechanical stirring, after the reaction, rotary evaporation, drying to prepare an intermediate; Step B2: hydroxybenzophenone, the intermediate and N, N-dimethylformamide are mixed uniformly, stirred and reacted at 80-100 DEG C for 3 h under nitrogen protection, after the reaction, cooled to room temperature, washed, filtered and dried to prepare the modified antioxidant.

2. The method of claim 1, wherein the oxidation-resistant antistatic PA plastic is prepared by adding the antioxidant and the antistatic agent to a polyamide (PA) resin, and then melt-kneading the mixture. The amount ratio of anhydrous ethanol, 2, 4, 6-tri (dimethylaminomethyl) phenol, 1-chlorohexane and methanol in step A1 is 50 mL: 0.01-0.03 mol: 0.03-0.09 mol: 2 mL.

3. The method of claim 1, wherein the oxidation-resistant antistatic PA plastic is prepared by adding the antioxidant and the antistatic agent to a polyamide (PA) resin, and then melt-kneading the mixture. The amount ratio of acryloyl chloride, N, N-dimethylformamide, compound a and triethylamine in step A2 is 0.01-0.03 mol: 13-15 mL: 0.01-0.03 mol: 2-6 mL.

4. The method of claim 1, wherein the oxidation-resistant antistatic PA plastic is prepared by adding 0.1 to 0.5 parts by weight of the antioxidant and 0.1 to 0.5 parts by weight of the antistatic agent to 100 parts by weight of the PA resin. The amount ratio of the pre-product, glycidyl methacrylate, acetonitrile and azobisisobutyronitrile in step A3 is 0.01-0.03 mol: 0.01-0.03 mol: 2 mL: 0.25-0.35 g.

5. The method of claim 1, wherein the oxidation-resistant antistatic PA plastic is prepared by adding 0.1 to 0.5 parts by weight of the antioxidant and 0.1 to 0.5 parts by weight of the antistatic agent to 100 parts by weight of the PA resin. The ratio of maleic anhydride, 6-amino-1, 3-dimethyluracil, tetrahydrofuran in step B1 is 0.01-0.03mol: 0.01-0.03mol: 40-60mL.

6. The method for preparing an oxidation-resistant and antistatic PA plastic according to claim 1, characterized in that, The ratio of hydroxybenzophenone, intermediate, N, N-dimethylformamide in step B2 is 0.01-0.03mol: 0.01-0.03mol: 10-20mL.

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

8. An oxidation resistant, antistatic PA plastic, characterized in that Prepared according to the preparation method of any one of claims 1-7. Prepared according to the preparation method of any one of claims 1-7.

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