Ionomer enhanced PA composite material and preparation method thereof

Abstract

The invention discloses an ionomer enhanced PA composite material and a preparation method thereof in the field of polyamide materials. The ionomer enhanced PA composite material comprises the following components in parts by weight: 70-80 parts of PA6, 20-30 parts of an ethylene-octylene copolymer, 1-3 parts of an enhancer, 0.02-0.05 part of an initiator and 0.05-0.1 part of an antioxidant. An ionomer reinforcing agent, ionic bonds and hydrogen bonds are added in a PA6 and POE system, so that the reinforcing agent and PA6 form a'synergistic stress network ', local stress concentration is reduced, strength is improved, 'strength-toughness-rigidity' synergistic improvement is achieved, an ionomer structure of the reinforcing agent is compatible with polar PA6 and a non-polar ethylene-octene copolymer at the same time, and the strength of the POE is improved. The phase separation defect is eliminated, and the material performance stability is high.

Description

Technical Field

[0001] This invention belongs to the field of polyamide material technology, specifically referring to an ionomer-reinforced PA composite material and its preparation method. Background Technology

[0002] Polyamide (PA, commonly known as nylon), as an important class of engineering plastics, is widely used in automotive manufacturing, electronics, and mechanical engineering due to its excellent mechanical properties, chemical resistance, wear resistance, and ease of processing. Among them, PA6 (polycaprolactam) has become one of the most widely used varieties in the PA family due to its low melting point (about 220°C), good flowability, and moderate cost. It is often used to manufacture key structural components such as automotive engine parts, electronic connectors, and gears. However, pure PA6 has significant performance defects: First, it lacks toughness, especially with low notched impact strength at low temperatures, making it prone to brittle fracture; second, it is difficult to balance rigidity and toughness. Simply increasing rigidity by filling with inorganic fillers (such as glass fiber) will lead to a sharp decrease in toughness, limiting its application in high-impact scenarios; third, it has poor compatibility with non-polar polymers (such as polyolefin elastomers). When elastomers are introduced for toughening modification, phase separation easily occurs due to weak interfacial bonding, resulting in a significant reduction in mechanical properties such as tensile strength and flexural strength. Various PA6 modification technologies have been developed in the industry, among which "elastomer toughening + compatibilizer regulation" is the most commonly used approach. Specifically, by adding non-polar elastomers such as ethylene-octene copolymer (POE) and ethylene-propylene-diene terpolymer (EPDM), the high elasticity of the elastomer absorbs impact energy, thereby improving the toughness of PA6. Simultaneously, maleic anhydride-grafted elastomers (such as POE-g-MAH) are introduced as compatibilizers. The anhydride groups of maleic anhydride covalently react with the terminal amine groups (-NH2) of PA6, improving the interfacial compatibility between PA6 and the elastomer. However, this approach still has significant limitations: firstly, the interfacial interaction strength of the maleic anhydride-grafted compatibilizer is limited. While covalent bonds improve compatibility, they lack dynamic reversibility. When materials are subjected to repeated stress or high temperatures, the interface is prone to fracture, leading to performance degradation. On the other hand, compatibilizers themselves do not have a reinforcing effect; they can only maintain basic interfacial bonding and cannot simultaneously improve the material's rigidity (such as flexural modulus). Therefore, additional rigid fillers (such as calcium carbonate and talc) are needed, but this further sacrifices toughness, creating a "rigidity-toughness" contradiction. Ionomers, due to their unique "ionic bond reinforcement" mechanism, have shown great potential in the modification of polymer composites. Ionomers are a class of polymers containing a small number of ionic groups (such as carboxylates and sulfonates). Their molecular chains can form "ionic clusters" through the electrostatic interaction of ionic groups. This physical cross-linking structure combines reversibility and high strength, improving both the rigidity and heat resistance of materials, and absorbing energy through the dynamic dissociation and recombination of ionic clusters, thus improving toughness. Meanwhile, the polar ionic groups of the ionomer can interact strongly with the amide groups (-CONH-) of PA6 through ionic bonds and hydrogen bonds, while the nonpolar backbone can form van der Waals forces with the hydrocarbon chain of the elastomer, thereby simultaneously improving the compatibility with PA6 and the elastomer.

[0003] However, the application of existing ionomers in PA composites still faces the following problems:

[0004] Unreasonable structural design: Most ionomers rely on imports (such as DuPont Surlyn series), and their ionic group density and main chain structure are not well matched with PA6 and elastomers, resulting in limited interfacial strength and failure to achieve the expected reinforcement and toughening effect.

[0005] The preparation process is complex: existing ionomers are mostly prepared by copolymerizing olefins with polar monomers and then neutralizing them. The reaction conditions are harsh (such as high-pressure polymerization), and the grafted polar groups are unevenly distributed, which affects the stability of performance.

[0006] Poor processing synergy: The melting temperature difference between the ionomer and PA6 and the elastomer is large. During twin-screw extrusion blending, it is easy to form agglomerates due to uneven dispersion, which leads to a decrease in the mechanical properties of the material.

[0007] Limited functionality: Existing ionomers are only used as compatibilizers or toughening agents, failing to fully utilize the reinforcing effect of their ion clusters and thus unable to achieve the synergistic effect of "toughening-reinforcing-compatibility". Summary of the Invention

[0008] To address the above issues and overcome the shortcomings of existing technologies, this invention provides an ionomer-reinforced PA composite material and its preparation method. By adding an ionomer reinforcing agent to the PA6 and POE system, ionic and hydrogen bonds enable the reinforcing agent and PA6 to form a "synergistic stress network," reducing local stress concentration and thus improving strength. This achieves a synergistic improvement in strength, toughness, and rigidity. The ionomer structure of the reinforcing agent simultaneously has affinity for both polar PA6 and non-polar ethylene-octene copolymers, eliminating phase separation defects and resulting in high material performance stability.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention proposes an ionomer-reinforced PA composite material, wherein the reinforced PA composite material comprises the following components in parts by weight: 70-80 parts of PA6, 20-30 parts of ethylene-octene copolymer, 1-3 parts of reinforcing agent, 0.02-0.05 parts of initiator, and 0.05-0.1 parts of antioxidant;

[0010] Preferably, the initiator includes at least one of dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP), tert-butyl peroxide (TBPB), and bis-tert-butyl peroxide (BIPB);

[0011] Preferably, the antioxidant includes at least one of Irganox 1010, Irganox 1076, Irganox 1098, Irganox 1035, and Irganox 245;

[0012] Preferably, the method for preparing the reinforcing agent specifically includes the following steps:

[0013] A1. Pass flowing argon gas into the flask, add 2-methylene-1,3-propanediol, dissolve it in anhydrous dichloromethane, add initiator and accelerator to the reaction system, mix well to obtain reaction solution 1;

[0014] Preferably, in step A1, the mass concentration of 2-methylene-1,3-propanediol in anhydrous dichloromethane is 10-20 mg / mL;

[0015] Preferably, in step A1, the mass ratio of the initiator to 2-methylene-1,3-propanediol is 0.35-0.43:1; the initiator includes at least one of 1,8-diazabicyclo[5.4.0]undecene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,1,3,3-tetramethylguanidine (TMG), and triethylenediamine (DABCO);

[0016] Preferably, in step A1, the mass ratio of the activator to 2-methylene-1,3-propanediol is 4.3-6.5:1; the activator includes at least one of N-phenylthiourea, N,N'-diphenylthiourea, and 1-methyl-3-phenylthiourea.

[0017] A2. Dissolve 4-chloro-1,3-dioxapentane-2-one in anhydrous dichloromethane and add it dropwise to the reaction solution 1 prepared in step A1 under an argon atmosphere. Maintain the reaction temperature to carry out the polymerization reaction. After the reaction is completed, add benzoic acid to terminate the reaction, add n-hexane for precipitation treatment, filter, collect the precipitate, purify, and vacuum dry to obtain the polymer.

[0018] Preferably, the mass ratio between 4-chloro-1,3-dioxolane-2-one and 2-methylene-1,3-propanediol is 3.5-7:0.1-0.2;

[0019] Preferably, in step A2, the polymerization reaction temperature is 30-40°C, and the polymerization reaction time is 3-4 hours.

[0020] A3. Dissolve the polymer prepared in step A2 in anhydrous DMF, introduce flowing nitrogen gas, add methyl mercaptoacetate and mix well, then add anhydrous sodium carbonate to form a homogeneous reaction system. Maintain the reaction temperature to carry out the substitution reaction. After the reaction is completed, add deionized water for precipitation treatment, collect the precipitate, dissolve it in DMF, transfer it to a dialysis bag, dialyze it with deionized water, and freeze-dry it to obtain the reinforcing agent.

[0021] Preferably, in step A3, the mass ratio of methyl mercaptoacetate to 4-chloro-1,3-dioxopentane-2-one is 1.28-1.73:1;

[0022] Preferably, in step A3, the mass ratio of methyl mercaptoacetate to anhydrous sodium carbonate is 0.5-1:1;

[0023] Preferably, in step A3, the reaction temperature of the substitution reaction is 30-40°C, and the reaction time of the substitution reaction is 20-30 h;

[0024] This invention also provides a method for preparing an ionomer-reinforced PA composite material, specifically comprising the following steps:

[0025] S1. After uniformly mixing ethylene-octene copolymer, initiator, and reinforcing agent, the mixture is transferred to a twin-screw extruder for melt reaction. The extruded sample is then water-cooled and granulated to obtain reinforced particles.

[0026] Preferably, in step S1, the screw speed for the melting reaction is 80-100 r / min, and the melting reaction temperature is 180-190℃;

[0027] S2. After vacuum drying, PA6 is transferred to a twin-screw extruder along with the reinforcing particles prepared in step S1 for a melt reaction. After the reaction is complete, the extruded sample is water-cooled and granulated to obtain the PA composite material.

[0028] Preferably, in step S2, the screw speed for the melting reaction is 180-220 r / min, and the temperature for the melting reaction is 240-260℃.

[0029] The beneficial effects achieved by this invention are as follows:

[0030] This invention provides an ionomer-reinforced PA composite material and its preparation method. By adding an ionomer reinforcing agent to the PA6 and POE system, ionic and hydrogen bonds create a "synergistic stress network" between the reinforcing agent and PA6, reducing local stress concentration and thus improving strength. This achieves a synergistic improvement in strength, toughness, and rigidity. The ionomer structure of the reinforcing agent simultaneously has affinity for both polar PA6 and non-polar ethylene-octene copolymers, eliminating phase separation defects and resulting in high material stability. In this invention, the PA6 molecular chain contains amide groups (-CONH-). The -COO⁻Na⁺ group of the reinforcing agent can interact strongly with the amide groups through ionic and hydrogen bonds, significantly improving the interfacial bonding force between the two phases and reducing interfacial delamination under stress. The non-polar segment of the reinforcing agent main chain generates van der Waals forces with the hydrocarbon chain of the ethylene-octene copolymer (a non-polar elastomer), while the ionic groups are stably dispersed through a "clustering effect," preventing reinforcing agent agglomeration. When the ethylene-octene copolymer, reinforcing agent, and initiator melt-react in a twin-screw extruder, the DCP decomposes to generate free radicals, which initiate the formation of free radicals in the ethylene-octene copolymer molecular chains. These free radicals then undergo a grafting reaction with the active sites of the reinforcing agent backbone, anchoring the reinforcing agent to the elastomer molecular chains through chemical bonding. This prevents the reinforcing agent from migrating or agglomerating during subsequent processing, achieving nanoscale uniform dispersion. The elastomer combines with the reinforcing agent through grafted chains, forming an "elastomer-reinforcing agent" composite toughening phase, providing a bridge for stress transfer during subsequent blending with PA6. After grafting with the reinforcing agent, the ethylene-octene copolymer forms uniformly dispersed microdomains in PA6. Under impact or tension, these elastomer microdomains absorb energy through deformation, inhibiting crack propagation. Simultaneously, the interfacial bonding of the reinforcing agent prevents the elastomer from delaminating from the matrix, significantly improving toughness. Attached Figure Description

[0031] Figure 1 The tensile properties of the PA composite materials prepared in Examples 1-3 and Comparative Examples 1-3 of this invention are shown in the figure.

[0032] Figure 2 The impact performance results of the PA composite materials prepared in Examples 1-3 and Comparative Examples 1-3 of this invention are shown in the figure.

[0033] Figure 3 The graph shows the bending performance results of the PA composite materials prepared in Examples 1-3 and Comparative Examples 1-3 of this invention.

[0034] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0037] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; unless otherwise specified, the experimental materials and test strains used in the following examples were purchased from commercial channels.

[0038] Example 1

[0039] This embodiment provides an ionomer-reinforced PA composite material, which comprises the following components in parts by weight: 75 parts PA6, 25 parts ethylene-octene copolymer, 1 part reinforcing agent, 0.02 parts DCP, and 0.05 parts Irganox1010;

[0040] The preparation method of the reinforcing agent specifically includes the following steps:

[0041] A1. Pass flowing argon gas into the reaction flask until there is no oxygen in the reaction system. Add 0.15g of 2-methylene-1,3-propanediol to the reaction flask. Add 10mL of anhydrous dichloromethane to completely dissolve the 2-methylene-1,3-propanediol. Then add 65mg of DBU and 0.65g of N-phenylthiourea to the reaction system. After mixing evenly, reaction solution 1 is obtained.

[0042] A2. Accurately weigh 5.2 g of 4-chloro-1,3-dioxapentane-2-one and place it in a flask. Add 90 mL of anhydrous dichloromethane to completely dissolve the 4-chloro-1,3-dioxapentane-2-one. Under an argon atmosphere, add the solution dropwise to the reaction solution 1 prepared in step A1 at a rate of 1 mL / min. Stir at 300 rpm and raise the reaction temperature to 35°C in an oil bath for polymerization. After 3 h, add benzoic acid and stir to terminate the reaction. Add 5 times the volume of 4°C n-hexane to precipitate the product. Filter, collect the precipitate, purify it, and then vacuum dry it at 30°C for 24 h to obtain the polymer.

[0043] A3. Place the polymer prepared in step A2 in a dry flask, add anhydrous DMF, and stir at 300 rpm to completely dissolve the polymer. After purging with flowing nitrogen for 30 min, add 9.0 g of methyl mercaptoacetate and 9.0 g of anhydrous sodium carbonate to the reaction system, and continue stirring for 10 min to form a homogeneous reaction system. Maintain the reaction temperature at 35°C and react for 24 h. After the reaction is completed, let the reaction system cool to room temperature, add 5 times the volume of deionized water for precipitation treatment, filter, collect the precipitate, wash repeatedly with deionized water, and vacuum dry at 30°C for 12 h to obtain the reinforcing agent.

[0044] This invention also provides a method for preparing an ionomer-reinforced PA composite material, specifically comprising the following steps:

[0045] S1. Ethylene-octene copolymer, initiator, and reinforcing agent are mixed evenly according to the weight proportions, and then transferred to a twin-screw extruder for melt reaction. The screw speed is set to 80 r / min, and the temperature of each section of the twin-screw extrusion is 190℃, 190℃, 185℃, 185℃, 180℃, 180℃, and 180℃. After the extruded sample is water-cooled and granulated, reinforced particles are obtained.

[0046] S2. After drying PA6 under vacuum at 100℃ for 6 hours, transfer it and the reinforcing particles prepared in step S1 to a twin-screw extruder for a melt reaction. Set the screw speed to 180 r / min and the temperatures of each section of the twin-screw extrusion to 260℃, 260℃, 255℃, 255℃, 250℃, 245℃, and 240℃. After water cooling and granulation, the extruded sample is used to obtain the PA composite material.

[0047] Example 2

[0048] This embodiment provides an ionomer-reinforced PA composite material, which comprises the following components in parts by weight: 80 parts PA6, 20 parts ethylene-octene copolymer, 3 parts reinforcing agent, 0.05 parts DTBP, and 0.1 parts Irganox 1076;

[0049] The preparation method of the reinforcing agent specifically includes the following steps:

[0050] A1. Pass flowing argon gas into the reaction flask until there is no oxygen in the reaction system. Add 0.20 g of 2-methylene-1,3-propanediol to the reaction flask. Add 10 mL of anhydrous dichloromethane to completely dissolve the 2-methylene-1,3-propanediol. Then add 70 mg of DBN and 1.3 g of N,N'-diphenylthiourea to the reaction system. Mix well to obtain reaction solution 1.

[0051] A2. Accurately weigh 7.0 g of 4-chloro-1,3-dioxapentane-2-one and place it in a flask. Add 120 mL of anhydrous dichloromethane to completely dissolve the 4-chloro-1,3-dioxapentane-2-one. Under an argon atmosphere, add the solution dropwise to the reaction solution 1 prepared in step A1 at a rate of 1 mL / min. Stir at 300 rpm and raise the reaction temperature to 30°C in an oil bath to carry out the polymerization reaction. After the reaction is completed, add benzoic acid and stir to terminate the reaction. Add 5 times the volume of 4°C n-hexane to precipitate the product. Filter, collect the precipitate, purify it, and then vacuum dry it at 30°C for 24 hours to obtain the polymer.

[0052] A3. Place the polymer prepared in step A2 in a dry flask, add anhydrous DMF, and stir at 300 rpm to completely dissolve the polymer. After purging with flowing nitrogen for 30 min, add 9.0 g of methyl mercaptoacetate and 10.0 g of anhydrous sodium carbonate to the reaction system. Continue stirring for 10 min to form a homogeneous reaction system. Maintain the reaction temperature at 30°C and react for 30 h. After the reaction is completed, wait for the reaction system to cool to room temperature, add 5 times the volume of deionized water for precipitation treatment, filter, collect the precipitate, wash repeatedly with deionized water, and vacuum dry at 30°C for 12 h to obtain the reinforcing agent.

[0053] This invention also provides a method for preparing an ionomer-reinforced PA composite material, specifically comprising the following steps:

[0054] S1. The ethylene-octene copolymer, initiator, and reinforcing agent are mixed evenly according to the weight proportions, and then transferred to a twin-screw extruder for melt reaction. The screw speed is set to 90 r / min, and the temperature of each section of the twin-screw extrusion is 190℃, 185℃, 185℃, 185℃, 180℃, 180℃, and 180℃. After the extruded sample is water-cooled and granulated, reinforced particles are obtained.

[0055] S2. After drying PA6 under vacuum at 100℃ for 6 hours, transfer it and the reinforcing particles prepared in step S1 to a twin-screw extruder for a melt reaction. Set the screw speed to 200 r / min and the temperatures of each section of the twin-screw extrusion to 260℃, 255℃, 255℃, 250℃, 245℃, 245℃, and 240℃. After water cooling and granulation, the extruded sample is used to obtain the PA composite material.

[0056] Example 3

[0057] This embodiment provides an ionomer-reinforced PA composite material, which comprises the following components in parts by weight:

[0058] PA6 70 parts, ethylene-octene copolymer 30 parts, reinforcing agent 2 parts, BIPB 0.03 parts, Irganox 1035 0.08 parts;

[0059] The preparation method of the reinforcing agent specifically includes the following steps:

[0060] A1. Pass flowing argon gas into the reaction flask until there is no oxygen in the reaction system. Add 0.10 g of 2-methylene-1,3-propanediol to the reaction flask. Add 10 mL of anhydrous dichloromethane to completely dissolve the 2-methylene-1,3-propanediol. Then add 35 mg of TMG and 0.5 g of 1-methyl-3-phenylthiourea to the reaction system. Mix well to obtain reaction solution 1.

[0061] A2. Accurately weigh 3.5 g of 4-chloro-1,3-dioxapentane-2-one and place it in a flask. Add 60 mL of anhydrous dichloromethane to completely dissolve the 4-chloro-1,3-dioxapentane-2-one. Under an argon atmosphere, add the solution dropwise to the reaction solution 1 prepared in step A1 at a rate of 1 mL / min. Stir at 300 rpm and raise the reaction temperature to 40°C in an oil bath for polymerization. After 3 h, add benzoic acid and stir to terminate the reaction. Add 5 times the volume of 4°C n-hexane to precipitate the product. Filter, collect the precipitate, purify it, and then vacuum dry it at 30°C for 24 h to obtain the polymer.

[0062] A3. Place the polymer prepared in step A2 in a dry flask, add anhydrous DMF, and stir at 300 rpm to completely dissolve the polymer. After purging with flowing nitrogen for 30 min, add 5.5 g of methyl mercaptoacetate and 11.0 g of anhydrous sodium carbonate to the reaction system. Continue stirring for 10 min to form a homogeneous reaction system. Maintain the reaction temperature at 40°C and react for 20 h. After the reaction is completed, wait for the reaction system to cool to room temperature, add 5 times the volume of deionized water for precipitation treatment, filter, collect the precipitate, wash repeatedly with deionized water, and vacuum dry at 30°C for 12 h to obtain the reinforcing agent.

[0063] This invention also provides a method for preparing an ionomer-reinforced PA composite material, specifically comprising the following steps:

[0064] S1. Mix the ethylene-octene copolymer, initiator, and reinforcing agent evenly according to the weight proportions, and transfer them to a twin-screw extruder for melt reaction. Set the screw speed to 100 r / min and the temperature of each section of the twin-screw extrusion to 185℃, 185℃, 185℃, 180℃, 180℃, 180℃, and 180℃. After water cooling and granulation, the extruded sample is used to obtain reinforced particles.

[0065] S2. After drying PA6 under vacuum at 100℃ for 6 hours, transfer it and the reinforcing particles prepared in step S1 to a twin-screw extruder for a melt reaction. Set the screw speed to 220 r / min and the temperatures of each section of the twin-screw extrusion to 255℃, 255℃, 250℃, 250℃, 245℃, 240℃, and 240℃. After water cooling and granulation, the extruded sample is used to obtain the PA composite material.

[0066] Comparative Example 1

[0067] This comparative example provides a PA composite material and its preparation method. The only difference between this and Example 1 is that the reinforcing agent in the PA composite material is replaced with the same weight parts of maleic anhydride, while the other components and their contents are the same as in Example 1.

[0068] Comparative Example 2

[0069] This comparative example provides a PA composite material and its preparation method. The only difference between this example and Example 1 is that the preparation method of the reinforcing agent does not include step S3, while the other components and their contents are the same as in Example 1.

[0070] Comparative Example 3

[0071] This comparative example provides a PA composite material and its preparation method. The only difference between this and Example 1 is that the PA composite material does not include reinforcing agents and initiators, while the remaining components and their contents are the same as in Example 1.

[0072] Experimental Example 1

[0073] The mechanical properties of the PA composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were tested. The PA composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were injection molded at 250°C on an injection molding machine to form standard specimens.

[0074] 1. Tensile test: The test was conducted according to ISO527-2-2012 using a Z010 universal tester, at a temperature of (23±2)℃ and a tensile speed of 50mm / min.

[0075] 2. Impact test: The impact test was conducted using an AJU-22 cantilever beam impact testing machine in accordance with ISO180-2000, at a temperature of (23±2)℃.

[0076] 3. Bending test: The test shall be conducted in accordance with ISO178-2010 using a Z010 universal tester at a temperature of (23±2)℃.

[0077] Figure 1 The figures show the tensile properties of the PA composite materials prepared in Examples 1-3 and Comparative Examples 1-3 of this invention. Figure 2The graphs show the impact performance results of the PA composite materials prepared in Examples 1-3 and Comparative Examples 1-3 of this invention. Figure 3 The figure shows the bending properties of the PA composite materials prepared in Examples 1-3 and Comparative Examples 1-3 of this invention. As shown in the figure, the tensile strength (50.2-53.1 MPa), elongation at break (158.7-162.3%), and impact strength (95.8-97.28.8 kJ·m) of Examples 1-3 are as follows: -2 The flexural strength (62.3-64.9 MPa) and flexural modulus (2536-2638 MPa) of Comparative Example 1 were significantly higher than those of all comparative examples. Comparative Example 1 showed slightly lower performance than the Example, but higher than Comparative Examples 2 and 3, indicating that maleic anhydride had a certain modifying effect, but the effect was weaker than the reinforcing agent in the Example. Comparative Example 2 showed significantly lower flexural strength (48.2 MPa) and flexural modulus (2159 MPa) than the Example, and also poorer tensile and impact properties, indicating that polycarbonate had a limited reinforcing effect in this system. Comparative Example 3 had the worst performance (e.g., impact strength of only 18.8 kJ·m). -2 This indicates that reinforcing agents and initiators are key to performance improvement. The reinforcing agent exhibits good compatibility with PA6 and ethylene-octene copolymers. It can improve the flexural strength and modulus of the material through a rigid structure, and also improve the bonding force between the two phases through interfacial interactions. Through the action of the initiator, it promotes grafting or cross-linking reactions between the ethylene-octene copolymer and the reinforcing agent and PA6, forming a three-dimensional network structure, reducing interfacial defects, and enabling effective stress transfer between the two phases, thereby improving tensile strength and toughness.

[0078] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

[0079] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. An ionomer-reinforced PA composite material, characterized in that: The reinforced PA composite material comprises the following components in parts by weight: 70-80 parts PA6, 20-30 parts ethylene-octene copolymer, 1-3 parts reinforcing agent, 0.02-0.05 parts initiator, and 0.05-0.1 parts antioxidant; the initiator includes at least one of dicumyl peroxide, di-tert-butyl peroxide, tert-butyl peroxide, and bis-tert-butyl peroxide; the antioxidant includes at least one of Irganox 1010, Irganox 1076, Irganox 1098, Irganox 1035, and Irganox 245.

2. The ionomer-reinforced PA composite material according to claim 1, characterized in that: The preparation method of the reinforcing agent specifically includes the following steps: A1. Pass flowing argon gas into the flask, add 2-methylene-1,3-propanediol, dissolve it in anhydrous dichloromethane, add initiator and accelerator to the reaction system, mix well to obtain reaction solution 1; A2. Dissolve 4-chloro-1,3-dioxapentane-2-one in anhydrous dichloromethane and add it dropwise to the reaction solution 1 prepared in step A1 under an argon atmosphere. Maintain the reaction temperature to carry out the polymerization reaction. After the reaction is completed, add benzoic acid to terminate the reaction, add n-hexane for precipitation treatment, filter, collect the precipitate, purify, and vacuum dry to obtain the polymer. A3. Dissolve the polymer prepared in step A2 in anhydrous DMF, introduce flowing nitrogen gas, add methyl mercaptoacetate and mix well, then add anhydrous sodium carbonate to form a homogeneous reaction system. Maintain the reaction temperature to carry out the substitution reaction. After the reaction is completed, add deionized water for precipitation treatment, collect the precipitate, dissolve it in DMF, transfer it to a dialysis bag, dialyze with deionized water, and freeze-dry to obtain the reinforcing agent.

3. The ionomer-reinforced PA composite material according to claim 2, characterized in that: In step A1, the mass concentration of 2-methylene-1,3-propanediol in anhydrous dichloromethane is 10-20 mg / mL.

4. The ionomer-reinforced PA composite material according to claim 3, characterized in that: In step A1, the mass ratio of the initiator to 2-methylene-1,3-propanediol is 0.35-0.43:1; the initiator includes at least one of 1,8-diazabicyclo[5.4.0]undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,1,3,3-tetramethylguanidine, and triethylenediamine.

5. The ionomer-reinforced PA composite material according to claim 4, characterized in that: In step A1, the mass ratio of the activator to 2-methylene-1,3-propanediol is 4.3-6.5:1; the activator includes at least one of N-phenylthiourea, N,N'-diphenylthiourea, and 1-methyl-3-phenylthiourea.

6. The ionomer-reinforced PA composite material according to claim 5, characterized in that: The mass ratio between 4-chloro-1,3-dioxolane-2-one and 2-methylene-1,3-propanediol is 3.5-7:0.1-0.2; in step A2, the polymerization reaction temperature is 30-40℃ and the polymerization reaction time is 3-4h.

7. The ionomer-reinforced PA composite material according to claim 6, characterized in that: In step A3, the mass ratio of methyl mercaptoacetate to 4-chloro-1,3-dioxapentane-2-one is 1.28-1.73:1; the mass ratio of methyl mercaptoacetate to anhydrous sodium carbonate is 0.5-1:1; the reaction temperature of the substitution reaction is 30-40℃, and the reaction time of the substitution reaction is 20-30h.

8. A method for preparing an ionomer-reinforced PA composite material according to claim 7, characterized in that: Specifically, the steps include the following: S1. After uniformly mixing ethylene-octene copolymer, initiator, and reinforcing agent, the mixture is transferred to a twin-screw extruder for melt reaction. The extruded sample is then water-cooled and granulated to obtain reinforced particles. S2. After vacuum drying, PA6 is transferred to a twin-screw extruder along with the reinforcing particles prepared in step S1 for a melt reaction. After the reaction is complete, the extruded sample is water-cooled and granulated to obtain the PA composite material.

9. The method for preparing an ionomer-reinforced PA composite material according to claim 8, characterized in that: In step S1, the screw speed for the melting reaction is 80-100 r / min, and the melting reaction temperature is 180-190℃.

10. The method for preparing an ionomer-reinforced PA composite material according to claim 9, characterized in that: In step S2, the screw speed for the melting reaction is 180-220 r / min, and the temperature for the melting reaction is 240-260℃.

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