Antibacterial and antifouling polymer composite material, and preparation method and application thereof

Abstract

The application discloses an antibacterial and antifouling polymer composite material and a preparation method and application thereof, the polymer composite material takes PA6 as a base body, is compounded with silane modified inorganic pigment, organic-inorganic composite antibacterial agent, reactive hyperbranched fluorosilicon polymer antifouling agent and an additive, is prepared by adopting a double-screw extrusion process combining multi-hopper feeding and late-stage side feeding, realizes synergism of antibacterial, antifouling and dyeing functions, and effectively solves problems such as easy migration of the antibacterial agent, easy falling of the antifouling layer and mutual interference of functional components.The obtained polymer composite material has an antibacterial rate of greater than or equal to 99%, an antifouling grade of greater than or equal to 4 levels, an antibacterial retention rate of greater than or equal to 90% after 50 times of water washing, a VOC release amount of less than 3.5 mg / m 3 , excellent processing dispersibility, and can be directly used for automobile carpet yarn melt spinning, and has environmental protection and practicability.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, specifically to an antibacterial and antifouling polymer composite material, its preparation method, and its application. Background Technology

[0002] As a core component of car interiors, car carpets are used in humid, high-temperature, dusty, and oily environments, making them highly susceptible to the growth of harmful microorganisms such as E. coli, Staphylococcus aureus, and mold. This not only produces unpleasant odors that affect the driving experience but may also threaten the health and safety of occupants. At the same time, water stains, oil stains, and other dirt on the carpet surface can easily penetrate into the fibers, making them difficult to clean, severely shortening the lifespan of car carpets and affecting the aesthetics of the interior.

[0003] Currently, traditional polymer composite materials used in automotive carpet yarns only possess a single dyeing function. Antibacterial and antifouling properties must be achieved through post-processing of the yarn or carpet, which suffers from cumbersome processing steps, high production costs, and poor functional durability. While there is some existing research on functional polymer composite materials, for example, CN103275370A discloses a multifunctional masterbatch with UV shielding, antibacterial, and antifouling properties. This masterbatch uses doped nano-titanium dioxide, nano-zinc oxide, and nano-zinc sulfide as its functional core, combined with coupling agents, lubricating dispersants, and matrix resins through a one-step melt extrusion process, achieving the integration of basic functions such as UV shielding, antibacterial, and antifouling. CN119081292A discloses an antibacterial masterbatch using epoxy-modified Ti3C2T... X The reaction product of the material and thiamine pyrophosphate serves as a composite antibacterial agent, effectively enhancing antibacterial performance and additional properties such as material mechanics and flame retardancy. However, several insurmountable technical bottlenecks remain: First, most antibacterial agents are of a single type, easily migrating and precipitating from the polymer matrix, resulting in rapid attenuation of antibacterial effect after washing, achieving only short-term antibacterial properties; second, the bonding force between antifouling auxiliaries and the polymer matrix is ​​weak, easily detaching during spinning, weaving, and use, resulting in limited antifouling effect; third, antibacterial and antifouling components are prone to chemical reactions or physical repulsion, leading to functional interference and preventing the simultaneous achievement of highly efficient antibacterial and excellent antifouling effects; fourth, antibacterial and antifouling agents are prone to decomposition and inactivation in the high-temperature environment of melt spinning yarn, resulting in poor processing stability; fifth, some antibacterial systems use heavy metal antibacterial agents, posing a migration risk and exceeding VOC emission standards, failing to meet the environmental standards for automotive interiors and limiting the product's market application scope.

[0004] Therefore, how to integrate dyeing, antibacterial, and antifouling functions into polymer composite materials, while also possessing long-lasting effects and high compatibility, has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the technical problems of existing polymer composite materials for automotive carpet yarns, such as single function, easy migration and precipitation of antibacterial agents, easy peeling of antifouling layer, mutual interference of functional components, and poor processing stability, this invention provides an antibacterial and antifouling polymer composite material, its preparation method, and its application. This polymer composite material integrates dyeing, antibacterial, and antifouling functions, and has long-lasting antibacterial effect, high efficiency in antifouling, and high processing stability. It can be directly adapted to melt spinning processing of automotive carpet yarns.

[0006] This invention provides an antibacterial and antifouling polymer composite material, which, by weight, comprises:

[0007] PA6 10-20 servings; 10-25 parts of silane-modified inorganic pigment; 8-15 parts organic pigment; 8-15 parts of compound antibacterial agent; 8-15 parts antifouling agent; Compatibilizer 2-5 parts; Antioxidant 5-8 parts; The polymer composite material has an antibacterial rate of ≥99%, a stain resistance level of ≥4, and an antibacterial retention rate of ≥90% after 50 water washes.

[0008] Furthermore, the silane-modified inorganic pigment is prepared by mixing the inorganic pigment and the silane coupling agent in a high-speed mixer at 100-120°C for 15-30 minutes, and then drying at 80-110°C for 2-4 hours.

[0009] Furthermore, by weight, the composite antibacterial agent comprises 30-50 parts of chitosan quaternary ammonium salt, 30-40 parts of nano zinc oxide, and 20-35 parts of silane-modified montmorillonite. The synergistic effect of the organic and inorganic antibacterial components can significantly improve the broad spectrum and effectiveness of antibacterial activity. The silane-modified montmorillonite, as a carrier, can effectively inhibit the migration and precipitation of antibacterial agents and prolong the antibacterial effect.

[0010] Furthermore, the preparation method of the composite antibacterial agent includes: Step 1: Disperse silane-modified montmorillonite in deionized water, add chitosan quaternary ammonium salt, insert the chitosan quaternary ammonium salt into the interlayer of montmorillonite through cation exchange reaction, and react at a constant temperature of 55-70℃ for 3-5 hours. Step 2: Adjust the pH of the system to 8-9, add zinc salt precursor, and perform hydrothermal reaction at 75-85℃ for 1-3 hours to generate nano zinc oxide in situ on the surface of montmorillonite sheets. Step 3: Add KH-570 silane coupling agent to the system for secondary coating modification, and then vacuum dry and grind to prepare the composite antibacterial agent. The process of combining in-situ generation and secondary coating can significantly improve the dispersibility and interfacial bonding of the antibacterial agent, and prevent the antibacterial agent from being lost during use and washing.

[0011] Furthermore, the antifouling agent is a reactive hyperbranched fluorosilicone polymer. The reactive hyperbranched fluorosilicone polymer has a hydroxyl-terminated hyperbranched polysiloxane as its backbone, with C4-C6 perfluoroalkyl segments grafted onto its side groups and maleic anhydride functional groups grafted onto its end groups. The number average molecular weight of the reactive hyperbranched fluorosilicone polymer is 8000-12000, and the fluorine content is 15-20wt%. The hyperbranched structure can improve the processing fluidity and matrix compatibility of the antifouling agent, the perfluoroalkyl groups give the material excellent water and oil repellency and antifouling properties, and the maleic anhydride end groups can enhance the chemical bonding with the resin matrix and prevent the antifouling layer from peeling off.

[0012] Furthermore, the method for preparing the reactive hyperbranched fluorosilicone polymer includes the following steps: A. Hydroxyl-terminated hyperbranched polysiloxane was prepared by Michael addition-hydrolysis condensation using trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane as raw materials. B. Under nitrogen protection, hydroxyl-terminated hyperbranched polysiloxane is condensed with C4-C6 perfluoroalkyltrimethoxysilane at a reaction temperature of 80-110℃ to obtain a side-chain perfluoroalkyl modified intermediate. C. The intermediate is subjected to a capping reaction with maleic anhydride at 100-130°C to obtain a reactive hyperbranched fluorosilicone polymer with end-group grafted maleic anhydride functional groups. The stepwise grafting process ensures a regular molecular structure, balances antifouling performance with high-temperature reactivity, and is suitable for the high-temperature processing environment of melt spinning.

[0013] Furthermore, the compatibilizer is maleic anhydride-grafted PA6; it can effectively improve the interfacial compatibility between the PA6 matrix and the antibacterial, antifouling, and pigment components, reduce phase separation defects, and ensure the processing stability of polymer composite materials and the yarn forming quality.

[0014] Furthermore, the antioxidant is a compound of antioxidant 1098 and antioxidant 168; the antioxidant can inhibit the oxidative degradation of resin and functional components at high temperatures, and improve the heat resistance stability and functional durability of polymer composite materials.

[0015] This invention provides a method for preparing the above-mentioned antibacterial and antifouling polymeric composite material, comprising the following steps: (1) Mix the compound antibacterial agent, antifouling agent and compatibilizer evenly to obtain the functional material; (2) PA6 base material masterbatch is fed into the main feed hopper of a twin-screw extruder, and silane-modified inorganic pigment, organic pigment and antioxidant are fed into the distribution hopper respectively. At the same time, the functional materials are added to the side feed of the rear section of the twin-screw extruder. The material is melt-extruded at 240-250℃, and then water-cooled, pelletized and dried to obtain the antibacterial and antifouling polymer composite material.

[0016] Furthermore, in step (2), the screw speed of the twin-screw extruder is 300-400 rpm; a reasonable speed can ensure that the material is fully melted and mixed, avoid overheating due to shearing leading to failure of functional components, and at the same time ensure that the polymer composite material particles are uniform.

[0017] The present invention also provides a color masterbatch, wherein the color masterbatch comprises the above-mentioned antibacterial and antifouling polymer composite material.

[0018] The beneficial effects of this application are as follows: This invention employs a specific dosage of a composite antibacterial agent, consisting of chitosan quaternary ammonium salt, nano-zinc oxide, and silane-modified montmorillonite. The chitosan quaternary ammonium salt is intercalated into montmorillonite sheets via cation exchange, followed by in-situ generation of zinc oxide, which is then secondary coated with silane. The organic and inorganic components synergistically disrupt the bacterial cell structure, while the montmorillonite sheets form a physical barrier inhibiting the migration and precipitation of the antibacterial agent. The appropriate dosage ensures uniform dispersion of the components, achieving both high antibacterial rate and antibacterial retention rate.

[0019] This invention uses a reactive hyperbranched fluorosilicone polymer as the antifouling agent, with hyperbranched polysiloxane as the backbone. The side-attached perfluoroalkyl groups reduce surface energy, achieving water and oil repellency. The terminal maleic anhydride groups form chemical bonds with the PA6 matrix, rather than through physical adsorption. The hyperbranched structure improves compatibility with the matrix, preventing phase separation and fundamentally solving the problem of antifouling layer peeling. Stains are not easily adhered to and are easy to clean, making it suitable for complex operating environments.

[0020] This invention employs a twin-screw extrusion process combining multi-bucket feeding and rear-end side feeding. This feeding method avoids direct contact between antibacterial, antifouling, and pigment components under high temperature and high shear, preventing mutual interference, agglomeration, or degradation. This ensures that each functional component is uniformly dispersed in the PA6 matrix, significantly improving the material's processing stability and dispersion level. Simultaneously, it reduces the volatilization of small molecules and VOC release, guaranteeing the synergistic and stable performance of antibacterial, antifouling, and dyeing functions. This is suitable for the continuous production requirements of high-temperature melt spinning of automotive carpet yarns.

[0021] This invention's polymer composite material achieves synergistic effects of dyeing, antibacterial, and antifouling through spatial partitioning, without component interference or performance degradation. The product combines highly efficient antibacterial, antifouling, and long-lasting stability, solving the defects of traditional polymer composite materials such as migration, shedding, and functional interference from a material principle perspective. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 The color masterbatch is prepared from the composite material of Example 1 of this application; Detailed Implementation The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] In the following examples and comparative examples, the silane-modified inorganic pigments were prepared by mixing the inorganic pigments with the silane coupling agent KH570 in a high-speed mixer at 120°C for 20 minutes, and then drying them at 100°C for 3 hours.

[0025] Example 1 An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 15 parts PA6, 18 parts silane-modified inorganic pigment, 10 parts organic pigment, 12 parts composite antibacterial agent, 12 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168.

[0026] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 60℃ for 4 hours. The pH was adjusted to 8.5, zinc salt precursor was added, and the reaction was carried out hydrothermally at 80℃ for 2 hours. KH-570 silane coupling agent was added for secondary coating modification, vacuum drying and grinding were performed to obtain composite antibacterial agent, which contained 40 parts of chitosan quaternary ammonium salt, 35 parts of nano zinc oxide and 25 parts of silane-modified montmorillonite.

[0027] Preparation of reactive hyperbranched fluorosilicone polymer: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxane by Michael addition-hydrolysis condensation. Under nitrogen protection, it was condensed with C6 perfluoroalkyltrimethoxysilane at 95°C to obtain a side-chain perfluoroalkyl modified intermediate, which was then end-capped with maleic anhydride at 115°C to obtain a reactive hyperbranched fluorosilicone polymer with a number average molecular weight of 10,000 and a fluorine content of 18 wt%.

[0028] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, while silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The material is melt-extruded at 240°C, water-cooled pelletized, and dried at a screw speed of 350 rpm to obtain the antibacterial and antifouling polymer composite material.

[0029] Example 2 An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 10 parts PA6, 10 parts silane-modified inorganic pigment, 8 parts organic pigment, 8 parts composite antibacterial agent, 8 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 2 parts maleic anhydride-grafted PA6 compatibilizer, 2 parts antioxidant 1098, and 3 parts antioxidant 168.

[0030] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 55℃ for 5 hours. The pH was adjusted to 8, zinc salt precursor was added, and the reaction was carried out at 75℃ for 3 hours. KH-570 silane coupling agent was added for secondary coating modification. The mixture was then vacuum dried and ground to obtain the composite antibacterial agent, which contained 30 parts of chitosan quaternary ammonium salt, 30 parts of nano zinc oxide, and 20 parts of silane-modified montmorillonite.

[0031] Preparation of reactive hyperbranched fluorosilicone polymer: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxane by Michael addition-hydrolysis condensation. Under nitrogen protection, it was condensed with C4 perfluorobutyltrimethoxysilane at 80°C to obtain a side-chain perfluoroalkyl modified intermediate, which was then end-capped with maleic anhydride at 100°C to obtain a reactive hyperbranched fluorosilicone polymer with a number average molecular weight of 8000 and a fluorine content of 15wt%.

[0032] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder. Silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The material is melt-extruded at 240°C, water-cooled pelletized, and dried. The screw speed is 300 rpm to obtain the antibacterial and antifouling polymer composite material.

[0033] Example 3 An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 20 parts PA6, 25 parts silane-modified inorganic pigment, 15 parts organic pigment, 15 parts composite antibacterial agent, 15 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 5 parts maleic anhydride-grafted PA6 compatibilizer, 3 parts antioxidant 1098, and 5 parts antioxidant 168.

[0034] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 70℃ for 3 hours. The pH was adjusted to 9, zinc salt precursor was added, and the reaction was carried out hydrothermally at 85℃ for 1 hour. KH-570 silane coupling agent was added for secondary coating modification, vacuum drying and grinding were performed to obtain composite antibacterial agent, which contained 50 parts of chitosan quaternary ammonium salt, 40 parts of nano zinc oxide, and 35 parts of silane-modified montmorillonite.

[0035] Preparation of reactive hyperbranched fluorosilicone polymer: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxane by Michael addition-hydrolysis condensation. Under nitrogen protection, it was condensed with C6 perfluorohexyltrimethoxysilane at 110℃ to obtain a side-chain perfluoroalkyl modified intermediate, which was then end-capped with maleic anhydride at 130℃ to obtain a reactive hyperbranched fluorosilicone polymer with a number average molecular weight of 12000 and a fluorine content of 20wt%.

[0036] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, while silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The mixture is melt-extruded at 250°C, water-cooled pelletized, and dried at a screw speed of 400 rpm to obtain the antibacterial and antifouling polymer composite material.

[0037] Example 4 An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 14 parts PA6, 17 parts silane-modified inorganic pigment, 10 parts organic pigment, 11 parts composite antibacterial agent, 12 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168.

[0038] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 60℃ for 4 hours. The pH was adjusted to 8.5, zinc salt precursor was added, and the reaction was carried out hydrothermally at 80℃ for 2 hours. KH-570 silane coupling agent was added for secondary coating modification, vacuum drying and grinding were performed to obtain composite antibacterial agent, which contained 40 parts of chitosan quaternary ammonium salt, 35 parts of nano zinc oxide and 25 parts of silane-modified montmorillonite.

[0039] Preparation of reactive hyperbranched fluorosilicone polymer: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxane by Michael addition-hydrolysis condensation. Under nitrogen protection, it was condensed with C5 perfluoropentyltrimethoxysilane at 95°C to obtain a side-chain perfluoroalkyl modified intermediate, which was then end-capped with maleic anhydride at 115°C to obtain a reactive hyperbranched fluorosilicone polymer with a number average molecular weight of 10,000 and a fluorine content of 18 wt%.

[0040] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, while silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The material is melt-extruded at 245°C, water-cooled pelletized, and dried at a screw speed of 400 rpm to obtain the antibacterial and antifouling polymer composite material.

[0041] Example 5 An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 16 parts PA6, 20 parts silane-modified inorganic pigment, 12 parts organic pigment, 13 parts composite antibacterial agent, 13 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 4 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168.

[0042] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 65℃ for 3.5h. The pH was adjusted to 8.5, zinc salt precursor was added, and the reaction was carried out hydrothermally at 82℃ for 1.5h. KH-570 silane coupling agent was added for secondary coating modification, vacuum drying and grinding were performed to obtain composite antibacterial agent, which contained 45 parts of chitosan quaternary ammonium salt, 35 parts of nano zinc oxide and 30 parts of silane-modified montmorillonite.

[0043] Preparation of reactive hyperbranched fluorosilicone polymer: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxane by Michael addition-hydrolysis condensation. Under nitrogen protection, the polysiloxane was condensed with C5 perfluoropentyltrimethoxysilane at 100°C to obtain a side-chain perfluoroalkyl modified intermediate. The intermediate was then capped with maleic anhydride at 120°C to obtain a reactive hyperbranched fluorosilicone polymer with a number average molecular weight of 11,000 and a fluorine content of 17 wt%.

[0044] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder. Silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The material is melt-extruded at 250°C, water-cooled pelletized, and dried. The screw speed is 350 rpm to obtain the antibacterial and antifouling polymer composite material.

[0045] Comparative Example 1 The preparation method and raw materials for this comparative example are the same as those in Example 1. The only difference is that the composite antibacterial agent in this comparative example does not contain silane-modified montmorillonite, but is prepared solely by compounding chitosan quaternary ammonium salt and nano-zinc oxide in a specific ratio. The specific scheme is as follows: An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 15 parts PA6, 18 parts silane-modified inorganic pigment, 10 parts organic pigment, 12 parts composite antibacterial agent, 12 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168.

[0046] Preparation of composite antibacterial agent: 40 parts of chitosan quaternary ammonium salt and 35 parts of nano zinc oxide were mixed evenly, and KH-570 silane coupling agent was added for coating modification. After vacuum drying and grinding, a non-montmorillonite composite antibacterial agent was obtained.

[0047] Preparation of reactive hyperbranched fluorosilicone polymer: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxane by Michael addition-hydrolysis condensation. Under nitrogen protection, it was condensed with C6 perfluorohexyltrimethoxysilane at 95°C to obtain a side-chain perfluoroalkyl modified intermediate, which was then end-capped with maleic anhydride at 115°C to obtain a reactive hyperbranched fluorosilicone polymer with a number average molecular weight of 10,000 and a fluorine content of 18 wt%.

[0048] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, while silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The material is melt-extruded at 240°C, water-cooled pelletized, and dried at a screw speed of 350 rpm to obtain the antibacterial and antifouling polymer composite material.

[0049] Comparative Example 2 The preparation method and raw materials for this comparative example are the same as those in Example 1. The only difference is that this comparative example uses a fluorocarbon-modified polyacrylate antifouling agent ZH-8008, and does not use a reactive hyperbranched fluorosilicone polymer. The specific scheme is as follows: An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 15 parts PA6, 18 parts silane-modified inorganic pigment, 10 parts organic pigment, 12 parts composite antibacterial agent, 12 parts fluorocarbon-modified polyacrylate antifouling agent ZH-8008, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168.

[0050] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 60℃ for 4 hours. The pH was adjusted to 8.5, zinc salt precursor was added, and the reaction was carried out hydrothermally at 80℃ for 2 hours. KH-570 silane coupling agent was added for secondary coating modification, vacuum drying and grinding were performed to obtain composite antibacterial agent, which contained 40 parts of chitosan quaternary ammonium salt, 35 parts of nano zinc oxide and 25 parts of silane-modified montmorillonite.

[0051] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, while silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The material is melt-extruded at 240°C, water-cooled pelletized, and dried at a screw speed of 350 rpm to obtain the antibacterial and antifouling polymer composite material.

[0052] Comparative Example 3 The preparation method and raw materials for this comparative example are the same as those in Example 1. The only difference is that the antifouling agent in this comparative example uses a hyperbranched fluorosilicone polymer with a number-average molecular weight of 6000 and a fluorine content of 12wt%. The specific scheme is as follows: An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 15 parts PA6, 18 parts silane-modified inorganic pigment, 10 parts organic pigment, 12 parts composite antibacterial agent, 12 parts hyperbranched fluorosilicone polymer antifouling agent, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168.

[0053] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 60℃ for 4 hours. The pH was adjusted to 8.5, zinc salt precursor was added, and the reaction was carried out hydrothermally at 80℃ for 2 hours. KH-570 silane coupling agent was added for secondary coating modification, vacuum drying and grinding were performed to obtain composite antibacterial agent, which contained 40 parts of chitosan quaternary ammonium salt, 35 parts of nano zinc oxide and 25 parts of silane-modified montmorillonite.

[0054] Preparation of reactive hyperbranched fluorosilicone polymers: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxanes via Michael addition-hydrolysis condensation. Under nitrogen protection, the polysiloxanes were condensed with C6 perfluorohexyltrimethoxysilane at 95°C to obtain a side-chain perfluoroalkyl modified intermediate. This intermediate was then capped with maleic anhydride at 115°C to obtain a hyperbranched fluorosilicone polymer with a number average molecular weight of 6000 and a fluorine content of 12wt%.

[0055] The composite antibacterial agent, antifouling agent, and compatibilizer are mixed evenly to obtain the functional material. PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, while silane-modified inorganic pigments, organic pigments, and antioxidants are fed into the distribution hoppers respectively. At the same time, the functional material is added to the side feed at the rear section of the extruder. The material is melt-extruded at 240°C, water-cooled pelletized, and dried at a screw speed of 350 rpm to obtain the antibacterial and antifouling polymer composite material.

[0056] Comparative Example 4 The preparation method and raw materials for this comparative example are the same as those in Example 1. The only difference is that the twin-screw extruder in this comparative example uses a one-step full main feeding process, without segmented side feeding. The specific scheme is as follows: An antibacterial and antifouling polymer composite material, by weight, is composed of the following components: 15 parts PA6, 18 parts silane-modified inorganic pigment, 10 parts organic pigment, 12 parts composite antibacterial agent, 12 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168.

[0057] Preparation of composite antibacterial agent: Silane-modified montmorillonite was dispersed in deionized water, chitosan quaternary ammonium salt was added, and the reaction was carried out at 60℃ for 4 hours. The pH was adjusted to 8.5, zinc salt precursor was added, and the reaction was carried out hydrothermally at 80℃ for 2 hours. KH-570 silane coupling agent was added for secondary coating modification, vacuum drying and grinding were performed to obtain composite antibacterial agent, which contained 40 parts of chitosan quaternary ammonium salt, 35 parts of nano zinc oxide and 25 parts of silane-modified montmorillonite.

[0058] Preparation of reactive hyperbranched fluorosilicone polymer: Trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane were used as raw materials to prepare hydroxyl-terminated hyperbranched polysiloxane by Michael addition-hydrolysis condensation. Under nitrogen protection, it was condensed with C6 perfluorohexyltrimethoxysilane at 95°C to obtain a side-chain perfluoroalkyl modified intermediate, which was then end-capped with maleic anhydride at 115°C to obtain a reactive hyperbranched fluorosilicone polymer with a number average molecular weight of 10,000 and a fluorine content of 18 wt%.

[0059] PA6, silane-modified inorganic pigments, organic pigments, composite antibacterial agents, antifouling agents, compatibilizers, and antioxidants are all mixed evenly and added in one go through the main feed of a twin-screw extruder. The mixture is melt-extruded at 240°C, water-cooled pelletized, and dried at a screw speed of 350 rpm to obtain an antibacterial and antifouling polymer composite material.

[0060] Test methods Antibacterial rate: GB / T 20944.3-2008, tested for Escherichia coli and Staphylococcus aureus.

[0061] Antibacterial retention rate after 50 washes: After washing 50 times according to GB / T8629-2017 standard, the retention rate was tested and calculated according to the shaking method in GB / T 20944.3-2008.

[0062] Stain resistance rating: FZ / T01118-2012 "Detection and evaluation of stain resistance of textiles - easy stain removal", level 1~5, level 5 is the best.

[0063] VOC emission: bag-gas chromatography method, to detect the total volatile organic compound content.

[0064] Dispersion rating: GB / T 18251-2019 Dispersion rating, 1 to 5, with 1 being the best.

[0065] Table 1. Performance test results of the polymer composite materials prepared in Examples 1-5 and Comparative Examples 1-4

[0066] As shown in Table 1, the polymer composite materials prepared in Examples 1-5 all exhibited an antibacterial rate ≥99.5%, maintained an antibacterial rate ≥92% after 50 water washes, consistently achieved a stain resistance level of 4, and had VOC emissions below 3.5 mg / m³. 3 All dispersion grades are optimal (Grade 1). Regarding antibacterial properties, the layered structure of silane-modified montmorillonite physically encapsulates and anchors antibacterial components, preventing chitosan quaternary ammonium salt and nano-zinc oxide from migrating and precipitating to the surface during high-temperature processing and long-term use, thus ensuring long-lasting antibacterial stability. In terms of antifouling, the reactive hyperbranched fluorosilicone polymer relies on the maleic anhydride functional groups at its end groups to form a chemical bond with the PA6 matrix, rather than physical adsorption. Therefore, it can form a continuous, robust, and non-detachable low surface energy layer on the material surface, resulting in stable and durable antifouling effects. Regarding processing and dispersion, the feeding method of this invention avoids direct competition, agglomeration, and mutual interference between functional additives, resulting in more uniform dispersion of each component in the matrix. This improves the molding stability of the polymer composite material and reduces VOC emissions from small molecule volatilization.

[0067] Comparative Example 1, lacking silane-modified montmorillonite, suffered from a lack of carrier binding for its antibacterial components. Under humid heat and friction, these components rapidly migrated and dissolved, resulting in a significant decrease in antibacterial retention after washing and an inability to achieve long-lasting antibacterial effects. Comparative Example 2 used a commercially available conventional antifouling agent, which lacked chemical bonding with the matrix. This resulted in easy detachment and migration during use, making it difficult to form a stable antifouling interface, thus significantly reducing the antifouling level. Simultaneously, the increased volatility of small-molecule additives led to a rise in VOCs. Comparative Example 3 used an antifouling agent with a low molecular weight and insufficient fluorine content, failing to construct a dense and continuous antifouling film. Its high surface energy resulted in insufficient water and oil repellency, ultimately leading to substandard antifouling performance. Comparative Example 4 employed a one-step co-extrusion process, where all components participated in melt mixing simultaneously. This easily resulted in uneven dispersion and localized agglomeration, preventing the functional components from fully exerting their effects, leading to a simultaneous decline in antibacterial durability, antifouling efficacy, and dispersibility.

[0068] The above data variation pattern fully demonstrates that, through the specific selection of antibacterial carrier structure, antifouling agent molecular structure, and segmented feeding process, the present invention achieves stable dispersion, synergistic effect, and non-interference among functional components. It solves the technical problems of easy migration, easy shedding, poor dispersibility, and mutual interference of functions in traditional functional polymer composite materials from the perspective of the internal action mechanism of the material, making the product have more reliable stability and durability.

[0069] It should be understood that this application is not limited to the processes and structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An antibacterial and antifouling polymer composite material, characterized in that, By weight, it consists of the following components: 15 parts PA6, 18 parts silane-modified inorganic pigment, 10 parts organic pigment, 12 parts composite antibacterial agent, 12 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168. The preparation method of the composite antibacterial agent is as follows: silane-modified montmorillonite is dispersed in deionized water, chitosan quaternary ammonium salt is added, the reaction is carried out at a constant temperature of 60°C for 4 hours, the pH is adjusted to 8.5, zinc salt precursor is added, the reaction is carried out at 80°C for 2 hours, KH-570 silane coupling agent is added for secondary coating modification, vacuum drying and grinding are performed to obtain the composite antibacterial agent, wherein the chitosan quaternary ammonium salt is 40 parts, the nano zinc oxide is 35 parts, and the silane-modified montmorillonite is 25 parts; The preparation method of the reactive hyperbranched fluorosilicone polymer antifouling agent is as follows: using trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane as raw materials, a terminal hydroxyl hyperbranched polysiloxane is prepared by Michael addition-hydrolysis condensation. Under nitrogen protection, the terminal hydroxyl hyperbranched polysiloxane is condensed with C6 perfluoroalkyltrimethoxysilane at 95°C to obtain a side-chain perfluoroalkyl modified intermediate. The side-chain perfluoroalkyl modified intermediate is then reacted with maleic anhydride at 115°C to obtain the reactive hyperbranched fluorosilicone polymer antifouling agent with a number average molecular weight of 10,000 and a fluorine content of 18 wt%. The preparation method of the antibacterial and antifouling polymer composite material is as follows: the composite antibacterial agent, the reactive hyperbranched fluorosilicone polymer antifouling agent, and the maleic anhydride-grafted PA6 compatibilizer are mixed evenly to obtain functional materials. The PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, and the silane-modified inorganic pigment, the organic pigment, and the antioxidant are fed into the distribution hoppers respectively. At the same time, the functional materials are added to the side feed of the rear section of the twin-screw extruder. The mixture is melt-extruded at 240°C, water-cooled pelletized, and dried at a screw speed of 350 rpm to obtain the antibacterial and antifouling polymer composite material.

2. An antibacterial and antifouling polymer composite material, characterized in that, By weight, it consists of the following components: 10 parts PA6, 10 parts silane-modified inorganic pigment, 8 parts organic pigment, 8 parts composite antibacterial agent, 8 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 2 parts maleic anhydride-grafted PA6 compatibilizer, 2 parts antioxidant 1098, and 3 parts antioxidant 168. The preparation method of the composite antibacterial agent is as follows: silane-modified montmorillonite is dispersed in deionized water, chitosan quaternary ammonium salt is added, the reaction is carried out at a constant temperature of 55°C for 5 hours, the pH is adjusted to 8, a zinc salt precursor is added, the reaction is carried out at a hydrothermal temperature of 75°C for 3 hours, KH-570 silane coupling agent is added for secondary coating modification, vacuum drying and grinding are performed to obtain the composite antibacterial agent, wherein the chitosan quaternary ammonium salt is 30 parts, the nano zinc oxide is 30 parts, and the silane-modified montmorillonite is 20 parts; The preparation method of the reactive hyperbranched fluorosilicone polymer antifouling agent is as follows: using trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane as raw materials, a terminal hydroxyl hyperbranched polysiloxane is prepared by Michael addition-hydrolysis condensation. Under nitrogen protection, the terminal hydroxyl hyperbranched polysiloxane is condensed with C4 perfluorobutyltrimethoxysilane at 80°C to obtain a side-chain perfluoroalkyl modified intermediate. The side-chain perfluoroalkyl modified intermediate is then reacted with maleic anhydride at 100°C to obtain the reactive hyperbranched fluorosilicone polymer antifouling agent with a number average molecular weight of 8000 and a fluorine content of 15wt%. The preparation method of the antibacterial and antifouling polymer composite material is as follows: the composite antibacterial agent, the reactive hyperbranched fluorosilicone polymer antifouling agent, and the maleic anhydride-grafted PA6 compatibilizer are mixed evenly to obtain functional materials. The PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, and the silane-modified inorganic pigment, the organic pigment, and the antioxidant are fed into the distribution hoppers respectively. At the same time, the functional materials are added to the side feed of the rear section of the twin-screw extruder. The mixture is melt-extruded at 240°C, water-cooled pelletized, and dried at a screw speed of 300 rpm to obtain the antibacterial and antifouling polymer composite material.

3. An antibacterial and antifouling polymer composite material, characterized in that, By weight, it consists of the following components: 20 parts PA6, 25 parts silane-modified inorganic pigment, 15 parts organic pigment, 15 parts composite antibacterial agent, 15 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 5 parts maleic anhydride-grafted PA6 compatibilizer, 3 parts antioxidant 1098, and 5 parts antioxidant 168. The preparation method of the composite antibacterial agent is as follows: silane-modified montmorillonite is dispersed in deionized water, chitosan quaternary ammonium salt is added, the reaction is carried out at a constant temperature of 70°C for 3 hours, the pH is adjusted to 9, a zinc salt precursor is added, the reaction is carried out at a hydrothermal temperature of 85°C for 1 hour, KH-570 silane coupling agent is added for secondary coating modification, vacuum drying and grinding are performed to obtain the composite antibacterial agent, wherein the chitosan quaternary ammonium salt is 50 parts, the nano zinc oxide is 40 parts, and the silane-modified montmorillonite is 35 parts; The preparation method of the reactive hyperbranched fluorosilicone polymer antifouling agent is as follows: using trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane as raw materials, a terminal hydroxyl hyperbranched polysiloxane is prepared by Michael addition-hydrolysis condensation. Under nitrogen protection, the terminal hydroxyl hyperbranched polysiloxane is condensed with C6 perfluorohexyltrimethoxysilane at 110°C to obtain a side-chain perfluoroalkyl modified intermediate. The side-chain perfluoroalkyl modified intermediate is then reacted with maleic anhydride at 130°C to obtain the reactive hyperbranched fluorosilicone polymer antifouling agent with a number average molecular weight of 12000 and a fluorine content of 20wt%. The preparation method of the antibacterial and antifouling polymer composite material is as follows: the composite antibacterial agent, the reactive hyperbranched fluorosilicone polymer antifouling agent, and the maleic anhydride-grafted PA6 compatibilizer are mixed evenly to obtain functional materials. The PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, and the silane-modified inorganic pigment, the organic pigment, and the antioxidant are fed into the distribution hoppers respectively. At the same time, the functional materials are added to the side feed of the rear section of the twin-screw extruder. The mixture is melt-extruded at 250°C, water-cooled pelletized, and dried at a screw speed of 400 rpm to obtain the antibacterial and antifouling polymer composite material.

4. An antibacterial and antifouling polymer composite material, characterized in that, By weight, it consists of the following components: 14 parts PA6, 17 parts silane-modified inorganic pigment, 10 parts organic pigment, 11 parts composite antibacterial agent, 12 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 3 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168. The preparation method of the composite antibacterial agent is as follows: silane-modified montmorillonite is dispersed in deionized water, chitosan quaternary ammonium salt is added, the reaction is carried out at a constant temperature of 60°C for 4 hours, the pH is adjusted to 8.5, zinc salt precursor is added, the reaction is carried out at 80°C for 2 hours, KH-570 silane coupling agent is added for secondary coating modification, vacuum drying and grinding are performed to obtain the composite antibacterial agent, wherein the chitosan quaternary ammonium salt is 40 parts, the nano zinc oxide is 35 parts, and the silane-modified montmorillonite is 25 parts; The preparation method of the reactive hyperbranched fluorosilicone polymer antifouling agent is as follows: using trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane as raw materials, a terminal hydroxyl hyperbranched polysiloxane is prepared by Michael addition-hydrolysis condensation. Under nitrogen protection, the terminal hydroxyl hyperbranched polysiloxane is condensed with C5 perfluoropentyltrimethoxysilane at 95°C to obtain a side-chain perfluoroalkyl modified intermediate. The side-chain perfluoroalkyl modified intermediate is then reacted with maleic anhydride at 115°C to obtain the reactive hyperbranched fluorosilicone polymer antifouling agent with a number average molecular weight of 10,000 and a fluorine content of 18 wt%. The preparation method of the antibacterial and antifouling polymer composite material is as follows: the composite antibacterial agent, the reactive hyperbranched fluorosilicone polymer antifouling agent, and the maleic anhydride-grafted PA6 compatibilizer are mixed evenly to obtain functional materials. The PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, and the silane-modified inorganic pigment, the organic pigment, and the antioxidant are fed into the distribution hoppers respectively. At the same time, the functional materials are added to the side feed of the rear section of the twin-screw extruder. The mixture is melt-extruded at 245°C, water-cooled pelletized, and dried at a screw speed of 400 rpm to obtain the antibacterial and antifouling polymer composite material.

5. An antibacterial and antifouling polymer composite material, characterized in that, By weight, it consists of the following components: 16 parts PA6, 20 parts silane-modified inorganic pigment, 12 parts organic pigment, 13 parts composite antibacterial agent, 13 parts reactive hyperbranched fluorosilicone polymer antifouling agent, 4 parts maleic anhydride-grafted PA6 compatibilizer, 2.5 parts antioxidant 1098, and 3.5 parts antioxidant 168. The preparation method of the composite antibacterial agent is as follows: silane-modified montmorillonite is dispersed in deionized water, chitosan quaternary ammonium salt is added, the reaction is carried out at a constant temperature of 65℃ for 3.5h, the pH is adjusted to 8.5, zinc salt precursor is added, the reaction is carried out at 82℃ for 1.5h, KH-570 silane coupling agent is added for secondary coating modification, vacuum drying and grinding are performed to obtain the composite antibacterial agent, wherein the chitosan quaternary ammonium salt is 45 parts, the nano zinc oxide is 35 parts, and the silane-modified montmorillonite is 30 parts; The preparation method of the reactive hyperbranched fluorosilicone polymer antifouling agent is as follows: using trimethylolpropane triacrylate and γ-aminopropyltriethoxysilane as raw materials, a terminal hydroxyl hyperbranched polysiloxane is prepared by Michael addition-hydrolysis condensation. Under nitrogen protection, the terminal hydroxyl hyperbranched polysiloxane is condensed with C5 perfluoropentyltrimethoxysilane at 100°C to obtain a side-chain perfluoroalkyl modified intermediate. The side-chain perfluoroalkyl modified intermediate is then reacted with maleic anhydride at 120°C to obtain the reactive hyperbranched fluorosilicone polymer antifouling agent with a number average molecular weight of 11000 and a fluorine content of 17wt%. The preparation method of the antibacterial and antifouling polymer composite material is as follows: the composite antibacterial agent, the reactive hyperbranched fluorosilicone polymer antifouling agent, and the maleic anhydride-grafted PA6 compatibilizer are mixed evenly to obtain functional materials. The PA6 base masterbatch is fed into the main feed hopper of a twin-screw extruder, and the silane-modified inorganic pigment, the organic pigment, and the antioxidant are fed into the distribution hoppers respectively. At the same time, the functional materials are added to the side feed of the rear section of the twin-screw extruder. The mixture is melt-extruded at 250°C, water-cooled pelletized, and dried at a screw speed of 350 rpm to obtain the antibacterial and antifouling polymer composite material.

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