PA6 nylon composite material for high-temperature-resistant filter screen and preparation method of PA6 nylon composite material

Abstract

The invention discloses a PA6 nylon composite material for a high-temperature-resistant filter screen and a preparation method of the PA6 nylon composite material, and relates to the technical field of composite materials. The invention discloses a PA6 nylon composite material for a high-temperature-resistant filter screen. The nylon material is prepared from the following raw materials in parts by weight: 60 to 80 parts of modified PA6 nylon, 10 to 20 parts of modified glass fiber, 2 to 5 parts of montmorillonite, 0.3 to 0.8 part of antioxidant 1010, 0.2 to 0.6 part of stearic acid, 0.5 to 1.0 part of ethoxylated fatty amine, 1 to 3 parts of nano titanium dioxide, 1 to 3 parts of polytetrafluoroethylene micro powder, 3 to 8 parts of aluminum hydroxide, 0.5 to 1.5 parts of chitosan, 1 to 3 parts of hyperbranched polyamide and 0.5 to 1.5 parts of urea-formaldehyde resin coated epoxy resin microcapsules. And 0.3 to 0.8 part of sodium polyacrylate. The PA6 nylon composite material for the high-temperature-resistant filter screen has remarkable advantages. The material disclosed by the invention is high in mechanical property, good in thermal stability and stable in size at high temperature; the self-cleaning, antibacterial and antistatic functions are realized, and the filtering efficiency is high; chemical corrosion resistance, wear resistance and low water absorption are achieved; part of the raw materials can be recycled, the environmental protection concept is met, and the use requirement of the high-temperature-resistant filter screen in a complex environment can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and specifically to a PA6 nylon composite material for high-temperature resistant filter screens and a preparation method thereof. Background Art

[0002] In modern industrial production and daily life, filter screens, as key filtering components, are widely and importantly applied. Especially in fields involving high-temperature environments, such as the chemical, power, aerospace and other industries, extremely stringent performance requirements are imposed on high-temperature resistant filter screens. When facing high temperatures, the performance of traditional filter screen materials will decline to varying degrees, making it difficult to meet the actual usage requirements.

[0003] PA6 nylon, as a common engineering plastic, has good mechanical properties, wear resistance and chemical stability, but there are certain limitations in its high-temperature resistance performance. In a high-temperature environment, the molecular chains of PA6 nylon are prone to thermal motion and decomposition, resulting in a decline in properties such as the strength and dimensional stability of the material, affecting the filtration accuracy and service life of the filter screen.

[0004] Although glass fiber has high strength, high modulus and good high-temperature resistance performance, its interfacial compatibility with the polymer matrix is poor, and it is difficult to fully play an enhancing role in composite materials, restricting its application in high-performance filter screens.

[0005] Existing composite materials for high-temperature resistant filter screens also have deficiencies in comprehensive performance. Some materials have certain high-temperature resistance, but perform poorly in terms of filtration efficiency, antibacterial performance, self-cleaning performance, etc.; for some materials, it is difficult to balance the mechanical properties and chemical stability, and they cannot work stably in complex high-temperature chemical environments. Moreover, with the increasing environmental protection requirements, traditional filter screen materials have difficulties in recycling, which does not conform to the concept of sustainable development.

[0006] Therefore, it is extremely urgent to develop a PA6 nylon composite material for high-temperature resistant filter screens with excellent comprehensive performance, which can meet the usage requirements in complex high-temperature environments and is environmentally friendly, and a preparation method thereof. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the present invention provides a PA6 nylon composite material for high-temperature resistant filter screens and a preparation method thereof, solving the above problems.

[0008] To achieve the above purposes, the present invention is realized through the following technical solutions:

[0009] A PA6 nylon composite material for high-temperature resistant filter screens, comprising the following raw materials in parts by weight: 60-80 parts of modified PA6 nylon, 10-20 parts of modified glass fiber, 2-5 parts of montmorillonite, 0.3-0.8 parts of antioxidant 1010, 0.2-0.6 parts of stearic acid, 0.5-1.0 parts of ethoxylated fatty amine, 1-3 parts of nano titanium dioxide, 1-3 parts of polytetrafluoroethylene micropowder, 3-8 parts of aluminum hydroxide, 0.5-1.5 parts of chitosan, 1-3 parts of hyperbranched polyamide, 0.5-1.5 parts of urea-formaldehyde resin-coated epoxy resin microcapsules, 0.3-0.8 parts of sodium polyacrylate.

[0010] Further, the modified PA6 nylon is prepared by the following specific steps:

[0011] A1. Introduce nitrogen into a three-necked flask, then add hexafluoroisopropanol to the flask, turn on the stirring device, slowly add PA6 nylon under stirring, continuously stir until it is completely dissolved, and then add silicon carbide nanowires for ultrasonic dispersion;

[0012] A2. Slowly add maleic anhydride, N,N'-methylenebisacrylamide and p-toluenesulfonic acid to the above system, raise the temperature to 80 °C and increase the stirring speed, then slowly add 2-hydroxyethyl acrylate, and continue stirring to obtain a PA6 nylon solution grafted with maleic anhydride;

[0013] A3. Under the continuous introduction of nitrogen, slowly dropwise add glycidyl methacrylate and benzoyl peroxide initiator, and slowly raise the temperature to 90 °C. When half of the glycidyl methacrylate has been added dropwise, start dropping triallyl isocyanurate, and continue the reaction after the addition is completed;

[0014] A4. After the reaction is completed, pour the substances in the system into a methanol precipitant, filter with a Buchner funnel, collect the precipitate, and wash with deionized water; transfer the washed product to a 60 °C vacuum drying oven and dry until the product has a constant weight;

[0015] A5. Take the dried product and a hyperbranched polymer containing amino groups, stir and mix them evenly, then add polyetheretherketone powder and yttrium oxide nanoparticles, continue stirring, and then put them into a twin-screw extruder for melt blending. After the material is extruded, it is cooled and solidified to obtain modified PA6 nylon.

[0016] Further, the flow rate of nitrogen gas introduced into A1 is 30 L / h, and the introduction duration is 30 minutes; stirring is carried out at a rotation speed of 200 r / min for 30 minutes, and ultrasonic dispersion is carried out for 15 minutes; the dosage ratio of hexafluoroisopropanol, PA6 nylon, and silicon carbide nanowires is 200 mL: 22.2 g: 1.0 g; the stirring speed of A2 is 300 r / min, the stirring reaction is carried out for 2 hours, and after adding hydroxyethyl acrylate, the stirring reaction is continued for 2 hours. The dosage ratio of maleic anhydride, N,N'-methylenebisacrylamide, p-toluenesulfonic acid, and hydroxyethyl acrylate is 1.1 g: 0.3 g: 0.07 g: 0.5 g.

[0017] Further, the stirring speed in A3 is 300 r / min, and after the dropping is completed, the reaction continues for 3 hours. The dosage ratio of glycidyl methacrylate, benzoyl peroxide, and triallyl isocyanurate is 1.8 g: 0.048 g: 0.2 g; in A5, the initial stirring is carried out for 1 hour, and after adding polyetheretherketone powder and yttrium oxide nanoparticles, the stirring is continued for 1 hour. The temperature of the twin-screw extruder is set at 220 °C, and the screw rotation speed is 200 r / min. The dosage ratio of the dried product, hyperbranched polymer containing amino groups, polyetheretherketone powder, and yttrium oxide nanoparticles is 20 g: 2 g: 1.0 g: 0.5 g.

[0018] p-Toluenesulfonic acid is used as a catalyst to lower the reaction activation energy. Under the stirring conditions of 80 °C and 300 r / min, the methylene group on the PA6 nylon molecular chain undergoes a radical addition reaction with maleic anhydride under the action of the catalyst. The double bond in maleic anhydride opens and binds to the PA6 nylon molecular chain to form PA6 nylon grafted with maleic anhydride, introducing active groups for subsequent reactions.

[0019] N,N'-Methylenebisacrylamide contains two double bonds and can undergo a radical copolymerization reaction with the active sites on the molecular chain of PA6 nylon grafted with maleic anhydride to form a cross-linked structure between the molecular chains, enhancing the mechanical properties of the material. The double bond of hydroxyethyl acrylate undergoes copolymerization with the PA6 nylon grafted with maleic anhydride and the already reacted N,N'-methylenebisacrylamide under the reaction conditions, introducing hydroxyl groups, increasing the polarity and reactivity of the molecular chain, and simultaneously improving the flexibility and water resistance of the material.

[0020] Benzoyl peroxide decomposes upon heating to generate free radicals, initiating a grafting reaction between the double bond of glycidyl methacrylate and the unreacted active sites on the PA6 nylon grafted with maleic anhydride, introducing epoxy groups onto the PA6 nylon molecular chain. Triallyl isocyanurate contains multiple double bonds and can further undergo a cross-linking reaction with the PA6 nylon grafted with maleic anhydride and the reaction product of glycidyl methacrylate to construct a more complex three-dimensional network structure, significantly improving the mechanical properties, thermal stability, and chemical stability of the material.

[0021] The amino groups of the hyperbranched polymer undergo a ring-opening reaction with the epoxy groups on the PA6 nylon grafted with maleic anhydride, followed by further cross-linking and curing to enhance the strength and toughness of the material. The polyetheretherketone powder has excellent high-temperature resistance and mechanical properties and is uniformly dispersed in the PA6 nylon matrix to play a reinforcing role. The yttrium oxide nanoparticles can refine the grains, improve the crystallinity of the material, and enhance the thermal stability and wear resistance of the material.

[0022] Furthermore, the modified glass fiber is prepared as follows:

[0023] B1. Mix the silane coupling agent in ethanol, gradually add glacial acetic acid dropwise to the solution until the pH value reaches 4. Place the container on a magnetic stirrer, then add the glass fiber, stir and soak at room temperature. After the soaking is completed, take out the glass fiber and put it into a blast drying oven.

[0024] B2. Pass nitrogen into a three-necked flask, add butyl acrylate and vinyltrimethoxysilane to prepare a mixed solution. Add an azobisisobutyronitrile initiator, polyhedral oligomeric silsesquioxane, and graphene nanosheets to the mixed solution, mix and stir. Immerse the silanized glass fiber in the above mixed solution, control the reaction temperature at 60 °C through a water bath, and continuously stir.

[0025] B3. Take out the glass fiber treated in B2, put it into a high-speed mixer together with nano-titanium dioxide, and mix well. Transfer the mixed material to a reaction container. Add a copper sulfate catalytic solution and aluminum borate whiskers to the dopamine hydrochloride solution, stir and dissolve, then add it to the reaction container containing the mixed material. Adjust the pH value of the solution to 8 with sodium hydroxide solution. Place the reaction container on a magnetic stirrer. After completion, take out the glass fiber, rinse it repeatedly with deionized water, and place the rinsed glass fiber in a ventilated place to dry to obtain the modified glass fiber.

[0026] Furthermore, in B1, the stirring speed is 100 r / min, stir and soak at room temperature for 2 hours, the drying oven temperature is 120 °C, and dry for 4 hours; the dosage ratio of ethanol, KH-550 silane coupling agent, and glass fiber is 475 mL: 25 mL: 50 g.

[0027] Furthermore, in B2, the nitrogen flow rate is 20 L / h, and the inlet time is 30 minutes; the stirring speed of the mixed solution is 200 r / min, stir for 15 minutes; the stirring speed during water bath heating is 200 r / min, and continuously stir and react for 6 hours; the dosage ratio of butyl acrylate, vinyltrimethoxysilane, azobisisobutyronitrile, polyhedral oligomeric silsesquioxane, and graphene nanosheets is 210 mL: 90 mL: 1.5 g: 0.5 g: 0.3 g.

[0028] Further, the rotation speed of the high-speed mixer in B3 is set to 1000 r / min and mixed thoroughly for 10 minutes; the stirring speed of the magnetic stirrer is 200 r / min and the stirring reaction lasts for 3 hours; the dosage ratio of nano-titanium dioxide, dopamine hydrochloride solution, copper sulfate catalytic solution, and aluminum borate whiskers is 5 g: 100 mL: 1.0 g: 0.5 g.

[0029] The molecular structure of the silane coupling agent contains hydrolyzable alkoxy groups and organic functional groups. Under acidic conditions, the alkoxy groups hydrolyze to form silanols, and the silanols undergo a condensation reaction with the hydroxyl groups on the surface of the glass fiber to form a -Si-O-Si- chemical bond, enabling the silane coupling agent to be firmly grafted onto the surface of the glass fiber, establishing a chemical bonding between the glass fiber and the organic polymer matrix, and improving the interfacial compatibility.

[0030] Azobisisobutyronitrile decomposes when heated to generate free radicals, initiating a free radical polymerization reaction of the double bonds of butyl acrylate and vinyltrimethoxysilane. The vinyl groups on the surface of the silanized glass fiber combine with the free radicals in the polymerization reaction, grafting the polymer chains onto the surface of the glass fiber, increasing the surface roughness and active sites of the glass fiber, improving the mechanical meshing and chemical bonding force with the matrix, and simultaneously endowing the glass fiber with certain flexibility and chemical corrosion resistance.

[0031] Polydopamine has strong adhesion and can firmly adhere to the surfaces of glass fiber and nano-titanium dioxide. The nano-titanium dioxide is uniformly dispersed in the polydopamine coating. On the one hand, it enhances the self-cleaning performance of the glass fiber. The electron-hole pairs generated by the nano-titanium dioxide under light can decompose the surface organic substances. On the other hand, it improves the anti-microbial performance and destroys the cell membranes and cell structures of microorganisms. The aluminum borate whiskers enhance the mechanical properties of the material. They are uniformly dispersed on the surface of the glass fiber, playing a role in enhancing and toughening, and simultaneously improving the high-temperature resistance of the material.

[0032] A preparation method of a PA6 nylon composite material for a high-temperature resistant filter screen specifically includes the following steps:

[0033] S1. Turn on the twin-screw extruder and set the temperature of each section of the extruder to 250 °C for preheating;

[0034] S2. Add the modified PA6 nylon, modified glass fiber, montmorillonite, and sodium polyacrylate into a high-speed mixer. After the temperature of the twin-screw extruder is stable, transfer the well-mixed material in the high-speed mixer to the hopper of the twin-screw extruder;

[0035] S3. Through the automatic feeding device of the hopper, sequentially add antioxidant 1010, stearic acid, ethoxylated fatty amine, nano-titanium dioxide, polytetrafluoroethylene micro-powder, aluminum hydroxide, chitosan, hyperbranched polyamide, and urea-formaldehyde resin-coated epoxy resin microcapsules into the twin-screw extruder for full melting and mixing;

[0036] S4. The material is extruded into a strip by the head and introduced into a cooling water tank for water cooling and solidification; the cooled strip is cut into uniformly sized particles and placed in a drying oven at 80 °C for drying to obtain a PA6 nylon composite material for high-temperature resistant filter screens.

[0037] Furthermore, in S2, the material is mixed in a mixer at 120 °C for 15 minutes; in S3, the screw speed of the twin-screw extruder is set at 300 r / min; in S4, at the front section of the cooling water tank, the water temperature is set at 40 °C and the water flow rate is 0.5 m / s to rapidly and preliminarily cool the sheath tube blank; in the middle section, the water temperature is reduced to 30 °C and the water flow rate is adjusted to 0.3 m / s for further cooling and solidification; in the rear section, the water temperature is maintained at 20 °C and the water flow rate is 0.2 m / s to complete the final cooling and shaping; after cooling, it is cut into particles with a diameter of 4 mm and dried in a drying oven for 2 hours.

[0038] The present invention provides a PA6 nylon composite material for high-temperature resistant filter screens and a preparation method thereof, having the following beneficial effects:

[0039] 1. Through the deep modification of PA6 nylon and glass fiber, maleic anhydride is grafted onto the PA6 nylon molecular chain, then an epoxy group is introduced, and a three-dimensional network structure is constructed with a hyperbranched polymer containing amino groups; the glass fiber is subjected to silanization treatment, grafted with a polymer chain, and a polydopamine coating is formed, greatly enhancing the interfacial bonding force between the two. This significantly enhances the tensile strength, flexural strength, and impact toughness of the composite material. When subjected to a large external force, it can effectively disperse stress, reduce deformation and damage. At the same time, the stable three-dimensional network structure and interfacial bonding improve the dimensional stability of the material in complex environments such as high temperature and chemical erosion, ensuring that the filter screen maintains an accurate shape and size during long-term use and maintaining good filtering performance.

[0040] 2. The addition of various functional additives endows the composite material with rich functions. Nano-titanium dioxide and the polydopamine coating endow the material with self-cleaning and anti-microbial properties. The free radicals generated by nano-titanium dioxide under light can decompose surface organic dirt and inhibit the growth of microorganisms; the flame retardant can effectively improve the flame retardant performance of the material. When encountering an open flame or high temperature, it can prevent the spread of fire by absorbing heat and generating non-combustible gases, ensuring use safety; ethoxylated fatty amine reduces the surface resistance of the material, avoiding the adsorption of dust due to electrostatic accumulation and affecting the filtering effect; polytetrafluoroethylene micropowder provides superhydrophobic self-lubricating performance, reduces fluid resistance, improves filtering efficiency, and is convenient for cleaning and maintenance, meeting the special requirements of filter screens in different scenarios.

[0041] 3. The modification of PA6 nylon and the addition of flame retardants, antioxidants, etc. have greatly improved the thermal stability of the material. In a high-temperature environment, the three-dimensional network structure and stable chemical bonds can effectively resist the thermal movement and decomposition of molecular chains. Antioxidants prevent the material from aging due to oxidation, and flame retardants inhibit combustion reactions, enabling the material to operate stably at high temperatures for a long time. At the same time, the self-healing agent and good chemical stability enable the material to self-repair and maintain its performance after being slightly damaged or chemically eroded, extending the service life of the filter screen, reducing the replacement frequency, and lowering the usage cost.

[0042] 4. Environmental protection factors were fully considered in the design of this composite material. On the one hand, some raw materials are recyclable. After the service life of the filter screen ends, they can be processed through appropriate recycling processes and reprocessed for reuse, reducing waste generation and the pressure on the environment. On the other hand, during use, the self-cleaning and anti-microbial properties reduce the use of chemical cleaners and avoid environmental pollution caused by cleaners. In addition, the high performance of the material extends the service life of the filter screen, indirectly reducing resource consumption caused by frequent filter screen replacement, conforming to the concept of sustainable development, and providing strong support for the development of the green environmental protection industry. Specific Embodiments

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0044] Example 1. A PA6 nylon composite material for preparing a high-temperature resistant filter screen was prepared, and the preparation method was as follows:

[0045] S1. Turn on the twin-screw extruder and set the temperature of each section of the extruder to 250 °C for preheating.

[0046] S2. Add 60 parts of modified PA6 nylon, 10 parts of modified glass fiber, 2 parts of montmorillonite, and 0.3 parts of sodium polyacrylate to a high-speed mixer, mix at 120 °C for 15 minutes, and transfer the mixed material in the high-speed mixer to the hopper of the twin-screw extruder after the temperature of the twin-screw extruder is stable.

[0047] S3. Through the automatic feeding device of the hopper, sequentially add 0.3 parts of antioxidant 1010, 0.2 parts of stearic acid, 0.5 parts of ethoxylated fatty amine, 1 part of nano-titanium dioxide, 1 part of polytetrafluoroethylene micropowder, 3 parts of aluminum hydroxide, 0.5 parts of chitosan, 1 part of hyperbranched polyamide, and 0.5 parts of urea-formaldehyde resin-coated epoxy resin microcapsules to the twin-screw extruder for melting and mixing. The screw speed of the twin-screw extruder is set to 300 r / min.

[0048] S4. The material is extruded into a strip by the head and introduced into a cooling water tank for water-cooling and solidification. In the front section of the cooling water tank, the water temperature is set at 40 °C and the water flow rate is 0.5 m / s to quickly and preliminarily cool the sheath tube blank; in the middle section, the water temperature is reduced to 30 °C and the water flow rate is adjusted to 0.3 m / s for further cooling and solidification; in the rear section, the water temperature is maintained at 20 °C and the water flow rate is 0.2 m / s to complete the final cooling and shaping; the cooled strip is cut into uniform particles with a diameter of 4 mm and placed in an 80 °C drying oven for 2 hours to obtain the PA6 nylon composite material for high-temperature resistant filter screens.

[0049] Example 2. The preparation method of the PA6 nylon composite material for high-temperature resistant filter screens is as follows:

[0050] S1. Turn on the twin-screw extruder and set the temperature of each section of the extruder at 250 °C for preheating.

[0051] S2. Add 80 parts of modified PA6 nylon, 20 parts of modified glass fiber, 5 parts of montmorillonite, and 0.8 part of sodium polyacrylate into a high-speed mixer, mix at 120 °C for 15 minutes, and transfer the mixed material in the high-speed mixer to the hopper of the twin-screw extruder after the temperature of the twin-screw extruder is stable.

[0052] S3. Through the automatic feeding device of the hopper, sequentially add 0.8 part of antioxidant 1010, 0.6 part of stearic acid, 1 part of ethoxylated fatty amine, 3 parts of nano-titanium dioxide, 3 parts of polytetrafluoroethylene micropowder, 8 parts of aluminum hydroxide, 1.5 parts of chitosan, 3 parts of hyperbranched polyamide, and 1.5 parts of urea-formaldehyde resin-coated epoxy resin microcapsules into the twin-screw extruder for melting and mixing, and set the screw speed of the twin-screw extruder at 300 r / min.

[0053] S4. The material is extruded into a strip by the head and introduced into a cooling water tank for water-cooling and solidification. In the front section of the cooling water tank, the water temperature is set at 40 °C and the water flow rate is 0.5 m / s to quickly and preliminarily cool the sheath tube blank; in the middle section, the water temperature is reduced to 30 °C and the water flow rate is adjusted to 0.3 m / s for further cooling and solidification; in the rear section, the water temperature is maintained at 20 °C and the water flow rate is 0.2 m / s to complete the final cooling and shaping; the cooled strip is cut into uniform particles with a diameter of 4 mm and placed in an 80 °C drying oven for 2 hours to obtain the PA6 nylon composite material for high-temperature resistant filter screens.

[0054] Example 3. The preparation method of the PA6 nylon composite material for high-temperature resistant filter screens is as follows:

[0055] S1. Turn on the twin-screw extruder and set the temperature of each section of the extruder at 250 °C for preheating.

[0056] S2. Add 70 parts of modified PA6 nylon, 15 parts of modified glass fiber, 3 parts of montmorillonite, and 0.5 part of sodium polyacrylate into a high-speed mixer, mix at 120 °C for 15 minutes. After the temperature of the twin-screw extruder is stabilized, transfer the well-mixed materials in the high-speed mixer to the hopper of the twin-screw extruder;

[0057] S3. Through the automatic feeding device of the hopper, sequentially add 0.5 part of antioxidant 1010, 0.4 part of stearic acid, 0.7 part of ethoxylated fatty amine, 2 parts of nano-titanium dioxide, 2 parts of polytetrafluoroethylene micropowder, 5 parts of aluminum hydroxide, 1 part of chitosan, 2 parts of hyperbranched polyamide, and 1 part of urea-formaldehyde resin-coated epoxy resin microcapsules into the twin-screw extruder for melting and mixing. The screw speed of the twin-screw extruder is set at 300 r / min;

[0058] S4. The material is extruded into a strip by the die head, introduced into a cooling water tank for water-cooling curing. In the front section of the cooling water tank, set the water temperature at 40 °C and the water flow rate at 0.5 m / s to rapidly cool the casing blank preliminarily; in the middle section, the water temperature is reduced to 30 °C and the water flow rate is adjusted to 0.3 m / s for further cooling and curing; in the rear section, the water temperature is maintained at 20 °C and the water flow rate is 0.2 m / s to complete the final cooling and shaping; the cooled strip is cut into uniform particles with a diameter of 4 mm and placed in a drying oven at 80 °C for drying for 2 hours to obtain the PA6 nylon composite material for high-temperature filter screens.

[0059] Example 4. Prepare modified PA6 nylon, and the preparation method is as follows:

[0060] A1. Continuously introduce nitrogen into the three-necked flask at a flow rate of 30 L / h for 30 minutes, then add 200 mL of hexafluoroisopropanol into the flask, turn on the stirring device, stir at 200 r / min, slowly add 22.2 g of PA6 nylon under stirring, continuously stir for 30 minutes until completely dissolved, and then add 1.0 g of silicon carbide nanowires and ultrasonically disperse for 15 minutes;

[0061] A2. Slowly add 1.1 g of maleic anhydride, 0.3 g of N,N'-methylenebisacrylamide, and 0.07 g of p-toluenesulfonic acid to the above system, raise the temperature to 80 °C, and increase the rotation speed to 300 r / min, continuously stir and react for 2 hours, then slowly add 0.5 g of 2-hydroxyethyl acrylate, and continue to stir and react for 2 hours to obtain a PA6 nylon solution grafted with maleic anhydride;

[0062] A3. Under the condition of continuously introducing nitrogen, slowly dropwise add 1.8 g of glycidyl methacrylate and 0.048 g of benzoyl peroxide initiator. During the dropping, maintain the stirring speed at 300 r / min and slowly raise the temperature to 90 °C. When half of the glycidyl methacrylate has been dropped, start to dropwise add 0.2 g of triallyl isocyanurate, and continue to react for 3 hours after the dropping ends;

[0063] A4. After the reaction is completed, pour the substances in the system into a methanol precipitant, filter with a Buchner funnel, collect the precipitate, and wash it with deionized water; transfer the washed product to a vacuum drying oven at 60 °C and dry until the product reaches a constant weight.

[0064] A5. Take 20 g of the dried product and 2 g of a hyperbranched polymer containing amino groups, stir for 1 hour to mix evenly, then add 1.0 g of polyetheretherketone powder and 0.5 g of yttrium oxide nanoparticles, continue to stir for 1 hour, and then put them into a twin-screw extruder. Set the temperature of the twin-screw extruder to 220 °C and the screw speed to 200 r / min for melt blending. After the material is extruded, it is cooled and solidified to obtain modified PA6 nylon.

[0065] Example 5. Preparation of modified glass fiber. The preparation method is as follows:

[0066] B1. Mix 25 mL of silane coupling agent in 475 mL of ethanol. Dropwise add glacial acetic acid to this solution until the pH value is 4. Place the container on a magnetic stirrer, then add 50 g of glass fiber, set the stirring speed to 100 r / min, and stir and soak at room temperature for 2 hours. After the soaking is completed, take out the glass fiber and dry it in a blast drying oven at 120 °C for 4 hours.

[0067] B2. Pass nitrogen into the three-necked flask at a flow rate of 20 L / h for 30 minutes. Add 210 mL of butyl acrylate and 90 mL of vinyltrimethoxysilane to prepare a mixed solution. Add 1.5 g of azobisisobutyronitrile initiator, 0.5 g of polyhedral oligomeric silsesquioxane, and 0.3 g of graphene nanosheets to the mixed solution, stir at a speed of 200 r / min for 15 minutes, immerse the silanized glass fiber in the above mixed solution, control the reaction temperature at 60 °C through a water bath, set the stirring speed to 200 r / min, and continuously stir and react for 6 hours.

[0068] B3. Take out the glass fiber treated in B2, put it into a high-speed mixer together with 5 g of nano-titanium dioxide, set the rotation speed to 1000 r / min, and mix well for 10 minutes. Transfer the mixed material to a reaction container; add 1.0 g of copper sulfate catalytic solution and 0.5 g of aluminum borate whiskers to 100 mL of dopamine hydrochloride solution, stir and dissolve, then add it to the reaction container containing the mixed material, adjust the pH value of the solution to 8 with sodium hydroxide solution, place the reaction container on a magnetic stirrer, set the stirring speed to 200 r / min, stir and react for 3 hours. After completion, take out the glass fiber, rinse it repeatedly with deionized water, and place the rinsed glass fiber in a ventilated place to dry, obtaining the modified glass fiber.

[0069] Comparative Example 1. Preparation of PA6 nylon composite material for high-temperature resistant filter mesh. The preparation method is as follows:

[0070] Keep the remaining steps unchanged, and only replace the modified PA6 nylon in Example 2 with PA6 nylon without any treatment to prepare the PA6 nylon composite material for high-temperature resistant filter mesh.

[0071] Comparative Example 2: Prepare the PA6 nylon composite material for high-temperature resistant filter mesh. The preparation method is as follows:

[0072] Keep the remaining steps unchanged, and only replace the modified glass fiber in Example 2 with glass fiber without any treatment to prepare the PA6 nylon composite material for high-temperature resistant filter mesh.

[0073] Performance Test Test Items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tensile Strength (MPa) 80 95 88 60 70 Flexural Strength (MPa) 90 105 98 70 80 Impact Toughness (kJ / m²) 60 75 68 40 50 Heat Distortion Temperature (°C) 180 200 190 150 160 Filtration Efficiency (%) 90 95 93 70 80 Self-Cleaning Performance (Dirt Residual Rate after 24 h of Illumination) (%) 20 15 18 40 35 Antibacterial Rate (against Escherichia coli) (%) 95 98 96 70 80 Surface Resistivity (Ω) <![CDATA[10 10 > <![CDATA[10 9 > <![CDATA[10 9 > <![CDATA[10 12 > <![CDATA[10 11 > Flame Retardant Grade V-0 V-0 V-0 V-2 V-1 Chemical Resistance (Mass Loss Rate after Immersion in 10% Hydrochloric Acid Solution for 24 h) (%) 2 1.5 1.8 5 4 Wear Resistance (Wear Loss, mg / 1000r) 50 40 45 70 60 Water Absorbency (Water Absorption Rate after Immersion for 24 h) (%) 1.5 1.2 1.3 3 2.5 Dimensional Stability (Dimensional Change Rate after Heating at 80 °C for 24 h) (%) 0.2 0.15 0.18 0.5 0.4 。

[0074] From the performance test results, the performance of Examples 3-5 is outstanding. In terms of chemical corrosion resistance and wear resistance, its mass loss rate is low and the abrasion amount is small; the water absorption is low, reducing the performance deterioration caused by water absorption; the dimensional stability is good, and the dimensional change at high temperature is tiny. While the performance of Comparative Example 1 and Comparative Example 2 is significantly inferior to that of the Examples. Comparative Example 1 uses unmodified PA6 nylon, and there are serious deteriorations in aspects such as chemical corrosion resistance, wear resistance, water absorption, and dimensional stability; Comparative Example 2 uses unmodified glass fiber, and all performances also decrease significantly. This fully shows that the modification of PA6 nylon and glass fiber is crucial for improving the comprehensive performance of the composite material. The modified composite material has significant advantages in various performances and is more in line with the use requirements of high-temperature resistant filter meshes in complex environments.

[0075] The above content is only an example and explanation of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution. As long as it does not deviate from the invention or exceed the scope defined by this claim book, it shall fall within the protection scope of the present invention.

Claims

1. A PA6 nylon composite material for high-temperature resistant filter screens, characterized in that: Comprising the following raw materials in parts by weight: 60 - 80 parts of modified PA6 nylon, 10 - 20 parts of modified glass fiber, 2 - 5 parts of montmorillonite, 0.3 - 0.8 part of antioxidant 1010, 0.2 - 0.6 part of stearic acid, 0.5 - 1.0 part of ethoxylated fatty amine, 1 - 3 parts of nano titanium dioxide, 1 - 3 parts of polytetrafluoroethylene micropowder, 3 - 8 parts of aluminum hydroxide, 0.5 - 1.5 parts of chitosan, 1 - 3 parts of hyperbranched polyamide, 0.5 - 1.5 parts of urea - formaldehyde resin - coated epoxy resin microcapsules, 0.3 - 0.8 part of sodium polyacrylate.

2. The PA6 nylon composite material for a high-temperature resistant filter screen according to claim 1, wherein: The specific preparation steps of the modified PA6 nylon are as follows: A1. Introduce nitrogen into a three - necked flask, then add hexafluoroisopropanol into the flask, start the stirring device, slowly add PA6 nylon under stirring, continuously stir until it is completely dissolved, and then add silicon carbide nanowires for ultrasonic dispersion; A2. Slowly add maleic anhydride, N,N'-methylenebisacrylamide and p - toluenesulfonic acid into the above - mentioned system, raise the temperature to 80 °C and increase the stirring speed, then slowly add 2 - hydroxyethyl acrylate, and continue stirring to obtain a PA6 nylon solution grafted with maleic anhydride; A3. Under the condition of continuously introducing nitrogen, slowly dropwise add glycidyl methacrylate and benzoyl peroxide initiator, and slowly raise the temperature to 90 °C. When half of the glycidyl methacrylate has been added dropwise, start to dropwise add triallyl isocyanurate, and continue the reaction after the addition is completed; A4. After the reaction is completed, pour the substances in the system into a methanol precipitant, filter with a Buchner funnel, collect the precipitate, and wash it with deionized water; Transfer the washed product to a 60 °C vacuum drying oven and dry it until the product has a constant weight; A5. Take the dried product and a hyperbranched polymer containing amino groups, stir and mix them evenly, then add polyetheretherketone powder and yttrium oxide nanoparticles, continue stirring, and then put them into a twin - screw extruder for melt blending. After the material is extruded, it is cooled and solidified to obtain the modified PA6 nylon.

3. The PA6 nylon composite material for a high-temperature resistant filter screen according to claim 2, characterized in that: In step A1, the flow rate of nitrogen introduced is 30 L / h, and the introduction time is 30 minutes; stir at a speed of 200 r / min for 30 minutes, and perform ultrasonic dispersion for 15 minutes; the dosage ratio of hexafluoroisopropanol, PA6 nylon, and silicon carbide nanowires is 200 mL:22.2 g:1.0 g; in step A2, the stirring speed is 300 r / min, stir and react for 2 hours, and continue to stir and react for 2 hours after adding 2 - hydroxyethyl acrylate. The dosage ratio of maleic anhydride, N,N'-methylenebisacrylamide, p - toluenesulfonic acid, and 2 - hydroxyethyl acrylate is 1.1 g:0.3 g:0.07 g:0.5 g.

4. The PA6 nylon composite material for a high-temperature resistant filter screen according to claim 2, wherein: The stirring speed in A3 is 300 r / min. After the dropping is completed, the reaction continues for 3 hours. The dosage ratio of glycidyl methacrylate, benzoyl peroxide, and triallyl isocyanurate is 1.8 g: 0.048 g: 0.2 g. In A5, the initial stirring is for 1 hour. After adding polyether ether ketone powder and yttrium oxide nanoparticles, the stirring continues for 1 hour. The temperature of the twin-screw extruder is set at 220 °C, and the screw speed is 200 r / min. The dosage ratio of the dried product, hyperbranched polymer containing amino groups, polyether ether ketone powder, and yttrium oxide nanoparticles is 20 g: 2 g: 1.0 g: 0.5 g.

5. A PA6 nylon composite material for a high-temperature resistant filter screen according to claim 1, characterized in that: The specific preparation steps of the modified glass fiber are as follows: B1. Mix the silane coupling agent in ethanol. Gradually add glacial acetic acid to this solution until the pH value reaches 4. Place the container on a magnetic stirrer, then add glass fiber, and stir and soak at room temperature. After the soaking is completed, take out the glass fiber and put it into a blast drying oven. B2. Pass nitrogen into a three-necked flask, add butyl acrylate and vinyltrimethoxysilane to prepare a mixed solution. Add an azobisisobutyronitrile initiator, polyhedral oligomeric silsesquioxane, and graphene nanosheets to the mixed solution, and mix and stir. Immerse the silanized glass fiber into the above mixed solution, and control the reaction temperature at 60 °C through a water bath, and continue stirring. B3. Take out the glass fiber treated in B2, put it into a high-speed mixer together with nano-titanium dioxide, and mix well. Transfer the mixed material to a reaction container. Add a copper sulfate catalytic solution and aluminum borate whiskers to the dopamine hydrochloride solution, stir and dissolve, then add it to the reaction container containing the mixed material. Adjust the pH value of the solution to 8 with sodium hydroxide solution. Place the reaction container on a magnetic stirrer. After completion, take out the glass fiber, rinse it repeatedly with deionized water, and place the rinsed glass fiber in a ventilated place to dry, obtaining the modified glass fiber.

6. The PA6 nylon composite material for a high-temperature resistant filter screen according to claim 5, wherein: In B1, the stirring speed is 100 r / min, the stirring and soaking at room temperature is for 2 hours, the temperature of the drying oven is 120 °C, and the drying time is 4 hours. The dosage ratio of ethanol, KH-550 silane coupling agent, and glass fiber is 475 mL: 25 mL: 50 g.

7. The PA6 nylon composite material for a high-temperature resistant filter screen according to claim 5, wherein: In B2, the nitrogen flow rate is 20 L / h, and the flow-through time is 30 minutes. The stirring speed of the mixed solution is 200 r / min, and the stirring time is 15 minutes. When heating in a water bath, the stirring speed is 200 r / min, and the continuous stirring reaction time is 6 hours. The dosage ratio of butyl acrylate, vinyltrimethoxysilane, azobisisobutyronitrile, polyhedral oligomeric silsesquioxane, and graphene nanosheets is 210 mL: 90 mL: 1.5 g: 0.5 g: 0.3 g.

8. The PA6 nylon composite material for a high-temperature resistant filter screen according to claim 5, characterized in that: In B3, the rotation speed in the high-speed mixer is set at 1000 r / min, and the full mixing time is 10 minutes. The stirring speed of the magnetic stirrer is 200 r / min, and the stirring reaction time is 3 hours. The dosage ratio of nano-titanium dioxide, dopamine hydrochloride solution, copper sulfate catalytic solution, and aluminum borate whiskers is 5 g: 100 mL: 1.0 g: 0.5 g.

9. A preparation method of a PA6 nylon composite material for a high-temperature resistant filter screen, characterized in that: Specifically, it includes the following steps: S1. Turn on the twin-screw extruder and set the temperatures of each section of the extruder to 250 °C for preheating; S2. Add modified PA6 nylon, modified glass fiber, montmorillonite, and sodium polyacrylate into a high-speed mixer. After the temperature of the twin-screw extruder is stable, transfer the well-mixed material in the high-speed mixer to the hopper of the twin-screw extruder; S3. Through the automatic feeding device of the hopper, sequentially add antioxidant 1010, stearic acid, ethoxylated fatty amine, nano-titanium dioxide, polytetrafluoroethylene micropowder, aluminum hydroxide, chitosan, hyperbranched polyamide, and urea-formaldehyde resin-coated epoxy resin microcapsules into the twin-screw extruder for full melting and mixing; S4. The material is extruded into a strip through the die head and introduced into a cooling water tank for water cooling and solidification; the cooled strip is cut into uniformly sized particles and placed in a drying oven at 80 °C for drying to obtain the PA6 nylon composite material for high-temperature filter screens.

10. The preparation method of a PA6 nylon composite material for a high-temperature resistant filter screen according to claim 9, characterized in that : In S2, the materials are mixed in a mixer at 120 °C for 15 minutes; in S3, the screw speed of the twin-screw extruder is set to 300 r / min; in S4, at the front section of the cooling water tank, the water temperature is set to 40 °C and the water flow rate is 0.5 m / s to quickly and preliminarily cool the sheath tube blank; in the middle section, the water temperature is reduced to 30 °C and the water flow rate is adjusted to 0.3 m / s for further cooling and solidification; in the rear section, the water temperature is maintained at 20 °C and the water flow rate is 0.2 m / s to complete the final cooling and shaping; after cooling, it is cut into particles with a diameter of 4 mm and dried in a drying oven for 2 hours.