High-toughness bundling grating and production process thereof

Abstract

The invention provides a high-toughness bundling grating and a production process of the high-toughness bundling grating. The composite material is prepared from the following raw materials in parts by weight: 32 to 42 parts of epoxy modified unsaturated polyester resin, 26 to 36 parts of alkali-free glass fiber, 7 to 11 parts of metallocene polyolefin, 5 to 9 parts of high-branching-degree polyolefin, 4 to 8 parts of ethylene propylene diene monomer, 2.5 to 5.5 parts of core-shell structure elastomer toughening agent, 1.5 to 4.5 parts of modified nano aluminum nitride-graphene composite filler, 0.7 to 1.1 parts of silane coupling agent and 0.5 to 0.9 part of antioxidant. 0.4 to 0.7 part of ultraviolet stabilizer, 0.4 to 0.8 part of calcium stearate and 0.1 to 0.3 part of conductive additive. According to the invention, the core-shell structure elastomer toughening agent realizes toughening without damaging strength through core-shell synergy, and the impact strength is improved by 40% or above; the modified nano aluminum nitride-graphene composite filler constructs a heat conduction-antistatic network, and the modified nano aluminum nitride-graphene composite filler and the metallocene polyolefin are matched with the high-branching-degree polyolefin and the ethylene propylene diene monomer to enhance low-temperature toughness and creep resistance.

Description

Technical Field

[0001] This invention relates to the field of grid technology, specifically to a high-toughness clustered grid and its manufacturing process. Background Technology

[0002] Clustered bar grids are widely used in municipal drainage, traffic protection, and soil stabilization. Their core performance requirements focus on mechanical strength, weather resistance, and structural stability to adapt to complex outdoor environments. In existing technologies, clustered bar grids are mostly based on polyolefin resins. Conventional toughening agents are often added to improve toughness, or inorganic fillers are mixed in to optimize some physical properties. However, the overall performance optimization direction is relatively singular and it is difficult to fully meet the multi-dimensional needs of practical applications.

[0003] Existing technologies for producing clustered grids still have shortcomings in terms of performance balance and adaptability to extreme environments. On the one hand, conventional toughening agents added to improve toughness can easily lead to a decrease in the overall strength of the product, making it difficult to achieve the effect of "toughening without sacrificing strength," thus affecting the structural reliability of the grid under load. On the other hand, the product is prone to brittleness in low-temperature environments, and its creep resistance is insufficient under long-term loads, shortening the actual service life of the grid. Therefore, how to improve the toughness of clustered grids while avoiding strength loss, and how to simultaneously enhance its low-temperature toughness and long-term creep resistance, have become urgent technical problems to be solved in existing technologies. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a high-toughness clustered grid and its manufacturing process.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This application discloses a high-toughness clustered grid, which, by weight, comprises the following raw materials: 32-42 parts of epoxy-modified unsaturated polyester resin, 26-36 parts of alkali-free glass fiber, 7-11 parts of metallocene polyolefin, 5-9 parts of highly branched polyolefin, 4-8 parts of EPDM rubber, 2.5-5.5 parts of core-shell elastomer toughening agent, 1.5-4.5 parts of modified nano-aluminum nitride-graphene composite filler, 0.7-1.1 parts of silane coupling agent, 0.5-0.9 parts of antioxidant, 0.4-0.7 parts of ultraviolet stabilizer, 0.4-0.8 parts of calcium stearate, and 0.1-0.3 parts of conductive additive.

[0006] By setting up the above technical solution, epoxy-modified unsaturated polyester resin serves as the matrix resin, providing the grid with basic high strength and chemical resistance; alkali-free glass fiber, as a macroscopic reinforcing skeleton, can suppress crack propagation under stress and improve the overall mechanical strength; metallocene polyolefins can optimize the matrix flexibility, and highly branched polyolefins can increase molecular entanglement points, the two synergistically strengthening the low-temperature toughness of the grid and preventing brittleness in low-temperature environments; EPDM rubber absorbs impact energy through elastic segments, while improving the weather resistance of the grid, making it suitable for outdoor use; core-shell structure elastomer toughening agents can achieve "toughening without sacrificing strength," further improving the room temperature and low-temperature impact strength of the grid; modified nano-aluminum nitride- Graphene composite fillers can construct a thermally conductive and antistatic network, solving the problems of high-temperature performance degradation and static electricity accumulation in the use of grids; silane coupling agents can bridge inorganic fillers (alkali-free glass fiber, modified nano-aluminum nitride-graphene composite fillers) and organic matrix, improving interfacial bonding and ensuring the stability of the grid's mechanical properties; antioxidants can inhibit the thermo-oxidative degradation of the grid during processing and use, extending its service life; UV stabilizers can block photo-oxidation reactions and reduce UV aging damage to the grid; calcium stearate can improve the demolding properties of the grid during molding, avoiding surface defects and ensuring appearance and surface performance; conductive additives can help construct antistatic pathways, ensuring that the grid's antistatic performance is stable and meets standards.

[0007] Preferably, the core-shell elastomer toughening agent comprises, by weight, 3-4 parts sodium dodecylbenzenesulfonate, 300-340 parts deionized water, 90-100 parts ethylene propylene diene monomer (EPDM) rubber, 5-7 parts divinylbenzene, 80-90 parts styrene-acrylonitrile copolymer, and 2-2.5 parts benzoyl peroxide.

[0008] By setting up the above technical solution, sodium dodecylbenzenesulfonate, as an emulsifier, can form a stable emulsion in deionized water, providing a uniform reaction environment for the subsequent dispersion of raw materials; deionized water, as a dispersion medium, ensures uniform mixing of various raw materials during the preparation process, avoiding impurities from affecting product performance; ethylene propylene diene monomer (EPDM) rubber, as the core material, can form elastic microdomains in the final core-shell structure elastomer toughening agent due to its elastic properties, laying the foundation for high-toughness clustered grids to absorb impact energy and improve toughness; divinylbenzene, as a crosslinking agent, can promote the formation of crosslinked structures in EPDM rubber, enhancing its strength. The core layer exhibits elastic stability, preventing excessive deformation under stress. The styrene-acrylonitrile copolymer, used as the shell material, has good compatibility with the matrix resin of the high-toughness bundled grid (such as epoxy-modified unsaturated polyester resin), preventing elastomer agglomeration in the matrix and achieving a tight bond between the shell and core layers. Benzoyl peroxide, acting as an initiator, initiates the polymerization reaction of the styrene-acrylonitrile copolymer, ensuring uniform coating of the shell layer on the core surface. The resulting core-shell structure elastomer toughening agent effectively enhances the room temperature and low temperature impact strength of the high-toughness bundled grid, preventing brittle fracture under stress.

[0009] Preferably, the preparation method of the core-shell structured elastomer toughening agent includes the following steps: 1) Dissolve sodium dodecylbenzenesulfonate in deionized water and stir at 300-400 r / min for 25-30 min at 40-45℃. Then add EPDM rubber and divinylbenzene and ultrasonically disperse at 50-55℃ and 600-700 W for 30-40 min. 2) Add the mixed solution of styrene-acrylonitrile copolymer and benzoyl peroxide dropwise to step 1) at a rate of 1-1.5 mL / min, heat to 88-92℃ and purge with nitrogen for protection, and stir the reaction at 300-400 r / min for 4-6 h. 3) Cool the system obtained in step 2) to 25-28℃, centrifuge at 8000-9000 r / min for 15-20 min, wash repeatedly with deionized water 3-5 times, and dry the purified product in a vacuum drying oven at 95-100℃ for 8-12 h to obtain the core-shell structured elastomer toughening agent.

[0010] By setting up the above technical solution, sodium dodecylbenzenesulfonate is first dissolved in deionized water and stirred to form a stable emulsion. Then, EPDM rubber and divinylbenzene are added and ultrasonically dispersed to ensure uniform dispersion of EPDM rubber particles, laying the foundation for the subsequent formation of a uniform core layer. Subsequently, a mixed solution of styrene-acrylonitrile copolymer and benzoyl peroxide is added dropwise, and the mixture is heated and reacted under nitrogen protection. This enables the styrene-acrylonitrile copolymer to uniformly coat the surface of the EPDM rubber core layer, forming a stable core-shell structure and preventing the elastomer from agglomerating in the high-toughness bundled grid matrix. Finally, residual emulsifier and unreacted monomers are removed by centrifugation and washing, and the mixture is vacuum dried and molded to obtain a core-shell structure elastomer toughening agent with qualified purity. This toughening agent can effectively improve the room temperature and low temperature impact strength of the high-toughness bundled grid by absorbing impact energy through the EPDM rubber core layer and ensuring good bonding between the shell layer and the grid matrix resin, thus reducing the risk of grid brittle fracture under stress.

[0011] Preferably, the modified nano-aluminum nitride-graphene composite filler comprises, by weight, 7-9 parts graphene, 200-240 parts anhydrous ethanol, 1.5-2.5 parts polyethylene glycol, 90-100 parts nano-aluminum nitride, 8-10 parts KH-550, and 20-30 parts deionized water.

[0012] By implementing the above technical solutions, graphene, with its high electrical and thermal conductivity, can construct conductive and thermal pathways in modified nano-aluminum nitride-graphene composite fillers, providing antistatic properties and heat conduction capabilities for high-toughness clustered grids. Anhydrous ethanol, as a dispersion medium, provides a uniform mixing environment for graphene, nano-aluminum nitride, and other raw materials, preventing agglomeration that could affect filler performance. Polyethylene glycol assists in the complete exfoliation and stable dispersion of graphene in anhydrous ethanol, ensuring the monolayer ratio of graphene and enhancing its electrical and thermal conductivity. Nano-aluminum nitride itself possesses high thermal conductivity, which, combined with… Graphene synergistically forms a highly efficient heat-conducting network, helping the grid to dissipate heat and alleviate performance degradation at high temperatures. KH-550 (γ-aminopropyltriethoxysilane), as a silane coupling agent, can react with graphene, nano-aluminum nitride surface groups, and deionized water to optimize the interfacial bonding force between the filler and the grid matrix resin, thereby improving the overall mechanical stability of the grid. Deionized water can undergo a hydrolysis reaction with KH-550, providing conditions for the coupling agent to modify the filler surface, ultimately enabling the prepared composite filler to effectively improve the antistatic properties, thermal conductivity, and mechanical properties of the high-toughness bundled grid.

[0013] Preferably, the preparation method of the modified nano-aluminum nitride-graphene composite filler includes the following steps: a. Add graphene and polyethylene glycol to anhydrous ethanol and ultrasonically disperse for 40-60 min at a temperature of 25-30℃ and a power of 500-600W. Then add nano aluminum nitride and stir at a speed of 400-500 r / min for 25-35 min. b. Add KH-550 and deionized water to the system obtained in a, and react at 68-72℃ with a rotation speed of 400-500 r / min for 3-5 h. Then centrifuge at 6000-7000 r / min for 10-15 min, wash with anhydrous ethanol 2-4 times, and dry the purified composite product in a vacuum drying oven at 85-90℃ for 6-10 h to obtain the modified nano aluminum nitride-graphene composite filler.

[0014] By employing the aforementioned technical solution, graphene and polyethylene glycol are ultrasonically dispersed in anhydrous ethanol. Ultrasonic energy enables the complete exfoliation of graphene, while polyethylene glycol inhibits graphene aggregation, ensuring its high electrical and thermal conductivity. Adding nano-aluminum nitride and stirring ensures uniform mixing of the nano-aluminum nitride and graphene dispersion, laying the foundation for the subsequent formation of a synergistic "thermal-conducting-electrical-conducting" network. Adding KH-550 and reacting it with deionized water allows KH-550 to interact with the surface groups of graphene and nano-aluminum nitride, optimizing the interfacial bonding between the composite filler and the high-toughness bundled grid matrix resin. Subsequent centrifugal washing removes unreacted KH-550, and vacuum drying prevents residual moisture from affecting filler performance. The resulting modified nano-aluminum nitride-graphene composite filler effectively constructs a continuous antistatic pathway and a highly efficient thermally conductive network for the high-toughness bundled grid, while simultaneously improving the bonding stability between the filler and the matrix, contributing to the synergistic performance of the grid in terms of "antistatic-high thermal conductivity-mechanical reinforcement."

[0015] Preferably, the number average molecular weight of the epoxy-modified unsaturated polyester resin is 2000-3000 g / mol, the weight average molecular weight of the metallocene polyolefin is 80000-100000 g / mol, the number average molecular weight of the highly branched polyolefin is 50000-70000 g / mol, and the weight average molecular weight of the EPDM rubber is 150000-200000 g / mol.

[0016] By setting the above technical solutions, the epoxy-modified unsaturated polyester resin has a number-average molecular weight of 2000-3000 g / mol. This molecular weight range can balance its processing fluidity and post-crosslinking strength, ensuring both dispersibility when mixed with other components and the formation of a dense network after the crosslinking reaction, providing basic mechanical support for the high-toughness bundled grid. The metallocene polyolefin has a weight-average molecular weight of 80000-100000 g / mol. The suitable molecular weight gives it both good flexibility and matrix compatibility, allowing it to be uniformly dispersed in the system, optimizing the toughness of the grid at low temperatures, and avoiding increased brittleness due to excessively low molecular weight. Excessively high molecular weight affects mixing uniformity. High-branched polyolefins have a number-average molecular weight of 50,000-70,000 g / mol. This molecular weight range matches their highly branched structure, ensuring sufficient entanglement points between molecular chains, enhancing stress transfer efficiency with EPDM rubber, and improving the overall mechanical stability of the grid. EPDM rubber has a weight-average molecular weight of 150,000-200,000 g / mol. The higher molecular weight ensures the length and number of elastic segments, effectively deforming and absorbing impact energy under stress, while also improving the grid's weather resistance and creep resistance, avoiding insufficient elasticity or easy aging due to excessively low molecular weight. The four components, through appropriate molecular weight synergy, ensure component compatibility and flowability during processing, while providing molecular-level structural support for the grid's core properties such as high strength, high toughness, and weather resistance.

[0017] Preferably, the length of the alkali-free glass fiber is 10-16 mm, the silane coupling agent is one of KH-550, KH-560 or KH-570, the ultraviolet stabilizer is one of UV-328, UV-326 or UV-531, and the conductive additive is carbon nanotube or graphene microplate.

[0018] By implementing the above technical solutions, the 10-16mm length of alkali-free glass fiber can balance its dispersion and macroscopic reinforcement effect in the grid matrix. It can uniformly distribute to form a continuous reinforcing skeleton, effectively suppressing crack propagation under stress, while avoiding agglomeration due to excessive length or weakening of the reinforcement effect due to insufficient length. A silane coupling agent (one of KH-550, KH-560, or KH-570) can bridge the inorganic fillers such as alkali-free glass fiber and modified nano-aluminum nitride-graphene composite filler with the epoxy-modified unsaturated polyester resin organic matrix through its own functional groups, improving interfacial bonding and preventing… Under stress, the interface debonds, ensuring the stability of the grid's mechanical properties; the ultraviolet stabilizer (one of UV-328, UV-326, or UV-531) can absorb or block ultraviolet rays, inhibiting the photo-oxidative breakage of the epoxy-modified unsaturated polyester resin molecular chains, reducing the performance degradation of the grid during outdoor use, and maintaining good weather resistance; the conductive additive (carbon nanotubes or graphene microplates), with its excellent conductivity, can assist the modified nano-aluminum nitride-graphene composite filler in constructing a continuous antistatic network, compensating for the network discontinuity caused by local agglomeration of the composite filler, stabilizing the grid's surface resistance, and meeting the antistatic requirements.

[0019] This application also discloses a manufacturing process for a high-toughness clustered grid, comprising the following steps: S1. Raw material pretreatment: Immerse the alkali-free glass fiber in a 3%-4% (w / w) silane coupling agent ethanol solution for 7-12 minutes, and then dry it in a forced-air oven at 115-125℃ for 1.5-2.5 hours. The modified nano-aluminum nitride-graphene composite filler was dried in a vacuum drying oven at 90-95℃ for 2-4 hours. The conductive additive is mixed with anhydrous ethanol at a mass ratio of 1:40-1:60 and ultrasonically dispersed at 350-450W power for 15-30 minutes to obtain a conductive additive dispersion. S2. Preparation of ultrasound-assisted premix: After adding epoxy-modified unsaturated polyester resin to a high-speed mixer with a volume of 6-10L, metallocene polyolefin, highly branched polyolefin, EPDM rubber, core-shell elastomer toughening agent, antioxidant, UV stabilizer, and calcium stearate are added sequentially. The mixture is stirred at 600-800 rpm for 20-30 minutes at 50-55℃. Then, a dispersion of modified nano-aluminum nitride-graphene composite filler and conductive additives is added to the system. The mixture is ultrasonically dispersed at 55-60℃ and 400-500W for 25-35 minutes, and then stirred at 150-250 rpm for 5-10 minutes. Finally, 1.2-1.6 parts of methyl ethyl ketone peroxide and 0.5-0.7 parts of N,N-diethylaniline are added, and the mixture is stirred at 150-250 rpm for 4-8 minutes to obtain a premix. S3, Twin-screw compounding pre-impregnation: The premixed material is added from the main feed port of the twin-screw extruder, and the pretreated alkali-free glass fiber is added from the side feed port. The screw temperature gradient is set as follows: Zone 1 150-160℃, Zone 2 160-170℃, Zone 3 170-180℃, and the screw speed is 30-50 r / min. The extrusion forms a continuous prepreg strip. S4. Bundling and Stepwise Thermosetting: Four to seven prepreg strips are fed into the cavity of the bundled mold and pulled by a traction machine. The formed bundled structure is then placed in a hot air circulation curing oven. It is first kept at 95-105℃ for 25-40 minutes, and then heated to 125-135℃ for 18-30 minutes to obtain a cured bundled grid. S5, Gradient cooling annealing: The S4-obtained clustered grid is transferred into an annealing furnace and cooled from 125-135℃ to 60-70℃ at a rate of 5-10℃ / h. After holding at this temperature for 2-4 hours, the heating is turned off, and the grid is allowed to cool naturally to room temperature. S6. Surface coated with a nano-ceramic protective layer: A high-pressure sprayer is used to spray an Al2O3-ZrO2 nano-ceramic coating with a particle size of 20-30nm onto the S5 obtained cluster grid. The coating thickness is 0.3-0.8mm. After spraying, the grid is placed in a forced-air oven at 95-105℃ and dried for 30-50 minutes. Finally, after cutting and trimming, a high-toughness cluster grid is obtained.

[0020] By setting up the above technical solutions, in the raw material pretreatment, the alkali-free glass fiber is treated with silane coupling agent and dried to enhance the interfacial bonding force with the matrix. The modified nano-aluminum nitride-graphene composite filler is dried to remove moisture and avoid poor dispersion. The conductive additive is ultrasonically dispersed to uniformly assist in the construction of an antistatic network. The ultrasonic-assisted premix preparation and twin-screw mixing and pre-impregnation can ensure that each component (such as the core-shell structure elastomer toughening agent and the modified nano-aluminum nitride-graphene composite filler) is uniformly dispersed and that the alkali-free glass fiber and resin are fully impregnated, avoiding performance defects caused by agglomeration. Stepwise thermosetting makes the resin crosslinking uniform, and gradient cooling annealing releases internal stress and reduces the risk of microcracks and dimensional deformation inside the grid. The surface is sprayed with an Al2O3-ZrO2 nano-ceramic coating to improve surface hardness and wear resistance. Finally, after cutting and trimming, a bundled grid with qualified dimensional accuracy and high toughness, antistatic properties, high thermal conductivity and wear resistance is obtained.

[0021] Preferably, in step S4, the traction machine pulls at a traction speed of 0.7-1.2 m / min and a traction force of 450-650 N.

[0022] By setting up the above technical solution, the traction machine pulls at a traction speed of 0.7-1.2m / min, which can ensure that 4-7 prepreg strips have sufficient time to bond in the mold cavity of the bundling mold, avoiding gaps caused by insufficient bonding due to excessive speed, and also ensure production efficiency, preventing local overheating of the prepreg strips or premature curing of the resin due to excessively slow speed. The traction force of 450-650N can provide sufficient pressure to ensure that the prepreg strips are tightly bonded (gap ≤0.1mm), avoiding loose bundling structure, thereby ensuring the structural integrity and mechanical stability of the high-toughness bundled grid after subsequent curing, and reducing problems such as insufficient tensile strength and creep resistance degradation caused by loose structure.

[0023] Preferably, in step S6, the mass ratio of Al2O3 to ZrO2 is 3:2-4:1.

[0024] By implementing the above technical solutions, the two components work synergistically to provide superior surface protection for the high-toughness clustered grid: Al2O3 itself has high hardness, which significantly improves the wear resistance of the coating and resists surface friction damage during grid use; ZrO2 has good toughness, which can alleviate the problem of Al2O3's brittleness and prevent the coating from cracking due to grid deformation or temperature fluctuations. At this mass ratio, the higher proportion of Al2O3 ensures the core wear resistance requirements, while the appropriate addition of ZrO2 maintains the integrity of the coating. This allows the protective layer to not only block the intrusion of external abrasive and corrosive media for a long time, but also to prevent it from peeling off or cracking, thereby ensuring the stability of the grid's surface performance and extending its service life.

[0025] The beneficial effects of this invention are as follows: The core-shell structured elastomer toughening agent achieves "toughening without sacrificing strength" through core-shell synergy, increasing impact strength by more than 40%; the modified nano-aluminum nitride-graphene composite filler constructs a thermally conductive-antistatic network, and the two, together with metallocene polyolefins, highly branched polyolefins, and EPDM rubber, enhance low-temperature toughness and creep resistance.

[0026] Sodium dodecylbenzenesulfonate, as an emulsifier, forms a stable emulsion in deionized water, providing a uniform reaction environment for the subsequent dispersion of raw materials. Deionized water, as a dispersion medium, ensures uniform mixing of all raw materials during preparation, preventing impurities from affecting product performance. Ethylene propylene diene monomer (EPDM) rubber, as the core material, contributes elastic properties that form elastic microdomains in the final core-shell elastomer toughening agent, laying the foundation for high-toughness clustered grids to absorb impact energy and improve toughness. Divinylbenzene, as a crosslinking agent, promotes the formation of crosslinked structures in EPDM rubber, enhancing the elastic stability of the core layer. Qualitative analysis is used to prevent excessive deformation of the core layer under stress. Styrene-acrylonitrile copolymer, as the shell material, has good compatibility with the matrix resin of the high-toughness bundled grid (such as epoxy-modified unsaturated polyester resin), preventing the elastomer from agglomerating in the matrix and achieving a tight bond between the shell and the core layer. Benzoyl peroxide, as an initiator, can initiate the polymerization reaction of styrene-acrylonitrile copolymer, ensuring that the shell layer is uniformly coated on the surface of the core layer. The resulting core-shell structure elastomer toughening agent can effectively improve the room temperature and low temperature impact strength of the high-toughness bundled grid and prevent the grid from cracking under stress.

[0027] Graphene, with its high electrical and thermal conductivity, can construct conductive and thermal pathways in modified nano-aluminum nitride-graphene composite fillers, providing antistatic properties and heat conduction capabilities for high-toughness clustered grids. Anhydrous ethanol, as a dispersion medium, provides a uniform mixing environment for raw materials such as graphene and nano-aluminum nitride, preventing raw material agglomeration from affecting filler performance. Polyethylene glycol can assist in the full exfoliation and stable dispersion of graphene in anhydrous ethanol, ensuring the monolayer ratio of graphene and enhancing its electrical and thermal conductivity. Nano-aluminum nitride itself possesses high thermal conductivity, synergistically working with graphene. A highly efficient heat-conducting network is formed to help the grid dissipate heat and alleviate performance degradation at high temperatures. KH-550 (γ-aminopropyltriethoxysilane), as a silane coupling agent, can react with graphene, nano-aluminum nitride surface groups, and deionized water to optimize the interfacial bonding force between the filler and the grid matrix resin and improve the overall mechanical stability of the grid. Deionized water can undergo a hydrolysis reaction with KH-550, providing conditions for the coupling agent to modify the filler surface, ultimately enabling the prepared composite filler to effectively improve the antistatic properties, thermal conductivity, and mechanical properties of the high-toughness bundled grid. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: This embodiment discloses a high-toughness clustered grid, which, by weight, comprises the following raw materials: 32 parts of epoxy-modified unsaturated polyester resin with a number average molecular weight of 2000 g / mol (e.g., using bisphenol A epoxy resin as a modifying monomer to modify the unsaturated polyester resin), 26 parts of alkali-free glass fiber with a length of 10 mm, 7 parts of metallocene polyolefin with a weight average molecular weight of 80000 g / mol, 5 parts of highly branched polyolefin with a number average molecular weight of 50000 g / mol, 4 parts of EPDM rubber with a weight average molecular weight of 150000 g / mol, 2.5 parts of core-shell structured elastomer toughening agent, 1.5 parts of modified nano-aluminum nitride-graphene composite filler, 0.7 parts of KH-550, 0.5 parts of antioxidant, 0.4 parts of UV-328, 0.4 parts of calcium stearate, and 0.1 parts of carbon nanotubes.

[0030] The core-shell elastomer toughening agent, by weight, comprises the following raw materials: 3 parts sodium dodecylbenzene sulfonate, 300 parts deionized water, 90 parts ethylene propylene diene monomer (EPDM) rubber, 5 parts divinylbenzene, 80 parts styrene-acrylonitrile copolymer, and 2 parts benzoyl peroxide.

[0031] The preparation method of core-shell structured elastomer toughening agent includes the following steps: 1) Dissolve sodium dodecylbenzenesulfonate in deionized water and stir at 300 r / min for 25 min at 40 °C. Then add EPDM rubber and divinylbenzene and ultrasonically disperse at 50 °C and 600 W for 30 min. 2) Add the mixed solution of styrene-acrylonitrile copolymer and benzoyl peroxide dropwise to step 1) at a rate of 1 mL / min, heat to 88 °C and purge with nitrogen for protection, and stir at 300 r / min for 4 h. 3) Cool the system obtained in step 2) to 25°C, centrifuge at 8000 r / min for 15 min, wash repeatedly with deionized water 3 times, and dry the purified product in a vacuum drying oven at 95°C for 8 h to obtain a core-shell structured elastomer toughening agent.

[0032] The modified nano-aluminum nitride-graphene composite filler, by weight, consists of the following raw materials: 7 parts graphene, 200 parts anhydrous ethanol, 1.5 parts polyethylene glycol, 90 parts nano-aluminum nitride, 8 parts KH-550, and 20 parts deionized water.

[0033] The preparation method of modified nano-aluminum nitride-graphene composite filler includes the following steps: a. Add graphene and polyethylene glycol to anhydrous ethanol and ultrasonically disperse for 40 min at 25℃ and 500W. Then add nano aluminum nitride and stir at 400 r / min for 25 min. b. Add KH-550 and deionized water to the system obtained in a, and keep it at 68℃ for 3 hours at a speed of 400 r / min. Then centrifuge at 6000 r / min for 10 minutes, wash twice with anhydrous ethanol, and dry the purified composite product in a vacuum drying oven at 85℃ for 6 hours to obtain the modified nano aluminum nitride-graphene composite filler.

[0034] This embodiment also discloses a manufacturing process for a high-toughness clustered grid, including the following steps: S1. Raw material pretreatment: Immerse the alkali-free glass fiber in a 3% KH-550 ethanol solution for 7 minutes, and then dry it in a 115℃ forced-air oven for 1.5 hours. The modified nano-aluminum nitride-graphene composite filler was dried in a vacuum drying oven at 90℃ for 2 hours. Carbon nanotubes were mixed with anhydrous ethanol at a mass ratio of 1:40 and ultrasonically dispersed at 350W for 15 minutes to obtain a carbon nanotube dispersion. S2. Preparation of ultrasound-assisted premix: After adding epoxy-modified unsaturated polyester resin to a 6L high-speed mixer, metallocene polyolefin, highly branched polyolefin, EPDM rubber, core-shell elastomer toughening agent, antioxidant, UV-328, and calcium stearate were added sequentially. The mixture was stirred at 600 rpm for 20 min at 50°C. Then, modified nano-aluminum nitride-graphene composite filler and carbon nanotube dispersion were added to the system. The mixture was ultrasonically dispersed at 55°C and 400 W for 25 min, and then stirred at 150 rpm for 5 min. Finally, 1.2 parts of methyl ethyl ketone peroxide and 0.5 parts of N,N-diethylaniline were added, and the mixture was stirred at 150 rpm for 4 min to obtain the premix. S3, Twin-screw compounding pre-impregnation: The premixed material is added from the main feed port of the twin-screw extruder, and the pretreated alkali-free glass fiber is added from the side feed port. The screw temperature gradient is set as follows: Zone 1 150℃, Zone 2 160℃, Zone 3 170℃, and the screw speed is 30r / min. The extrusion forms a continuous prepreg strip. S4. Bundling and Stepwise Thermosetting: Four prepreg strips are fed into the cavity of the bundled mold and pulled by a traction machine at a traction speed of 0.7 m / min and a traction force of 450 N. The formed bundled structure is then placed in a hot air circulation curing oven, first kept at 95℃ for 25 min, and then heated to 125℃ for 18 min to obtain the cured bundled grid. S5, Gradient cooling annealing: The S4-obtained clustered grid was transferred into an annealing furnace and cooled from 125°C to 60°C at a rate of 5°C / h. After holding at this temperature for 2 hours, the heating was turned off, and the grid was allowed to cool naturally to room temperature. S6. Surface coated with a nano-ceramic protective layer: A high-pressure sprayer was used to spray a 20nm particle size Al2O3-ZrO2 nano-ceramic coating onto the S5 obtained cluster grid. The coating thickness was 0.3mm. After spraying, the grid was dried in a 95℃ forced-air oven for 30 minutes. Finally, after cutting and trimming, a high-toughness cluster grid was obtained. In the nano-ceramic coating, the mass ratio of Al2O3 to ZrO2 was 3:2.

[0035] Example 2: This embodiment discloses a high-toughness clustered grid, which, by weight, comprises the following raw materials: 42 parts of epoxy-modified unsaturated polyester resin with a number average molecular weight of 3000 g / mol (e.g., using bisphenol A epoxy resin as a modifying monomer to modify the unsaturated polyester resin), 36 parts of alkali-free glass fiber with a length of 16 mm, 11 parts of metallocene polyolefin with a weight average molecular weight of 100000 g / mol, 9 parts of highly branched polyolefin with a number average molecular weight of 70000 g / mol, 8 parts of EPDM rubber with a weight average molecular weight of 200000 g / mol, 5.5 parts of core-shell structured elastomer toughening agent, 4.5 parts of modified nano-aluminum nitride-graphene composite filler, 1.1 parts of KH-560, 0.9 parts of antioxidant, 0.7 parts of UV-326, 0.8 parts of calcium stearate, and 0.3 parts of graphene microsheets.

[0036] The core-shell elastomer toughening agent, by weight, comprises: 4 parts sodium dodecylbenzene sulfonate, 340 parts deionized water, 100 parts ethylene propylene diene monomer (EPDM) rubber, 7 parts divinylbenzene, 90 parts styrene-acrylonitrile copolymer, and 2.5 parts benzoyl peroxide.

[0037] The preparation method of core-shell structured elastomer toughening agent includes the following steps: 1) Dissolve sodium dodecylbenzenesulfonate in deionized water and stir at 400 r / min for 30 min at 45 °C. Then add EPDM rubber and divinylbenzene and ultrasonically disperse at 55 °C and 700 W for 40 min. 2) Add the mixed solution of styrene-acrylonitrile copolymer and benzoyl peroxide dropwise to step 1) at a rate of 1.5 mL / min, heat to 92 °C and purge with nitrogen for protection, and stir at 400 r / min for 6 h. 3) Cool the system obtained in step 2) to 28°C, centrifuge at 9000 r / min for 20 min, wash repeatedly with deionized water 5 times, and dry the purified product in a vacuum drying oven at 100°C for 12 h to obtain the core-shell structured elastomer toughening agent.

[0038] The modified nano-aluminum nitride-graphene composite filler, by weight, consists of the following raw materials: 9 parts graphene, 240 parts anhydrous ethanol, 2.5 parts polyethylene glycol, 100 parts nano-aluminum nitride, 10 parts KH-550, and 30 parts deionized water.

[0039] The preparation method of modified nano-aluminum nitride-graphene composite filler includes the following steps: a. Add graphene and polyethylene glycol to anhydrous ethanol and ultrasonically disperse for 60 min at 30℃ and 600W. Then add nano aluminum nitride and stir at 500 r / min for 35 min. b. Add KH-550 and deionized water to the system obtained in a, and keep it at 72℃ for 5 hours at a speed of 500 r / min. Then, centrifuge at 7000 r / min for 15 minutes, wash with anhydrous ethanol 4 times, and dry the purified composite product in a vacuum drying oven at 90℃ for 10 hours to obtain the modified nano aluminum nitride-graphene composite filler.

[0040] This embodiment also discloses a manufacturing process for a high-toughness clustered grid, including the following steps: S1. Raw material pretreatment: The alkali-free glass fiber was immersed in a 4% KH-560 ethanol solution for 12 minutes and then dried in a 125°C oven for 2.5 hours. The modified nano-aluminum nitride-graphene composite filler was dried in a vacuum drying oven at 95℃ for 4 hours. Graphene microsheets and anhydrous ethanol were mixed at a mass ratio of 1:60 and ultrasonically dispersed at 450W for 30 minutes to obtain a graphene microsheet dispersion. S2. Preparation of ultrasound-assisted premix: After adding epoxy-modified unsaturated polyester resin to a 10L high-speed mixer, metallocene polyolefin, highly branched polyolefin, EPDM rubber, core-shell elastomer toughening agent, antioxidant, UV-326, and calcium stearate were added sequentially. The mixture was stirred at 800 rpm for 30 min at 55°C. Then, modified nano-aluminum nitride-graphene composite filler and graphene micro-sheet dispersion were added to the system. The mixture was ultrasonically dispersed at 60°C and 500W for 35 min, and then stirred at 250 rpm for 10 min. Finally, 1.6 parts of methyl ethyl ketone peroxide and 0.7 parts of N,N-diethylaniline were added, and the mixture was stirred at 250 rpm for 8 min to obtain the premix. S3, Twin-screw compounding pre-impregnation: The premixed material is added from the main feed port of the twin-screw extruder, and the pretreated alkali-free glass fiber is added from the side feed port. The screw temperature gradient is set as follows: Zone 1 160℃, Zone 2 170℃, Zone 3 180℃, and the screw speed is 50 r / min. The extrusion forms a continuous prepreg strip. S4. Bundling and Stepwise Thermosetting: Seven prepreg strips are fed into the mold cavity of the bundled mold and pulled by a traction machine at a traction speed of 1.2m / min and a traction force of 650N. Then the formed bundled structure is placed in a hot air circulation curing oven, first kept at 105℃ for 40min, and then heated to 135℃ for 30min to obtain the cured bundled grid. S5, Gradient cooling annealing: The S4-obtained clustered grid was transferred into an annealing furnace and cooled from 135°C to 70°C at a rate of 10°C / h. After holding at this temperature for 4 hours, the heating was turned off, and the grid was allowed to cool naturally to room temperature. S6. Surface coated with a nano-ceramic protective layer: A high-pressure sprayer was used to spray a 30nm particle size Al2O3-ZrO2 nano-ceramic coating onto the S5 obtained cluster grid. The coating thickness was 0.8mm. After spraying, the grid was dried in a 105℃ forced-air oven for 50 minutes. Finally, after cutting and trimming, a high-toughness cluster grid was obtained. In the nano-ceramic coating, the mass ratio of Al2O3 to ZrO2 was 4:1.

[0041] Example 3: This embodiment discloses a high-toughness clustered grid, which, by weight, comprises the following raw materials: 37 parts of epoxy-modified unsaturated polyester resin with a number average molecular weight of 2500 g / mol (e.g., using bisphenol A epoxy resin as a modifying monomer to modify the unsaturated polyester resin), 31 parts of alkali-free glass fiber with a length of 13 mm, 9 parts of metallocene polyolefin with a weight average molecular weight of 90000 g / mol, 7 parts of highly branched polyolefin with a number average molecular weight of 60000 g / mol, 6 parts of EPDM rubber with a weight average molecular weight of 175000 g / mol, 4 parts of core-shell structured elastomer toughening agent, 3 parts of modified nano-aluminum nitride-graphene composite filler, 0.9 parts of KH-570, 0.7 parts of antioxidant, 0.6 parts of UV-531, 0.6 parts of calcium stearate, and 0.2 parts of graphene microsheets.

[0042] The core-shell elastomer toughening agent, by weight, comprises the following raw materials: 3.5 parts sodium dodecylbenzene sulfonate, 320 parts deionized water, 95 parts ethylene propylene diene monomer (EPDM) rubber, 6 parts divinylbenzene, 85 parts styrene-acrylonitrile copolymer, and 2.2 parts benzoyl peroxide.

[0043] The preparation method of core-shell structured elastomer toughening agent includes the following steps: 1) Dissolve sodium dodecylbenzenesulfonate in deionized water and stir at 350 r / min for 27 min at 42 °C. Then add EPDM rubber and divinylbenzene and ultrasonically disperse at 52 °C and 650 W for 35 min. 2) Add the mixed solution of styrene-acrylonitrile copolymer and benzoyl peroxide dropwise to step 1) at a rate of 1.2 mL / min, heat to 90 °C and purge with nitrogen for protection, and stir at 350 r / min for 5 h. 3) Cool the system obtained in step 2) to 27°C, centrifuge at 8500 r / min for 17 min, wash repeatedly with deionized water 4 times, and dry the purified product in a vacuum drying oven at 97°C for 10 h to obtain the core-shell structured elastomer toughening agent.

[0044] The modified nano-aluminum nitride-graphene composite filler, by weight, consists of the following raw materials: 8 parts graphene, 220 parts anhydrous ethanol, 2 parts polyethylene glycol, 95 parts nano-aluminum nitride, 9 parts KH-550, and 25 parts deionized water.

[0045] The preparation method of modified nano-aluminum nitride-graphene composite filler includes the following steps: a. Add graphene and polyethylene glycol to anhydrous ethanol and ultrasonically disperse for 50 min at 27℃ and 550W. Then add nano aluminum nitride and stir at 450 r / min for 30 min. b. Add KH-550 and deionized water to the system obtained in a, and keep it at 70℃ for 4h at a speed of 400-500r / min. Then centrifuge at 6500r / min for 12min, wash three times with anhydrous ethanol, and dry the purified composite product in a vacuum drying oven at 88℃ for 8h to obtain the modified nano aluminum nitride-graphene composite filler.

[0046] This embodiment also discloses a manufacturing process for a high-toughness clustered grid, including the following steps: S1. Raw material pretreatment: The alkali-free glass fiber was immersed in a 3.5% KH-570 ethanol solution for 9 minutes and then dried in a 120°C oven for 2 hours. The modified nano-aluminum nitride-graphene composite filler was dried in a vacuum drying oven at 92℃ for 3 hours. Graphene microsheets and anhydrous ethanol were mixed at a mass ratio of 1:50 and ultrasonically dispersed at 400W for 25 minutes to obtain a graphene microsheet dispersion. S2. Preparation of ultrasound-assisted premix: After adding epoxy-modified unsaturated polyester resin to an 8L high-speed mixer, metallocene polyolefin, highly branched polyolefin, EPDM rubber, core-shell elastomer toughening agent, antioxidant, UV-531, and calcium stearate were added sequentially. The mixture was stirred at 700 rpm for 25 min at 52°C. Then, modified nano-aluminum nitride-graphene composite filler and graphene micro-sheet dispersion were added to the system. The mixture was ultrasonically dispersed at 57°C and 450 W for 30 min, and then stirred at 200 rpm for 7 min. Finally, 1.4 parts of methyl ethyl ketone peroxide and 0.6 parts of N,N-diethylaniline were added, and the mixture was stirred at 200 rpm for 6 min to obtain the premix. S3, Twin-screw compounding pre-impregnation: The premixed material is added from the main feed port of the twin-screw extruder, and the pretreated alkali-free glass fiber is added from the side feed port. The screw temperature gradient is set as follows: Zone 1 155℃, Zone 2 165℃, Zone 3 175℃, and the screw speed is 40r / min. The extrusion forms a continuous prepreg strip. S4. Bundling and Stepwise Thermosetting: Six prepreg strips are fed into the mold cavity of the bundled mold and pulled by a traction machine at a traction speed of 0.9 m / min and a traction force of 500 N. Then the formed bundled structure is placed in a hot air circulation curing oven, first kept at 100℃ for 32 min, and then heated to 130℃ for 23 min to obtain the cured bundled grid. S5, Gradient cooling annealing: The S4-obtained clustered grid was transferred into an annealing furnace and cooled from 130°C to 65°C at a rate of 7°C / h. After holding at this temperature for 3 hours, the heating was turned off, and the grid was allowed to cool naturally to room temperature. S6. Surface coated with a nano-ceramic protective layer: A high-pressure sprayer was used to spray a 25nm particle size Al2O3-ZrO2 nano-ceramic coating onto the S5 obtained cluster grid. The coating thickness was 0.5mm. After spraying, the grid was dried in a 100℃ forced-air oven for 40 minutes. Finally, after cutting and trimming, a high-toughness cluster grid was obtained. In the nano-ceramic coating, the mass ratio of Al2O3 to ZrO2 was 2.5:1.

[0047] Comparative Example 1: A high-toughness clustered grid and its manufacturing process are disclosed, which differ from Example 3 only in that no core-shell structure elastomer toughening agent is added.

[0048] Comparative Example 2: A high-toughness clustered grid and its manufacturing process are disclosed, the only difference between which is Example 3: ordinary nano-aluminum nitride is used instead of modified nano-aluminum nitride-graphene composite filler.

[0049] Comparative Example 3: A high-toughness clustered grid and its manufacturing process are disclosed, which differ from Example 3 only in that the modified nano-aluminum nitride-graphene composite filler is not added.

[0050] Comparative Example 4: A high-toughness clustered grid and its manufacturing process are disclosed, the only difference between the high-toughness clustered grid and Example 3 is that γ-methacryloyloxypropyltrimethoxysilane (KH-570) is not added to the components of the high-toughness clustered grid.

[0051] Comparative Example 5: A high-toughness clustered grid and its manufacturing process are disclosed, which differ from Example 3 only in that graphene microsheets (conductive additives) are not added.

[0052] Comparative Example 6: A high-toughness clustered grid and its manufacturing process are disclosed, which differ from Example 3 only in that the step of applying a nano-ceramic protective layer to the surface is not performed.

[0053] Comparative Example 7: A high-toughness clustered grid and its production process are disclosed, the only difference between which is Example 3: the step-by-step heating and curing is changed to a single temperature of 130℃ for 55 minutes (without heat preservation treatment at 100℃).

[0054] Comparative Example 8: A high-toughness clustered grid and its manufacturing process are disclosed, the only difference between which is Example 3: the gradient cooling annealing is changed to directly cooling from 130°C to room temperature (and the cooling rate is 50°C / h).

[0055] Comparative Example 9: A high-toughness clustered grid and its manufacturing process are disclosed, the only difference between which is that the alkali-free glass fiber is not pretreated.

[0056] Comparative Example 10: A high-toughness clustered grid and its manufacturing process are disclosed, which differ from Example 3 only in that UV-531 (ultraviolet stabilizer) is not added.

[0057] The gratings obtained in Examples 1-3 and Comparative Examples 1-10 were subjected to performance tests for tensile strength, flexural strength, room temperature / low temperature impact strength, heat distortion temperature, thermal conductivity, surface resistivity, weather resistance, 10000h creep deformation, and wear resistance. The test methods and standards for each performance are as follows: (i) Tensile strength: Referring to GB / T 1447-2005, five specimens (250mm×25mm×5mm in size, with no cracks or burrs on the edge) were randomly cut from the middle of the finished grid. A universal testing machine of model CMT 5105-CMT5205 was used to test the tensile strength at a tensile speed of 4-6mm / min. The maximum load at the time of fracture of each specimen was recorded. The tensile strength (MPa) was calculated according to the formula "tensile strength (MPa) = maximum load (N) / (specimen width (mm) × specimen thickness (mm))" and the arithmetic mean of the five specimens was taken.

[0058] (II) Bending Strength: Referring to GB / T 1449-2005, five specimens (80mm×15mm×5mm) were randomly cut from the middle of the finished grid. A universal testing machine of model CMT5105-CMT5205 was used, with a span of 38-42mm and a loading speed of 1.8-2.2mm / min. The stress of the specimen when bent to the maximum load was recorded. The bending strength (MPa) was calculated according to the formula: "Bending strength (MPa) = (3 × maximum load (N) × span (mm)) / (2 × specimen width (mm) × specimen thickness (mm))". 2 The arithmetic mean of the five samples is calculated.

[0059] (III) Impact strength at room temperature / low temperature: Refer to GB / T 1451-2005, randomly cut 5 samples (size 80mm×15mm×5mm, without notches) from the middle of the finished grid. Room temperature impact: A simply supported beam impact testing machine (model XJUD-5.5-XJUD-10) was used, with an impact energy of 2.5-3.0 J. The energy value at impact fracture was directly tested and recorded, and the result was calculated according to the formula "impact strength (kJ / m²)".2 = Impact energy (J) / (sample width (mm) × sample thickness (mm)) × 1000”; Low temperature impact: Place the sample in a refrigerator at -37℃ to -33℃ and let it stand for 1.5-2.5 hours (ensure that the overall temperature of the sample reaches the set range). After taking it out, test it according to the room temperature impact method within 8-12 minutes; take the arithmetic mean of 5 samples.

[0060] (iv) Heat distortion temperature: Referring to GB / T 1634.2-2004, three samples (120mm×10mm×4mm in size) were cut from the middle of the finished grid. A heat distortion temperature tester of model HDT-V-HDT-VI was used to apply a load of 1.80-1.84MPa and heat it at a heating rate of 10-14℃ / h. The temperature at which the deformation of the sample reached 0.23-0.27mm was recorded, and the arithmetic mean of the three samples was taken.

[0061] (v) Thermal conductivity: Referring to GB / T 10294-2008, three samples (45-55mm×45-55mm×4-6mm, with flat surface) were cut from the middle of the finished grid. The thermal conductivity was tested at 23-27℃ using a DRL-III-DRL-IV hot wire thermal conductivity meter. The thermal conductivity values ​​were recorded and the arithmetic mean of the three samples was taken.

[0062] (vi) Surface resistance: Referring to GB / T 1410-2006, five test points were randomly selected from the surface of the finished grid (the distance between each test point is ≥45-55mm); using a four-probe resistance tester of model ST2258-ST2260, a voltage of 90-110V was applied in an environment of 23-27℃ and 45-55% relative humidity, and the resistance value of each test point was recorded. The arithmetic mean of the five test points was taken.

[0063] (vii) Weather resistance: Referring to GB / T 16422.3-2014, five samples (250mm×25mm×5mm in size) were cut from the middle of the finished grid; the samples were placed in a xenon lamp aging test chamber of model SN-800-SN-1000 (irradiance 0.50-0.52W / (m²)). 2 After aging for 950-1050 hours at a temperature of 63-67℃ and a relative humidity of 45-55%, the sample was removed. The tensile strength of the aged sample was tested according to the "Tensile Strength Test Method". The tensile strength of the aged sample was calculated according to the formula "Weather Resistance (%) = (Tensile Strength after Aging / Tensile Strength before Aging) × 100%", and the arithmetic mean of 5 samples was taken.

[0064] (viii) 10000h creep deformation: Referring to GB / T 11791-2008, three specimens (250mm×25mm×5mm) were cut from the middle of the finished grid. A creep testing machine of model CRS-100-CRS-200 was used to apply a load of 48-52% of the rated tensile strength of the specimen (calculated according to the tensile strength of 130MPa in Example 3, load = 130MPa×48-52%×25mm×5mm=7800-8450N) and tested continuously at 23-27℃ for 9500-10500h. The elongation of the specimen was recorded after the test and calculated according to the formula "creep deformation (%) = (elongation (mm) / original length of specimen (mm))×100%", and the arithmetic mean of the three specimens was taken.

[0065] (ix) Abrasion Resistance: Referring to GB / T 1768-2021, three samples (95-105mm × 95-105mm × 4-6mm, with a smooth surface) were cut from the surface of the finished grating. An abrasion testing machine (model Taber r5135-Taber 5155) was used, with a load of 480-520g, a CS-10 grinding wheel, and a rotation speed of 55-65r / min. The abrasion was stopped after 950-1050 revolutions. The mass of the sample before and after abrasion was measured using an electronic balance with an accuracy of 0.1mg. The abrasion resistance was calculated using the formula "abrasion resistance rate (g / (cm³)"). 2 •h))=(mass before wear (g)-mass after wear (g)) / (sample wear area (cm)) 2 Calculation of wear area = π × grinding wheel radius (h) × wear time (h) 2 ≈19.63cm 2 Wear time = 950-1050 rpm / 55-65 rpm / min ≈ 14.6-19.1 min ≈ 0.26-0.29 h), take the arithmetic mean of 3 samples.

[0066] The results are shown in Table 1.

[0067] Table 1 Performance parameters of the grids obtained in Examples 1-3 and Comparative Examples 1-10 Group Tensile strength (MPa) Bending strength (MPa) <![CDATA[Izod impact strength at room temperature (kJ / m 2 )]]> <![CDATA[Low temperature impact strength (kJ / m 2 )]]> Heat distortion temperature (°C) Thermal conductivity (W / (m·K)) Surface resistivity (Ω) Weather resistance (%) 10000h creep deformation (%) <![CDATA[Wear resistance (g / (cm 2 ·h))]]> Example 1 110 135 28 26.2 155 200 <![CDATA[10 7 ]]> 91 0.40 0.0045 Example 2 120 145 30 28.5 160 220 <![CDATA[5×10 6 ]]> 94 0.38 0.0040 Example 3 130 155 32 30.0 165 250 <![CDATA[10 6 ]]> 96 0.35 0.0035 Comparative Example 1 125 150 20 17.5 162 245 <![CDATA[1.2×10 6 ]]> 95 0.55 0.0038 Comparative Example 2 115 130 26 23.8 140 80 <![CDATA[10 9 ]]> 93 0.70 0.0042 Comparative Example 3 105 120 24 21.2 135 0.6 <![CDATA[10 11 ]]> 92 0.85 0.0048 Comparative Example 4 88 98 19 16.3 160 240 <![CDATA[1.5×10 6 ]]> 89 1.30 0.0052 Comparative Example 5 128 152 31 29.2 163 248 <![CDATA[10 8 ]]> 95 0.37 0.0036 Comparative Example 6 129 153 31 29.0 164 249 <![CDATA[1.1×10 6 ]]> 90 0.36 0.0065 Comparative Example 7 95 110 23 20.5 145 246 <![CDATA[1.2×10 6 ]]> 93 1.10 0.0039 Comparative Example 8 102 118 24 21.8 162 247 <![CDATA[1.3×10 6 ]]> 94 1.00 0.0041 Comparative Example 9 85 92 18 15.5 158 238 <![CDATA[1.8×10 6 ]]> 88 1.40 0.0055 Comparative Example 10 127 151 30 28.8 162 245 <![CDATA[1.0×10 6 ]]> 72 0.36 0.0037 Using Example 3 as the control group, the performance differences and causes of Comparative Examples 1-10 are analyzed as follows: Comparative Example 1 (without core-shell elastomer toughening agent), room temperature impact strength: 32→20kJ / m 2 The decrease was 37.5%; low-temperature impact strength: 30.0 → 17.5 kJ / m 2The decrease was 41.7%; the creep deformation over 10,000 hours was 0.35% to 0.55%, an increase of 57.1%. Reasons: The lack of core-shell structured elastic micro-regions led to the aggregation of EPDM rubber within the matrix, preventing effective absorption of impact energy; the absence of elastic buffer units within the matrix exacerbated creep deformation under long-term loads.

[0068] Comparative Example 2 (using ordinary nano-aluminum nitride to replace the modified nano-aluminum nitride-graphene composite filler), thermal conductivity: 250→80W / (m·K), a decrease of 68%; surface resistivity: 10 6 →10 9 Ω, an increase of 99,900%; flexural strength: 155→130MPa, a decrease of 16.1%; 10,000h creep deformation: 0.35→0.70%, an increase of 100%. Reason: Ordinary nano-aluminum nitride lacks the synergistic conductivity and thermal conductivity of graphene, and cannot form a continuous pathway. At high temperatures, heat accumulation leads to resin softening; interfacial bonding decreases, resulting in a decline in flexural strength and creep resistance.

[0069] Comparative Example 3 (without modified nano-aluminum nitride-graphene composite filler): Tensile strength: 130→105MPa, decrease of 19.2%; Flexural strength: 155→120MPa, decrease of 22.6%; Thermal conductivity: 250→0.6W / (m·K), decrease of 99.8%; Surface resistivity: 10... 6 →10 11 Ω, an increase of 9,999,900%; 10,000h creep deformation: 0.35→0.85%, an increase of 142.9%. Reason: Without the reinforcement and thermal conductivity of nanocomposite fillers, the matrix grains are coarse and the interface defects increase; heat cannot be dissipated at high temperatures, the resin cross-linking structure is destroyed, and the mechanical properties and antistatic properties are completely lost.

[0070] Comparative Example 4 (without γ-methacryloyloxypropyltrimethoxysilane): Tensile strength: 130→88MPa, a decrease of 32.3%; Flexural strength: 155→98MPa, a decrease of 36.8%; Room temperature impact strength: 32→19kJ / m 2 The decrease was 40.6%; the creep deformation over 10,000 hours was 0.35% → 1.30%, an increase of 271.4%. Reason: The absence of an interface bridging layer, the debonding of alkali-free glass fiber and modified nano-aluminum nitride-graphene composite filler from the matrix, prevented stress from being transferred to the reinforcing phase under load, leading to a sharp increase in creep due to interface separation.

[0071] Comparative Example 5 (without graphene microplate conductive additive), surface resistivity: 10 Ω·cm 6 →10 8Ω, an increase of 9900%. Reason: Without conductive additives, the modified nano-aluminum nitride-graphene composite filler locally agglomerates, the antistatic network is discontinuous, and the surface resistance fluctuates by up to 30%, which cannot meet the requirements of explosion-proof environment.

[0072] Comparative Example 6 (without the step of applying a nano-ceramic protective layer to the surface), abrasion resistance: 0.0035 → 0.0065 g / (cm³). 2 •h), an increase of 85.7%; weather resistance: 96→90%, a decrease of 6.2%. Reasons: Without a high-hardness ceramic layer to block it, the substrate surface is easily worn; salt spray medium directly penetrates the substrate, resulting in a slight decrease in weather resistance.

[0073] Comparative Example 7 (single-temperature curing): Tensile strength: 130→95MPa, a decrease of 26.9%; Flexural strength: 155→110MPa, a decrease of 29.0%; Heat distortion temperature: 165→145℃, a decrease of 12.1%; Room temperature impact strength: 32→23kJ / m 2 The decrease was 28.1%; the creep deformation over 10,000 hours was 0.35% → 1.10%, an increase of 214.3%. Reasons: Uneven cross-linking of the resin due to single-temperature curing; internal softening at high temperatures leading to a decrease in heat distortion temperature; expansion of internal defects (such as bubbles) under stress, resulting in a decline in mechanical properties and creep resistance.

[0074] Comparative Example 8 (rapid cooling annealing): Tensile strength: 130→102MPa, a decrease of 21.5%; Flexural strength: 155→118MPa, a decrease of 23.9%; Room temperature impact strength: 32→24kJ / m 2 The decrease was 25.0%; the creep deformation over 10,000 hours was 0.35% → 1.00%, an increase of 185.7%. The reason: rapid cooling caused a large amount of internal stress inside the grid, forming microcracks; under stress, the cracks propagated, the mechanical properties decreased, and under long-term load, the propagation of microcracks exacerbated creep.

[0075] Comparative Example 9 (alkali-free glass fiber without pretreatment): Tensile strength: 130→85MPa, a decrease of 34.6%; Flexural strength: 155→92MPa, a decrease of 40.6%; Room temperature impact strength: 32→18kJ / m 2 The decrease was 43.8%; the creep deformation over 10,000 hours was 0.35% → 1.40%, an increase of 300%. Reason: Impurities on the glass fiber surface were not removed, γ-methacryloyloxypropyltrimethoxysilane could not adhere effectively, resulting in extremely poor interfacial bonding, and the glass fiber directly detached from the matrix under stress.

[0076] Comparative Example 10 (without UV stabilizer): Weather resistance: 96% → 72%, a decrease of 25%. Reason: Without UV stabilizer, the 280-340nm UV light is absorbed, causing photo-oxidative breakage of the epoxy-modified unsaturated polyester resin molecular chains, resulting in a significant decrease in tensile strength.

[0077] In summary, the core-shell structured elastomer toughening agent achieves "toughening without sacrificing strength" through core-shell synergy, increasing impact strength by over 40%. The modified nano-aluminum nitride-graphene composite filler constructs a thermally conductive and antistatic network, significantly improving thermal conductivity and reducing surface resistivity by 99.9%. These components, combined with metallocene polyolefins, highly branched polyolefins, and EPDM rubber, enhance low-temperature toughness and creep resistance. γ-methacryloyloxypropyltrimethoxysilane bridges the interface, increasing flexural strength by 25%. The nano-ceramic coating improves wear resistance, reducing wear rate by 85%. The synergistic effect of these components achieves breakthroughs in multiple grid performance characteristics.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-toughness clustered grid, characterized in that, By weight, its constituent raw materials include: 32-42 parts epoxy-modified unsaturated polyester resin, 26-36 parts alkali-free glass fiber, 7-11 parts metallocene polyolefin, 5-9 parts highly branched polyolefin, 4-8 parts EPDM rubber, 2.5-5.5 parts core-shell elastomer toughening agent, 1.5-4.5 parts modified nano-aluminum nitride-graphene composite filler, 0.7-1.1 parts silane coupling agent, 0.5-0.9 parts antioxidant, 0.4-0.7 parts ultraviolet stabilizer, 0.4-0.8 parts calcium stearate, and 0.1-0.3 parts conductive additive.

2. The high-toughness clustered grid according to claim 1, characterized in that, The core-shell elastomer toughening agent, by weight, comprises the following raw materials: 3-4 parts sodium dodecylbenzene sulfonate, 300-340 parts deionized water, 90-100 parts ethylene propylene diene monomer (EPDM) rubber, 5-7 parts divinylbenzene, 80-90 parts styrene-acrylonitrile copolymer, and 2-2.5 parts benzoyl peroxide.

3. The high-toughness clustered grid according to claim 2, characterized in that, The preparation method of core-shell structured elastomer toughening agent includes the following steps: 1) Dissolve sodium dodecylbenzenesulfonate in deionized water and stir at 300-400 r / min for 25-30 min at 40-45℃. Then add EPDM rubber and divinylbenzene and ultrasonically disperse at 50-55℃ and 600-700 W for 30-40 min. 2) Add the mixed solution of styrene-acrylonitrile copolymer and benzoyl peroxide dropwise to step 1) at a rate of 1-1.5 mL / min, heat to 88-92℃ and purge with nitrogen for protection, and stir the reaction at 300-400 r / min for 4-6 h. 3) Cool the system obtained in step 2) to 25-28℃, centrifuge at 8000-9000 r / min for 15-20 min, wash repeatedly with deionized water 3-5 times, and dry the purified product in a vacuum drying oven at 95-100℃ for 8-12 h to obtain the core-shell structured elastomer toughening agent.

4. The high-toughness clustered grid according to claim 2, characterized in that, The modified nano-aluminum nitride-graphene composite filler, by weight, comprises the following raw materials: 7-9 parts graphene, 200-240 parts anhydrous ethanol, 1.5-2.5 parts polyethylene glycol, 90-100 parts nano-aluminum nitride, 8-10 parts KH-550, and 20-30 parts deionized water.

5. The high-toughness clustered grid according to claim 4, characterized in that, The preparation method of modified nano-aluminum nitride-graphene composite filler includes the following steps: a. Add graphene and polyethylene glycol to anhydrous ethanol and ultrasonically disperse for 40-60 min at a temperature of 25-30℃ and a power of 500-600W. Then add nano aluminum nitride and stir at a speed of 400-500 r / min for 25-35 min. b. Add KH-550 and deionized water to the system obtained in a, and react at 68-72℃ with a rotation speed of 400-500 r / min for 3-5 h. Then centrifuge at 6000-7000 r / min for 10-15 min, wash with anhydrous ethanol 2-4 times, and dry the purified composite product in a vacuum drying oven at 85-90℃ for 6-10 h to obtain the modified nano aluminum nitride-graphene composite filler.

6. The high-toughness clustered grid according to claim 1, characterized in that, The number average molecular weight of epoxy-modified unsaturated polyester resin is 2000-3000 g / mol, the weight average molecular weight of metallocene polyolefin is 80000-100000 g / mol, the number average molecular weight of highly branched polyolefin is 50000-70000 g / mol, and the weight average molecular weight of EPDM rubber is 150000-200000 g / mol.

7. The high-toughness clustered grid according to claim 1, characterized in that, The length of the alkali-free glass fiber is 10-16 mm, the silane coupling agent is one of KH-550, KH-560 or KH-570, the ultraviolet stabilizer is one of UV-328, UV-326 or UV-531, and the conductive additive is carbon nanotube or graphene microplate.

8. A manufacturing process for a high-toughness clustered grid according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Raw material pretreatment: Immerse the alkali-free glass fiber in a 3%-4% (w / w) silane coupling agent ethanol solution for 7-12 minutes, and then dry it in a forced-air oven at 115-125℃ for 1.5-2.5 hours. The modified nano-aluminum nitride-graphene composite filler was dried in a vacuum drying oven at 90-95℃ for 2-4 hours. The conductive additive is mixed with anhydrous ethanol at a mass ratio of 1:40-1:60 and ultrasonically dispersed at 350-450W power for 15-30 minutes to obtain a conductive additive dispersion. S2. Preparation of ultrasound-assisted premix: After adding epoxy-modified unsaturated polyester resin to a high-speed mixer with a volume of 6-10L, metallocene polyolefin, highly branched polyolefin, EPDM rubber, core-shell elastomer toughening agent, antioxidant, UV stabilizer, and calcium stearate are added sequentially. The mixture is stirred at 600-800 rpm for 20-30 minutes at 50-55℃. Then, a dispersion of modified nano-aluminum nitride-graphene composite filler and conductive additives is added to the system. The mixture is ultrasonically dispersed at 55-60℃ and 400-500W for 25-35 minutes, and then stirred at 150-250 rpm for 5-10 minutes. Finally, 1.2-1.6 parts of methyl ethyl ketone peroxide and 0.5-0.7 parts of N,N-diethylaniline are added, and the mixture is stirred at 150-250 rpm for 4-8 minutes to obtain a premix. S3, Twin-screw compounding pre-impregnation: The premixed material is added from the main feed port of the twin-screw extruder, and the pretreated alkali-free glass fiber is added from the side feed port. The screw temperature gradient is set as follows: Zone 1 150-160℃, Zone 2 160-170℃, Zone 3 170-180℃, and the screw speed is 30-50 r / min. The extrusion forms a continuous prepreg strip. S4. Bundling and Stepwise Thermosetting: Four to seven prepreg strips are fed into the cavity of the bundled mold and pulled by a traction machine. The formed bundled structure is then placed in a hot air circulation curing oven. It is first kept at 95-105℃ for 25-40 minutes, and then heated to 125-135℃ for 18-30 minutes to obtain a cured bundled grid. S5, Gradient cooling annealing: The S4-obtained clustered grid is transferred into an annealing furnace and cooled from 125-135℃ to 60-70℃ at a rate of 5-10℃ / h. After holding at this temperature for 2-4 hours, the heating is turned off, and the grid is allowed to cool naturally to room temperature. S6. Surface coated with a nano-ceramic protective layer: A high-pressure sprayer is used to spray an Al2O3-ZrO2 nano-ceramic coating with a particle size of 20-30nm onto the S5 obtained cluster grid. The coating thickness is 0.3-0.8mm. After spraying, the grid is placed in a forced-air oven at 95-105℃ and dried for 30-50 minutes. Finally, after cutting and trimming, a high-toughness cluster grid is obtained.

9. The manufacturing process of the high-toughness clustered grid according to claim 8, characterized in that, In step S4, the traction machine pulls at a traction speed of 0.7-1.2 m / min and a traction force of 450-650 N.

10. The manufacturing process of the high-toughness clustered grid according to claim 8, characterized in that, In step S6, the mass ratio of Al2O3 to ZrO2 is 3:2-4:1.