A glass fiberboard and a method for manufacturing the same

Abstract

The application discloses a glass fiber plate and a preparation method thereof. The preparation method of the glass fiber plate comprises the following steps: providing glass fibers and a modified resin, wherein the modified resin comprises a matrix resin, a multifunctional silane coupling agent and a nano filler; performing surface activation treatment on the glass fibers, and then applying the modified resin on the activated glass fibers to form a prepreg; and performing laminating and curing molding on the prepreg; wherein during the curing molding process, one end of the multifunctional silane coupling agent is covalently bonded to the surface of the glass fibers, and the other end of the multifunctional silane coupling agent participates in the cross-linking and curing of the matrix resin, and meanwhile, the nano filler is enriched in the interface region between the glass fibers and the matrix resin to form an interface interpenetrating network layer. In the above manner, the preparation method of the glass fiber plate can greatly improve the tensile strength and the bending modulus of the glass fiber plate.

Description

Technical Field

[0001] This application relates to the field of composite materials technology, and in particular to a fiberglass board and its preparation method. Background Technology

[0002] Glass fiber reinforced resin matrix composites (GFMC) are widely used in electronic circuit boards, aerospace, automotive lightweighting, and building materials due to their excellent mechanical properties, heat resistance, and insulation. The macroscopic mechanical properties of GFMC largely depend on the interfacial bonding state between the glass fibers and the resin matrix. The interface not only transfers stress but also prevents crack propagation.

[0003] In recent years, to improve the interfacial bonding between glass fiber and resin, conventional silane coupling agents are commonly used to pretreat the glass fiber surface, or coupling agents are directly added to the resin for physical blending. However, conventional coupling agents have limited chemical bond strength at the interface, often only achieving single-end bonding or physical adsorption, resulting in a lack of rigid support and shear resistance in the interfacial region. Under external stress or thermal shock, debonding and peeling easily occur at the interface, leading to a bottleneck in improving the tensile strength and flexural modulus of glass fiber sheets.

[0004] Therefore, there is an urgent need for a method that can fundamentally strengthen interfacial chemical bonding and microstructure, thereby significantly improving the strength and modulus of fiberglass boards. Summary of the Invention

[0005] This application provides a fiberglass board and its preparation method to solve the technical problems of weak interfacial bonding and easy debonding of current fiberglass boards, which limit the improvement of strength and modulus.

[0006] To solve the above-mentioned technical problems, this application adopts a technical solution as follows: providing a method for preparing a fiberglass board. The method includes: S1: providing glass fibers and a modified resin, wherein the modified resin comprises a matrix resin, a multifunctional silane coupling agent, and nanofillers; S2: performing surface activation treatment on the glass fibers, and then applying the modified resin onto the activated glass fibers to form a prepreg; S3: laminating and curing the prepreg; wherein, during the curing process, one end of the multifunctional silane coupling agent forms a covalent bond with the surface of the glass fiber, and the other end participates in the crosslinking and curing of the matrix resin, while the nanofillers are enriched in the interface region between the glass fibers and the matrix resin, forming an interpenetrating network layer.

[0007] In some embodiments, in step S1, the matrix resin is any one of epoxy resin, phenolic resin, polyurethane resin, or unsaturated polyester resin; the multifunctional silane coupling agent is a silane coupling agent containing at least two hydrolyzable alkoxy groups, and its organic functional group is epoxy, amino, or methacryloxy; the nanofiller is nano-silica, nano-alumina, or nano-silicon carbide with hydroxyl groups on its surface, and its average particle size is 10nm-100nm.

[0008] In some embodiments, based on a total weight of 100 parts of the modified resin, the matrix resin accounts for 80-95 parts, the multifunctional silane coupling agent accounts for 1-5 parts, and the nanofiller accounts for 0.5-5 parts.

[0009] In some embodiments, in step S2, the surface activation treatment is plasma treatment or low-temperature ozone treatment, and the treatment time is 1 min to 10 min. The plasma treatment has a power of 100W-500W and a vacuum degree of 10Pa-50Pa.

[0010] In some embodiments, in step S2, the weight content of the modified resin in the prepreg is 30%-60%.

[0011] In some embodiments, in step S3, the lamination curing molding includes a pre-pressing stage and a main pressing stage; The temperature of the pre-compression stage is 80℃-120℃, the pressure is 0.5MPa-2MPa, and the time is 30min-60min; The temperature of the main pressure stage is 140℃-180℃, the pressure is 3MPa-8MPa, and the time is 60min-120min.

[0012] In some embodiments, step S3 is followed by a post-curing step, wherein the post-curing temperature is 180℃-200℃ and the time is 2h-4h.

[0013] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a fiberglass board. The fiberglass board includes glass fibers and a modified resin matrix, and an interpenetrating network layer is formed between the glass fibers and the modified resin matrix; the interpenetrating network layer contains a multifunctional silane coupling agent and nanofillers, one end of the multifunctional silane coupling agent is covalently bonded to the surface of the glass fiber, and the other end is cross-linked to the polymer network of the modified resin matrix, and the nanofillers are enriched in the interpenetrating network layer.

[0014] In some embodiments, the fiberglass board comprises at least two layers of fiberglass cloth, with the modified resin matrix and the interpenetrating network layer filling the space between adjacent layers of fiberglass cloth.

[0015] In some embodiments, the thickness of the interpenetrating network layer is 100 nm-2 μm.

[0016] The beneficial effects of this application are as follows: Unlike existing technologies, this application discloses a fiberglass board and its preparation method. The embodiments of this application utilize a multifunctional silane coupling agent, which, during the curing process, forms a covalent bond between one end and the activated glass fiber surface, while the other end participates in the cross-linking and curing of the matrix resin, constructing a robust two-way chemical bridge. This completely solves the problem of easy debonding caused by traditional single-end bonding or physical adsorption. Simultaneously, nanofillers accumulate in the interfacial region, forming an interfacial interpenetrating network layer in conjunction with the aforementioned cross-linked network. This significantly improves the rigidity and toughness of the interface, effectively transferring and dispersing stress, and blocking the propagation of microcracks. This results in a more than 50% increase in the tensile strength and flexural modulus of the fiberglass board compared to conventional systems, thus significantly breaking through the bottleneck in improving the tensile strength and flexural modulus of fiberglass boards. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic flowchart of an embodiment of the fiberglass board preparation method provided in this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] The terms "first," "second," and "third" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] To address the problems of weak interfacial bonding, easy debonding, and limited improvement in tensile strength and flexural modulus of fiberglass boards caused by conventional monofunctional coupling agents or physical blending modifications in existing technologies, this application provides a solution for reinforcing fiberglass boards using an interfacial interpenetrating network layer. This solution achieves tight anchoring of inorganic fiberglass and organic resin at the molecular level through bidirectional bonding of multifunctional silane coupling agents and interfacial enrichment of nanofillers, constructing a robust interfacial interpenetrating network layer. This process can be completed using only conventional impregnation and hot-pressing equipment with a specific modified resin, significantly reducing the complexity of the process and substantially improving material properties.

[0022] Specifically, see Figure 1 , Figure 1 This is a schematic flowchart of an embodiment of the fiberglass board preparation method provided in this application. The fiberglass board preparation method includes: Step S1: Provide glass fiber and modified resin, the modified resin comprising a matrix resin, a multifunctional silane coupling agent and nanofillers.

[0023] In step S1, glass fibers and a specific modified resin are first required. Glass fibers are the main load-bearing skeleton in the fiberglass board, and their morphology, type, and surface condition directly determine the final macroscopic mechanical properties and physical characteristics of the fiberglass board. In this embodiment, the glass fibers are at least one of continuous glass fiber yarn, chopped glass fibers, or glass fiber cloth.

[0024] Specifically, continuous glass fiber yarn possesses extremely high axial tensile strength, making it suitable for structural components requiring unidirectional or bidirectional extremely high tensile stress, such as pipes and profiles manufactured through winding or pultrusion processes. Chopped glass fibers, due to their isotropic nature, are commonly used in molding or injection molding processes, enabling the fabrication of parts with complex shapes and uneven wall thicknesses. Furthermore, chopped fibers exhibit good dispersion in resin, effectively preventing bridging of long fibers in complex molds. Glass fiber cloth (such as plain weave, twill weave, or satin weave) is the most commonly used reinforcing material for copper-clad laminates and laminates. Different weave structures of glass fiber cloth exhibit different drape and resin impregnation properties. Plain weave cloth has a stable structure and is not easily deformed, but impregnation with resin is relatively difficult; satin weave cloth has better impregnation and molding properties, making it suitable for fabricating laminates with curved surfaces or high resin content requirements.

[0025] In practical implementation, the choice of one or more hybrid forms of glass fibers can be flexibly made according to the application scenario of the final product, such as electronic circuit boards, aerospace structural components, and lightweight automotive parts. Furthermore, the glass fibers are typically composed of alkali-free glass (E-glass) or medium-alkali glass (C-glass). In high-end high-frequency electronic applications, low-dielectric-constant quartz glass fibers or high-strength glass fibers can also be selected.

[0026] It is worth noting that glass fibers are typically coated with a sizing agent during the drawing process. This sizing agent mainly contains organic components such as film-forming agents, lubricants, and antistatic agents, and its primary function is to protect the fibers from mechanical damage and facilitate subsequent textile processing. However, these organic sizing agents form a weak interface layer on the glass fiber surface, severely hindering the chemical bonding and physical interlocking between the resin and the glass fiber. Therefore, in actual production, if glass fibers with commercially available sizing agents are used, they usually require high-temperature heat treatment, such as calcination or hot cleaning, before subsequent processes to remove the surface organic sizing agents and expose a pure glass surface, thereby ensuring the effectiveness of subsequent activation treatment and coupling agent bonding. The desizing agent-free glass fiber surface is rich in silanol groups (Si-OH), which provides the necessary reactive sites for the subsequent hydrolysis and condensation reaction of multifunctional silane coupling agents.

[0027] Furthermore, the modified resin comprises a matrix resin, a multifunctional silane coupling agent, and nanofillers.

[0028] The matrix resin is the continuous phase in the fiberglass board. It not only binds the glass fibers together, but also transmits stress and protects the fibers from external environmental erosion.

[0029] In this embodiment, the matrix resin is any one of epoxy resin, phenolic resin, polyurethane resin, or unsaturated polyester resin. Epoxy resin is one of the most widely used matrix resins in the field of composite materials, possessing excellent adhesion, low curing shrinkage, good chemical corrosion resistance, and good mechanical and electrical insulation properties. Epoxy resin molecules contain active epoxy groups, enabling them to undergo cross-linking and curing reactions with various curing agents (such as amines and acid anhydrides) to form a three-dimensional network structure. In electronic circuit board applications (such as copper-clad laminates), bisphenol A type epoxy resin or phenolic epoxy resin with a high glass transition temperature (Tg) is typically selected to meet the heat resistance requirements during lead-free soldering processes.

[0030] Phenolic resin was the first synthetic resin to be industrially produced, possessing excellent heat resistance, flame retardancy, and low smoke emission. Phenolic resin can carbonize at high temperatures to form a robust carbonized layer, thus holding an irreplaceable position in fields such as aerospace fire-resistant components and flame-retardant building materials. Its curing process typically relies on further polycondensation reactions of the resin itself under heating conditions, releasing moisture. Although cured phenolic resin products are relatively brittle, the interface modification technology described in this application, which introduces a high-strength interpenetrating network layer, can significantly improve its brittleness and prevent crack propagation.

[0031] Polyurethane resin is formed through the reaction of isocyanate and polyol. Its key characteristic is its high designability; materials with varying hardness, elasticity, and strength can be obtained by adjusting the ratio of hard and soft segments. In glass fiber composites requiring impact resistance and toughness, the polyurethane matrix exhibits unique advantages. Unsaturated polyester resin is commonly used for room-temperature or medium-temperature contact molding of large structural components. Its advantages include simple processing, room-temperature curing, and low cost, making it widely used in large glass fiber composite products such as yachts, wind turbine blades, and cooling towers.

[0032] Conventional silane coupling agents typically have only one hydrolyzable group, such as monochlorosilanes or monoalkoxysilanes. They can only form single-end connections on the glass fiber surface and cannot form a dense cross-linked network in the interfacial region. In this embodiment, however, the multifunctional silane coupling agent is a silane coupling agent containing at least two hydrolyzable alkoxy groups, and its organic functional group is an epoxy, amino, or methacryloxy group.

[0033] When coupling agent molecules come into contact with moisture, alkoxy groups such as methoxy and ethoxy groups rapidly hydrolyze to generate silanols (Si-OH). These silanol groups can not only undergo condensation reactions with the silanol groups on the glass fiber surface to form strong Si-O-Si covalent bonds, but also, due to the presence of at least two hydrolyzable groups, coupling agent molecules can also undergo mutual condensation to form an oligomeric siloxane network on the glass fiber surface, rather than an isolated single molecular layer. This networked underlying structure lays a solid foundation for the subsequent formation of interpenetrating network layers.

[0034] Simultaneously, the other end of the multifunctional silane coupling agent must possess an organic functional group capable of participating in the cross-linking and curing of the matrix resin. In this embodiment, the organic functional group of the multifunctional silane is an epoxy group, an amino group, or a methacryloyloxy group. For example, when the matrix resin is an epoxy resin, γ-glycidoxypropyltrimethoxysilane (KH-560) containing an epoxy group is selected, as its epoxy group can undergo ring-opening cross-linking with the epoxy resin matrix under the action of a curing agent; or γ-aminopropyltriethoxysilane (KH-550) containing an amino group is selected, as its active hydrogen can directly react with the epoxy group, acting as a curing agent or accelerator, allowing the coupling agent molecule to be directly anchored in the three-dimensional network of the resin matrix. When the matrix resin is an unsaturated polyester resin, γ-methacryloyloxypropyltrimethoxysilane (KH-570) containing a methacryloyloxy group is selected, as its carbon-carbon double bond can undergo free radical copolymerization with the unsaturated polyester under the action of an initiator. By forming this two-way chemical bond bridge design, the weak interfacial interaction between glass fiber and resin is completely eliminated at the molecular level, allowing stress to be effectively transferred from the flexible resin matrix to the rigid glass fiber skeleton.

[0035] Furthermore, to further enhance the rigidity and toughness of the interface layer, this application also introduces nanofillers into the modified resin. These nanofillers are nano-silica, nano-alumina, or nano-silicon carbide with hydroxyl groups on their surface, and their average particle size is 10 nm-100 nm. Nanomaterials possess extremely high specific surface area and surface energy, and their surface and volume effects enable them to exhibit excellent reinforcing and toughening effects in composite materials.

[0036] Because the coupling agent generates a large number of silanol groups after hydrolysis, these silanol groups not only react with the glass fiber surface but also undergo condensation reactions with the hydroxyl groups on the surface of the nanofillers, or form strong hydrogen bonds. Before resin curing, the distribution of nanofillers in the liquid resin is affected by interfacial tension. Since the coupling agent molecules have been initially anchored to the glass fiber surface, the reactive nanofillers spontaneously migrate and accumulate towards the high-energy glass fiber surface region. During the curing process, with the cross-linking of the resin and the formation of the coupling agent network, the nanofillers are locked in situ in the interfacial region, intertwining with the organosiloxane network to form an interfacial interpenetrating network layer with high strength and a certain degree of toughness.

[0037] Specifically, the average particle size of the nanofiller is controlled within the range of 10nm-100nm. If the particle size is less than 10nm, the surface energy of the nanoparticles is extremely high, making them prone to aggregation. This not only makes it difficult to disperse uniformly in the resin but may also form defects at the interface, becoming stress concentration points and thus reducing the mechanical properties of the material. If the particle size is greater than 100nm, the specific surface area of ​​the particles decreases, reducing the contact area with the coupling agent and resin. The interfacial enrichment effect and reinforcing effect are not obvious, and large particles are easily trapped by the pores of the fiberglass cloth during the impregnation process, failing to effectively enter the interfacial microregions. Therefore, a particle size range of 10nm-100nm is the optimal balance point to ensure dispersibility and interfacial enrichment effect.

[0038] Regarding the formulation ratio, based on a total weight of 100 parts of modified resin, the matrix resin accounts for 80-95 parts, the multifunctional silane coupling agent accounts for 1-5 parts, and the nanofiller accounts for 0.5-5 parts.

[0039] A matrix resin content of 80-95 parts is fundamental to ensuring sufficient bulk strength, toughness, and processing fluidity of the composite material. If the matrix resin content is below 80 parts, it means that the modifier and filler content is too high, and the viscosity of the resin system will increase sharply. This will prevent sufficient penetration during glass fiber impregnation, resulting in dry spots or resin-rich areas, which will not only impair mechanical properties but also affect electrical insulation properties. If the matrix resin content is above 95 parts, the absolute content of coupling agent and nanofiller is too low, making it impossible to form a continuous and dense interpenetrating network layer at the interface. The interface strengthening effect will be negligible, negating the significance of the modification proposed in this application.

[0040] The amount of multifunctional silane coupling agent is 1-5 parts, and the amount of coupling agent directly determines the density of interfacial covalent bridges. When it is less than 1 part, the reactive sites on the glass fiber surface cannot be fully utilized, and the improvement in interfacial bonding force is not significant; when it is more than 5 parts, the excess coupling agent molecules cannot all be anchored on the interface, but are free in the resin matrix. These excess coupling agent small molecules may become plasticizers after curing, reducing the heat resistance and strength of the resin matrix, or they may polymerize to form an overly rigid interfacial layer. When heated or stressed, internal stress is generated due to the mismatch of thermal expansion coefficients, leading to the initiation of interfacial microcracks.

[0041] Nanofillers comprise 0.5-5 parts, and their main function is to construct a rigid framework and provide toughening. When the content is less than 0.5 parts, the nanoparticle density in the interfacial region is too low to form an effective interpenetrating network support; when the content is more than 5 parts, not only is dispersion difficult and viscosity drastically increased, but excessive inorganic particles also make the interfacial layer too rigid, losing its ability to absorb and disperse stress, making it prone to brittle fracture under impact. Therefore, strictly controlling the proportions of each component is crucial for balancing the resin's processing performance, the matrix's bulk properties, and the interfacial strengthening effect.

[0042] This embodiment solves the technical problem of weak interfacial bonding between glass fiber and resin from the source through the synergistic effect of the above-mentioned specific components and their proportions, laying a solid material foundation for the subsequent molding of glass fiber boards with ultra-high tensile strength and flexural modulus.

[0043] Step S2: Surface-activate the glass fiber, and then apply the modified resin onto the activated glass fiber to form a prepreg.

[0044] After preparing the raw materials, the primary task of step S2 is to perform surface activation treatment on the glass fibers. As mentioned earlier, glass fibers are usually coated with a wetting agent during manufacturing. Even after removing the wetting agent, although the pure glass fiber surface contains silanol groups, their distribution density and reactivity are often insufficient to support high-density, high-strength coupling agent grafting. Therefore, it is necessary to activate the glass fiber surface through physical or chemical means to significantly increase the number of surface-active groups and improve the surface microstructure, thereby providing optimal reaction conditions for the subsequent covalent bonding of multifunctional silane coupling agents.

[0045] In this embodiment, the surface activation treatment is plasma treatment or low-temperature ozone treatment, and the treatment time is 1 min to 10 min.

[0046] Specifically, plasma treatment is an advanced dry surface modification technology. In a vacuum environment, typically maintained between 10 Pa and 50 Pa, a high-frequency, high-voltage electric field is applied to ionize the introduced gas, creating a plasma atmosphere containing a large number of electrons, ions, free radicals, and excited-state molecules. The introduced gas can be air, oxygen, argon, or nitrogen, etc. When glass fibers pass through this plasma region, the high-energy particles in the plasma bombard the glass fiber surface, producing two effects: first, physical etching, where the impact of high-energy particles removes extremely weak contaminant layers and low-molecular-weight substances from the glass fiber surface, while simultaneously forming a nanoscale rough and uneven structure on the glass fiber surface. This roughening greatly increases the specific surface area of ​​the glass fiber, thereby increasing the physical contact area with resins and coupling agents; second, chemical activation, where oxygen free radicals and excited-state oxygen molecules in the plasma break the Si-O-Si network bonds on the glass fiber surface and introduce a large number of oxygen-containing polar groups, such as hydroxyl (-OH), carboxyl (-COOH), and carbonyl (-C=O). In particular, the sharp increase in surface hydroxyl density provides abundant condensation reaction sites for the silanol groups after hydrolysis of the multifunctional silane coupling agent, enabling the coupling agent to form a dense chemical bonding network on the glass fiber surface.

[0047] In this embodiment, the plasma treatment power is 100W-500W, and the vacuum level is 10Pa-50Pa. If the power is below 100W, the plasma energy density is insufficient, resulting in weak etching and activation effects, and failing to significantly improve the surface hydroxyl density. If the power is above 500W, excessive particle bombardment may cause mechanical damage to the main structure of the glass fiber, leading to a decrease in the tensile strength of the glass fiber itself. This not only violates the original purpose of the reinforcing material but may also cause fiber breakage under subsequent stress. Vacuum level control is equally crucial. If the vacuum level is below 10Pa, i.e., the gas pressure is too high, the mean free path of gas molecules is short, particle collisions are frequent, and the energy reaching the glass fiber surface is severely attenuated, making it impossible to form an effective plasma sheath. If the vacuum level is above 50Pa, i.e., the gas pressure is too low, approaching a high vacuum, gas molecules are scarce, the plasma concentration generated by ionization is too low, and the processing efficiency is extremely slow.

[0048] The processing time of 1-10 minutes is also the optimal range determined through extensive experimentation. A time shorter than 1 minute results in insufficient activation, with the surface hydroxyl group generation not reaching saturation; a time longer than 10 minutes not only fails to significantly improve the activation effect due to reaching saturation, but may also lead to surface pulverization or strength loss due to excessive etching. In actual industrial production, continuous roll-to-roll plasma treatment equipment is often used, with the fiberglass cloth passing through the treatment chamber at a specific speed. The processing time is precisely controlled within the aforementioned range by adjusting the speed.

[0049] In addition to plasma treatment, this embodiment also provides a low-temperature ozone treatment as an alternative. Ozone is a strong oxidant that can oxidize and decompose organic impurities on the glass fiber surface at room temperature or low temperature. It can also oxidize the silicon-oxygen bonds on the glass fiber surface, causing them to break and generate new silanol groups. Compared to plasma treatment, ozone treatment equipment is simpler, requiring no complex vacuum system; the glass fiber is simply placed in a sealed chamber filled with ozone. Ozone not only cleans the surface but also forms an oxygen-rich activation layer on the glass fiber surface. Similarly, the treatment time is controlled between 1 and 10 minutes to ensure the oxidation and activation reaction proceeds fully without damaging the substrate.

[0050] After the surface activation treatment is completed, the glass fiber surface is in an ideal state of high energy and high activity. At this time, the impregnation operation must be carried out immediately to prevent secondary pollution from dust in the air or deactivation of surface hydroxyl groups due to prolonged exposure to air.

[0051] Subsequently, the modified resin is applied to the activated glass fibers to form a prepreg. In this embodiment, the modified resin is applied to the glass fibers by impregnation, spraying, or scraping.

[0052] For fiberglass cloth, the most common and efficient method is impregnation. Activated fiberglass cloth is continuously fed into an impregnation tank containing modified resin solution. Passing through a series of guide rollers and extrusion rollers, the resin fully penetrates into the fiber bundles and the interlacing pores of the fiberglass cloth. The extrusion rollers control the resin content in the prepreg and scrape off excess surface resin. The advantages of impregnation are thorough wetting, high uniformity, and suitability for large-scale continuous production.

[0053] For chopped glass fibers, especially in molding or injection molding processes, spraying is more suitable. Modified resin is atomized using a high-pressure spray gun and evenly sprayed onto the randomly distributed chopped glass fibers. Simultaneously, an electrostatic generator can be used to give the resin droplets and glass fibers opposite charges, utilizing electrostatic adsorption to better encapsulate the fibers with the resin. This method is not limited by fiber morphology and is suitable for preparing premixes with irregular shapes.

[0054] The blade coating method is suitable for preparing prepregs with high resin content or specific thicknesses. Glass fibers are laid flat on a carrier tape, and modified resin is evenly coated onto the glass fiber surface using a blade with a specific gap. The blade gap determines the coating thickness, thus precisely controlling the resin content.

[0055] Regardless of the application method used, the core objective is to ensure that the modified resin can uniformly and completely coat each glass fiber. In particular, it is necessary to ensure that the resin system containing multifunctional silane coupling agents and nanofillers can fully contact the activated glass fiber surface, so as to provide material support for the in-situ formation of the subsequent interpenetrating network layer.

[0056] During the prepreg formation process, the resin content of the prepreg must be strictly controlled. In this embodiment, the weight content of modified resin in the prepreg is 30%-60%.

[0057] If the modified resin content is below 30%, it means the volume fraction of glass fiber is too high. Although glass fiber itself has extremely high tensile strength, the resin, as the stress-transferring medium, will cause dry spots or void defects to form inside the board if the amount of resin is insufficient to completely fill all the tiny pores between the glass fibers. These voids will not only significantly reduce the interlaminar shear strength and flexural modulus of the board, but will also become sources of water absorption and stress concentration. In addition, during the lamination process, too low a resin content will not be able to form sufficient resin flow to lubricate the fibers, causing the fibers to rub against each other or even break under high pressure, seriously impairing the mechanical properties.

[0058] Conversely, if the modified resin content exceeds 60%, although the impregnation is extremely thorough, the load-bearing ratio of glass fiber in the board is too low. The overall tensile strength and flexural modulus of the board will be significantly reduced due to the presence of resin-rich zones. At the same time, excessively high resin content will cause a large amount of resin to overflow during hot pressing, resulting not only in material waste and environmental pollution, but also making it difficult to control the dimensional accuracy of the board. After curing, the large resin shrinkage rate will lead to severe warping deformation and internal stress.

[0059] Precisely controlling the resin content within the range of 30%-60% ensures that the resin has sufficient fluidity during lamination and curing to further wet the fiber bundles, eliminate air bubbles, and form a dense, non-porous composite material after final curing. Within this range, the skeletal support of the glass fiber and the adhesive force transfer effect of the resin achieve an optimal balance. Especially for the system containing nanofillers and multifunctional coupling agents in this application, this ratio ensures sufficient enrichment of nanofillers and network structures at the interface without forming enrichment defects within the matrix.

[0060] At this point, through precisely controlled surface activation and sizing processes, the modified resin rich in reactive groups has been uniformly coated on the highly active glass fiber surface, and the prepreg preparation stage has been successfully completed, laying a solid foundation for subsequent complex chemical crosslinking and microstructure recombination under hot pressing conditions.

[0061] Step S3: Laminate and cure the prepreg.

[0062] During this stage, under certain temperature and pressure conditions, the matrix resin of the prepreg undergoes cross-linking and curing, the multifunctional silane coupling agent undergoes hydrolysis and condensation and participates in cross-linking, and the nanofiller undergoes interfacial migration and enrichment. A series of complex physicochemical changes occur simultaneously or sequentially, ultimately transforming the loose prepreg into a dense solid board with high strength and high modulus.

[0063] In this embodiment, the lamination curing process includes a pre-pressing stage and a main press stage. The staged pressurization and heating are designed to accommodate the rheological changes of the thermosetting resin, ensuring that the resin can flow sufficiently and release air before the curing reaction becomes vigorous.

[0064] Specifically, the temperature during the pre-compression stage is 80℃-120℃, the pressure is 0.5MPa-2MPa, and the time is 30min-60min.

[0065] The pre-compression stage has three main objectives: first, to melt and soften the resin, reducing its viscosity and restoring its fluidity when heated, as the resin in the prepreg is in a semi-cured or viscous state at room temperature; second, to remove volatiles, as a small amount of low-molecular-weight volatiles or dissolved air may remain in the resin during synthesis or formulation, and these volatiles will escape during the heating stage. Lower pre-compression pressure and appropriate time allow them sufficient opportunity to escape from the board, preventing bubbles or pinholes from forming inside the final board; and third, to allow the resin to further penetrate into the glass fiber bundles. Under the combined action of pressure and capillary action, the resin further penetrates into the tiny gaps between the activated glass fiber monofilaments, ensuring that the interfacial reaction can occur fully.

[0066] The pre-compression temperature is set at 80℃-120℃. If the temperature is below 80℃, the resin viscosity remains high and the flowability is poor. Not only is it difficult for volatiles to be discharged, but the resin also cannot further impregnate the fibers, and gaps or voids are likely to appear at the interface. If the temperature is above 120℃, especially for epoxy or phenolic resin systems, the curing reaction rate has already begun to accelerate significantly. The resin will gel before it has fully flowed and impregnated, that is, premature cross-linking and curing. This causes the volatiles to be tightly sealed inside the board, and the interpenetrating network layer cannot be uniformly formed because the gel blocks the interfacial migration path of the nanofiller.

[0067] The pressure is set at 0.5MPa-2MPa. This low pressure is sufficient to compact the prepreg layer, preventing interlayer slippage, while also preventing excessive extrusion of ungelled resin. The time is 30-60 minutes to ensure that the above physical process has sufficient time to complete.

[0068] With the end of the pre-compression stage, the resin system begins to enter the gelation stage, at which point the temperature and pressure must be increased to enter the main compression stage. In this embodiment, the temperature of the main compression stage is 140℃-180℃, the pressure is 3MPa-8MPa, and the time is 60min-120min.

[0069] The main pressure temperature of 140℃-180℃ can provide sufficient activation energy to promote the radical resin to undergo vigorous ring-opening or addition polymerization reactions. At the same time, the organic functional groups of the multifunctional silane coupling agent also actively participate in the construction of the resin crosslinking network within this temperature range.

[0070] Increasing the main pressure to 3MPa-8MPa serves two main purposes: first, it compacts the substrate, overcoming the volume shrinkage that occurs during resin curing and cross-linking, and preventing microcracks or internal stress at the glass fiber-resin interface due to shrinkage; second, it increases the intermolecular contact density. Under high pressure, the distance between the hydroxyl-containing nanofiller, the highly active glass fiber surface, and the coupling agent molecules is drastically compressed. This not only promotes the formation of hydrogen bonds but also facilitates the dehydration condensation reaction between silanol groups (forming Si-O-Si covalent bonds). Furthermore, the high-pressure environment significantly promotes the anchoring of the nanofiller in the interfacial region and the densification of the interpenetrating network structure.

[0071] A main pressing time of 60-120 minutes ensures that the cross-linking reaction can proceed to completion, allowing the resin to achieve a curing degree of over 90%. If the time is too short, the resin will not cure completely, resulting in a lower glass transition temperature and an incompletely formed interfacial network structure, preventing the mechanical properties from reaching their peak. If the time is too long, it will not only reduce production efficiency but may also cause the resin to undergo thermal degradation at high temperatures, leading to brittle material and a decrease in flexural modulus.

[0072] During the main pressure stage, as the temperature rises, the multifunctional silane coupling agent first absorbs trace amounts of moisture in the resin system or the crystal water inherent in the coupling agent itself, undergoing a hydrolysis reaction to generate highly active silanols. These silanol molecules rapidly diffuse to the high-energy glass fiber surface, undergoing a condensation reaction with the abundant surface silanols generated by the activation treatment, removing water molecules, and forming strong Si-O-Si covalent bonds. Since this embodiment uses a multifunctional coupling agent containing at least two hydrolyzable alkoxy groups, the coupling agent molecules not only connect to the glass fiber surface but also condense with each other on the glass fiber surface, forming a two-dimensional or even three-dimensional siloxane oligomer network.

[0073] Meanwhile, during the transition from liquid resin to gel state, nanofillers with surface hydroxyl groups spontaneously migrate towards the vicinity of the glass fiber surface due to the dual driving forces of interfacial tension and chemical affinity. The hydroxyl groups on the surface of these nanoparticles can also participate in the aforementioned silanol condensation network, becoming rigid crosslinking points in the network structure. As the matrix resin cures and crosslinks, the organic functional groups at the other end of the coupling agent are captured by the long-chain polymer network and chemically bonded.

[0074] Finally, when the resin is fully cured, a complex three-dimensional network structure, namely the interfacial region, is formed within a certain thickness range from the glass fiber surface to the interior of the matrix resin. This network consists of interpenetrating and chemically cross-linked inorganic nanoparticles, siloxane networks, and organic polymer segments. This interfacial interpenetrating network layer structure enables a performance gradient transition from inorganic glass fiber to organic resin, greatly eliminating abrupt performance changes and stress concentrations at the interface.

[0075] Furthermore, in order to further improve the heat resistance and dimensional stability of the material and completely eliminate residual internal stress during the curing process, this embodiment includes a post-curing step after step S3. The post-curing temperature is 180℃-200℃ and the time is 2h-4h.

[0076] Post-curing is a high-temperature heat treatment process performed under no pressure or normal pressure. Its purpose is to allow residual functional groups that did not fully react during the main compression stage to continue reacting at higher temperatures, further increasing the crosslinking density. At the same time, high-temperature treatment can promote the relaxation of polymer chain segments, releasing residual thermal stress and curing shrinkage stress accumulated inside the material due to temperature and pressure gradients during hot pressing.

[0077] The post-curing temperature of 180℃-200℃ is usually higher than the glass transition temperature of the material. At this temperature, the chain segments have sufficient mobility to adjust their conformation and achieve a more thermodynamically stable equilibrium state. After 2-4 hours of post-curing, the Tg of the fiberglass board usually increases by 5-10℃, and the warpage rate during subsequent high-temperature service is significantly reduced. This is especially important for high-precision applications such as electronic substrates.

[0078] Through the carefully designed S1 to S3 steps described above, not only were macroscopically complete fiberglass boards prepared, but more importantly, an interpenetrating network layer with bidirectional chemical bonds and rigid nano-supports was successfully constructed at the microscale. The successful construction of this microstructure directly determines the huge leap in the macroscopic mechanical properties of the fiberglass board.

[0079] This application also provides a fiberglass board (not shown) prepared by the above method. The microstructural characteristics of this fiberglass board and its impact on performance will be analyzed in detail below.

[0080] A fiberglass board, characterized in that it comprises glass fibers and a modified resin matrix, wherein an interpenetrating network layer is provided between the glass fibers and the modified resin matrix; the interpenetrating network layer comprises a multifunctional silane coupling agent and nanofillers, one end of the multifunctional silane coupling agent is covalently bonded to the surface of the glass fibers, and the other end is cross-linked to the polymer network of the modified resin matrix, and the nanofillers are enriched in the interpenetrating network layer.

[0081] It should be noted that in the above method steps, the matrix resin is the starting reactant, while the modified resin matrix is ​​the final cross-linked product of the matrix resin after treatment. Specifically, the modified resin matrix refers to the three-dimensional cross-linked solid network structure formed after the initial matrix resin undergoes chemical cross-linking with the organic functional groups of the multifunctional silane coupling agent and encapsulates the remaining nanofillers that are not enriched at the interface, following the lamination and curing molding in step S3.

[0082] As a multiphase composite material, the overall performance of fiberglass board is not a simple sum of the properties of its individual components, but rather highly dependent on the quality of the interfacial bonding between the phases. In traditional fiberglass boards, the interface is merely a simple physical encapsulation of glass fibers by resin, or at most, a monolayer of coupling agent adsorption. However, in the fiberglass board of this embodiment, the glass fibers and the modified resin matrix are no longer two completely separate phases, but rather organically fused through an interpenetrating network layer.

[0083] The presence of this interpenetrating network layer fundamentally alters the stress transfer mechanism when the material is subjected to external forces. When a fiberglass board is subjected to bending or tensile stress, the stress is initially applied to the softer resin matrix. If the interfacial bonding is weak, the stress cannot be effectively transferred to the high-strength fiberglass, and the resin matrix itself will deform or even crack first. In this embodiment, because one end of the multifunctional silane coupling agent is firmly anchored to the fiberglass surface through strong Si-O-Si covalent bonds, and the other end is chemically cross-linked with the polymer network, stress can be transferred from the resin matrix to the fiberglass skeleton without damage and efficiently through these chemical bond bridges, fully utilizing the high strength potential of the fiberglass.

[0084] Meanwhile, the nanofillers enriched in the interpenetrating network layer possess extremely high rigidity and modulus. They are uniformly dispersed and cross-linked in the network at the nanoscale, forming a microscopic reinforced concrete-like structure. When microcracks initiate in the resin matrix due to localized stress concentration and propagate towards the interface, the dense interpenetrating network layer hinders their propagation. When the crack front encounters high-modulus nanoparticles, it is deflected, or a large amount of energy is required to break these chemical bonds and network structures, thus effectively preventing further crack propagation and avoiding interfacial debonding and peeling. This toughening and crack-resistant mechanism is the core microscopic mechanism by which the tensile strength and flexural modulus of the fiberglass board in this application are significantly improved.

[0085] The fiberglass board comprises at least two layers of fiberglass cloth, with a modified resin matrix and an interpenetrating network layer filling the space between adjacent layers of fiberglass cloth.

[0086] In practical engineering applications, single-layer fiberglass reinforced boards are often extremely thin and highly anisotropic, failing to meet the mechanical requirements of structural components. Therefore, fiberglass boards are typically made by laminating and pressing multiple layers of fiberglass cloth. This embodiment explicitly states that in the multilayer structure, not only are the monofilaments within each layer of fiberglass cloth encapsulated in resin, but the spaces between adjacent layers are also completely filled with a modified resin matrix. More importantly, an interpenetrating network layer is formed in situ on the surface of each layer of fiberglass cloth. This means that in the interlayer regions of the multilayer board, not only is there resin matrix bonding, but also interlocking of the interpenetrating network layers. This strengthening of the interlayer interface greatly enhances the interlaminar shear strength of the fiberglass board, preventing delamination failure under bending stress and further ensuring the reliability of the overall structure.

[0087] The thickness of the interpenetrating network layer is 100 nm to 2 μm. If the thickness is less than 100 nm, due to space constraints, the number of nanofillers that can accumulate in this region is extremely limited, and the coupling agent molecules also struggle to form a sufficiently deep cross-linked network, resulting in insignificant interfacial strengthening and an inability to effectively prevent the propagation of microcracks. If the thickness is greater than 2 μm, the interfacial layer is too thick. Although its crack-resistant ability is enhanced, an excessively thick interfacial layer will reduce the overall rigidity of this region. This is because the concentration of nanofillers decreases with increasing distance from the glass fiber surface, with more pure resin or weakly cross-linked networks at a distance. Under bending stress, an excessively thick interfacial layer is prone to large shear deformation, which in turn reduces the overall flexural modulus of the board. Furthermore, an excessively thick interpenetrating network layer may consume too much coupling agent and nanofiller, leading to formulation instability.

[0088] Therefore, controlling the thickness within the range of 100 nm to 2 μm ensures both sufficient network density and nanoparticle concentration while maintaining the rigidity of the interface layer, achieving a perfect balance between strength and modulus. This thickness can be precisely adjusted by controlling process parameters such as the amount of coupling agent and nanofiller added, resin viscosity, and curing temperature rise rate.

[0089] To more fully disclose the technical solution of this application and verify its technical effects, a detailed description is provided below with reference to specific embodiments and comparative examples. It should be noted that the following embodiments are only for explaining this application and are not intended to limit the scope of protection of this application. Specific conditions not specified in the embodiments are generally performed under conventional conditions or conditions recommended by the manufacturer. Performance testing methods are as follows: tensile strength is tested according to GB / T 1447-2005; flexural modulus is tested according to GB / T 1449-2005; water absorption rate is tested according to GB / T 1034-2008; dielectric constant and dielectric loss tangent are tested at 1 GHz frequency according to IPC-TM-650 2.5.5.5; glass transition temperature (Tg) is tested according to the DSC method.

[0090] Example 1: Core Basic Formula and Process We provide 0.1mm thick E-glass plain weave fiberglass cloth (fiberglass) and modified resin. The modified resin comprises bisphenol A type epoxy resin (matrix resin), γ-glycidoxypropyltrimethoxysilane (multifunctional silane coupling agent), and hydroxyl-coated fumed silica nanoparticles (nanofiller, average particle size 50nm). By weight, it consists of 90 parts epoxy resin, 3 parts KH-560 coupling agent, 2 parts nano-silica, and 5 parts matching amine curing agent.

[0091] Fiberglass was placed in a low-temperature plasma treatment device for surface activation treatment. The process parameters were: power 200W, vacuum degree 20Pa, and treatment time 5min. Subsequently, modified resin was applied to the activated fiberglass cloth through an impregnation process. The weight content of modified resin in the prepreg was controlled to be 45% by the extrusion roller to form a prepreg.

[0092] Ten layers of prepreg were stacked in the same direction and placed in a hot press for lamination and curing. Pre-pressing stage: temperature 100℃, pressure 1MPa, time 45min; Main pressing stage: temperature 160℃, pressure 5MPa, time 90min. After curing, post-curing was performed at 180℃ for 2h to obtain a fiberglass board with a thickness of 1.0mm.

[0093] Microstructure verification: Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the interface of the glass fiber board. The results showed a distinct transition layer (interfacial interpenetrating network layer) with a thickness of approximately 500 nm between the glass fiber and the modified resin matrix. Energy dispersive spectroscopy (EDS) analysis revealed significantly higher silicon and oxygen concentrations in this region compared to the matrix interior, indicating enrichment of nano-silica in this area. Infrared spectroscopy confirmed the formation of Si-O-Si covalent bonds.

[0094] Performance testing: Tensile strength reached 385 MPa, flexural modulus reached 22.5 GPa, and Tg was 162℃. The interpenetrating network layer effectively transferred stress, avoiding interface failure caused by stress concentration.

[0095] Example 2: Comparison of different coupling agents, fillers, and activation methods This embodiment is basically the same as Embodiment 1, except that: In step S1, the multifunctional silane coupling agent is replaced with γ-aminopropyltriethoxysilane (KH-550), and the nanofiller is replaced with nano-alumina with an average particle size of 30 nm.

[0096] In step S2, the surface activation treatment does not use plasma, but instead uses a low-temperature ozone generator to place the glass fiber in a chamber with an ozone concentration of 50 ppm for 8 minutes.

[0097] Performance testing: The fiberglass board exhibits a tensile strength of 392 MPa, a flexural modulus of 23.1 GPa, and a Tg of 158℃. The aminosilane exhibits extremely high reactivity with epoxy resin, and ozone treatment generates a large number of oxygen-containing polar groups on the fiberglass surface. Combined with the high modulus characteristics of nano-alumina, the rigidity of the interpenetrating network layer is further enhanced, indicating that optimized activation conditions and appropriate selection of raw materials further improve the interfacial strengthening effect.

[0098] Example 3: Optimization of Formulation Ratio and Curing Process This embodiment is basically the same as Embodiment 1, except for the boundary value testing of the formulation and process: The modified resin formulation (based on a total weight of 100 parts) is as follows: 88 parts epoxy resin, 3 parts KH-560 coupling agent, 4 parts nano silica, and 5 parts curing agent.

[0099] The curing process is as follows: pre-compression stage temperature 120℃, pressure 2MPa, time 30min; main compression stage temperature 180℃, pressure 8MPa, time 60min. After curing, post-curing is performed at 190℃ for 3h.

[0100] Performance Testing: The glass transition temperature of the fiberglass board prepared in this embodiment reached 165℃, the tensile strength was 380MPa, and the flexural modulus was 22.0GPa. Appropriately increasing the curing temperature and pressure, and extending the post-curing temperature and time, resulted in a more thorough crosslinking reaction between the matrix resin and the coupling agent, achieving optimal density in the interpenetrating network layer. The optimized component ratio ensured a balance between resin flowability and interfacial strength, significantly improving the material's dimensional stability and mechanical strength retention at high temperatures.

[0101] Example 4: Adaptability to different matrix resins and fiber morphologies This embodiment is basically the same as Embodiment 1, except that: In step S1, the matrix resin is replaced with a high-Tg phenolic epoxy resin, and continuous glass fiber yarn is used. A prepreg blank containing a 10-layer glass fiber structure is prepared by a fiber winding process.

[0102] In step S3, the molding method is compression molding, without post-curing.

[0103] Performance Testing: Phenolic resin itself possesses excellent heat resistance and flame retardancy. Combined with the high strength load-bearing capacity of continuous fibers and a multi-layered structural design, this fiberglass board is suitable for structural load-bearing components. The interpenetrating network layer effectively compensates for the high brittleness of phenolic resin, preventing crack propagation along the interlayer. In this embodiment, the interlaminar shear strength of the board is increased by 40% compared to conventional phenolic fiberglass boards, with a tensile strength reaching 370 MPa and a flexural modulus of 21.5 GPa.

[0104] Example 5: Functionalized Surface Treatment and Electrical Performance Testing** Based on the fiberglass board (using bisphenol A epoxy resin) prepared in Example 1, further performance tests and post-treatments were performed: The fiberglass board prepared in Example 1 was cut into test strips. A 20 μm thick flame-retardant acrylic coating was applied to one side of the board using a roller coating process, and an 18 μm thick conductive copper foil was applied to the other side by hot pressing (forming a conductive shielding layer).

[0105] Performance Testing: Due to the presence of a dense interface network, the water absorption rate of the substrate in Example 5 was only 0.25% during a 24-hour immersion test. At 1 GHz, the dielectric constant was 4.2, and the dielectric loss tangent was 0.015. The addition of a flame-retardant coating and a conductive shielding layer allows for direct application to high-frequency electronic packaging substrates and electromagnetic shielding covers, demonstrating excellent prospects for industrial applications.

[0106] To further highlight the inventive contribution of the core technical features of this application, the following comparative analysis is provided: Comparative Example 1: Surface activation treatment omitted This comparative example is basically the same as Example 1, except that in step S2, the glass fiber cloth is not subjected to plasma treatment, but is directly immersed in the modified resin.

[0107] Test results: Tensile strength is 260 MPa, and flexural modulus is 15.2 GPa.

[0108] Analysis: Due to the lack of activation, the density of silanol groups on the glass fiber surface is insufficient. The multifunctional silane coupling agent cannot form a dense Si-O-Si covalent network on the glass fiber surface, resulting in a significant reduction in interfacial bonding strength. Under stress, interfacial debonding is very likely to occur, leading to a substantial decrease in strength and modulus.

[0109] Comparative Example 2: Coupling agent and nanofiller omitted (pure matrix resin) This comparative example is basically the same as Example 1, except that no multifunctional silane coupling agent and nanofiller are added to the modified resin, and only pure bisphenol A epoxy resin and curing agent are used.

[0110] Test results: Tensile strength is 240 MPa, and flexural modulus is 14.0 GPa.

[0111] Analysis: This represents the basic properties of traditional unmodified fiberglass boards. Due to the interface being merely a physical adsorption process, stress cannot be effectively transferred, resulting in the worst performance. Using this comparative example as a benchmark, the tensile strength of Example 1 was calculated to be (385-240) / 240 = 60.4%, and the flexural modulus was calculated to be (22.5-14.0) / 14.0 = 60.7%, fully meeting the requirement in claim 14 that "under the same preparation conditions, the fiberglass board prepared from a matrix resin without multifunctional silane coupling agents and nanofillers exhibits an improvement of more than 50%", thus demonstrating the high inventiveness of this application.

[0112] Comparative Example 3: Only the nanofiller is omitted This comparative example is basically the same as Example 1, except that no nano-silica is added to the modified resin, and only the KH-560 coupling agent is retained.

[0113] Test results: tensile strength is 295 MPa, flexural modulus is 17.8 GPa.

[0114] Analysis: Although coupling agents construct chemical bonds, the interfacial region lacks rigid support. When the resin expands due to heat or is subjected to shear stress, the purely organic interfacial layer is prone to yielding deformation and cannot effectively prevent the propagation of microcracks. This demonstrates that the enrichment of nanofillers at the interface to form an "interpenetrating network" to provide rigid support is an indispensable technical feature.

[0115] Through detailed data comparison of the above embodiments and comparative examples, it can be conclusively demonstrated that this application, through surface activation treatment, introduction of multifunctional silane coupling agents and nanofillers of specific particle sizes, and curing under optimized process conditions, successfully constructs an interpenetrating network layer between glass fiber and resin that combines chemical bonding and rigid support. The formation of this microstructure completely breaks through the bottleneck of weak interfacial bonding in traditional glass fiber composite materials, achieving a leapfrog improvement of over 50% in tensile strength and flexural modulus, and synergistically endowing the material with excellent heat resistance, low water absorption, and high-frequency dielectric properties, possessing extremely high industrial practical value and patent protection significance.

[0116] The above description is merely a preferred embodiment of this application and does not limit the scope of patent protection of this application. Any equivalent structural or procedural modifications made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A method for preparing a fiberglass board, characterized in that, include: S1: Provide glass fiber and modified resin, wherein the modified resin comprises a matrix resin, a multifunctional silane coupling agent and a nanofiller; S2: The glass fiber is surface activated, and then the modified resin is applied to the activated glass fiber to form a prepreg; S3: The prepreg is laminated and cured to form a mold; During the curing process, one end of the multifunctional silane coupling agent forms a covalent bond with the surface of the glass fiber, while the other end participates in the cross-linking and curing of the matrix resin. At the same time, the nanofiller is enriched in the interface region between the glass fiber and the matrix resin to form an interpenetrating network layer.

2. The method for preparing fiberglass board according to claim 1, characterized in that, In step S1, the matrix resin is any one of epoxy resin, phenolic resin, polyurethane resin or unsaturated polyester resin; the multifunctional silane coupling agent is a silane coupling agent containing at least two hydrolyzable alkoxy groups, and its organic functional group is epoxy, amino or methacryloxy; the nanofiller is nano-silica, nano-alumina or nano-silicon carbide with hydroxyl groups on the surface, and its average particle size is 10nm-100nm.

3. The method for preparing fiberglass board according to claim 1, characterized in that, Based on a total weight of 100 parts of the modified resin, the matrix resin accounts for 80-95 parts, the multifunctional silane coupling agent accounts for 1-5 parts, and the nanofiller accounts for 0.5-5 parts.

4. The method for preparing fiberglass board according to claim 1, characterized in that, In step S2, the surface activation treatment is plasma treatment or low-temperature ozone treatment, and the treatment time is 1 min to 10 min. The plasma treatment has a power of 100W-500W and a vacuum degree of 10Pa-50Pa.

5. The method for preparing fiberglass board according to claim 1, characterized in that, In step S2, the weight content of the modified resin in the prepreg is 30%-60%.

6. The method for preparing fiberglass board according to claim 1, characterized in that, In step S3, the lamination curing molding includes a pre-pressing stage and a main pressing stage; The temperature of the pre-compression stage is 80℃-120℃, the pressure is 0.5MPa-2MPa, and the time is 30min-60min; The temperature of the main pressure stage is 140℃-180℃, the pressure is 3MPa-8MPa, and the time is 60min-120min.

7. The method for preparing fiberglass board according to claim 1, characterized in that, The step S3 is followed by a post-curing step, wherein the post-curing temperature is 180℃-200℃ and the time is 2h-4h.

8. A fiberglass board, characterized in that, It includes glass fibers and a modified resin matrix, with an interfacial interpenetrating network layer formed between the glass fibers and the modified resin matrix. The interpenetrating network layer comprises a multifunctional silane coupling agent and nanofillers. One end of the multifunctional silane coupling agent is covalently bonded to the surface of the glass fiber, and the other end is cross-linked to the polymer network of the modified resin matrix. The nanofillers are enriched in the interpenetrating network layer.

9. The fiberglass board according to claim 8, characterized in that, The fiberglass board comprises at least two layers of fiberglass cloth, with the modified resin matrix and the interpenetrating network layer filling the space between adjacent layers of fiberglass cloth.

10. The fiberglass board according to claim 8, characterized in that, The thickness of the interpenetrating network layer is 100nm-2μm.

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