A novel glass fiber cloth and its preparation method

Abstract

The present invention relates to the technical field of glass fiber cloth, and in particular to a novel glass fiber cloth and a preparation method thereof. The glass fiber cloth comprises a base cloth layer and a functional bonding layer, wherein the functional bonding layer comprises the following components in parts by weight: 45-55 parts by weight of bisphenol F epoxy resin; 25-35 parts by weight of 4-epoxypropyloxy-N,N-diglycidyl aniline; 15-25 parts by weight of epoxidized soybean oil; 20-30 parts by weight of methylhexahydrophthalic anhydride; 2-5 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol; 3-8 parts by weight of N-aminoethylpiperazine; 0.8-1.5 parts by weight of gamma-glycidyloxypropyltrimethoxysilane; and 0.5-1.0 parts by weight of vinyltriethoxysilane. The bisphenol F epoxy resin provides a rigid skeleton, the multifunctional monomer provides crosslinking points, and the flexible chain segments impart necessary toughness to the material. The three components synergistically form an interpenetrating network structure with gradient characteristics.

Description

Technical Field

[0001] The present invention relates to the technical field of glass fiber cloth, and in particular to a novel glass fiber cloth and a preparation method thereof. Background Art

[0002] As an important composite reinforcement material, glass fiber cloth is widely used in aerospace, electronics, construction engineering and other fields. As the application field continues to expand, the performance requirements of glass fiber cloth are also increasing. At present, the main technical problems of glass fiber cloth are as follows:

[0003] First, traditional fiberglass fabrics generally utilize a single epoxy resin system, resulting in a simple molecular chain structure and a relatively simple cross-linking network. This makes it difficult for the material to meet the mechanical properties and durability requirements of high-end applications. This is especially true in applications requiring both high strength and high toughness, where existing technologies often struggle to achieve a good balance of performance.

[0004] Secondly, the interface between glass fiber and the resin matrix has always been a technical difficulty in this field. Due to the poor compatibility of the hydroxyl groups on the glass fiber surface with the organic resin matrix, the traditional single silane coupling agent modification method has difficulty in forming a stable chemically bonded interface. Especially in harsh service environments, the interface is prone to failure.

[0005] Thirdly, existing glass fiber cloth curing processes typically use a single curing agent and a simple curing process, which results in an uneven cross-linking network and internal stress concentration, affecting the overall performance and service life of the product. This uneven curing process is particularly prominent in large-scale products. Summary of the Invention

[0006] In view of the above problems, the present invention provides a novel glass fiber cloth and a preparation method thereof.

[0007] The object of the present invention is to provide a novel glass fiber cloth, comprising a base cloth layer and a functional bonding layer, wherein the functional bonding layer is arranged on one side of the base cloth layer, wherein:

[0008] The functional bonding layer comprises the following components in parts by weight:

[0009] 45-55 parts by weight of bisphenol F epoxy resin;

[0010] 25-35 parts by weight of 4-epoxypropyloxy-N,N-diglycidylaniline;

[0011] 15-25 parts by weight of epoxidized soybean oil;

[0012] 20-30 parts by weight of methylhexahydrophthalic anhydride;

[0013] 2-5 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol;

[0014] 3-8 parts by weight of N-aminoethylpiperazine;

[0015] γ-glycidyloxypropyltrimethoxysilane 0.8-1.5 parts by weight;

[0016] 0.5-1.0 parts by weight of vinyltriethoxysilane

[0017] Specifically, the bisphenol F epoxy

[0018] The epoxy value of the resin is 0.18-0.191, the epoxy value of the epoxidized soybean oil is 0.15-0.17, and the functionality of the 4-epoxypropyloxy-N,N-diglycidylaniline is 4.

[0019] Specifically, the base fabric layer is formed by weaving, disorderly arranging or randomly distributing glass fiber yarns.

[0020] Specifically, the thickness of the functional bonding layer is 20-30 μm.

[0021] Specifically, it further comprises a covering layer, which is arranged on a side of the functional adhesive layer away from the base fabric layer, and has a thickness of 100-180 μm.

[0022] A method for preparing the novel glass fiber cloth comprises the following steps:

[0023] (1) treating the glass fiber with plasma using an oxygen / argon mixed gas at a power of 100-150 W for 30-60 seconds to obtain a surface-activated glass fiber;

[0024] (2) forming a base fabric layer by weaving, randomly arranging or randomly distributing the surface-activated glass fibers;

[0025] (3) stirring the base resin component at 60-70° C. and 300-500 r / min for 20-30 min to obtain a resin mixture;

[0026] (4) stirring the curing agent component at room temperature at a speed of 200-300 r / min for 10-15 minutes to obtain a curing agent mixture;

[0027] (5) stirring the interfacial modifier components uniformly at room temperature to obtain a modifier mixture;

[0028] (6) The resin mixture, curing agent mixture and modifier mixture are mixed to obtain a functional adhesive layer coating liquid.

[0029] Specifically, the method further comprises the following steps:

[0030] At a temperature of 25±2° C. and a relative humidity of 45-55%, the functional bonding layer coating liquid is coated on the base fabric layer at a speed of 2-3 m / min and dried for 5-10 minutes.

[0031] Specifically, the method further comprises the following steps:

[0032] At a temperature of 30±2°C and a relative humidity of 40-50%, the second coating is carried out at a speed of 1.5-2.5 m / min and dried for 8-12 minutes.

[0033] Specifically, the second coating is followed by a curing treatment, wherein:

[0034] The pre-curing temperature is 50℃, keep warm for 30min, and the heating rate is 2-3℃ / min;

[0035] Medium temperature curing temperature is 80℃, holding temperature is 20min, heating rate is 3-4℃ / min;

[0036] The post-curing temperature is 120℃, the temperature is kept for 10 minutes, and the heating rate is 4-5℃ / min.

[0037] Specifically, the base fabric layer has a gram weight of 100-300 g / m 2 The weight of the glass fiber cloth is 200-500g / m 2 The thickness of the glass fiber cloth is 80-300 μm.

[0038] Compared with the prior art, the novel glass fiber cloth and its preparation method of the present invention can achieve the following

[0039] Beneficial effects:

[0040] At the molecular level, a ternary resin system consisting of bisphenol F epoxy resin, 4-epoxypropyloxy-N,N-diglycidylaniline, and epoxidized soybean oil was employed. Through precise control of molecular weight, functional group type, and content, a multi-layered crosslinked network was constructed. The bisphenol F epoxy resin provides a rigid backbone, the multifunctional monomers provide crosslinking points, and the flexible segments impart the necessary toughness. These three components synergistically form an interpenetrating network structure with gradient properties.

[0041] In terms of interface design, this invention innovatively utilizes a dual-silane synergistic modification system, combined with plasma surface activation. γ-Glycidoxypropyltrimethoxysilane undergoes a ring-opening addition reaction with the resin via its epoxy group, while vinyltriethoxysilane provides an unsaturated double bond. These two silanes form a chemically gradient transition layer at the molecular scale, significantly enhancing the interfacial bonding strength and stability.

[0042] In terms of process innovation, this invention employs a unique three-stage curing process, combined with a composite curing agent system. Through precise control of temperature, time, and heating rate, the crosslinking reaction is carried out in stages, effectively reducing internal stress and improving the uniformity of crosslink density. In particular, during the pre-curing stage, the lower temperature promotes the orderly arrangement of molecular chains, laying a good foundation for subsequent high-temperature curing.

[0043] First, the material exhibits excellent comprehensive mechanical properties, with a tensile strength of up to 210 MPa and an elongation at break of 5.5%, achieving a good balance of strength and toughness. This is due to the unique network structure formed by the multi-component resin system and the significant synergistic effect between the components.

[0044] Secondly, the interface bonding performance is greatly improved, with the interlaminar shear strength reaching 55MPa, and the water resistance and heat resistance are significantly improved. Through electron microscopy, it was found that a transition layer with uniform thickness and dense structure was formed in the interface area. This special interface structure is an important guarantee for the excellent performance of the material.

[0045] Finally, the product exhibits excellent durability and maintains stable performance even in harsh environments. This is mainly due to the optimized curing process, which forms a uniform cross-linked network structure and significantly increases the service life of the material.

[0046] In summary, the present invention successfully solves the key technical problems existing in traditional glass fiber cloth through the organic combination of molecular design, interface engineering and process innovation, achieves a comprehensive improvement in performance, and provides a new technical solution for the development of related fields. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] Example 1 Lightweight and high-strength new glass fiber cloth

[0049] The novel glass fiber cloth of this embodiment is prepared by the following components and methods:

[0050] First, the functional bonding layer components were prepared. These included 45 parts by weight of bisphenol F epoxy resin (epoxy value 0.18), 25 parts by weight of 4-epoxypropyloxy-N,N-diglycidylaniline (functionality 4, Tg 145°C), and 15 parts by weight of epoxidized soybean oil (epoxy value 0.15, molecular weight 1000 g / mol). Added to this were 20 parts by weight of methylhexahydrophthalic anhydride, 2 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol, 3 parts by weight of N-aminoethylpiperazine, 0.8 parts by weight of γ-glycidyloxypropyltrimethoxysilane, and 0.5 parts by weight of vinyltriethoxysilane.

[0051] The preparation method comprises the following steps:

[0052] Step (1): The glass fiber was plasma treated with an oxygen / argon mixture (volume ratio 80:20) at a power of 100 W and a treatment time of 30 seconds. The plasma treatment significantly improved the activity of the glass fiber surface and increased the hydroxyl content, providing a good chemical basis for subsequent interfacial bonding.

[0053] Step (2): The surface activated glass fiber is woven into a 100 g / m 2 base fabric layer.

[0054] Step (3): Stir the base resin components at 60°C and 300 rpm for 20 minutes to obtain a uniform resin mixture. This temperature is conducive to reducing the viscosity of the resin and promoting thorough mixing between the components.

[0055] Step (4): Stir the curing agent component at room temperature at a speed of 200 r / min for 10 minutes to obtain a curing agent mixture. Mild stirring conditions can avoid premature activation of the curing agent.

[0056] Step (5): The interfacial modifier component is gently stirred at room temperature until uniform, to obtain a modifier mixture.

[0057] Step (6): The above mixture is mixed according to the proportions to prepare a functional adhesive layer coating solution. Preferably, the first coating is performed at a speed of 2 m / min at 25°C and a relative humidity of 45%, and dried for 5 minutes. Subsequently, a second coating is performed at a speed of 1.5 m / min at 30°C and a relative humidity of 40%, and dried for 8 minutes. The final thickness of the functional adhesive layer is 20 μm.

[0058] The curing process adopts a three-stage method: pre-curing at 50℃ for 30 minutes, with a heating rate of 2℃ / min; medium-temperature curing at 80℃ for 20 minutes, with a heating rate of 3℃ / min; post-curing at 120℃ for 10 minutes, with a heating rate of 4℃ / min. The weight of the glass fiber cloth produced is 200g / m 2 , with a total thickness of 80μm.

[0059] Example 2 High-Toughness New Glass Fiber Cloth

[0060] The novel glass fiber cloth of this embodiment uses the following components: First, a functional adhesive layer is prepared: 50 parts by weight of bisphenol F epoxy resin (epoxy value 0.185), 30 parts by weight of 4-epoxypropyloxy-N,N-diglycidylaniline (functionality 4, Tg 150°C), and 20 parts by weight of epoxidized soybean oil (epoxy value 0.16, molecular weight 1000 g / mol). Then, 25 parts by weight of methylhexahydrophthalic anhydride, 3.5 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol, 5 parts by weight of N-aminoethylpiperazine, 1.2 parts by weight of γ-glycidyloxypropyltrimethoxysilane, and 0.8 parts by weight of vinyltriethoxysilane are added.

[0061] The preparation method comprises the following steps:

[0062] Step (1): Plasma treatment is preferably performed using an oxygen / argon mixed gas (volume ratio 70:30) at a power of 125 W and a treatment time of 45 seconds. This process parameter selection can form more active sites on the glass fiber surface, which is beneficial for improving the interfacial bonding strength.

[0063] Step (2): The surface activated glass fiber is made into a 200g / m2 glass fiber by a random arrangement process. 2 The disordered structural design helps to improve the isotropy of the material.

[0064] Step (3): Stir the base resin component at 400 rpm for 25 minutes at 65° C. Higher temperature and stirring speed are conducive to the thorough mixing of the resin system and improve the uniformity of the system.

[0065] Step (4): Stir the curing agent component at 250 rpm for 12 minutes at room temperature. Moderate stirring conditions ensure uniform dispersion of the curing agent while avoiding local overheating.

[0066] Step (5): Stir the interfacial modifier components uniformly at room temperature. The synergistic effect of the bissilane coupling agent can significantly improve the interfacial bonding performance.

[0067] Step (6): The above mixture was mixed according to the proportions to prepare a functional bonding layer coating solution. The first coating was performed at a speed of 2.5 m / min at 25°C and a relative humidity of 50%, and dried for 7 minutes. Subsequently, a second coating was performed at a speed of 2 m / min at 30°C and a relative humidity of 45%, and dried for 10 minutes. The final thickness of the functional bonding layer was 25 μm.

[0068] The curing process adopts a three-stage method: pre-curing at 60℃ for 35 minutes, with a heating rate of 2.5℃ / min; medium-temperature curing at 90℃ for 15 minutes, with a heating rate of 3.5℃ / min; post-curing at 120℃ for 10 minutes, with a heating rate of 4.5℃ / min. The weight of the glass fiber cloth produced is 350g / m 2 , with a total thickness of 150μm.

[0069] Example 3 High temperature resistant new glass fiber cloth

[0070] This example uses the following components: First, a functional adhesive layer is prepared. The components include 55 parts by weight of bisphenol F epoxy resin (epoxy value 0.191), 35 parts by weight of 4-epoxypropyloxy-N,N-diglycidylaniline (functionality 4, Tg 155°C), and 25 parts by weight of epoxidized soybean oil (epoxy value 0.17, molecular weight 1000 g / mol). Then, 30 parts by weight of methylhexahydrophthalic anhydride, 5 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol, 8 parts by weight of N-aminoethylpiperazine, 1.5 parts by weight of γ-glycidyloxypropyltrimethoxysilane, and 1.0 part by weight of vinyltriethoxysilane are added.

[0071] The preparation method comprises the following steps:

[0072] Step (1): Plasma treatment was performed using an oxygen / argon mixed gas (volume ratio 60:40) with a power of 150 W and a treatment time of 60 s. High power and long treatment time can form more chemical bonding sites on the fiber surface.

[0073] Step (2): The surface activated glass fiber is randomly distributed to form a 300 g / m 2 base fabric layer.

[0074] Step (3): Stir the base resin component at 500 rpm for 30 minutes at 70°C. High-temperature and high-speed stirring is beneficial to improving the uniformity and stability of the system.

[0075] Step (4): Stir the curing agent component at a speed of 300 r / min for 15 minutes at room temperature.

[0076] Step (5): Stir the interfacial modifier components thoroughly at room temperature. A higher content of the disilane system can form a denser interfacial structure.

[0077] Step (6): The above mixture was mixed according to the proportions to prepare a functional adhesive layer coating solution. The first coating was performed at a speed of 3 m / min at 27°C and a relative humidity of 55%, and the coating was dried for 10 minutes. Subsequently, a second coating was performed at a speed of 2.5 m / min at 32°C and a relative humidity of 50%, and the coating was dried for 12 minutes. The final thickness of the functional adhesive layer was 30 μm.

[0078] The curing process adopts a three-stage method: pre-curing at 70℃ for 40 minutes, heating rate 3℃ / min; medium-temperature curing at 100℃ for 10 minutes, heating rate 4℃ / min; post-curing at 120℃ for 10 minutes, heating rate 5℃ / min. The weight of the glass fiber cloth is 500g / m 2 , with a total thickness of 300μm.

[0079] Example 4 Lightweight and highly flexible new glass fiber cloth

[0080] This example uses the following components: First, a functional adhesive layer is prepared: 47 parts by weight of bisphenol F epoxy resin (epoxy value 0.188), 28 parts by weight of 4-epoxypropyloxy-N,N-diglycidylaniline (functionality 4, Tg 148°C), and 18 parts by weight of epoxidized soybean oil (epoxy value 0.16, molecular weight 1000 g / mol). Then, 23 parts by weight of methylhexahydrophthalic anhydride, 3 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol, 6 parts by weight of N-aminoethylpiperazine, 1.0 part by weight of γ-glycidyloxypropyltrimethoxysilane, and 0.7 part by weight of vinyltriethoxysilane are added.

[0081] The preparation method comprises the following steps:

[0082] Step (1): plasma treatment was performed using an oxygen / argon mixed gas (volume ratio 75:25) with a power of 135 W and a treatment time of 40 s.

[0083] Step (2): The surface activated glass fiber is woven into a 150g / m 2 base fabric layer.

[0084] Step (3): Stir the base resin component at 68°C and 450 r / min for 23 minutes.

[0085] Step (4): Stir the curing agent component at a speed of 275 r / min for 13 minutes at room temperature.

[0086] Step (5): Stir the interfacial modifier component uniformly at room temperature.

[0087] Step (6): The above mixture was mixed according to the proportions to prepare a functional adhesive layer coating solution. The first coating was performed at a speed of 2.8 m / min at 26°C and a relative humidity of 48%, and dried for 8 minutes. Subsequently, a second coating was performed at a speed of 2.2 m / min at 31°C and a relative humidity of 43%, and dried for 11 minutes. The final thickness of the functional adhesive layer was 28 μm.

[0088] The curing process adopts a three-stage method: pre-curing at 65℃ for 38 minutes, with a heating rate of 2.8℃ / min; medium-temperature curing at 95℃ for 18 minutes, with a heating rate of 3.8℃ / min; post-curing at 120℃ for 10 minutes, with a heating rate of 4.8℃ / min. The weight of the glass fiber cloth produced is 300g / m 2 , with a total thickness of 200μm.

[0089] The above four embodiments fully demonstrate the feasibility scope of the present invention through different component ratios and process parameters, and verify the synergistic effect of various technical features.

[0090] Comparative Example 1 Single Resin System Glass Fiber Cloth (Comparative Example 1)

[0091] This comparative example uses 85 parts by weight of a single bisphenol F epoxy resin (epoxy value 0.18), without adding 4-epoxypropyloxy-N,N-diglycidylaniline and epoxidized soybean oil. The other components are the same as those in Example 1. This comparative example verifies the necessity of a multi-resin synergistic system. A single resin system results in a single cross-linked network structure and lacks the synergistic effect of a multi-level cross-linked network, resulting in a significant decrease in the toughness and heat resistance of the final product. The preparation method is the same as that in Example 1, and the obtained glass fiber cloth exhibits obvious brittleness, with an elongation at break of only 60% of that in Example 1.

[0092] Comparative Example 2 Glass Fiber Cloth without Interfacial Coupling Agent (Comparative Example 2)

[0093] In this comparative example, γ-glycidyloxypropyltrimethoxysilane and vinyltriethoxysilane were removed, with the remaining component ratios consistent with Example 2. The preparation process was identical to Example 2, but due to the lack of interfacial coupling, the interfacial bonding strength between the resin matrix and the glass fiber was significantly reduced. Test results showed that the interlaminar shear strength was only 45% of that in Example 2, and the strength retention after water boiling dropped to 65%, fully demonstrating the critical role of the synergistic modification system of the disilane on interfacial properties.

[0094] Comparative Example 3: Glass fiber cloth not treated with plasma (Comparative Example 3)

[0095] This comparative example used the same formulation as Example 3, but omitted the plasma treatment step. The results showed that the interfacial bonding between the glass fiber and the resin matrix without surface activation was poor, resulting in a decrease in the overall performance of the composite. The tensile strength was only 70% of that in Example 3, and the strength retention after thermal aging dropped to 75%, fully demonstrating the importance of plasma treatment in improving interfacial bonding strength.

[0096] Comparative Example 4 Curing Agent Single System Glass Fiber Cloth (Comparative Example 2)

[0097] This comparative example used only 28 parts by weight of methylhexahydrophthalic anhydride as the curing agent, omitting 2,4,6-tris(dimethylaminomethyl)phenol and N-aminoethylpiperazine. The remaining components were the same as in Example 2. Due to the lack of a synergistic curing system, the crosslinking reaction was incomplete, resulting in a less dense cured network structure. Test results showed a 25°C decrease in glass transition temperature and a significant reduction in heat resistance.

[0098] Comparative Example 5 Non-optimized curing process glass fiber cloth (Comparative Example 4)

[0099] This comparative example used the same formulation as Example 4, but simplified the curing process to a single step: curing at 120°C for 60 minutes. The results showed that not adopting a three-stage curing process led to internal stress concentration in the material, resulting in microcracks. The flexural strength was only 65% of that of Example 4, and significant delamination was observed during thermal cycling testing. This demonstrates the significant impact of the staged curing process on product performance.

[0100] Comparative Example 6 Glass Fiber Cloth with Unbalanced Resin Ratio (Comparative Example 3)

[0101] In this comparative example, the resin ratio was adjusted: bisphenol F epoxy resin was increased to 70 parts by weight, 4-epoxypropyloxy-N,N-diglycidylaniline was reduced to 15 parts by weight, and epoxidized soybean oil was reduced to 15 parts by weight. Other components and processes were the same as in Example 3. Due to the imbalanced resin ratio and the excessive amount of rigid components, the product's toughness was insufficient. The elongation at break was reduced by 45%, and the impact strength was only 55% of that in Example 3. This clearly demonstrates the necessity of optimizing the resin system ratio.

[0102] Through the above six comparative examples, the three core innovations of the present invention are systematically verified:

[0103] 1. Necessity of a multi-resin synergistic system (Comparative Examples 1 and 6)

[0104] 2. The key role of the interface modification system (Comparative Examples 2 and 3)

[0105] 3. Importance of process parameter optimization (Comparative Examples 4 and 5)

[0106] These comparative examples demonstrate the necessity and synergistic effects of the various technical features of the present invention from different perspectives, fully demonstrating the inventiveness of the present invention. Through systematic comparisons of material properties, the significant advantages of the present invention in terms of mechanical properties, interfacial properties, and durability are clearly demonstrated.

[0107] The present invention comprehensively evaluates the performance of glass fiber cloth according to standard test methods. All tests were conducted under standard laboratory conditions (23±2°C, relative humidity 50±5%), and each set of data was the average of five parallel samples.

[0108] 1. Mechanical properties test

[0109] First, tensile properties were tested according to GB / T1447-2005 using a universal testing machine with specimens measuring 250mm x 25mm and a tensile rate of 10mm / min. Second, flexural properties were tested according to GB / T1449-2005 using the three-point bending method with a 160mm span and a loading rate of 2mm / min. Finally, impact strength was tested according to GB / T1043.1-2008 using the simply supported beam impact method, with unnotched specimens.

[0110] 2. Interface performance characterization

[0111] Scanning electron microscopy (SEM) was used to observe the interface structure. Samples were subjected to liquid nitrogen brittle fracture and then gold-sprayed. Interlaminar shear strength was tested according to ASTM D2344, with specimens measuring 25 mm x 6 mm. Dynamic mechanical analysis (DMA) was used to further test the interface bonding condition at a heating rate of 3°C / min and a frequency of 1 Hz.

[0112] 3. Durability assessment

[0113] Water resistance testing follows GB / T1034-2008, with mechanical properties tested after immersion in 98°C water for 2 hours. Thermal aging testing follows GB / T1634-2004, with residual strength tested after aging at 150°C for 24 hours. Furthermore, thermal cycling testing was conducted from -40°C to 80°C for 50 cycles.

[0114] 4. Microstructure Analysis

[0115] The degree of crosslinking was analyzed using differential scanning calorimetry (DSC) at a heating rate of 10°C / min. The chemical structure was characterized by Fourier transform infrared (FTIR) spectroscopy in the range of 400-4000 cm⁻¹. The thermal stability was assessed by dynamic thermogravimetric analysis (TGA) at a heating rate of 20°C / min.

[0116] The test results are shown in the following table:

[0117] Table 1 Mechanical properties test results

[0118] [Table contents include: sample number, tensile strength (MPa), elongation at break (%), flexural strength (MPa), impact strength (kJ / m 2 )]

[0119] sample tensile strength Elongation at break Bending strength Impact strength Example 1 182 4.8 205 52 Example 2 195 5.2 218 58 Example 3 210 4.5 235 61 Example 4 188 5.5 212 55 Comparative Example 1 125 2.9 145 32 Comparative Example 2 140 3.8 160 38 Comparative Example 3 147 3.2 165 43 Comparative Example 4 135 3.5 155 35 Comparative Example 5 142 3.1 138 37 Comparative Example 6 152 2.5 172 34

[0120] Table 2 Interface performance and durability test results

[0121] [Table contents include: sample number, interlaminar shear strength (MPa), strength retention after boiling (%), strength retention after heat aging (%), interface bonding index]

[0122] sample Shear strength Boiling retention rate Heat aging retention rate Binding index Example 1 48 88 92 0.92 Example 2 52 91 94 0.95 Example 3 55 93 95 0.98 Example 4 50 90 93 0.94 Comparative Example 1 28 65 70 0.65 Comparative Example 2 25 58 65 0.58 Comparative Example 3 30 62 68 0.62 Comparative Example 4 32 68 72 0.70 Comparative Example 5 35 70 75 0.72 Comparative Example 6 33 65 70 0.68

[0123] According to the test results, the present invention has achieved the following unexpected technical effects:

[0124] First, in terms of mechanical properties, Example 3 performed the best, with a tensile strength of 210 MPa, a 68% increase over Comparative Example 1. This significant improvement stems from the interpenetrating network structure formed by the synergistic combination of multiple resins. DSC analysis revealed that the crosslink density of the multi-component system was 45% higher than that of a single resin system, and the crosslinked network was more uniform.

[0125] Secondly, the interfacial properties are outstanding. The interlaminar shear strength of Example 3 reaches 55 MPa, 2.2 times that of Comparative Example 2. SEM observations show that the present invention forms a distinct gradient transition interface layer with a thickness of approximately 0.5-0.8 μm. This unique interfacial structure is derived from the synergistic modification mechanism of the double silane. FTIR spectra confirm that the silane molecules form chemical bonds with both the matrix and the fiber surface.

[0126] Finally, the durability is excellent, with the strength retention rates of Examples 2-4 after boiling exceeding 90%, far exceeding the 58-70% of the comparative examples. This is due to the dense cross-linked network structure and strong interfacial bonding. TGA analysis shows that the initial decomposition temperature of the present invention is 35°C higher than that of the comparative samples.

[0127] Finally, DMA analysis revealed a unique phenomenon: the glass transition peak of the present invention exhibits a bimodal characteristic, indicating the formation of a true interpenetrating network structure, rather than a simple physical blend. This special structure gives the material excellent comprehensive properties.

[0128] Example 3 is the best embodiment of the present invention, and its comprehensive performance index is the best, which is due to the synergistic effects of the following aspects:

[0129] 1. The resin ratio is optimized to achieve a balance between rigidity and toughness;

[0130] 2. The curing process parameters are precisely controlled to form an ideal network structure;

[0131] 3. The interface modification effect is the best, and a strong interface bond is established.

[0132] These in-depth experimental data fully confirm the innovation and superiority of this invention, and also provide reliable technical support for subsequent industrial applications.

[0133] The foregoing is merely an embodiment of the present invention and is not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A glass fiber cloth, characterized in that: It comprises a base fabric layer and a functional bonding layer, wherein the functional bonding layer is arranged on one side of the base fabric layer, wherein: The functional bonding layer comprises the following components in parts by weight: 45-55 parts by weight of bisphenol F epoxy resin; 25-35 parts by weight of 4-epoxypropyloxy-N,N-diglycidylaniline; 15-25 parts by weight of epoxidized soybean oil; 20-30 parts by weight of methylhexahydrophthalic anhydride; 2-5 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol; 3-8 parts by weight of N-aminoethylpiperazine; γ-glycidyloxypropyltrimethoxysilane 0.8-1.5 parts by weight; 0.5-1.0 parts by weight of vinyltriethoxysilane; The base fabric layer is formed by weaving, disorderly arranging or randomly distributing glass fiber yarns; The method for preparing the glass fiber cloth comprises the following steps: (1) treating the glass fiber with plasma using an oxygen / argon mixed gas at a power of 100-150 W for 30-60 seconds to obtain a surface-activated glass fiber; (2) forming a base fabric layer by weaving, randomly arranging or randomly distributing the surface-activated glass fibers; (3) stirring the base resin component at 60-70° C. and 300-500 r / min for 20-30 min to obtain a resin mixture; (4) stirring the curing agent component at room temperature at a speed of 200-300 r / min for 10-15 minutes to obtain a curing agent mixture; (5) stirring the interfacial modifier components uniformly at room temperature to obtain a modifier mixture; (6) mixing the resin mixture, the curing agent mixture, and the modifier mixture to obtain a functional bonding layer coating solution; Further comprising the steps of: At a temperature of 25±2°C and a relative humidity of 45-55%, the functional adhesive layer coating liquid is applied to the base fabric layer at a speed of 2-3 m / min and dried for 5-10 minutes; Further comprising the steps of: At a temperature of 30±2°C and a relative humidity of 40-50%, apply the second coat at a speed of 1.5-2.5 m / min and dry for 8-12 minutes. After the second coating, a curing treatment is performed, wherein: The pre-curing temperature is 50℃, keep warm for 30min, and the heating rate is 2-3℃ / min; Medium temperature curing temperature is 80℃, holding temperature is 20min, heating rate is 3-4℃ / min; The post-curing temperature is 120℃, the temperature is kept for 10 minutes, and the heating rate is 4-5℃ / min.

2. The glass fiber cloth according to claim 1, characterized in that The epoxy value of the bisphenol F epoxy resin is 0.18-0.191, the epoxy value of the epoxidized soybean oil is 0.15-0.17, and the functionality of the 4-epoxypropyloxy-N,N-diglycidylaniline is 3.

3. The glass fiber cloth according to claim 1, characterized in that The thickness of the functional bonding layer is 20-30 μm.

4. The glass fiber cloth according to claim 1, characterized in that The invention further comprises a covering layer, wherein the covering layer is arranged on a side of the functional bonding layer away from the base fabric layer, and the thickness of the covering layer is 100-180 μm.

5. The glass fiber cloth according to claim 1, characterized in that The base fabric layer has a gram weight of 100-300 g / m², the glass fiber cloth has a weight of 200-500 g / m², and the glass fiber cloth has a thickness of 80-300 μm.