An organic fiber composite and a method for producing the same

Abstract

This invention relates to the field of polymer materials technology, and discloses an organic fiber composite material and its preparation method. The organic fiber composite material, by weight, comprises the following raw materials: 100 parts epoxy resin, 60-200 parts organic fibers, 60-75 parts curing agent, 0.6-1 parts accelerator, 0-20 parts filler, and 0-5 parts additives; the epoxy resin comprises 40.0%-60.0% bisphenol A type epoxy resin, 30.0%-50.0% glycidyl ester type epoxy resin, and 10.0%-30.0% hyperbranched epoxy resin; based on 100% by weight of the total polymer forming the organic fibers, the polymer comprises 20%-100% polyamide ester and the balance polyester. By implementing this invention, the organic fibers and epoxy resin exhibit good interfacial strength, thereby improving the interlaminar shear strength and tensile strength of the resulting organic fiber composite material.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to an organic fiber composite material and its preparation method. Background Technology

[0002] Composite materials are new materials created by optimizing and combining material components with different properties using advanced material preparation technologies. The matrix materials of composite materials are divided into two main categories: metals and non-metals. Commonly used metal matrices include aluminum, magnesium, copper, titanium, and their alloys, while non-metal matrices mainly include synthetic resins, rubber, ceramics, graphite, and carbon. Reinforcing materials used in composite materials mainly include glass fiber (GF), carbon fiber, boron fiber, aramid fiber, silicon carbide fiber, asbestos fiber, whiskers, and metals. Among these, composite materials using synthetic resins such as epoxy resin, unsaturated polyester resin, phenolic resin, and polyurethane resin as the matrix material and glass fiber as the reinforcing material (commonly known as fiberglass) have been widely used due to their outstanding cost-effectiveness. However, this traditional fiberglass has low toughness, poor weather resistance, and high water absorption. Weathering of the resin layer in fiberglass reinforced sheets leads to exposed glass fibers, which absorb water, accelerating weathering and rapidly reducing the strength of the fiberglass. In addition, the matrix resin in fiberglass is thermosetting, and the fiberglass is an inorganic, insoluble, and infusible material, making the recycling and reuse of the product relatively easy and of low value.

[0003] Therefore, in recent years, people have begun to gradually develop and produce composite materials that use non-specialty organic fibers such as polyester, polypropylene, and nylon as reinforcing materials. Thermoplastic organic fibers, as reinforcing materials in composite materials, are easier to recycle, especially those with high fiber content. The ground powder can even be directly plasticized and molded for use in other products, making them more environmentally friendly.

[0004] One of the key technologies for composite materials is to achieve good interfacial strength between the matrix and the fiber reinforcement so that the composite material can exhibit the required strength. Therefore, how to improve the interfacial strength between the matrix and the fiber used has always been a technical challenge and research focus of composite materials. Current research focuses mainly on fiber surface treatment technology, but existing technical solutions still have shortcomings in the preparation of cost-effective organic fiber composite materials. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an organic fiber composite material and a method for preparing the same, wherein the organic fiber and epoxy resin have good interfacial strength, thereby improving the interlaminar shear strength and tensile strength of the obtained organic fiber composite material.

[0006] To solve the above-mentioned technical problems, the first aspect of the present invention provides an organic fiber composite material, the raw materials for which, by weight, are: 100 parts epoxy resin, 60-200 parts organic fiber, 60-75 parts curing agent, 0.6-1 parts accelerator, 0-20 parts filler and 0-5 parts additives; Based on a total amount of epoxy resin of 100% by weight, the epoxy resin comprises 40.0%-60.0% bisphenol A type epoxy resin, 30.0%-50.0% glycidyl ester type epoxy resin and 10.0%-30.0% hyperbranched epoxy resin. The total amount of the polymer forming the organic fiber is 100% by weight, and the polymer comprises 20%-100% polyamide ester and the balance polyester.

[0007] As an improvement to the above scheme, the total amount of polymer forming the organic fiber is 100% by weight, and the polymer includes 20%-60% polyamide ester and the balance polyester.

[0008] As an improvement to the above scheme, the organic fiber is a composite fiber obtained by spinning a mixture of polyamide ester chips and polyester fiber chips, wherein the molar fraction of amide in the polymer is 2.0 mol%-15.0%.

[0009] As an improvement to the above solution, the organic fibers are compounded with the epoxy resin by means of organic fiber cloth; The fineness of the organic fiber yarn in the organic fiber fabric is 1600dtex-2800dtex; The organic fiber cloth has a warp density of 3 threads / 10cm to 10 threads / 10cm, a weft density of 3 threads / 10cm to 10 threads / 10cm, and a total thickness of 1mm to 10mm.

[0010] As an improvement to the above scheme, the bisphenol A type epoxy resin has an epoxy equivalent of 180 g / mol-200 g / mol and a viscosity of 8000 MPa.s-20000 MPa.s at 25°C. The epoxy equivalent of the glycidyl ester type epoxy resin is 140 g / mol-190 g / mol, and the viscosity at 25°C is 300 MPa.s-2000 MPa.s; The hyperbranched epoxy resin has an epoxy value of 0.19 mol / 100g-0.25 mol / 100g, a viscosity of 500 cp-2000 cp at 25℃, and an average molecular weight of 2000 g / mol-5000 g / mol.

[0011] As an improvement to the above scheme, the accelerator is a tertiary amine carboxylic acid complex salt and / or an imidazole accelerator.

[0012] As an improvement to the above scheme, the accelerator is a tertiary amine carboxylic acid complex salt and an imidazole accelerator, and the weight ratio of the tertiary amine carboxylic acid complex salt and the imidazole accelerator is 1:(1-3). The tertiary amine carboxylic acid complex salt is tri-2-ethylhexanoate of DMP-30, and the imidazole accelerator is 2-ethyl-4-methylimidazole.

[0013] As an improvement to the above solution, the curing agent is an acid anhydride curing agent, which is one or more of methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and trimellitic anhydride.

[0014] As an improvement to the above solution, the filler is selected from one or more of glass fiber, calcium carbonate, talc, kaolin, mica, glass fiber powder, wollastonite, and diatomaceous earth. The additive is selected from at least one of color powder and lubricant, and the lubricant is selected from one or more of silicone, montan wax, lignite wax and ethylene wax.

[0015] A second aspect of the present invention also provides a method for preparing the aforementioned organic fiber composite material, comprising the following steps: The polymer is made into organic fiber yarn, and then the organic fiber yarn is made into fiber cloth; Epoxy resin is mixed evenly with curing agent, accelerator, filler and additives to form epoxy resin matrix; Organic fiber composite materials are prepared by combining a resin matrix and reinforcing materials.

[0016] Implementing this invention has the following beneficial effects: In this invention, bisphenol A type epoxy resin, glycidyl ester type epoxy resin, and hyperbranched epoxy resin are selected as the matrix resins of the composite material. Under the action of accelerators and curing agents, the curing process proceeds in an orderly manner, resulting in a fully cured organic fiber composite material with high overall performance. Among them, the epoxy resin has a low viscosity and better wetting effect. Organic fibers containing polyamide ester components are selected to reinforce the epoxy resin, resulting in good interfacial strength between the organic fibers and the epoxy resin. The interlaminar shear strength and tensile strength of the resulting organic fiber composite material are significantly improved, making it suitable for use in industries such as building materials, rail transportation, automobile manufacturing, new energy equipment, electronic and electrical housings, and outdoor anti-corrosion products. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described in further detail below.

[0018] Polyester (PET) has the molecular structure shown in Formula 1 below. It possesses characteristics such as high strength, high modulus, low elongation, impact resistance, fatigue resistance, good chemical stability, and acid resistance. Furthermore, it has a lower density and lower price than fibers such as glass fiber, carbon fiber, and aramid. Therefore, polyester has become the preferred organic fiber reinforcement for composite materials research and development. However, conventional polyester fibers exhibit strong chemical inertness due to their symmetrical molecular structure, lack of polar groups, strong intermolecular forces, high crystallinity, and smooth, dense surface morphology. This makes them difficult to impregnate with resins and results in poor adhesion, which greatly limits their application in the field of composite materials.

[0019]

[0020] Formula 1 To improve the wettability and adhesion of polyester fibers to matrix resins, current research focuses on fiber surface treatment technologies. Numerous researchers have conducted in-depth studies on surface treatment technologies such as ultraviolet radiation, plasma treatment, high-energy radiation (electron beam), high-energy radiation (gamma rays), laser treatment, alkali treatment, silane coupling agent treatment, and enzyme treatment. However, the cost-effectiveness of these technologies is not satisfactory. For example, high-energy radiation (electron beam) treatment is highly efficient and effective, but expensive; silane coupling agent treatment is relatively inexpensive, but its efficiency and effectiveness are poor; alkali treatment is not particularly expensive, but its efficiency and effectiveness are low, and it significantly affects the strength and hardness of the fibers after treatment.

[0021] To address the aforementioned problems, the first aspect of this invention provides an organic fiber composite material, the raw materials for which, by weight, are: 100 parts epoxy resin, 60-200 parts organic fiber, 60-75 parts curing agent, 0.6-1 parts accelerator, 0-20 parts filler, and 0-5 parts additives.

[0022] In this invention, bisphenol A type epoxy resin, glycidyl ester type epoxy resin, and hyperbranched epoxy resin are selected as the matrix resins of the composite material. The polymer forming the organic fiber includes polyamide ester. Under the action of accelerator and curing agent, the curing process proceeds in an orderly manner, resulting in a fully cured organic fiber composite material with high overall performance. The epoxy resin has a low viscosity and better wetting effect. Organic fibers containing polyamide ester are selected to reinforce the epoxy resin, resulting in good interfacial strength between the organic fibers and the epoxy resin. The interlaminar shear strength and tensile strength of the resulting organic fiber composite material are significantly improved. The obtained organic fiber composite material can be used in industries such as building materials, rail transportation, automobile manufacturing, new energy equipment, electronic and electrical enclosures, and outdoor anti-corrosion products.

[0023] Preferably, based on 100% by weight of the total epoxy resin, the epoxy resin comprises 40.0%-60.0% bisphenol A type epoxy resin, 30.0%-50.0% glycidyl ester type epoxy resin, and 10.0%-30.0% hyperbranched epoxy resin. The compounding of bisphenol A type epoxy resin, glycidyl ester type epoxy resin, and hyperbranched epoxy resin maintains good mechanical properties while having low viscosity, easily achieving good wetting effects. Furthermore, the glycidyl ester groups contained in the glycidyl ester type epoxy resin have better compatibility with organic fibers and can react with ester groups at high temperatures, thereby improving interfacial strength. Among them, bisphenol A epoxy resin serves as the basic skeleton; glycidyl ester epoxy resin has better compatibility with polyester, and under conditions where polyester can be fully impregnated, the two can improve interfacial strength through reaction; hyperbranched epoxy resin, due to its good fluidity and wetting effect, can improve the interfacial wetting effect between epoxy resin and organic fibers, thus providing kinetic conditions for the reaction between glycidyl ester epoxy resin and polyester. Furthermore, by adjusting the ratio of bisphenol A epoxy resin, glycidyl ester epoxy resin, and hyperbranched epoxy resin, the toughness of the resin can be enhanced while ensuring its excellent strength and rigidity, promoting adhesion to organic fibers, and meeting the requirements of subsequent high-speed pultrusion processes.

[0024] Furthermore, in the epoxy resin, bisphenol A type epoxy resin is used as the main component. Its epoxy equivalent directly affects the crosslinking density of the epoxy resin matrix, and its viscosity directly affects the degree of wetting of the organic fiber cloth by the epoxy resin, thereby affecting the composite effect of the epoxy resin matrix and the organic fiber. This application specifies that the epoxy equivalent of the bisphenol A type epoxy resin is 180 g / mol-200 g / mol, and the viscosity at 25°C is 8000 MPa.s-20000 MPa.s. This effectively balances the rigidity and brittleness of the composite material, promotes the wetting effect of the epoxy resin on the organic fiber material, and prevents problems such as porosity from occurring in the pultrusion composite process.

[0025] Furthermore, the glycidyl ester type epoxy resin has an epoxy equivalent of 140 g / mol-190 g / mol and a viscosity of 300 MPa.s-2000 MPa.s at 25°C, which can further increase the crosslinking density of the epoxy resin matrix, form flexible ester segments, improve the segment length of the epoxy resin, improve the toughness of the matrix, and at the same time synergistically improve wettability, form a stronger fiber-resin interface, and improve the interlaminar shear strength and fatigue resistance of the composite material.

[0026] Furthermore, the hyperbranched epoxy resin has an epoxy value of 0.19 mol / 100g-0.25 mol / 100g, a viscosity of 500 cp-2000 cp at 25°C, and an average molecular weight of 2000 g / mol-5000 g / mol. This allows for synergistic regulation of the system viscosity, making it easier for the resin to enter the fiber bundle during the pultrusion impregnation process, thus improving the impregnation effect. At the same time, it increases the reactivity and local crosslinking density, playing a rigid filling role, thereby further improving the toughness of the composite material.

[0027] Preferably, based on 100% by weight of the total amount of polymer forming the organic fiber, the polymer comprises 20%-100% polyamide ester and the balance polyester. The polymer forming the organic fiber includes polyamide ester, with the molecular structure shown in Formula 2 below. When used as a reinforcing material for the epoxy resin matrix, the polyamide ester introduces molecular chain segments containing -CO-NH- groups into its main chain, effectively reducing the surface energy of the organic fiber surface. This results in greater conformational changes, increased flexibility, and increased gaps between molecular chains, allowing disperse dyes to easily penetrate the fiber interior, achieving an easy-dyeing effect. Furthermore, the introduction of a certain number of polar hydrophilic groups into the main chain improves the fiber's hydrophilicity and hygroscopic properties, reducing the contact angle between the fiber surface and water, and improving the diffusion performance of water molecules on the fiber surface. In addition, the organic fiber increases the reaction probability with the curing agent, further enhancing the interfacial strength between the epoxy resin and the organic fiber.

[0028]

[0029] Formula 2 Furthermore, based on a total polymer content of 100% by weight in forming the organic fiber, the polymer comprises 20%-60% polyamide ester and the balance polyester. Using a blending solution of polyamide ester and polyester as a blending agent can adjust the surface polarity of the fibers, thereby improving the wetting effect. Moreover, the high reactivity between polyester and epoxy resin further enhances the performance of the organic fiber composite material.

[0030] Furthermore, the organic fiber is a composite fiber obtained by spinning a mixture of polyamide ester chips and polyester fiber chips, wherein the molar fraction of amide in the polymer is 2.0 mol%-15.0%, which can ensure the wetting effect of epoxy resin on the organic fiber and the interfacial adhesion strength. Exemplarily, the molar fraction of amide in the polymer is 2.0 mol%, 4.0 mol%, 6.0 mol%, 8.0 mol%, 10.0 mol%, 12.0 mol%, 14.0 mol%, or 15.0 mol%, but is not limited thereto. Optionally, the polyamide ester chips contain 15mol%-25mol% amide, the polyamide ester chips have a melt crystallization temperature (Tm) of 160℃-200℃, and a breaking elongation of 15%-40%. High-strength fibers with intact surfaces are obtained through spinning. The fineness of the organic fiber yarn is 1600dtex-2800dtex. Through textile processes, the fiber cloth can withstand the high temperatures of pultrusion processes and is well compatible with epoxy resin matrices. For example, the fineness of the organic fiber yarn is 1600dtex, 1800dtex, 2000dtex, 2200dtex, 2400dtex, 2600dtex, or 2800dtex, but is not limited to these.

[0031] In some specific and preferred embodiments, the organic fibers are composited with the epoxy resin via an organic fiber cloth. The organic fiber cloth has a monofilament linear density of 5-20 dtex and a yarn linear density of 1500-2700 dtex, with a warp density of 3-10 threads / 10cm and a weft density of 3-10 threads / 10cm. The organic fiber cloth has a multi-layer structure with a total thickness of 1-10mm, and each layer is laid with a pre-set angle staggered at 40°-60°.

[0032] Preferably, the curing agent is an anhydride-based curing agent, which contains anhydride groups that can react with the amide groups of the polyamide ester at high temperatures, thereby improving the interfacial strength. Optionally, the anhydride-based curing agent is one or more of methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and trimellitic anhydride.

[0033] Preferably, the accelerator is a tertiary amine carboxylic acid complex salt and / or an imidazole accelerator, which enables the matrix resin to be more stable at low temperatures and the curing process to proceed in an orderly and gradual manner. Optionally, the tertiary amine carboxylic acid complex salt includes, but is not limited to, DMP-30 tri-2-ethylhexanoate, benzyl dimethylamine acetate, triethanolamine carboxylate, dimethylaniline carboxylate, etc., and the imidazole accelerator includes, but is not limited to, 2-ethyl-4-methylimidazolium, 2-methylimidazolium, and 1-cyano-2-ethyl-4-methylimidazolium.

[0034] Furthermore, the accelerator is a tertiary amine carboxylic acid complex salt and an imidazole accelerator, and the weight ratio of the tertiary amine carboxylic acid complex salt and the imidazole accelerator is 1:(1-3). This allows the epoxy resin matrix to be fully impregnated with the fiber cloth during the composite process, and also allows for complete curing, resulting in an organic fiber composite material that is bubble-free, has good mechanical properties, and is completely intact.

[0035] More preferably, the tertiary amine carboxylic acid complex salt is tri-2-ethylhexanoate of DMP-30, and the imidazole accelerator is 2-ethyl-4-methylimidazole.

[0036] Preferably, the filler is selected from one or more of glass fiber, calcium carbonate, talc, kaolin, mica, glass fiber powder, wollastonite, and diatomaceous earth. The filler is used as an auxiliary component in this invention and can be added in appropriate amounts as needed; however, this invention is not limited thereto.

[0037] Preferably, the additive is selected from at least one of color powder and lubricant. The lubricant includes, but is not limited to, silicones, montmorillonite wax, lignite wax, ethylene wax, etc.; the color powder includes, but is not limited to, titanium dioxide, zinc sulfide, iron oxide red, titanium blue, titanium yellow, etc. The additive exists as an auxiliary component in this invention and can be added in appropriate amounts as needed. This invention is not limited thereto.

[0038] Accordingly, the present invention also provides a method for preparing the aforementioned organic fiber composite material, comprising the following steps: (1) The polymer is made into organic fiber yarn, and then the organic fiber yarn is made into fiber cloth; (2) Mix epoxy resin with curing agent, accelerator, filler and additives evenly to form epoxy resin matrix; (3) The resin matrix and the reinforcing material are combined to prepare an organic fiber composite material.

[0039] Specifically, in step (1), the process of forming the polymer into organic fiber yarn and then forming the organic fiber yarn into a fiber cloth includes: Polyamide chips or a mixture of polyamide chips and polyester chips are spun to obtain organic fibers. These fibers are then twisted to obtain organic fiber yarns. Finally, the organic fiber yarns are woven into organic fiber fabrics using a loom as reinforcing materials.

[0040] Specifically, in step (2), the epoxy resin is mixed evenly with the curing agent, accelerator, filler, and additives to form an epoxy resin matrix, including: (21) Mix bisphenol A type epoxy resin, glycidyl ester type epoxy resin and hyperbranched epoxy resin in proportion to obtain epoxy resin mixture. (22) Add the curing agent to the epoxy resin mixture and stir until homogeneous; (23) Continue to add accelerator to the epoxy resin mixture and stir until homogeneous; (24) Add filler and additives to the epoxy resin mixture at the end and stir evenly to obtain the final product.

[0041] Specifically, in step (3), the organic fiber cloth obtained in step (1) is immersed in the epoxy resin matrix obtained in step (2), and then processed by pultrusion equipment to prepare organic fiber composite material.

[0042] Preferably, the pultrusion equipment is divided into four temperature zones in the reverse direction of the material travel: a feeding wetting zone, a gel zone, a curing zone, and a shaping and cooling zone. The temperature of the feeding wetting zone is 80℃-100℃, the temperature of the gel zone is 120℃-140℃, the temperature of the curing zone is 160℃-180℃, and the temperature of the shaping and cooling zone is 80℃-100℃.

[0043] Furthermore, the pultrusion speed is 0.8m / min-1.5m / min, and the traction force of the pultrusion equipment can be reasonably adjusted according to the fabric specifications, specifically set to 8kN-12kN.

[0044] The present invention will be further described below with reference to specific embodiments: Example 1 This embodiment provides an organic fiber composite material, which, by weight, comprises: 100 parts epoxy resin, 100 parts organic fiber, 68 parts curing agent methylhexahydrophthalic anhydride, and tri-2-ethylhexanoate of DMP-30 (ANCAMINE). TM 0.3 parts of K61B and 0.5 parts of 2-ethyl-4-methylimidazole; Based on a total weight percentage of 100%, the epoxy resin comprises 50% bisphenol A type epoxy resin, 35% glycidyl ester type epoxy resin, and 15% hyperbranched epoxy resin; wherein the bisphenol A type epoxy resin has an epoxy equivalent of 184 g / mol-195 g / mol and a viscosity at 25°C of 10000 MPa.s-16000 MPa.s (Nantong Xingchen Synthetic Materials Co., Ltd., WSR618); the glycidyl ester type epoxy resin is diglycidyl tetrahydrophthalate, and the epoxy equivalent is... The amount is 150g / mol-180g / mol, the viscosity at 25℃ is 500Mpa.s-1500Mpa.s, and the CAS number is 21544-03-6 (Henan Xinjing New Materials Co., Ltd., S-182); the epoxy value of the hyperbranched epoxy resin is 0.20±0.05mol / 100g, the viscosity at 25℃ is 700cp-1000cp, and the average molecular weight is 3200g / mol-3600g / mol (Wuhan Hyperbranched Resin Technology Co., Ltd., HyPerE102).

[0045] The polymer forming the organic fiber is polyamide ester. Specifically, the organic fiber is a fiber obtained by spinning polyamide ester chips. The polyamide ester chips are YL100, the amide content in the polyamide ester chips is 20 mol%, the melt crystallization temperature is 170℃-180℃, and the elongation at break is 20%-30%.

[0046] The organic fiber has a monofilament linear density of 8 dtex, an organic fiber yarn fineness of 2200 dtex, an organic fiber fabric yarn linear density of 2220 dtex, a warp density of 6.5 threads / 10cm, a weft density of 6.5 threads / 10cm, and is laid in 4 layers at a 45-degree angle, with a total thickness of 2.5mm.

[0047] This embodiment also provides a method for preparing the aforementioned organic fiber composite material, comprising the following steps: (1) Spin the polyamide ester chips to obtain organic fibers, and then obtain organic fiber yarns through twisting and other operations. Finally, weave the organic fiber yarns into organic fiber cloth through a plain weave machine. (2) Bisphenol A type epoxy resin, glycidyl ester type epoxy resin and hyperbranched epoxy resin are mixed evenly in proportion to obtain epoxy resin mixture; then, a curing agent is added to the epoxy resin mixture and stirred evenly; then, an accelerator is added to the epoxy resin mixture and stirred evenly to form a resin matrix. (3) The organic fiber cloth obtained in step (1) is immersed in the epoxy resin matrix obtained in step (2), and then processed by pultrusion equipment to prepare organic fiber composite material; wherein, the temperature of the feeding and wetting zone is 90℃, the temperature of the gel zone is 130℃, the temperature of the curing zone is 170℃, the temperature of the setting and cooling zone is 90℃, the pultrusion speed is 1.1m / min, and the traction force of the pultrusion equipment can be reasonably adjusted according to the fabric specifications, specifically it can be set to 10kN.

[0048] Example 2 This embodiment provides an organic fiber composite material, which is basically the same as that in Example 1, except that: Based on a total weight percentage of 100% of the organic fibers, the polymer comprises 30% polyamide ester and 70% polyester; specifically, the organic fibers are composite fibers obtained by spinning a mixture of polyamide ester chips and polyester chips, wherein the polyester chips are IG703 (Sinopec Yizheng Chemical Fiber Co., Ltd.).

[0049] Example 3 This embodiment provides an organic fiber composite material, which is basically the same as that in Embodiment 2, except that: Based on a total weight percentage of 100%, the epoxy resin comprises 40% bisphenol A type epoxy resin, 40% glycidyl ester type epoxy resin and 20% hyperbranched epoxy resin.

[0050] Example 4 This embodiment provides an organic fiber composite material, which is basically the same as that in Embodiment 2, except that: The polymer comprising 60% polyamide ester and 40% polyester is based on a total polymer content of 100% by weight in forming the organic fiber.

[0051] Comparative Example 1 This comparative example provides an organic fiber composite material, which is basically the same as that in Example 1, except that: The epoxy resin is a bisphenol A type epoxy resin.

[0052] Comparative Example 2 This comparative example provides an organic fiber composite material, which is basically the same as that in Example 1, except that: The polymer forming the organic fiber is polyester (Sinopec's high-strength industrial filament 707), which has a breaking strength of 8 cN / dtex, a breaking elongation of 14.0%, an elongation of 6.00% under a 4.0 cN / dtex load, and a dry heat shrinkage rate (177°C, 10 min) of 7.5%.

[0053] Comparative Example 3 This comparative example provides an organic fiber composite material, which is basically the same as that in Example 4, except that: The polymer forming the organic fiber is polyester (Sinopec's high-strength industrial filament 707), which has a breaking strength of 8 cN / dtex, a breaking elongation of 14.0%, an elongation of 6.00% under a 4.0 cN / dtex load, and a dry heat shrinkage rate (177°C, 10 min) of 7.5%.

[0054] Comparative Example 4 This comparative example provides an organic fiber composite material, which is basically the same as that in Example 2, except that: The polymer forming the organic fiber is polyester. Specifically, the organic fiber is a fiber obtained by spinning polyester chips, and the polyester chips are IG703 (China Petrochemical Yizheng Chemical Fiber Co., Ltd.).

[0055] Performance testing: 1. Interlaminar Shear Strength: The test was conducted according to ASTM D2344, "Standard Test Method for Determining Apparent Interlaminar Shear Strength of Parallel Fiber Composites by Short Beam Method." Samples obtained from the examples and comparative examples were cut to 12.0 mm × 4.0 mm × 4.0 mm and tested on an electronic universal testing machine. The loading speed was set to 1 mm / min, and the test temperature was 23℃. During the test, the span-to-thickness ratio was 4:1, therefore the span was set to 16 mm. Five specimens were tested for each experimental scheme, and the average value was taken. The interlaminar shear strength was calculated using the formula τ = 3Pb / (4bh), where τ is the interlaminar shear strength, Pb is the maximum load the specimen withstands at failure, b is the width of the specimen, and h is the thickness of the specimen.

[0056] 2. Tensile Properties: The tensile properties were tested according to GB / T 1447-2005 "Test Method for Tensile Properties of Fiber Reinforced Plastics". Samples obtained from the examples and comparative examples were cut to 250mm × 25mm × 4.0mm and tested on an electronic universal testing machine. The loading speed was set to 5mm / min, and the test temperature was 23℃. Five specimens were tested for each experimental scheme, and the average value was taken. The tensile strength was calculated using the formula σ = F / (bd), where σ is the tensile strength, F is the breaking load, b is the specimen width, and d is the specimen thickness.

[0057] The test results are shown in Table 1.

[0058] Table 1 Performance test results of the examples and comparative examples

[0059] The results above show that the interlaminar shear strength and tensile strength of Examples 1-4 are higher than those of Comparative Example 1, indicating that the epoxy resin composites used in Examples 1-4 have lower viscosity and better wetting effect. They are also higher than those of Comparative Examples 2-3, indicating that the fiber reinforcement containing amide groups has higher interlaminar shear strength and tensile strength than Comparative Examples 2 and 3. While the interlaminar shear strength of Examples 2-4 is weaker than that of Example 1, the tensile strength is higher because the polyamide ester fiber in Example 1 has strong polarity but relatively low strength. Therefore, in this invention, selecting organic fibers containing polyamide ester components to reinforce epoxy resin results in good interfacial strength between the organic fibers and the epoxy resin, significantly improving the interlaminar shear strength and tensile strength of the resulting organic fiber composite material.

[0060] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An organic fiber composite material, characterized by, The raw materials for its preparation, by weight, include: 100 parts epoxy resin, 60-200 parts organic fiber, 60-75 parts curing agent, 0.6-1 parts accelerator, 0-20 parts filler and 0-5 parts additives; Based on a total amount of epoxy resin of 100% by weight, the epoxy resin comprises 40.0%-60.0% bisphenol A type epoxy resin, 30.0%-50.0% glycidyl ester type epoxy resin and 10.0%-30.0% hyperbranched epoxy resin. The total amount of the polymer forming the organic fiber is 100% by weight, and the polymer comprises 20%-100% polyamide ester and the balance polyester.

2. The organic fiber composite of claim 1, wherein The polymer comprising 20%-60% polyamide ester and the balance polyester, based on a total weight percentage of 100% of the polymer forming the organic fiber.

3. The organic fiber composite of claim 2, wherein The organic fiber is a composite fiber obtained by spinning a mixture of polyamide ester chips and polyester fiber chips, wherein the molar fraction of amide in the polymer is 2.0 mol%-15.0 mol%.

4. Organic fibre composite according to any of claims 1 to 3, characterised in that The organic fibers are composited with the epoxy resin via an organic fiber cloth. The fineness of the organic fiber yarn in the organic fiber fabric is 1600dtex-2800dtex; The organic fiber cloth has a warp density of 3 threads / 10cm to 10 threads / 10cm, a weft density of 3 threads / 10cm to 10 threads / 10cm, and a total thickness of 1mm to 10mm.

5. The organic fiber composite of claim 1, wherein, The bisphenol A type epoxy resin has an epoxy equivalent of 180 g / mol-200 g / mol and a viscosity of 8000 MPa.s-20000 MPa.s at 25°C. The epoxy equivalent of the glycidyl ester type epoxy resin is 140 g / mol-190 g / mol, and the viscosity at 25°C is 300 MPa.s-2000 MPa.s; The hyperbranched epoxy resin has an epoxy value of 0.19 mol / 100g-0.25 mol / 100g, a viscosity of 500 cp-2000 cp at 25℃, and an average molecular weight of 2000 g / mol-5000 g / mol.

6. The organic fiber composite of claim 1, wherein, The accelerator is a tertiary amine carboxylic acid complex salt and / or an imidazole accelerator.

7. The organic fiber composite of claim 6, wherein The accelerator is a tertiary amine carboxylic acid complex salt and an imidazole accelerator, and the weight ratio of the tertiary amine carboxylic acid complex salt and the imidazole accelerator is 1:(1-3). The tertiary amine carboxylic acid complex salt is tri-2-ethylhexanoate of DMP-30, and the imidazole accelerator is 2-ethyl-4-methylimidazole.

8. The organic fiber composite of claim 1, wherein, The curing agent is an acid anhydride curing agent, which is one or more of methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and trimellitic anhydride.

9. The organic fiber composite material as described in claim 1, characterized in that, The filler is selected from one or more of the following: glass fiber, calcium carbonate, talc, kaolin, mica, glass fiber powder, wollastonite, and diatomaceous earth. The additive is selected from at least one of color powder and lubricant, and the lubricant is selected from one or more of silicone, montan wax, lignite wax and ethylene wax.

10. A method for preparing an organic fiber composite material according to any one of claims 1-9, characterized in that, Includes the following steps: The polymer is made into organic fiber yarn, and then the organic fiber yarn is made into fiber cloth; Epoxy resin is mixed evenly with curing agent, accelerator, filler and additives to form epoxy resin matrix; Organic fiber composite materials are prepared by combining a resin matrix and reinforcing materials.

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