A kind of impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and its prepreg manufacturing method

Abstract

The present invention provides an impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and a method for producing the same. The composite material comprises the following components [A] to [E]: component [A] is a thermoplastic particle with a particle size of 10 to 20 μm that is insoluble in epoxy resin; component [B] is a crystalline particle with a particle size of 10 to 20 μm that is insoluble in epoxy resin. The prepreg comprises a primary prepreg comprising component [C], a reinforcing fiber base material; and component [C] impregnated with an epoxy resin composition [D] containing at least an epoxy resin and a thermoplastic resin soluble in epoxy resin, and component [B]. The surface layer comprises the epoxy resin composition [E] containing at least an epoxy resin and a thermoplastic resin soluble in epoxy resin, and component [A], formed on one or both sides of the primary prepreg. The resulting material exhibits excellent impact resistance and environmental adaptability.

Description

Technical Field

[0001] The present invention relates to a fiber-reinforced resin-based composite material and a prepreg manufacturing method suitable for automobiles, ships, engineering infrastructure, sports and leisure or other fields with high strength, high toughness and environmental adaptability. Background Art

[0002] With the development of lightweight, polymer-based composite materials have been widely used in aerospace, wind turbine blades, automobiles and ships due to their high specific strength, high specific modulus and low density. The emergence and wide application of intermediate prepregs have greatly shortened the product manufacturing cycle and expanded the application field. Among them, thermosetting epoxy resin prepregs are the most widely used, but they often show low impact resistance in composite materials prepared from prepregs due to their high cross-linking density. Existing methods for improving the impact resistance of composite materials are mainly based on thermoplastic resins and films, but their high dosage and other characteristics lead to high resin viscosity and high void ratio of composite materials after molding, resulting in low utilization rate of final mechanical properties and low environmental adaptability. The present invention mainly starts from the perspective of improving resin toughness and interlayer toughness of composite materials. A prepreg with high toughness, impact resistance and environmental adaptability is provided, and a method for appropriately obtaining the fiber-reinforced resin-based composite material and its prepreg. Summary of the Invention

[0003] In response to the widespread shortcomings of existing epoxy resin-based composites, which suffer from poor out-of-plane performance, the present invention aims to provide a prepreg with high strength, high toughness, impact resistance, and environmental adaptability, as well as a suitable method for obtaining the fiber-reinforced resin-based composite and its prepreg. This approach aims to enhance the ability of the resulting high-performance composite to withstand external loads in the longitudinal direction, thereby broadening the application areas of resin-based composites.

[0004] The present invention adopts the following technical solutions:

[0005] An impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material comprising components [A] to [C], wherein the prepreg comprises a primary prepreg comprising a fiber substrate reinforced by component [C] and an epoxy resin composition [D] containing at least an epoxy resin and a thermoplastic resin soluble in the epoxy resin, and component [B], impregnated within component [C]; and a surface layer comprising an epoxy resin composition [E] containing at least an epoxy resin and a thermoplastic resin soluble in the epoxy resin, and component [A], formed on one or both surfaces of the primary prepreg.

[0006] [A] Thermoplastic particles with a particle size of 10 to 20 μm that are insoluble in epoxy resin;

[0007] [B] Crystalline particles with a particle size of 10 to 20 μm that are insoluble in epoxy resin;

[0008] [C] Reinforced fiber base material;

[0009] [D] an epoxy resin composition comprising at least an epoxy resin and a thermoplastic resin soluble in the epoxy resin, and the component [B];

[0010] [E] An epoxy resin composition comprising at least an epoxy resin, a thermoplastic resin soluble in the epoxy resin, and the component [A].

[0011] In the above-mentioned impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and prepreg manufacturing method thereof, component [A] is thermoplastic particles that are insoluble in epoxy resin.

[0012] Specifically, component [A] accounts for 5% to 15% by weight of component [E]. The thermoplastic particles are selected from at least one of amorphous nylon, nylon 6, nylon 66, polyimide, and polyurethane. The thermoplastic particles may have a three-dimensional modified structure. The thermoplastic particles have a particle size distribution of 10 to 20 μm and a sphericity greater than 95%.

[0013] In the above-mentioned impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and prepreg manufacturing method thereof, component [B] is thermoplastic particles that are insoluble in epoxy resin.

[0014] Specifically, component [B] accounts for 5% to 15% by weight of component [D]. The epoxy resin-insoluble thermoplastic particles are selected from at least one of crystalline nylon, nylon 6, nylon 66, and crystalline polyimide, and have a particle size distribution of 10 to 20 μm. The melting point of the crystalline thermoplastic particles is no higher than the curing temperature of the prepared prepreg.

[0015] In the aforementioned impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and prepreg manufacturing method, the reinforcing fiber of component [C] is one of carbon fiber, glass fiber, aramid fiber, basalt fiber, and ultra-high molecular weight polyethylene fiber. The reinforcing fiber of component [C] may be in the form of fibers, fabrics, or felt.

[0016] In the above-mentioned impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and prepreg manufacturing method thereof, components [D] and [E] contain at least a thermoplastic resin and a curing agent, component [D] contains component [A], and component [E] contains component [B].

[0017] Specifically, the epoxy resin is selected from one or more of a glycidyl ether epoxy resin, an alicyclic epoxy resin, a glycidylamine epoxy resin, an epoxidized olefin, a polyurethane-modified epoxy resin, or an isocyanate-modified epoxy resin. The thermoplastic resin is a thermoplastic resin soluble in the epoxy resin. The soluble thermoplastic resin may be one of polysulfone, polyethersulfone, polyarylethersulfone, polyetheretherketone, and polycarbonate. The curing agent is an amine curing agent, which may be one or more mixtures of diaminodiphenylsulfone, diaminodiphenylmethane, dicyandiamide, or derivatives and isomers thereof.

[0018] In the above-mentioned impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and its prepreg manufacturing method, it is characterized in that it is a primary prepreg composed of component [C] reinforcing fiber substrate and epoxy resin composition [D] containing at least epoxy resin and thermoplastic resin soluble in epoxy resin and component [B] impregnated in component [C]; and a surface layer composed of epoxy resin composition [E] containing at least epoxy resin and thermoplastic resin soluble in epoxy resin and component [A] formed on one side or both sides of the primary prepreg.

[0019] In the above-mentioned impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and its prepreg manufacturing method, it is characterized in that when the prepared prepreg is formed, the molten component [B] has the function of connecting the component [A].

[0020] The above-mentioned impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material and its prepreg manufacturing method are characterized in that the prepared fiber-reinforced composite material has excellent impact resistance and environmental adaptability.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] The present invention uses thermoplastic particles and crystalline particles to toughen epoxy resin-based composite materials between layers. When the prepared prepreg is cured, the melted crystal particles can be tightly combined with the highly active three-dimensional cross-linked thermoplastic particles. At the same time, compared with the existing prepreg molding technology, the present invention adopts a two-step impregnation technology. During the prepreg molding process, epoxy resins containing thermoplastic particles and crystalline particles are separately prepared. The first impregnated epoxy resin film containing crystalline particles exists on the surface of the reinforcing material, which can prevent the subsequent impregnated epoxy resin film containing thermoplastic particles from entering the interlayer due to the impregnation process. After impregnation, the thermoplastic particles and crystalline particles can be evenly distributed on the surface. The thermoplastic particles tightly combined by the crystal particles can withstand greater external forces when subjected to longitudinal loads, thereby improving the impact resistance of the composite laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the material of the present invention.

[0024] In the figure, A represents thermoplastic particles insoluble in epoxy resin, B represents crystalline particles insoluble in epoxy resin, C represents reinforcing fibers, D represents an epoxy resin composition comprising an epoxy resin, a thermoplastic resin soluble in epoxy resin, and component [B], and E represents an epoxy resin composition comprising an epoxy resin, a thermoplastic resin soluble in epoxy resin, and component [A].

[0025] The primary prepreg is formed by D on one or both sides of C. The prepreg of the present invention is formed by E on one or both sides of the primary prepreg. DETAILED DESCRIPTION

[0026] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0027] In the embodiment, the bifunctional epoxy resin is bisphenol F epoxy resin, the tetrafunctional epoxy resin is tetraglycidyl ether amine epoxy resin, and the trifunctional resin is triglycidyl ether amine epoxy resin.

[0028] The thermoplastic resin is polyethersulfone; the thermoplastic particles are polyurethane particles; and the crystal particles are nylon 6 particles and nylon 12 particles.

[0029] The curing agent is 4,4-diaminodiphenyl sulfone.

[0030] The reinforcing fiber is T800 grade carbon fiber.

[0031] Example 1:

[0032] Using a blender with integrated stirring and dispersing functions, the thermoplastic resin polyethersulfone was dissolved in an epoxy resin at 120°C. The polyethersulfone accounted for 12% of the epoxy resin by weight. The epoxy resin consisted of a difunctional glycidyl ether epoxy resin, a trifunctional glycidyl ether epoxy resin, and a tetrafunctional amine epoxy resin. The mass ratio of the difunctional glycidyl ether epoxy resin, the trifunctional glycidyl ether epoxy resin, and the tetrafunctional amine epoxy resin was 2:1:7. The epoxy value of the difunctional glycidyl ether epoxy resin was 0.51-0.54, the trifunctional glycidyl ether epoxy resin was 0.7-0.9, and the tetrafunctional amine epoxy resin was 0.7-0.9. The polyethersulfone particle size was 20 μm. After the polyethersulfone is dissolved, the mixture is cooled to 70-80°C and crystal particles are added, mixed and stirred for 40 minutes. The crystal particles are nylon 6 particles with an average particle size of 20 μm and a sphericity greater than 95%. The nylon 6 particles account for 10% by weight of the epoxy resin composition. Finally, a curing agent is added and mixed for 40 minutes to prepare the epoxy resin composition [D]. The curing agent is 4,4-diaminodiphenylsulfone.

[0033] An epoxy resin composition [E] was prepared in the same manner. During the preparation of the epoxy resin composition [E], the thermoplastic particles were three-dimensional cross-linked polyurethane particles with an average particle size of 15 μm and a glass transition temperature of 90° C. The polyurethane particles accounted for 10 wt % of the epoxy resin composition.

[0034] The epoxy resin composition [D] and the epoxy resin composition [E] were coated on release paper using a coating machine to obtain epoxy resin composition films [D] and epoxy resin composition films [E] with a unit area mass of 25 g / m 2 The prepared prepreg resin film has a unit area mass of 100g / m 2 .

[0035] The 4-film impregnation process is used in the prepreg impregnation machine. The T800 carbon fiber is introduced into the gap between the impregnation machine rollers through the impregnation machine unwinding device. The prepreg fiber unit area mass is 194g / m 2 An epoxy resin composition film [D] was first applied to the surface of the T800 carbon fiber using an unwinding device. The epoxy resin composition film [D] was then pressurized and heated at 120°C with a pressure of 4 kg to produce a primary prepreg. An epoxy resin composition film [E] was then applied to the primary prepreg using an unwinding device. The epoxy resin composition film [E] was then pressurized and heated at 100°C with a pressure of 4 kg to produce a prepreg having a resin content of 34% by mass. The resulting prepreg thermoplastic particles exhibited excellent resistance to external loads after curing on the prepreg surface.

[0036] In Example 2 and Comparative Examples 1 and 2, different thermoplastic particles and crystal particles were used, and the preparation process was the same as that of Example 1.

[0037] In Example 2, the crystal particles used in the epoxy resin composition [D] are nylon 6 particles with an average particle size of 20 μm, and the thermoplastic particles used in the epoxy resin composition [E] are nylon 12 particles with an average particle size of 20 μm.

[0038] In Comparative Example 1, the crystal particles used in the epoxy resin composition [D] were nylon 6 particles having an average particle size of 20 μm, and the epoxy resin composition [E] did not use thermoplastic particles.

[0039] In Comparative Example 2, the epoxy resin composition [D] does not use crystal particles, and the thermoplastic particles used in the epoxy resin composition [E] are 3D cross-linked polyurethane particles.

[0040]

[0041] The prepregs prepared by the present invention are all obtained by a vacuum-assisted autoclave molding process to obtain test specimens. A comparison between Example 1 and Comparative Example 1 shows that the toughness of the composite material prepared by using only crystal particles for interlayer toughening is limited. A comparison between Example 1 and Comparative Example 2 shows that the toughness of the composite material prepared by using only cross-linked thermoplastic particles for interlayer toughening is improved to a certain extent, but it is lower than that of the composite material prepared by using a combination of thermoplastic particles and crystal particles. Examples 1 and 2 all use thermoplastic particles and crystal particles. Both Examples 1 and 2 have high post-impact compressive strength, type I fracture toughness, and type II fracture toughness. The prepregs prepared in Examples 1 and 2 are first impregnated with an epoxy resin film containing crystalline particles, which exists on the surface of the reinforcing material. This can prevent the subsequent impregnation of the epoxy resin film containing thermoplastic particles from entering the interlayer due to the impregnation process. After impregnation, the thermoplastic particles and crystal particles can be evenly distributed on the surface. When the prepreg is cured, the melted crystal particles can be tightly combined with the highly active three-dimensional cross-linked structure thermoplastic particles. When the workpiece is subjected to a longitudinal load, it can withstand greater external forces, thereby improving the impact resistance of its composite laminate.

Claims

1. An impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material, characterized by: The invention comprises components [A] to [E]; component [C] is a reinforcing fiber substrate, and component [C] is impregnated with an epoxy resin composition [D] to form a primary prepreg; The surface layer is composed of an epoxy resin composition [E] formed on one or both sides of the primary prepreg; Component [A] is thermoplastic particles having a particle size of 10 to 20 μm and insoluble in epoxy resin; Component [B] is a crystalline particle having a particle size of 10 to 20 μm and is insoluble in epoxy resin; An epoxy resin composition [D] comprising at least an epoxy resin and a thermoplastic resin soluble in the epoxy resin, and a component [B]; The epoxy resin composition [E] contains at least an epoxy resin, a thermoplastic resin soluble in the epoxy resin, and the component [A].

2. The impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material according to claim 1, wherein component [A] is thermoplastic particles insoluble in epoxy resin; specifically, component [A] accounts for 5 wt% to 15 wt% of the epoxy resin composition [E]; the thermoplastic particles are selected from at least one of amorphous nylon, polyimide, and polyurethane; and the thermoplastic particles have a particle size distribution of 10 to 20 μm and a sphericity greater than 95%.

3. The impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material according to claim 1, wherein component [B] is crystalline particles insoluble in epoxy resin; component [B] accounts for 5 wt% to 15 wt% of the epoxy resin composition [D]; the crystalline particles insoluble in epoxy resin are selected from at least one of crystalline nylon and crystalline polyimide, and the particle size distribution of the crystalline particles is 10 to 20 μm.

4. The impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material according to claim 1, wherein the reinforcing fiber in component [C] is one of carbon fiber, glass fiber, aramid fiber, basalt fiber, and ultra-high molecular weight polyethylene fiber.

5. The impact-resistant and environmentally adaptable fiber-reinforced resin-based composite material according to claim 1, wherein the epoxy resin compositions [D] and [E] contain at least a thermoplastic resin and a curing agent; The epoxy resin is selected from one or more of glycidyl ether epoxy resin, alicyclic epoxy resin, glycidyl amine epoxy resin, epoxidized olefin, polyurethane modified epoxy resin or isocyanate modified epoxy resin; the thermoplastic resin is a thermoplastic resin soluble in the epoxy resin; the thermoplastic resin soluble in the epoxy resin is one of polysulfone, polyethersulfone, polyarylethersulfone, polyetheretherketone and polycarbonate; the curing agent is an amine curing agent.

6. A method for preparing the composite material according to claim 1, characterized in that A primary prepreg comprising a reinforcing fiber base material as component [C], and an epoxy resin composition [D] containing at least an epoxy resin and a thermoplastic resin soluble in the epoxy resin, and component [B], impregnated within component [C]; and a surface layer comprising an epoxy resin composition [E] containing at least an epoxy resin and a thermoplastic resin soluble in the epoxy resin, and component [A], formed on one or both surfaces of the primary prepreg.

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