Epoxy resin composition for winding high-strength carbon fibers and preparation method of epoxy resin composition

Abstract

The invention relates to the technical field of epoxy resin, in particular to an epoxy resin composition for high-strength carbon fiber winding and a preparation method thereof.The preparation method of the epoxy resin composition comprises the steps that S1, modified epoxy resin, a compatilizer, a retarder, a defoaming agent and nano filler are added into a reaction kettle and mixed and stirred, and a mixture A is obtained; s2, a composite curing agent is added into the mixture A, stirring and mixing are conducted, and the epoxy resin composition is obtained and has the advantages of being appropriate in viscosity, good in heat resistance, excellent in impact resistance, large in bending strength, small in volume shrinkage rate in the curing process, moderate in gelation time and capable of being wound with carbon fibers conveniently to prepare the composite material.

Description

Technical Field

[0001] The present application relates to the technical field of epoxy resins, and more specifically, to an epoxy resin composition for high-strength carbon fiber winding and a preparation method thereof. Background Art

[0002] Carbon fiber winding molding technology is one of the key ways to prepare high-performance carbon fiber composites. In this process, the resin matrix and carbon fiber work closely together to effectively transfer the load to the fiber, which not only can bring out the excellent mechanical properties of carbon fiber, but also can make the load evenly distributed and prevent fiber damage. Therefore, the composite materials prepared by carbon fiber winding molding technology have extremely broad application prospects in many fields such as aerospace, petrochemical, and automobile.

[0003] Due to the high chemical activity of the epoxy groups in epoxy resin, it can undergo a ring-opening reaction with a variety of compounds containing active hydrogen, and then solidify and cross-link to form a three-dimensional network structure. This thermosetting resin is favored for its excellent physical properties and bonding properties, and it also has the characteristics of simple operation process and flexible curing process. However, the molecular chain of traditional epoxy resin is mainly composed of a cross-linked structure formed by the reaction of rigid epoxy groups and curing agents. This highly cross-linked structure makes it difficult for the molecular chain segments of epoxy resin to deform to absorb energy when subjected to external force. It is brittle and has poor fatigue resistance, which shortens the service life of epoxy resin materials. In addition, as the temperature rises, the thermal motion of the molecular chain intensifies, the stability of the cross-linked structure decreases, and even chemical bonds are broken, resulting in a large curing shrinkage rate, which causes deformation, warping, and even cracks in the product.

[0004] The fiber winding molding technology has high requirements on the viscosity, wettability and operability time of the epoxy resin matrix. If the viscosity of the epoxy resin matrix is ​​too high at the winding temperature, or the viscosity increases too fast, the wettability of the carbon fiber will deteriorate, which will lead to the deterioration of the interface bonding force between the epoxy resin matrix and the fiber, and the performance of the prepared product will deteriorate. Therefore, it is urgent to prepare an epoxy resin composition for carbon fiber winding with moderate viscosity, long operability time, high interface bonding force, good heat resistance and impact resistance. Summary of the invention

[0005] In order to solve the technical problems mentioned in the background technology, the present application provides an epoxy resin composition for high-strength carbon fiber winding and a preparation method thereof.

[0006] In a first aspect, the present application provides an epoxy resin composition for high-strength carbon fiber winding, which adopts the following technical solution: An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45-50 parts of modified epoxy resin, 6-8 parts of composite curing agent, 1-2 parts of compatibilizer, 0.1-0.5 parts of retarder, 0.5-1 parts of defoamer and 1-2 parts of nano filler.

[0007] Preferably, the preparation of the modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100-120°C, add aluminum chloride, and react for 4-8 hours under stirring and nitrogen protection to obtain a prepolymer; (2) Add polyglycerol and polyether polyol to the prepolymer, stir evenly, then add triethylamine, heat to 120-150°C, react for 6-10 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin.

[0008] Preferably, in step (1), the mass ratio of nitrile rubber, carboxyl nitrile rubber and epichlorohydrin is 25-35:5-8:42-48.

[0009] Preferably, in step (2), the mass ratio of the prepolymer, polyglycerol and polyether polyol is 40-70:15-25:5-8.

[0010] Preferably, the polyglycerol in step (2) consists of diglycerol and tetraglycerol in a mass ratio of 8-9:1-1.2.

[0011] Preferably, the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4-6:1-1.2.

[0012] Preferably, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70-75°C, react for 2-3h, then add maleic anhydride, continue to react for 1-2h, cool naturally, remove the solvent by rotary evaporation, and then dry at 50-60°C for 6-8h to obtain a compatibilizer.

[0013] Preferably, the mass ratio of the polyurethane, the amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20-30; 1-3: 40-50: 0.1-0.5: 3-5.

[0014] Preferably, the polyurethane is thermoplastic polyurethane.

[0015] Preferably, the amino-containing silane coupling agent is one or more of N-aminoethyl-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and 3-aminopropyltriethoxysilane.

[0016] Preferably, the retarder is one or more of trisodium phosphate, citric acid, diethanolamine, triethanolamine and hydroquinone.

[0017] Preferably, the defoaming agent is one of polydimethylsiloxane, polyoxyethylene-polyoxypropylene block copolymer, and high carbon alcohol polyether defoaming agent.

[0018] Preferably, the nano filler is one of nano calcium carbonate, nano silicon dioxide and nano alumina.

[0019] In a second aspect, the present application also provides a method for preparing an epoxy resin composition for high-strength carbon fiber winding, comprising the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reaction kettle, heat and control the temperature of the reaction kettle to 45-50°C, control the stirring speed to 200-300rpm, mix and stir for 0.5-1h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30-50° C. for 20-40 minutes to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0020] In summary, this application has the following beneficial effects: The present application introduces two kinds of nitrile rubbers in the preparation process of preparing modified epoxy resin prepolymer, wherein the nitrile rubber has good flexibility, and its molecular chain can provide a certain elastic deformation ability, and can absorb energy by stretching and retracting the chain segment when subjected to external force impact, and the carboxyl nitrile rubber contains a large number of carboxyl groups, which can participate in the reaction to form a more complex cross-linked network. When the two rubbers exist at the same time, in the prepolymer formation process, the flexible chain segment of the nitrile rubber can be used as the "main force" of energy absorption, and the carboxyl nitrile rubber can react chemically with epichlorohydrin and other components in the subsequent steps due to the presence of carboxyl groups, fix the chain segment position, form a stable chemical cross-linked structure, and prevent deformation under stress. The two nitrile rubbers are used together to significantly improve the toughness of the material, and will not limit the activity space of the molecular chain due to excessive cross-linking, making the material hard and brittle, and reducing toughness.

[0021] In the process of preparing the modified epoxy resin of the present application, when polyglycerol and polyether polyol are added at the same time, they can play a synergistic role. The cross-linked structure formed by polyglycerol can provide a certain strength support for the material, and the flexible molecular chain of polyether polyol can better disperse the stress on this basis. The cross-linked structure of polyglycerol and the stable molecular chain of polyether polyol work together to better resist high temperature and better adjust the viscosity and hardness of the epoxy resin.

[0022] When the polyglycerol of the present application adopts diglycerol and tetraglycerol, they can complement each other. The cross-linked structure formed by diglycerol can improve the strength of the material, and the long-chain structure of tetraglycerol can better play its flexibility advantage on this basis, enhance the toughness of the material, and the cross-linked network formed by the reaction of diglycerol and prepolymer can limit the movement of molecular chains to a certain extent under high temperature environment. The product after the reaction of hydroxyl and epoxy groups in its molecular structure has certain thermal stability, which helps to improve the heat resistance of the material. The long-chain molecules of tetraglycerol can maintain the structural stability of the material through the interaction between molecular chains at high temperatures, and improve the wettability of epoxy resin.

[0023] This application first introduces nitrile rubber and carboxyl nitrile rubber to react with epichlorohydrin to form a prepolymer, and constructs a basic network structure with a rubber elastic phase. The molecular chains of nitrile rubber and carboxyl nitrile rubber can play a role of physical crosslinking and flexible support in this prepolymer network. After the prepolymer is formed, polyglycerol and polyether polyol are introduced to react with the active groups (such as epoxy groups, etc.) in the prepolymer. Polyglycerol can react with the epoxy groups in the prepolymer through its hydroxyl groups to form more crosslinking points and increase the crosslinking density of the network. The ether bonds and hydroxyl groups of the polyether polyol can further modify the network structure on this basis to make it more complex and perfect. This method of first constructing the basic network and then perfecting it can make the final modified epoxy resin have a more uniform and stable structure, and the toughness, heat resistance and bonding properties are significantly improved.

[0024] When the present application utilizes dicyandiamide and triglycidyl-p-aminophenol to form a composite curing agent, the reaction activity characteristics of the two can be combined. In the initial stage of curing, triglycidyl-p-aminophenol plays a role first, so that the epoxy resin begins to cure at a lower temperature, quickly forms a preliminary cross-linked network, and prevents the resin from flowing or deforming before it is completely cured. As the temperature rises, dicyandiamide further improves the cross-linked structure, making the curing reaction more sufficient. This step-by-step curing method can effectively control the curing reaction rate, which not only meets the requirements for the initial fluidity of the resin during the process operation, but also can achieve complete curing at an appropriate temperature. The two curing agents work synergistically to reduce the shrinkage rate of curing.

[0025] The application utilizes the good flexibility and elasticity possessed by the polyurethane processed by silane coupling agent, and a flexible transition layer can be formed between epoxy resin and nanofiller. This helps to alleviate the internal stress caused by the large modulus difference between epoxy resin and nanofiller, reduces the stress concentration at the interface, thereby improving the overall mechanical properties of composite material, such as the impact resistance and fatigue resistance of reinforced composite material, and the addition of maleic anhydride further improves the compatibility and reactivity of compatibilizer and epoxy resin. Maleic anhydride can react with the active groups such as hydroxyl in epoxy resin by esterification, increases the chemical crosslinking point between compatibilizer and epoxy resin, further strengthens the interface bonding, and makes the interface bonding of composite material tighter. DETAILED DESCRIPTION

[0026] The present application is further described in detail below with reference to the embodiments.

[0027] The nitrile rubber (brand name: SH-P830F) used in the examples and comparative examples of the present application was purchased from Dongguan Mingyuan Plastic Co., Ltd.; carboxylated nitrile rubber was purchased from Shanghai Xiangxing Industrial Co., Ltd.; diglycerol (article number: 94423-19-5) and tetraglycerol were purchased from Nantong Yuanrong Chemical Co., Ltd.; polyether polyol (model number: 4110) was purchased from Shandong Huibang New Materials Technology Co., Ltd.; dicyandiamide was purchased from Shandong Zhijia Chemical Technology Co., Ltd.; triglycidyl p-aminophenol (model number: AFG-90) was purchased from Wuhan Kamik Technology Co., Ltd.; polyurethane (brand name: UD-64D10) was purchased from Shanghai Tingyuan Plastic Technology Co., Ltd.; N-aminoethyl-3-aminopropyltriethoxysilane (model number: 225-806-1) was purchased from Wuhan Maikairui Chemical Co., Ltd.

[0028] Embodiments 1-3 provide an epoxy resin composition for high-strength carbon fiber winding and a preparation method thereof.

[0029] Example 1 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of composite curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 1 part of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4:1; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0030] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 300 rpm, react for 4 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 25:5:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, heat to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8:1.

[0031] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add maleic anhydride, continue to react for 1 hour, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0032] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0033] Example 2 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 48 parts of modified epoxy resin, 7 parts of composite curing agent, 1.5 parts of compatibilizer, 0.3 parts of retarder, 0.8 parts of defoamer, and 1.5 parts of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 5:1.1; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0034] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 110°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 350 rpm, react for 6 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 30:7:45:210:2; (2) Add polyglycerol and polyether polyol to the prepolymer, stir evenly, set the stirring speed to 250 rpm, add triethylamine, raise the temperature to 135°C, react for 8 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 65:20:6:2; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8.5:1.1.

[0035] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 72°C, react for 2.5 hours, then add maleic anhydride, continue to react for 1.5 hours, cool naturally, remove the solvent by rotary evaporation, and then dry at 55°C for 7 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 25; 2:45:0.3:4; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0036] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 48°C, control the stirring speed to 250 rpm, mix and stir for 0.8 h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 40° C. for 30 minutes at a stirring speed of 500 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0037] Example 3 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 50 parts of modified epoxy resin, 8 parts of composite curing agent, 2 parts of compatibilizer, 0.5 parts of retarder, 1 part of defoamer, and 2 parts of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 6:1.2; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0038] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 120°C, add aluminum chloride, stir and nitrogen protection at a stirring speed of 400 rpm, react for 8 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 35:8:48:220:3; (2) Add polyglycerol and polyether polyol to the prepolymer, stir evenly, set the stirring speed to 300 rpm, add triethylamine, raise the temperature to 150°C, react for 10 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 70:25:8:3; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 9:1.2.

[0039] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 75°C, react for 3 hours, then add maleic anhydride, continue to react for 2 hours, cool naturally, remove the solvent by rotary evaporation, and then dry at 60°C for 8 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 30; 3:50:0.5:5; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0040] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 50°C, control the stirring speed to 300 rpm, mix and stir for 1 hour to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 50° C. for 40 minutes at a stirring speed of 600 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0041] Comparative Example 1 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of composite curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 1 part of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4:1; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0042] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber and epichlorohydrin to toluene, heat to 100°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 300 rpm, react for 4 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 30:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, heat to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8:1.

[0043] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add maleic anhydride, continue to react for 1 hour, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0044] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0045] Comparative Example 2 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of composite curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 1 part of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4:1; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0046] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Carboxylated nitrile rubber and epichlorohydrin are added to toluene, the temperature is raised to 100°C, aluminum chloride is added, and the mixture is stirred at a speed of 300 rpm under nitrogen protection for 4 hours to obtain a prepolymer, wherein the mass ratio of carboxylated nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 30:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, heat to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8:1.

[0047] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add maleic anhydride, continue to react for 1 hour, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0048] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0049] Comparative Example 3 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of composite curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 1 part of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4:1; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0050] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 300 rpm, react for 4 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 25:5:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, raise the temperature to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is diglycerol.

[0051] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add maleic anhydride, continue to react for 1 hour, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0052] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0053] Comparative Example 4 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of composite curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 1 part of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4:1; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0054] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 300 rpm, react for 4 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 25:5:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, raise the temperature to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is tetraglycerol.

[0055] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add maleic anhydride, continue to react for 1-2 hours, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0056] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0057] Comparative Example 5 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 1 part of nanofiller; wherein the curing agent is dicyandiamide; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0058] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 300 rpm, react for 4 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 25:5:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, heat to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8:1.

[0059] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add maleic anhydride, continue to react for 1 hour, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0060] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0061] Comparative Example 6 An epoxy resin composition for high-strength carbon fiber winding comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 1 part of nanofiller; wherein the curing agent is triglycidyl p-aminophenol; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0062] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 300 rpm, react for 4 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 25:5:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, heat to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8:1.

[0063] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add maleic anhydride, continue to react for 1 hour, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0064] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0065] Comparative Example 7 A high-strength carbon fiber winding epoxy resin composition comprises the following raw materials in parts by weight: 45 parts of modified epoxy resin, 6 parts of composite curing agent, 1 part of compatibilizer, 0.1 part of retarder, 0.5 part of defoamer, and 2 parts of nanofiller; wherein the composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4:1; the retarder is trisodium phosphate; the defoamer is polydimethylsiloxane; and the nanofiller is nano silicon dioxide.

[0066] Wherein, the preparation of modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100°C, add aluminum chloride, stir and protect with nitrogen at a stirring speed of 300 rpm, react for 4 hours to obtain a prepolymer, wherein the mass ratio of nitrile rubber, carboxyl nitrile rubber, epichlorohydrin, toluene and aluminum chloride is 25:5:42:200:1; (2) Add polyglycerol and polyether polyol to the prepolymer and stir evenly at a stirring speed of 200 rpm, add triethylamine, heat to 120°C, react for 6 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin, wherein the mass ratio of the prepolymer, polyglycerol, polyether polyol and triethylamine is 40:15:5:1; the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8:1.

[0067] Wherein, the preparation of the compatibilizer comprises the following steps: Add polyurethane and maleic anhydride to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70°C, react for 2 hours, then add amino-containing silane coupling agent, continue to react for 1 hour, cool naturally, remove the solvent by rotary evaporation, and then dry at 50°C for 6 hours to obtain a compatibilizer, wherein the mass ratio of polyurethane, amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20; 1:40:0.1:3; polyurethane is thermoplastic polyurethane, and the amino-containing silane coupling agent is N-aminoethyl-3-aminopropyltriethoxysilane.

[0068] A method for preparing an epoxy resin composition for high-strength carbon fiber winding comprises the following steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reactor, heat and control the temperature of the reactor to 45°C, control the stirring speed to 200 rpm, mix and stir for 0.5 h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30° C. for 20 minutes at a stirring speed of 400 rpm, to obtain an epoxy resin composition for high-strength carbon fiber winding.

[0069] Performance Testing The high-strength carbon fiber winding epoxy resin composition prepared in Examples 1-3 and Comparative Examples 1-7 was placed in a glue tank, heated to 60° C., and the carbon fiber was impregnated and wound to obtain a product; the product was placed in an oven, heated to 100° C. at a heating rate of 8° C. / min, kept warm for 60 minutes, and then heated to 150° C. at a heating rate of 5° C. / min, kept warm for 90 minutes, to obtain a final product; Viscosity: The viscosity of the epoxy resin composition at 60°C was tested in accordance with the national standard GB / T 10247-2008; Gel time: Pour the epoxy resin composition into a 150°C hot plate and measure the time from pouring to wire drawing; Glass transition temperature: The epoxy resin composition is tested according to the international standard ASTM E1640-23; Total volume shrinkage: Test the final product in accordance with the national standard GB / T 24148.9-2014; Impact strength: The final product is tested in accordance with the national standard GB / T 2567-2008; Bending strength: Test the final product in accordance with the national standard GB / T 2567-2008; The test results are shown in Table 1.

[0070] Table 1 Performance parameters

[0071] As can be seen from Table 1, the high-strength carbon fiber winding epoxy resin composition prepared in the present application has suitable viscosity, good heat resistance, excellent impact resistance, high bending strength, small volume shrinkage during the curing process, and moderate gelation time, which is convenient for winding with carbon fiber to prepare a composite material.

[0072] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An epoxy resin composition for high-strength carbon fiber winding, characterized in that: The invention comprises the following raw materials in parts by weight: 45-50 parts of modified epoxy resin, 6-8 parts of composite curing agent, 1-2 parts of compatibilizer, 0.1-0.5 parts of retarder, 0.5-1 parts of defoamer and 1-2 parts of nano filler.

2. The epoxy resin composition for high-strength carbon fiber winding according to claim 1, characterized in that: The preparation of the modified epoxy resin comprises the following steps: (1) Add nitrile rubber, carboxyl nitrile rubber and epichlorohydrin into toluene, heat to 100-120°C, add aluminum chloride, and react for 4-8 hours under stirring and nitrogen protection to obtain a prepolymer; (2) Add polyglycerol and polyether polyol to the prepolymer, stir evenly, then add triethylamine, heat to 120-150°C, react for 6-10 hours under stirring and nitrogen protection, cool to room temperature, and distill under reduced pressure to obtain a modified epoxy resin.

3. The epoxy resin composition for high-strength carbon fiber winding according to claim 2, characterized in that: In the step (1), the mass ratio of nitrile rubber, carboxyl nitrile rubber and epichlorohydrin is 25-35:5-8:42-48.

4. The epoxy resin composition for high-strength carbon fiber winding according to claim 2, characterized in that: In the step (2), the mass ratio of the prepolymer, polyglycerol and polyether polyol is 40-70:15-25:5-8.

5. The epoxy resin composition for high-strength carbon fiber winding according to claim 2, characterized in that: In the step (2), the polyglycerol is composed of diglycerol and tetraglycerol in a mass ratio of 8-9:1-1.

2.

6. The epoxy resin composition for high-strength carbon fiber winding according to claim 1, characterized in that: The composite curing agent is composed of dicyandiamide and triglycidyl p-aminophenol in a mass ratio of 4-6:1-1.

2.

7. The epoxy resin composition for high-strength carbon fiber winding according to claim 1, characterized in that: The preparation of the compatibilizer comprises the following steps: Add polyurethane and amino-containing silane coupling agent to toluene, mix evenly, add dibutyltin dilaurate, pass nitrogen protection, heat to 70-75°C, react for 2-3h, then add maleic anhydride, continue to react for 1-2h, cool naturally, remove the solvent by rotary evaporation, and then dry at 50-60°C for 6-8h to obtain a compatibilizer.

8. The epoxy resin composition for high-strength carbon fiber winding according to claim 7, characterized in that: The mass ratio of the polyurethane, the amino-containing silane coupling agent, toluene, dibutyltin dilaurate and maleic anhydride is 20-30; 1-3: 40-50: 0.1-0.5: 3-5; the polyurethane is thermoplastic polyurethane; the amino-containing silane coupling agent is one or more of N-aminoethyl-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and 3-aminopropyltriethoxysilane.

9. The epoxy resin composition for high-strength carbon fiber winding according to claim 1, characterized in that: The retarder is one or more of trisodium phosphate, citric acid, diethanolamine, triethanolamine and hydroquinone; the defoamer is one of polydimethylsiloxane, polyoxyethylene-polyoxypropylene block copolymer and high-carbon alcohol polyether defoamer; the nano filler is one of nano calcium carbonate, nano silicon dioxide and nano aluminum oxide.

10. A method for preparing the epoxy resin composition for high-strength carbon fiber winding according to any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: Step S1, modifying epoxy resin, compatibilizer, retarder, defoamer and nanofiller Add into the reaction kettle, heat and control the temperature of the reaction kettle to 45-50°C, control the stirring speed to 200-300rpm, mix and stir for 0.5-1h to obtain mixed material A; Step S2, adding the composite curing agent into the mixture A, stirring and mixing at 30-50° C. for 20-40 minutes to obtain an epoxy resin composition for high-strength carbon fiber winding.

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