A composite material repair slurry and its preparation process

Abstract

The present invention relates to the technical field of composite materials, and specifically relates to a composite material repair slurry and a preparation process thereof. The composite material repair slurry includes component A and component B. Component A includes hydroxyacrylate monomer, polyethylene glycol monomethyl ether, polyisocyanate, acrylate monomer, blocking agent, and initiator; component B includes epoxy resin, reinforcing fiber, nano-particle, ethyl acetate, and phosphoric acid. The reinforcing fiber includes carbon fiber and asbestos fiber, and the weight ratio of carbon fiber to asbestos fiber is 1-4:1. Modifying isocyanate with acrylate monomer improves the crosslinking effect of isocyanate emulsion as a curing agent; reacting ethyl acetate, epoxy resin, and phosphoric acid to open the epoxy ring and react with isocyanate, further improving the curing crosslinking degree of epoxy resin and isocyanate, and greatly improving the bonding strength and heat resistance of the composite material repair slurry.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and particularly relates to a composite material repair slurry and a preparation process thereof. Background Art

[0002] Carbon fiber reinforced resin matrix composites are widely used in the fields of aviation, aerospace, spacecraft and missiles. Carbon fiber composite materials have a large modulus of elasticity and a small density, with high specific strength and specific stiffness, and have unique advantages that cannot be compared with metals. The specific strength and specific stiffness of carbon fiber composite materials modified with epoxy resin are significantly better than those of aluminum alloys. However, during the production process of carbon fiber composite materials, due to design changes or components being subjected to low-speed impacts, different degrees of damage may occur. In the carbon fiber composite material panel, there are phenomena such as fiber fracture, matrix fragmentation and interlayer delamination. In the carbon fiber composite material core, there will be phenomena such as honeycomb crushing or foam fragmentation, and debonding from the panel. Once the carbon fiber composite material components are severely damaged, not repairing them in time will not only affect work efficiency, but also may pose safety hazards.

[0003] Patent US4358480 discloses a method for repairing surface damage of a porous refractory substrate, including first hydrolyzing tetraethyl orthosilicate, and then curing the hydrolyzed tetraethyl orthosilicate under heating conditions, so as to use it as an inorganic adhesive. However, the tetraethyl orthosilicate adhesive of the repair material in this method is extremely prone to powdering at high temperatures, resulting in the failure of the repair material. Patent CN112848417A discloses a method for repairing cracks in a carbon fiber composite material product of a hydrogen fuel cell vehicle, using carbon fiber cloth and A / B two-component epoxy resin to repair the crack area of the carbon fiber composite material product. However, this technology has the disadvantages of cumbersome repair process operation steps and inconvenience for repair. Moreover, most of the A / B two-component epoxy resins have a heat resistance of about 100°C, and only some can reach about 280°C, with poor high-temperature resistance. Summary of the Invention

[0004] Aiming at the technical problems of low bonding strength, poor high-temperature resistance and cumbersome repair process operation of existing composite material repair materials, the present invention provides a composite material repair slurry and a preparation process thereof.

[0005] In the first aspect, the present invention provides a composite material repair slurry, including component A and component B.

[0006] By weight, component A includes: 5 - 15 parts of hydroxyacrylate monomer, 50 - 60 parts of polyethylene glycol monomethyl ether, 50 - 60 parts of polyisocyanate, 20 - 40 parts of acrylate monomer, 10 - 60 parts of blocking agent, 3 - 10 parts of initiator.

[0007] Component B includes: 30 - 40 parts of epoxy resin, 10 - 20 parts of reinforcing fiber, 4 - 10 parts of nanoparticles, 4 - 10 parts of ethyl acetate, and 2 - 5 parts of phosphoric acid; the reinforcing fiber includes carbon fiber and asbestos fiber, and the weight ratio of carbon fiber to asbestos fiber is 1 - 4:1.

[0008] Further, the polyisocyanate is one or a mixture of two or more of toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.

[0009] Further, the blocking agent is one or a mixture of two or more of 3,5 - dimethylpyrazole, acetone oxime, ethanol, diethyl malonate, and phenol.

[0010] Further, the initiator is one or more of potassium persulfate, ammonium persulfate, potassium persulfate - sodium bisulfite, or ammonium persulfate - sodium bisulfite.

[0011] Further, the nanoparticles are selected from one of nano - titanium dioxide, nano - aluminum oxide, and carbon nanotubes.

[0012] In a second aspect, the present invention also provides a preparation process for the above - mentioned composite material repair slurry, including the following steps:

[0013] (1) Prepare Component A: Mix hydroxyacrylate monomer, polyethylene glycol monomethyl ether, and polyisocyanate, stir evenly, protect with nitrogen, and react at 60 - 120°C for 1 - 5 hours; add the blocking agent and react at 50 - 70°C for 1 - 2 hours; add acrylate monomer, perform high - speed shearing at 1000 - 2000 rpm for 30 - 120 min, and then homogenize for 30 - 120 min; add the initiator and react at 60 - 90°C for 3 - 9 hours to obtain Component A;

[0014] (2) Prepare Component B: Soak the nanoparticles and reinforcing fiber with half of the mass of ethyl acetate for 48 - 56 h for later use; dissolve the epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, and stir at 45 - 50°C for more than 10 min; add the soaked nanoparticles and reinforcing fiber, and stir at 300 - 1500 rpm for 25 - 30 min to obtain Component B;

[0015] (3) Mix Component A and Component B, and stir while heating to prepare the composite material repair slurry.

[0016] Further, in step (1), the temperatures of high - speed shearing and homogenization are both maintained at 30 - 100°C.

[0017] Further, in step (2), after adding the soaked nanoparticles and reinforcing fiber, stir at a low speed of 300 - 500 rpm for 15 - 20 min, and then stir at a high speed of 1000 - 1500 rpm for 5 - 10 min.

[0018] Further, in step (3), the heating temperature is 50 - 80 °C, and the stirring speed is 1000 - 1200 rpm.

[0019] The beneficial effects of the present invention are as follows:

[0020] A composite material repair slurry provided by the present invention uses acrylate monomers to modify isocyanate, improving the cross-linking effect of isocyanate emulsion as a curing agent; reacting ethyl acetate, epoxy resin, and phosphoric acid to open the epoxy ring and react with isocyanate, further improving the curing cross-linking degree of epoxy resin and isocyanate, and greatly enhancing the bonding strength and heat resistance of the composite material repair slurry. In addition, adding nanoparticles can improve the efficiency of curing cross-linking; the reinforcing fibers are carbon fibers and asbestos fibers, so that the strength and heat resistance of the repair slurry after curing are improved simultaneously. Specific Embodiments

[0021] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0022] Example 1

[0023] A composite material repair slurry includes component A and component B.

[0024] By weight, component A includes: 15 parts of hydroxyacrylate monomer, 50 parts of polyethylene glycol monomethyl ether, 50 parts of toluene diisocyanate, 20 parts of acrylate monomer, 40 parts of 3,5-dimethylpyrazole, and 3 parts of potassium persulfate.

[0025] Component B includes: 30 parts of epoxy resin, 10 parts of reinforcing fiber, 4 parts of nano-titanium dioxide, 4 parts of ethyl acetate, and 2 parts of phosphoric acid; the reinforcing fiber includes carbon fiber and asbestos fiber, and the weight ratio of carbon fiber to asbestos fiber is 1:1.

[0026] Its preparation process is as follows:

[0027] (1) Preparation of Component A: Mix hydroxyl acrylate monomer, methoxypolyethylene glycol, and toluene diisocyanate, stir evenly, protect with nitrogen, and react at 60 - 120°C for 1 hour; add 3,5 - dimethylpyrazole and react at 50 - 70°C for 1 hour; add acrylate monomer, perform high - speed shearing at 1000 rpm for 120 min, then homogenize for 30 min. The temperatures of high - speed shearing and homogenization are both maintained at 30 - 100°C; add potassium persulfate and react at 60 - 90°C for 3 hours to obtain Component A;

[0028] (2) Preparation of Component B: Moisten nano - titanium dioxide and reinforcing fibers with half of the mass of ethyl acetate for 48 h for later use; dissolve epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, and stir at 45 - 50°C for 10 min; add the moistened nano - titanium dioxide and reinforcing fibers, stir at low speed of 300 rpm for 20 min, and stir at high speed of 1000 rpm for 10 min to obtain Component B;

[0029] (3) Mix Component A and Component B, heat and stir simultaneously. The heating temperature is 50 - 80°C and the stirring speed is 1000 rpm to prepare the composite material repair slurry.

[0030] Comparative Example 1

[0031] The difference from Example 1 is that in step (1), acrylate monomer is not added, and other treatments are the same.

[0032] Example 2

[0033] A composite material repair slurry, including Component A and Component B,

[0034] By weight, Component A includes: 5 parts of hydroxyl acrylate monomer, 50 parts of methoxypolyethylene glycol, 20 parts of diphenylmethane diisocyanate, 30 parts of hexamethylene diisocyanate, 20 parts of acrylate monomer, 10 parts of acetone oxime, 3 parts of ammonium persulfate;

[0035] Component B includes: 30 parts of epoxy resin, 10 parts of reinforcing fibers, 4 parts of carbon nanotubes, 4 parts of ethyl acetate, 2 parts of phosphoric acid; The reinforcing fibers include carbon fibers and asbestos fibers, and the weight ratio of carbon fibers to asbestos fibers is 2:1.

[0036] Its preparation process is as follows:

[0037] (1) Preparation of Component A: Mix hydroxyacrylate monomer, methoxypolyethylene glycol, diphenylmethane diisocyanate and hexamethylene diisocyanate, stir evenly, protect with nitrogen, and react at 60 - 120°C for 1 hour; add acetone oxime and react at 50 - 70°C for 2 hours; add acrylate monomer, perform high-speed shearing at 1200 rpm for 60 min, then homogenize for 60 min, and keep the temperature of high-speed shearing and homogenization at 30 - 100°C; add ammonium persulfate and react at 60 - 90°C for 6 hours to obtain Component A;

[0038] (2) Preparation of Component B: Moisten carbon nanotubes and reinforcing fibers with half of the mass of ethyl acetate for 50 h for later use; dissolve epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, and stir at 45 - 50°C for 11 min; add the moistened carbon nanotubes and reinforcing fibers, stir at low speed of 400 rpm for 18 min, and stir at high speed of 1200 rpm for 8 min to obtain Component B;

[0039] (3) Mix Component A and Component B, heat and stir simultaneously, with the heating temperature at 50 - 80°C and the stirring speed at 1200 rpm to prepare the composite material repair slurry.

[0040] Comparative Example 2

[0041] The difference from Example 2 is that in step (2), ethyl acetate and phosphoric acid are not used, and epoxy resin is directly mixed with carbon nanotubes and reinforcing fibers, with other treatments being the same.

[0042] Example 3

[0043] A composite material repair slurry, comprising Component A and Component B,

[0044] By weight, Component A includes: 10 parts of hydroxyacrylate monomer, 55 parts of methoxypolyethylene glycol, 55 parts of diphenylmethane diisocyanate, 30 parts of acrylate monomer, 35 parts of ethanol, 6 parts of potassium persulfate - sodium bisulfite;

[0045] Component B includes: 35 parts of epoxy resin, 15 parts of reinforcing fibers, 7 parts of nano-aluminum oxide, 7 parts of ethyl acetate, 3 parts of phosphoric acid; the reinforcing fibers include carbon fibers and asbestos fibers, and the weight ratio of carbon fibers to asbestos fibers is 3:1.

[0046] Its preparation process is as follows:

[0047] (1) Preparation of Component A: Mix hydroxyacrylate monomer, methoxypolyethylene glycol, and diphenylmethane diisocyanate, stir evenly, protect with nitrogen, and react at 60 - 120°C for 3 hours; add ethanol and react at 50 - 70°C for 1.5 hours; add acrylate monomer, perform high-speed shearing at 1500 rpm for 30 min, and then homogenize for 80 min. The temperatures of high-speed shearing and homogenization are both maintained at 30 - 100°C; add potassium persulfate - sodium bisulfite and react at 60 - 90°C for 6 hours to obtain Component A;

[0048] (2) Preparation of Component B: Moisten nano-aluminum oxide and reinforcing fibers with half of the mass of ethyl acetate for 48 - 56 h for later use; dissolve epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, and stir at 45 - 50°C for more than 10 min; add the moistened nano-aluminum oxide and reinforcing fibers, stir at low speed of 400 rpm for 18 min, and stir at high speed of 1200 rpm for 8 min to obtain Component B;

[0049] (3) Mix Component A and Component B, heat and stir simultaneously. The heating temperature is 50 - 80°C, and the stirring speed is 1100 rpm to obtain the composite material repair slurry.

[0050] Comparative Example 3

[0051] The difference from Example 3 is that nano-aluminum oxide is not added, and other treatments are the same.

[0052] Example 4

[0053] A composite material repair slurry, comprising Component A and Component B,

[0054] By weight, Component A includes: 10 parts of hydroxyacrylate monomer, 55 parts of methoxypolyethylene glycol, 55 parts of hexamethylene diisocyanate, 30 parts of acrylate monomer, 35 parts of diethyl malonate, 7 parts of ammonium persulfate - sodium bisulfite;

[0055] Component B includes: 35 parts of epoxy resin, 15 parts of reinforcing fibers, 8 parts of nano-aluminum oxide, 5 parts of ethyl acetate, 4 parts of phosphoric acid; The reinforcing fibers include carbon fibers and asbestos fibers, and the weight ratio of carbon fibers to asbestos fibers is 4:1.

[0056] Its preparation process is as follows:

[0057] (1) Preparation of Component A: Mix hydroxyacrylate monomer, methoxypolyethylene glycol, and hexamethylene diisocyanate, stir evenly, protect with nitrogen, and react at 60 - 120°C for 4 hours; add diethyl malonate and react at 50 - 70°C for 2 hours; add acrylate monomer, perform high-speed shearing at 3000 - 10000 rpm for 80 min, then homogenize for 80 min. The temperatures for high-speed shearing and homogenization are both maintained at 30 - 100°C; add ammonium persulfate - sodium bisulfite and react at 60 - 90°C for 5 hours to obtain Component A;

[0058] (2) Preparation of Component B: Moisten nano-aluminum oxide and reinforcing fibers with half of the mass of ethyl acetate for 50 h for later use; dissolve epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, and stir at 45 - 50°C for 10 min; add the moistened nano-aluminum oxide and reinforcing fibers, stir at low speed of 500 rpm for 15 min, and stir at high speed of 1200 rpm for 10 min to obtain Component B;

[0059] (3) Mix Component A and Component B, heat and stir simultaneously. The heating temperature is 50 - 80°C and the stirring speed is 1200 rpm to prepare the composite material repair slurry.

[0060] Comparative Example 4

[0061] The difference from Example 4 is that no reinforcing fibers are added.

[0062] Example 5

[0063] A composite material repair slurry, comprising Component A and Component B,

[0064] By weight, Component A includes: 15 parts of hydroxyacrylate monomer, 60 parts of methoxypolyethylene glycol, 30 parts of toluene diisocyanate, 30 parts of diphenylmethane diisocyanate, 40 parts of acrylate monomer, 60 parts of phenol, 10 parts of ammonium persulfate - sodium bisulfite;

[0065] Component B includes: 40 parts of epoxy resin, 20 parts of reinforcing fibers, 10 parts of carbon nanotubes, 10 parts of ethyl acetate, 5 parts of phosphoric acid; the reinforcing fibers include carbon fibers and asbestos fibers, and the weight ratio of carbon fibers to asbestos fibers is 2:1.

[0066] Its preparation process is as follows:

[0067] (1) Preparation of Component A: Mix hydroxyacrylate monomer, polyethylene glycol monomethyl ether and polyisocyanate, stir evenly, protect with nitrogen, and react at 60 - 120 °C for 3 hours; add toluene diisocyanate and diphenylmethane diisocyanate, and react at 50 - 70 °C for 1 hour; add acrylate monomer, perform high-speed shearing at 1200 rpm for 60 min, and then homogenize for 60 min. The temperatures of high-speed shearing and homogenization are both maintained at 30 - 100 °C; add ammonium persulfate - sodium bisulfite, and react at 60 - 90 °C for 3 hours to obtain Component A;

[0068] (2) Preparation of Component B: Soak carbon nanotubes and reinforcing fibers with half of the mass of ethyl acetate for 56 h for later use; dissolve epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, and stir at 45 - 50 °C for 10 min; add the soaked carbon nanotubes and reinforcing fibers, stir at low speed of 300 rpm for 20 min, and stir at high speed of 1000 rpm for 10 min to obtain Component B;

[0069] (3) Mix Component A and Component B, stir while heating, the heating temperature is 50 - 80 °C, and the stirring speed is 1000 rpm to prepare the composite material repair slurry.

[0070] Comparative Example 5

[0071] The difference from Example 5 is that the weight ratio of carbon fiber to asbestos fiber is 5:1, and other treatments are the same.

[0072] Example 6

[0073] A composite material repair slurry, comprising Component A and Component B,

[0074] By weight, Component A includes: 15 parts of hydroxyacrylate monomer, 60 parts of polyethylene glycol monomethyl ether, 30 parts of toluene diisocyanate, 30 parts of hexamethylene diisocyanate, 40 parts of acrylate monomer, 60 parts of diethyl malonate, 5 parts of ammonium persulfate, and 5 parts of potassium persulfate - sodium bisulfite;

[0075] Component B includes 40 parts of epoxy resin, 20 parts of reinforcing fibers, 10 parts of carbon nanotubes, 10 parts of ethyl acetate, and 5 parts of phosphoric acid; the reinforcing fibers include carbon fibers and asbestos fibers, and the weight ratio of carbon fibers to asbestos fibers is 3:1.

[0076] Its preparation process is as follows:

[0077] (1) Preparation of Component A: Mix hydroxyacrylate monomer, methoxypolyethylene glycol, and polyisocyanate, stir evenly, protect with nitrogen, and react at 60 - 120 °C for 5 hours; add a blocking agent and react at 50 - 70 °C for 2 hours; add acrylate monomer, perform high-speed shearing at 1500 rpm for 60 min, then homogenize for 120 min, and keep the temperature of high-speed shearing and homogenization at 30 - 100 °C; add an initiator and react at 60 - 90 °C for 9 hours to obtain Component A;

[0078] (2) Preparation of Component B: Moisten carbon nanotubes and reinforcing fibers with half of the mass of ethyl acetate for 56 h for later use; dissolve epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, and stir at 45 - 50 °C for 10 min; add the moistened carbon nanotubes and reinforcing fibers, stir at low speed of 500 rpm for 20 min, and stir at high speed of 1500 rpm for 10 min to obtain Component B;

[0079] (3) Mix Component A and Component B, stir while heating, with the heating temperature at 50 - 80 °C and the stirring speed at 1200 rpm to prepare the composite material repair slurry.

[0080] Example 7 Repair of Carbon Fiber Composite Materials

[0081] Test the performance of the composite material repair slurries prepared in Examples 1 - 6. Coat the composite material repair slurry on the carbon fiber composite material to be repaired, perform heat curing treatment at 120 °C for 24 h, and then conduct heat resistance and strength tests. The strength tests include the tensile strength and flexural strength at the repaired part of the carbon fiber composite material. The results are shown in Table 1. The carbon fiber composite material to be repaired is a material obtained by shearing a commercially available carbon fiber composite material. The commercially available carbon fiber composite material is purchased from Xinyu Chulu Trading Co., Ltd., and the product model is Guka Beast bike frame. The heat resistance performance is determined by the method shown in "GB / T 1634.2 - 2019 Plastics - Determination of Vicat softening temperature - Part 2: Plastics and hard rubbers"; the tensile strength test method is determined by the method shown in "GB / T 1040.1 - 2006 Plastics - Determination of tensile properties".

[0082] Table 1 Test Results of the Performance of Composite Material Repair Slurries

[0083]

[0084] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, those of ordinary skill in the art can make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions should all be within the scope of the present invention. / Any person skilled in the art within the technical scope disclosed by the present invention can easily conceive of changes or substitutions, which should all be covered by the protection scope of the present invention.

Claims

1. A composite material repair slurry, characterized in that, It includes Component A and Component B. By weight, Component A includes: 5 - 15 parts of hydroxyacrylate monomer, 50 - 60 parts of polyethylene glycol monomethyl ether, 50 - 60 parts of polyisocyanate, 20 - 40 parts of acrylate monomer, 10 - 60 parts of blocking agent, 3 - 10 parts of initiator. Component B includes: 30 - 40 parts of epoxy resin, 10 - 20 parts of reinforcing fiber, 4 - 10 parts of nano - particle, 4 - 10 parts of ethyl acetate, 2 - 5 parts of phosphoric acid; The reinforcing fiber includes carbon fiber and asbestos fiber, and the weight ratio of carbon fiber to asbestos fiber is 2:

1. Its preparation process includes the following steps: (1) Prepare Component A: Mix the hydroxyacrylate monomer, polyethylene glycol monomethyl ether and polyisocyanate, stir evenly, protect with nitrogen, react at 60 - 120 °C for 1 - 5 hours; Add the blocking agent and react at 50 - 70 °C for 1 - 2 hours; Add the acrylate monomer, perform high - speed shearing at 1000 - 2000 rpm for 30 - 120 min, and then homogenize for 30 - 120 min; Add the initiator and react at 60 - 90 °C for 3 - 9 hours to obtain Component A. (2) Prepare Component B: Moisten the nano - particle and reinforcing fiber with half of the mass of ethyl acetate for 48 - 56 h for standby; Dissolve the epoxy resin in the other half of the mass of ethyl acetate, add phosphoric acid, stir at 45 - 50 °C for more than 10 min; Add the moistened nano - particle and reinforcing fiber, stir at 300 - 1500 rpm for 25 - 30 min to obtain Component B; The nano - particle is carbon nanotube. (3) Mix Component A and Component B, heat and stir simultaneously to prepare the composite repair slurry.

2. The composite material repair slurry according to claim 1, wherein The polyisocyanate is one or a mixture of two or more of toluene diisocyanate, diphenylmethane diisocyanate and hexamethylene diisocyanate.

3. The composite material repair slurry according to claim 1, wherein The blocking agent is one or a mixture of two or more of 3,5 - dimethylpyrazole, acetone oxime, ethanol, diethyl malonate, phenol.

4. The composite material repair slurry according to claim 1, wherein The initiator is one or more of potassium persulfate, ammonium persulfate, potassium persulfate - sodium bisulfite or ammonium persulfate - sodium bisulfite.

5. The composite repair slurry according to claim 1, wherein, In step (1), the temperatures of high - speed shearing and homogenization are both maintained at 30 - 100 °C.

6. The composite material repair slurry according to claim 1, wherein, In step (2), after adding the moistened nano - particle and reinforcing fiber, stir at a low speed of 300 - 500 rpm for 15 - 20 min, and then stir at a high speed of 1000 - 1500 rpm for 5 - 10 min.

7. The composite material repair slurry according to claim 1, characterized in that, In step (3), the heating temperature is 50 - 80 °C, and the stirring speed is 1000 - 1200 rpm.

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