Preparation method of glass fiber prepreg and PU composite material

Abstract

The invention relates to the technical field of synthetic leather composite materials, and particularly discloses a preparation method of a glass fiber prepreg and PU composite material, which comprises the following steps: pre-impregnating a dopamine / boron nitride modified glass fiber cloth with polyurethane synthesized by polybutylene adipate glycol, polypropylene oxide glycol and diphenylmethane diisocyanate as a resin matrix; the prepreg is filled with fillers such as silicon dioxide modified titanium dioxide, the composite material formed by hot-pressing and compounding the prepreg and the PU synthetic leather is excellent in performance, a hot melt adhesive film is not needed in the forming process, the technological process is simplified, the production efficiency is improved, errors caused by manual lamination are reduced, the percent of pass is improved, and the production cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of synthetic leather composite materials, in particular to a method for preparing a glass fiber prepreg and PU composite material. Background Art

[0002] Prepreg, also known as molding compound, is a material formed by impregnating fibers or fabrics with a resin matrix and then combining them. It can be used for ply design and making various composite materials. At present, the manufacture of prepreg has become a special process technology. However, in the conventional process of using prepreg to prepare composite materials, it is necessary to pre-paste the hot melt adhesive sheet on the base material sheet before hot pressing and composite molding with the prepreg. This causes the hot melt adhesive sheet to be crooked or the hot melt adhesive sheet to fall off during the production process, resulting in the composite materials produced not being bonded together or the composite materials being debonded and cracked, resulting in an increase in the product failure rate and increasing the production cost of the enterprise. Therefore, the present invention develops a glass fiber prepreg and PU composite material that does not require pre-pasting of hot melt adhesive and has excellent composite material performance. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a glass fiber prepreg and PU composite material, and to develop a glass fiber prepreg and PU composite material that does not require pre-attachment of hot melt adhesive and has excellent composite material properties.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A preparation method of a glass fiber prepreg and PU composite material, the preparation method comprising:

[0006] The PU synthetic leather and the glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 0.8 to 1.2 MPa, a time of 25 to 35 minutes, and a temperature of 90 to 130°C. After hot-pressing and compounding, the material is cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 0.8 to 1.2 MPa, and the secondary shaping time is 5 to 15 minutes. After shaping, the material is taken out to obtain a glass fiber prepreg and PU composite material.

[0007] As a limitation of the present invention, the preparation method of the glass fiber prepreg resin material is:

[0008] After dopamine / boron nitride modified glass fiber cloth is placed in the mold, polyurethane prepolymer, pentaerythritol acrylate, acrylate resin and 1,4-butanediol are mixed and stirred evenly, melamine, stannous octoate and silica-modified titanium dioxide filler are added, and then injected into the mold, and reacted at 80-90°C and a vacuum degree of 80-120Pa for 3-5 hours. After the reaction is completed, nitrogen is introduced to restore normal pressure, and the mold is taken out after cooling, trimmed and cut into shape, sealed and packaged, and cured at 80-90°C for 1-3 days to obtain glass fiber prepreg resin material.

[0009] As a limitation of the present invention, the preparation of glass fiber prepreg resin material includes, by mass, 84.4-84.8 parts of polyurethane prepolymer, 5.90-5.95 parts of pentaerythritol acrylate, 8.44-8.46 parts of acrylate resin, 0.89-0.93 parts of 1,4-butanediol, 1.5-2.5 parts of melamine, 0.4-0.8 parts of stannous octoate, and 1.0-2.0 parts of silica-modified titanium dioxide filler.

[0010] As a limitation of the present invention, the preparation method of the dopamine / boron nitride modified glass fiber cloth is:

[0011] The glass fiber cloth is heated at 500-700°C for 0.5-1.5h, cooled to room temperature, washed with deionized water to obtain pretreated glass fiber cloth, trihydroxymethylaminomethane, dopamine hydrochloride and deionized water are mixed and stirred evenly to obtain dopamine impregnation solution, hexagonal boron nitride and deionized water are mixed to obtain hexagonal boron nitride impregnation solution, the pretreated glass fiber cloth is immersed in the dopamine impregnation solution, immersed at 25-30°C for 14-18h, the glass fiber cloth is taken out, dried at 45-55°C, added to the hexagonal boron nitride impregnation solution, immersed at 25-30°C for 1-3h, taken out after impregnation, and dried at 45-55°C to obtain dopamine / boron nitride modified glass fiber cloth.

[0012] As a limitation of the present invention, the preparation method of the polyurethane prepolymer is:

[0013] Polybutylene adipate diol, polyoxypropylene diol and diphenylmethane diisocyanate are vacuum dried at 95-105° C. for 0.5-1.5 h, mixed, stirred evenly, and reacted at 70-80° C. for 2-4 h to obtain a polyurethane prepolymer.

[0014] As a limitation of the present invention, the preparation method of the pentaerythritol acrylate is:

[0015] Acrylic acid, pentaerythritol and toluene are mixed and stirred evenly, p-toluenesulfonic acid and hydroquinone / anhydrous copper sulfate complex are added, reflux reaction is carried out at 110-130°C for 3-5 hours, cooled, saturated brine is added, allowed to stand for stratification, filtered, washed with sodium hydroxide solution and deionized water, and distilled under reduced pressure to obtain pentaerythritol acrylate.

[0016] As a limitation of the present invention, the preparation of pentaerythritol acrylate includes 14.2 to 14.6 parts of acrylic acid, 13.4 to 13.8 parts of pentaerythritol, 1.0 to 1.4 parts of p-toluenesulfonic acid, and 1.0 to 1.4 parts of a hydroquinone / anhydrous copper sulfate mixture, calculated by weight.

[0017] As a limitation of the present invention, the preparation method of the silica-modified titanium dioxide filler is:

[0018] Titanium dioxide, ethanol, ammonia water and deionized water are mixed, and ultrasonically dispersed for 20 to 40 minutes to obtain an alkaline titanium dioxide suspension. Ethanol and tetraethyl orthosilicate are mixed, stirred evenly, and slowly added dropwise to the alkaline titanium dioxide suspension. The mixture is reacted at 75 to 85° C. and 150 to 250 rpm for 5 to 7 hours, centrifuged, washed with deionized water, and dried at 50 to 70° C. to obtain a silica-modified titanium dioxide filler.

[0019] As a limitation of the present invention, the preparation of the silica-modified titanium dioxide filler includes 9 to 11 parts of titanium dioxide, 1.85 to 1.90 parts of ammonia water, and 0.75 to 0.80 parts of ethyl orthosilicate, calculated by weight.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The polyurethane prepolymer is synthesized by using two diols, polybutylene adipate diol and polyoxypropylene diol, and diphenylmethane diisocyanate. The polymer chain contains both -COOC-groups and -COC-groups with relatively small polarity, which not only make the resin matrix have certain bonding strength but also have certain flexibility and wettability, and can better combine with glass fiber. At the same time, pentaerythritol acrylate is added to the resin matrix for modification, which reacts with the isocyanate groups in the prepolymer, increases the number of polar bonds, increases the intermolecular force, and plays the role of chain extension, is embedded in the polymer molecules, increases the molecular weight of the polymer, and improves the viscosity of the resin. In addition, the acrylate group in pentaerythritol acrylate has good compatibility with the resin matrix, which can improve the wettability between the resin and the adherend and enhance the bonding force between the resin and the adherend.

[0022] After the glass fiber cloth is impregnated with dopamine and boron nitride solution, dopamine and boron nitride are coated on the smooth surface of the glass fiber, amino and oxygen-containing functional groups are introduced, the roughness of the glass fiber surface and the number of active functional groups are increased, the entanglement and hydrogen bonding with the resin matrix are improved, the interfacial bonding strength between the glass fiber and the resin matrix is ​​improved, and the mechanical properties of the polymer are enhanced.

[0023] Using tetraethyl orthosilicate as the silicon source, silicon dioxide is deposited on the surface of titanium dioxide, which hinders the contact between titanium dioxide and organic matter. While retaining the ultraviolet absorption and blocking ability of titanium dioxide, it inhibits the catalytic degradation of titanium dioxide on the matrix resin, improves the dispersibility and stability of titanium dioxide in the matrix resin, and enhances the mechanical properties of the polymer. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Wet polyurethane resin (100% modulus: 10MPa) was provided by Jining Huakai, plain woven fabric (115g / m 2 ) was provided by Shaanxi Xinxing, wood powder (325 mesh) was provided by Jiangsu Jinyufeng, glass fiber cloth (200g / m 2 ) was provided by Zhejiang Zhengxin, trimethylolaminomethane (T110598) was provided by Shanghai Aladdin, polybutylene adipate diol (Mn=3000), polyoxypropylene glycol (Mn=2000), diphenylmethane diisocyanate (M813280), hydroquinone / anhydrous copper sulfate compound (mass ratio 1:1), tetraethyl orthosilicate (T819505), titanium dioxide (rutile type, 60nm), S-80 surfactant (0.994g / mL) were provided by Shanghai Maclean, and acrylate resin (BR113, Mw=30000) was provided by Shanghai Kaiyin.

[0026] Embodiment 1: A method for preparing a glass fiber prepreg and PU composite material, specifically:

[0027] Step 1: Preparation of dopamine / boron nitride modified glass fiber cloth

[0028] By mass, the glass fiber cloth was heated at 600°C for 1h, cooled to room temperature, washed with deionized water to obtain a pretreated glass fiber cloth, 1.22 parts of trimethylolaminomethane, 0.8 parts of dopamine hydrochloride and 400 parts of deionized water were mixed and stirred evenly to obtain a dopamine impregnation solution, 3 parts of hexagonal boron nitride and 400 parts of deionized water were mixed to obtain a hexagonal boron nitride impregnation solution, 30 parts of the pretreated glass fiber cloth were immersed in 402.2 parts of the dopamine impregnation solution, immersed at 27°C for 16h, the glass fiber cloth was taken out, dried at 50°C, added to 403 parts of the hexagonal boron nitride impregnation solution, immersed at 27°C for 2h, taken out after the impregnation was completed, and dried at 50°C to obtain dopamine / boron nitride modified glass fiber cloth.

[0029] Step 2: Preparation of silica-modified titania filler

[0030] By mass, 10 parts of titanium dioxide, 81.3 parts of ethanol, 1.87 parts of ammonia water, and 3.2 parts of deionized water were mixed, and ultrasonically dispersed for 30 minutes to obtain an alkaline titanium dioxide suspension. 40.65 parts of ethanol and 0.78 parts of tetraethyl orthosilicate were mixed, stirred evenly, and slowly added dropwise to 96.37 parts of the alkaline titanium dioxide suspension. The mixture was reacted at 80°C and 200 rpm for 6 hours, centrifuged, washed with deionized water, and dried at 60°C to obtain a silica-modified titanium dioxide filler.

[0031] Step 3: Preparation of Pentaerythritol Acrylate

[0032] Mix 14.4 parts of acrylic acid, 13.6 parts of pentaerythritol and 30 parts of toluene by mass, stir evenly, add 1.2 parts of p-toluenesulfonic acid and 1.2 parts of hydroquinone / anhydrous copper sulfate compound, reflux at 120°C for 4 hours, cool, add saturated brine, stand for stratification, filter, wash with sodium hydroxide solution and deionized water, and distill under reduced pressure to obtain pentaerythritol acrylate.

[0033] Step 4: Preparation of polyurethane prepolymer

[0034] 14.2 parts of polybutylene adipate diol, 3.1 parts of polyoxypropylene diol and 25 parts of diphenylmethane diisocyanate were vacuum dried at 100° C. for 1 hour, mixed, stirred evenly and reacted at 75° C. for 3 hours to obtain a polyurethane prepolymer.

[0035] Step 5: Prepare glass fiber prepreg resin material.

[0036] After dopamine / boron nitride modified glass fiber cloth is placed in the mold, 84.6 parts of polyurethane prepolymer, 5.92 parts of pentaerythritol acrylate, 8.46 parts of acrylate resin, and 0.91 parts of 1,4-butanediol are mixed and stirred evenly. After adding 2 parts of melamine, 0.6 parts of stannous octoate, and 1.5 parts of silica-modified titanium dioxide filler, the mixture is injected into the mold, and the mixture is reacted at 85°C and a vacuum degree of 100 Pa for 4 hours. After the reaction is completed, nitrogen is introduced to restore normal pressure, the mixture is taken out after cooling, trimmed and cut into shape, sealed and packaged, and cured at 85°C for 2 days to obtain a glass fiber prepreg resin material.

[0037] Step 6: Prepare PU synthetic leather

[0038] 26 parts of wet-process polyurethane resin, 2.5 parts of wood powder, 1.5 parts of S-80 surfactant and 70 parts of N,N-dimethylformamide were mixed, stirred evenly, vacuum degassed for 40 minutes, and filtered with a 100-mesh sieve to obtain a polyurethane slurry. The plain fabric was immersed in deionized water to absorb the water and then squeezed dry. The polyurethane slurry was applied on the surface of the plain fabric, and then placed in a 20% by mass N,N-dimethylformamide solution for curing for 20 minutes. After curing, it was taken out, washed with deionized water, and dried at 120°C to obtain PU synthetic leather.

[0039] Step 7: Preparation of glass fiber prepreg and PU composite materials

[0040] The PU synthetic leather and glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 1.0 MPa, a time of 30 min, and a temperature of 110°C. After hot-pressing and compounding, they are cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 1.0 MPa and the secondary shaping time is 10 min. After shaping, they are taken out to obtain a glass fiber prepreg and PU composite material.

[0041] Embodiment 2: A method for preparing a glass fiber prepreg and PU composite material, specifically:

[0042] Step 1: Preparation of dopamine / boron nitride modified glass fiber cloth

[0043] By mass, the glass fiber cloth was heated at 600°C for 1h, cooled to room temperature, washed with deionized water to obtain a pretreated glass fiber cloth, 1.22 parts of trimethylolaminomethane, 0.8 parts of dopamine hydrochloride and 400 parts of deionized water were mixed and stirred evenly to obtain a dopamine impregnation solution, 3 parts of hexagonal boron nitride and 400 parts of deionized water were mixed to obtain a hexagonal boron nitride impregnation solution, 30 parts of the pretreated glass fiber cloth were immersed in 402.2 parts of the dopamine impregnation solution, immersed at 27°C for 16h, the glass fiber cloth was taken out, dried at 50°C, added to 403 parts of the hexagonal boron nitride impregnation solution, immersed at 27°C for 2h, taken out after the impregnation was completed, and dried at 50°C to obtain dopamine / boron nitride modified glass fiber cloth.

[0044] Step 2: Preparation of silica-modified titania filler

[0045] By mass, 10 parts of titanium dioxide, 81.3 parts of ethanol, 1.87 parts of ammonia water, and 3.2 parts of deionized water were mixed, and ultrasonically dispersed for 30 minutes to obtain an alkaline titanium dioxide suspension. 40.65 parts of ethanol and 0.78 parts of tetraethyl orthosilicate were mixed, stirred evenly, and slowly added dropwise to 96.37 parts of the alkaline titanium dioxide suspension. The mixture was reacted at 80°C and 200 rpm for 6 hours, centrifuged, washed with deionized water, and dried at 60°C to obtain a silica-modified titanium dioxide filler.

[0046] Step 3: Preparation of Pentaerythritol Acrylate

[0047] Mix 14.4 parts of acrylic acid, 13.6 parts of pentaerythritol and 30 parts of toluene by mass, stir evenly, add 1.2 parts of p-toluenesulfonic acid and 1.2 parts of hydroquinone / anhydrous copper sulfate compound, reflux at 120°C for 4 hours, cool, add saturated brine, stand for stratification, filter, wash with sodium hydroxide solution and deionized water, and distill under reduced pressure to obtain pentaerythritol acrylate.

[0048] Step 4: Preparation of polyurethane prepolymer

[0049] 14.2 parts of polybutylene adipate diol, 3.1 parts of polyoxypropylene diol and 25 parts of diphenylmethane diisocyanate were vacuum dried at 100° C. for 1 hour, mixed, stirred evenly and reacted at 75° C. for 3 hours to obtain a polyurethane prepolymer.

[0050] Step 5: Prepare glass fiber prepreg resin material.

[0051] After placing dopamine / boron nitride modified glass fiber cloth in the mold, 84.4 parts of polyurethane prepolymer, 5.90 parts of pentaerythritol acrylate, 8.44 parts of acrylate resin, and 0.89 parts of 1,4-butanediol were mixed and stirred evenly. After adding 1.5 parts of melamine, 0.4 parts of stannous octoate, and 1.0 parts of silica-modified titanium dioxide filler, the mixture was injected into the mold, and the mixture was reacted at 85°C and a vacuum degree of 100 Pa for 4 hours. After the reaction was completed, nitrogen was introduced to restore normal pressure, the mixture was taken out after cooling, trimmed and cut into shape, sealed and packaged, and cured at 85°C for 2 days to obtain a glass fiber prepreg resin material.

[0052] Step 6: Prepare PU synthetic leather

[0053] 26 parts of wet-process polyurethane resin, 2.5 parts of wood powder, 1.5 parts of S-80 surfactant and 70 parts of N,N-dimethylformamide were mixed, stirred evenly, vacuum degassed for 40 minutes, and filtered with a 100-mesh sieve to obtain a polyurethane slurry. The plain fabric was immersed in deionized water to absorb the water and then squeezed dry. The polyurethane slurry was applied on the surface of the plain fabric, and then placed in a 20% by mass N,N-dimethylformamide solution for curing for 20 minutes. After curing, it was taken out, washed with deionized water, and dried at 120°C to obtain PU synthetic leather.

[0054] Step 7: Preparation of glass fiber prepreg and PU composite materials

[0055] The PU synthetic leather and glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 1.0 MPa, a time of 30 min, and a temperature of 110°C. After hot-pressing and compounding, they are cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 1.0 MPa and the secondary shaping time is 10 min. After shaping, they are taken out to obtain a glass fiber prepreg and PU composite material.

[0056] Embodiment 3: A method for preparing a glass fiber prepreg and PU composite material, specifically:

[0057] Step 1: Preparation of dopamine / boron nitride modified glass fiber cloth

[0058] By mass, the glass fiber cloth was heated at 600°C for 1h, cooled to room temperature, washed with deionized water to obtain a pretreated glass fiber cloth, 1.22 parts of trimethylolaminomethane, 0.8 parts of dopamine hydrochloride and 400 parts of deionized water were mixed and stirred evenly to obtain a dopamine impregnation solution, 3 parts of hexagonal boron nitride and 400 parts of deionized water were mixed to obtain a hexagonal boron nitride impregnation solution, 30 parts of the pretreated glass fiber cloth were immersed in 402.2 parts of the dopamine impregnation solution, immersed at 27°C for 16h, the glass fiber cloth was taken out, dried at 50°C, added to 403 parts of the hexagonal boron nitride impregnation solution, immersed at 27°C for 2h, taken out after the impregnation was completed, and dried at 50°C to obtain dopamine / boron nitride modified glass fiber cloth.

[0059] Step 2: Preparation of silica-modified titania filler

[0060] By mass, 10 parts of titanium dioxide, 81.3 parts of ethanol, 1.87 parts of ammonia water, and 3.2 parts of deionized water were mixed, and ultrasonically dispersed for 30 minutes to obtain an alkaline titanium dioxide suspension. 40.65 parts of ethanol and 0.78 parts of tetraethyl orthosilicate were mixed, stirred evenly, and slowly added dropwise to 96.37 parts of the alkaline titanium dioxide suspension. The mixture was reacted at 80°C and 200 rpm for 6 hours, centrifuged, washed with deionized water, and dried at 60°C to obtain a silica-modified titanium dioxide filler.

[0061] Step 3: Preparation of Pentaerythritol Acrylate

[0062] Mix 14.4 parts of acrylic acid, 13.6 parts of pentaerythritol and 30 parts of toluene by mass, stir evenly, add 1.2 parts of p-toluenesulfonic acid and 1.2 parts of hydroquinone / anhydrous copper sulfate compound, reflux at 120°C for 4 hours, cool, add saturated brine, stand for stratification, filter, wash with sodium hydroxide solution and deionized water, and distill under reduced pressure to obtain pentaerythritol acrylate.

[0063] Step 4: Preparation of polyurethane prepolymer

[0064] 14.2 parts of polybutylene adipate diol, 3.1 parts of polyoxypropylene diol and 25 parts of diphenylmethane diisocyanate were vacuum dried at 100° C. for 1 hour, mixed, stirred evenly and reacted at 75° C. for 3 hours to obtain a polyurethane prepolymer.

[0065] Step 5: Prepare glass fiber prepreg resin material.

[0066] By mass, after dopamine / boron nitride modified glass fiber cloth is placed in the mold, 84.8 parts of polyurethane prepolymer, 5.95 parts of pentaerythritol acrylate, 8.48 parts of acrylate resin, and 0.91 parts of 1,4-butanediol are mixed and stirred evenly, 2.5 parts of melamine, 0.8 parts of stannous octoate, and 2.0 parts of silica-modified titanium dioxide filler are added, and then injected into the mold, and reacted at 85°C and a vacuum degree of 100 Pa for 4 hours. After the reaction is completed, nitrogen is introduced to restore normal pressure, and the mold is taken out after cooling, trimmed and cut, sealed and packaged, and cured at 85°C for 2 days to obtain a glass fiber prepreg resin material.

[0067] Step 6: Prepare PU synthetic leather

[0068] 26 parts of wet-process polyurethane resin, 2.5 parts of wood powder, 1.5 parts of S-80 surfactant and 70 parts of N,N-dimethylformamide were mixed, stirred evenly, vacuum degassed for 40 minutes, and filtered with a 100-mesh sieve to obtain a polyurethane slurry. The plain fabric was immersed in deionized water to absorb the water and then squeezed dry. The polyurethane slurry was applied on the surface of the plain fabric, and then placed in a 20% by mass N,N-dimethylformamide solution for curing for 20 minutes. After curing, it was taken out, washed with deionized water, and dried at 120°C to obtain PU synthetic leather.

[0069] Step 7: Preparation of glass fiber prepreg and PU composite materials

[0070] The PU synthetic leather and glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 1.0 MPa, a time of 30 min, and a temperature of 110°C. After hot-pressing and compounding, they are cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 1.0 MPa and the secondary shaping time is 10 min. After shaping, they are taken out to obtain a glass fiber prepreg and PU composite material.

[0071] Based on Example 1, control experiments were carried out, specifically Comparative Example 1, Comparative Example 2 and Comparative Example 3, as described below:

[0072] Comparative Example 1: The titanium dioxide filler was not modified, and the other conditions were the same as those in Example 1.

[0073] A method for preparing a glass fiber prepreg and PU composite material, specifically comprising:

[0074] Step 1: Preparation of dopamine / boron nitride modified glass fiber cloth

[0075] By mass, the glass fiber cloth was heated at 600°C for 1h, cooled to room temperature, washed with deionized water to obtain a pretreated glass fiber cloth, 1.22 parts of trimethylolaminomethane, 0.8 parts of dopamine hydrochloride and 400 parts of deionized water were mixed and stirred evenly to obtain a dopamine impregnation solution, 3 parts of hexagonal boron nitride and 400 parts of deionized water were mixed to obtain a hexagonal boron nitride impregnation solution, 30 parts of the pretreated glass fiber cloth were immersed in 402.2 parts of the dopamine impregnation solution, immersed at 27°C for 16h, the glass fiber cloth was taken out, dried at 50°C, added to 403 parts of the hexagonal boron nitride impregnation solution, immersed at 27°C for 2h, taken out after the impregnation was completed, and dried at 50°C to obtain dopamine / boron nitride modified glass fiber cloth.

[0076] Step 2: Preparation of Pentaerythritol Acrylate

[0077] Mix 14.4 parts of acrylic acid, 13.6 parts of pentaerythritol and 30 parts of toluene by mass, stir evenly, add 1.2 parts of p-toluenesulfonic acid and 1.2 parts of hydroquinone / anhydrous copper sulfate compound, reflux at 120°C for 4 hours, cool, add saturated brine, stand for stratification, filter, wash with sodium hydroxide solution and deionized water, and distill under reduced pressure to obtain pentaerythritol acrylate.

[0078] Step 3: Preparation of polyurethane prepolymer

[0079] 14.2 parts of polybutylene adipate diol, 3.1 parts of polyoxypropylene diol and 25 parts of diphenylmethane diisocyanate were vacuum dried at 100° C. for 1 hour, mixed, stirred evenly and reacted at 75° C. for 3 hours to obtain a polyurethane prepolymer.

[0080] Step 4: Prepare glass fiber prepreg resin material.

[0081] After placing dopamine / boron nitride modified glass fiber cloth in the mold, 84.6 parts of polyurethane prepolymer, 5.92 parts of pentaerythritol acrylate, 8.46 parts of acrylate resin, and 0.91 parts of 1,4-butanediol were mixed and stirred evenly. After adding 2 parts of melamine, 0.6 parts of stannous octoate, and 1.5 parts of titanium dioxide filler, the mixture was injected into the mold and reacted at 85°C and a vacuum degree of 100 Pa for 4 hours. After the reaction was completed, nitrogen was introduced to restore normal pressure, the mixture was taken out after cooling, trimmed and cut into shape, sealed and packaged, and cured at 85°C for 2 days to obtain a glass fiber prepreg resin material.

[0082] Step 5: Prepare PU synthetic leather

[0083] 26 parts of wet-process polyurethane resin, 2.5 parts of wood powder, 1.5 parts of S-80 surfactant and 70 parts of N,N-dimethylformamide were mixed, stirred evenly, vacuum degassed for 40 minutes, and filtered with a 100-mesh sieve to obtain a polyurethane slurry. The plain fabric was immersed in deionized water to absorb the water and then squeezed dry. The polyurethane slurry was applied on the surface of the plain fabric, and then placed in a 20% by mass N,N-dimethylformamide solution for curing for 20 minutes. After curing, it was taken out, washed with deionized water, and dried at 120°C to obtain PU synthetic leather.

[0084] Step 6: Preparation of glass fiber prepreg and PU composite materials

[0085] The PU synthetic leather and glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 1.0 MPa, a time of 30 min, and a temperature of 110°C. After hot-pressing and compounding, they are cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 1.0 MPa and the secondary shaping time is 10 min. After shaping, they are taken out to obtain a glass fiber prepreg and PU composite material.

[0086] Comparative Example 2: Dopamine / boron nitride modified glass fiber cloth was not used, and other conditions were the same as those in Example 1.

[0087] A method for preparing a glass fiber prepreg and PU composite material, specifically comprising:

[0088] Step 1: Preparation of silica-modified titania filler

[0089] By mass, 10 parts of titanium dioxide, 81.3 parts of ethanol, 1.87 parts of ammonia water, and 3.2 parts of deionized water were mixed, and ultrasonically dispersed for 30 minutes to obtain an alkaline titanium dioxide suspension. 40.65 parts of ethanol and 0.78 parts of tetraethyl orthosilicate were mixed, stirred evenly, and slowly added dropwise to 96.37 parts of the alkaline titanium dioxide suspension. The mixture was reacted at 80°C and 200 rpm for 6 hours, centrifuged, washed with deionized water, and dried at 60°C to obtain a silica-modified titanium dioxide filler.

[0090] Step 2: Preparation of Pentaerythritol Acrylate

[0091] Mix 14.4 parts of acrylic acid, 13.6 parts of pentaerythritol and 30 parts of toluene by mass, stir evenly, add 1.2 parts of p-toluenesulfonic acid and 1.2 parts of hydroquinone / anhydrous copper sulfate compound, reflux at 120°C for 4 hours, cool, add saturated brine, stand for stratification, filter, wash with sodium hydroxide solution and deionized water, and distill under reduced pressure to obtain pentaerythritol acrylate.

[0092] Step 3: Preparation of polyurethane prepolymer

[0093] 14.2 parts of polybutylene adipate diol, 3.1 parts of polyoxypropylene diol and 25 parts of diphenylmethane diisocyanate were vacuum dried at 100° C. for 1 hour, mixed, stirred evenly and reacted at 75° C. for 3 hours to obtain a polyurethane prepolymer.

[0094] Step 4: Prepare glass fiber prepreg resin material.

[0095] By mass, the glass fiber cloth was heated at 600°C for 1h, cooled to room temperature, and washed with deionized water to obtain a pretreated glass fiber cloth. After the pretreated glass fiber cloth was placed in the mold, 84.6 parts of polyurethane prepolymer, 5.92 parts of pentaerythritol acrylate, 8.46 parts of acrylate resin, and 0.91 parts of 1,4-butanediol were mixed and stirred evenly. After adding 2 parts of melamine, 0.6 parts of stannous octoate, and 1.5 parts of silica-modified titanium dioxide filler, it was injected into the mold, and reacted at 85°C and a vacuum degree of 100Pa for 4h. After the reaction was completed, nitrogen was introduced to restore normal pressure, and it was taken out after cooling, trimmed and cut, sealed and packaged, and cured at 85°C for 2 days to obtain a glass fiber prepreg resin material.

[0096] Step 6: Prepare PU synthetic leather

[0097] 26 parts of wet-process polyurethane resin, 2.5 parts of wood powder, 1.5 parts of S-80 surfactant and 70 parts of N,N-dimethylformamide were mixed, stirred evenly, vacuum degassed for 40 minutes, and filtered with a 100-mesh sieve to obtain a polyurethane slurry. The plain fabric was immersed in deionized water to absorb the water and then squeezed dry. The polyurethane slurry was applied on the surface of the plain fabric, and then placed in a 20% by mass N,N-dimethylformamide solution for curing for 20 minutes. After curing, it was taken out, washed with deionized water, and dried at 120°C to obtain PU synthetic leather.

[0098] Step 6: Preparation of glass fiber prepreg and PU composite materials

[0099] The PU synthetic leather and glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 1.0 MPa, a time of 30 min, and a temperature of 110°C. After hot-pressing and compounding, they are cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 1.0 MPa and the secondary shaping time is 10 min. After shaping, they are taken out to obtain a glass fiber prepreg and PU composite material.

[0100] Comparative Example 3: Pentaerythritol acrylate was not added, and other conditions were the same as those in Example 1.

[0101] A method for preparing a glass fiber prepreg and PU composite material, specifically comprising:

[0102] Step 1: Preparation of dopamine / boron nitride modified glass fiber cloth

[0103] By mass, the glass fiber cloth was heated at 600°C for 1h, cooled to room temperature, washed with deionized water to obtain a pretreated glass fiber cloth, 1.22 parts of trimethylolaminomethane, 0.8 parts of dopamine hydrochloride and 400 parts of deionized water were mixed and stirred evenly to obtain a dopamine impregnation solution, 3 parts of hexagonal boron nitride and 400 parts of deionized water were mixed to obtain a hexagonal boron nitride impregnation solution, 30 parts of the pretreated glass fiber cloth were immersed in 402.2 parts of the dopamine impregnation solution, immersed at 27°C for 16h, the glass fiber cloth was taken out, dried at 50°C, added to 403 parts of the hexagonal boron nitride impregnation solution, immersed at 27°C for 2h, taken out after the impregnation was completed, and dried at 50°C to obtain dopamine / boron nitride modified glass fiber cloth.

[0104] Step 2: Preparation of silica-modified titania filler

[0105] By mass, 10 parts of titanium dioxide, 81.3 parts of ethanol, 1.87 parts of ammonia water, and 3.2 parts of deionized water were mixed, and ultrasonically dispersed for 30 minutes to obtain an alkaline titanium dioxide suspension. 40.65 parts of ethanol and 0.78 parts of tetraethyl orthosilicate were mixed, stirred evenly, and slowly added dropwise to 96.37 parts of the alkaline titanium dioxide suspension. The mixture was reacted at 80°C and 200 rpm for 6 hours, centrifuged, washed with deionized water, and dried at 60°C to obtain a silica-modified titanium dioxide filler.

[0106] Step 3: Preparation of polyurethane prepolymer

[0107] 14.2 parts of polybutylene adipate diol, 3.1 parts of polyoxypropylene diol and 25 parts of diphenylmethane diisocyanate were vacuum dried at 100° C. for 1 hour, mixed, stirred evenly and reacted at 75° C. for 3 hours to obtain a polyurethane prepolymer.

[0108] Step 4: Prepare glass fiber prepreg resin material.

[0109] By mass, after dopamine / boron nitride modified glass fiber cloth is placed in the mold, 84.6 parts of polyurethane prepolymer, 8.46 parts of acrylic resin, and 0.91 parts of 1,4-butanediol are mixed and stirred evenly, 2 parts of melamine, 0.6 parts of stannous octoate, and 1.5 parts of silica-modified titanium dioxide filler are added, and then injected into the mold, and reacted at 85°C and a vacuum degree of 100 Pa for 4 hours. After the reaction is completed, nitrogen is introduced to restore normal pressure, and the mold is taken out after cooling, trimmed and cut, sealed and packaged, and cured at 85°C for 2 days to obtain a glass fiber prepreg resin material.

[0110] Step 6: Prepare PU synthetic leather

[0111] 26 parts of wet-process polyurethane resin, 2.5 parts of wood powder, 1.5 parts of S-80 surfactant and 70 parts of N,N-dimethylformamide were mixed, stirred evenly, vacuum degassed for 40 minutes, and filtered with a 100-mesh sieve to obtain a polyurethane slurry. The plain fabric was immersed in deionized water to absorb the water and then squeezed dry. The polyurethane slurry was applied on the surface of the plain fabric, and then placed in a 20% by mass N,N-dimethylformamide solution for curing for 20 minutes. After curing, it was taken out, washed with deionized water, and dried at 120°C to obtain PU synthetic leather.

[0112] Step 6: Preparation of glass fiber prepreg and PU composite materials

[0113] The PU synthetic leather and glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 1.0 MPa, a time of 30 min, and a temperature of 110°C. After hot-pressing and compounding, they are cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 1.0 MPa and the secondary shaping time is 10 min. After shaping, they are taken out to obtain a glass fiber prepreg and PU composite material.

[0114] Detection experiment:

[0115] Bonding strength test: According to the "Adhesive Single Lap Tensile Shear Strength Test Method (Composite Material to Composite Material)" (GB / T 33334-2016), a bonding strength testing machine was used for testing. According to the preparation methods in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3, 6 kinds of glass fiber prepreg resin materials with a size of 12.5 mm×25 mm were prepared. The 6 kinds of glass fiber prepreg resin materials were hot-pressed and compounded with two pieces of 100 mm×25 mm PU synthetic leather to form 6 kinds of bonding strengths. The bonding strength specimens were installed on the testing machine fixture and tested at a loading rate of 5 mm / min to measure the bonding strength of the specimens.

[0116] Tensile strength test: According to the "Test Method for Tensile Properties of Oriented Fiber Reinforced Plastics" (GB / T3354-1999), a universal mechanical testing machine was used for testing. According to the preparation methods in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3, 6 kinds of glass fiber prepreg resin materials with a size of 250mm×50mm were prepared. The samples were placed flat on the support, and load was applied to the samples at a uniform speed to measure the tensile strength of the samples.

[0117] Boiling aging test: According to the preparation methods in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3, 6 kinds of glass fiber prepreg resin materials with a size of 250 mm × 50 mm were prepared. The samples were placed in a container filled with distilled water, and the container was placed in a constant temperature water bath aging equipment and boiled at 100°C for 24 hours. After 24 hours, the samples were taken out, the tensile strength of the samples was measured, and the tensile strength retention rate after boiling aging was calculated.

[0118]

[0119] Conclusion: It can be seen from the experiment that the bonding strength, tensile strength and water boiling aging resistance of the glass fiber prepreg prepared by the preparation method of Example 1 are better than those of the glass fiber prepreg prepared by the preparation methods of Comparative Example 1, Comparative Example 2 and Comparative Example 3. The prepared glass fiber prepreg and PU composite material can be well bonded together without pre-application of hot melt adhesive, and at the same time have excellent composite material performance.

[0120] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A method for preparing a glass fiber prepreg and PU composite material, characterized in that: The preparation method is: The PU synthetic leather and the glass fiber prepreg resin material are stacked together and hot-pressed at a pressure of 0.8 to 1.2 MPa, a time of 25 to 35 minutes, and a temperature of 90 to 130°C. After hot-pressing and compounding, the material is cooled to room temperature and pressed again for shaping. The secondary shaping pressure is 0.8 to 1.2 MPa, and the secondary shaping time is 5 to 15 minutes. After shaping, the material is taken out to obtain a glass fiber prepreg and PU composite material.

2. The method for preparing a glass fiber prepreg and PU composite material according to claim 1, characterized in that: The preparation method of glass fiber prepreg resin material is as follows: After dopamine / boron nitride modified glass fiber cloth is placed in the mold, polyurethane prepolymer, pentaerythritol acrylate, acrylate resin and 1,4-butanediol are mixed and stirred evenly, melamine, stannous octoate and silica-modified titanium dioxide filler are added, and then injected into the mold, and reacted at 80-90°C and a vacuum degree of 80-120Pa for 3-5 hours. After the reaction is completed, nitrogen is introduced to restore normal pressure, and the mold is taken out after cooling, trimmed and cut into shape, sealed and packaged, and cured at 80-90°C for 1-3 days to obtain glass fiber prepreg resin material.

3. The method for preparing a glass fiber prepreg and PU composite material according to claim 2, characterized in that: The glass fiber prepreg resin material includes 84.4-84.8 parts of polyurethane prepolymer, 5.90-5.95 parts of pentaerythritol acrylate, 8.44-8.46 parts of acrylate resin, 0.89-0.93 parts of 1,4-butanediol, 1.5-2.5 parts of melamine, 0.4-0.8 parts of stannous octoate, and 1.0-2.0 parts of silica-modified titanium dioxide filler, calculated by mass.

4. The method for preparing a glass fiber prepreg and PU composite material according to claim 2, characterized in that: The preparation method of dopamine / boron nitride modified glass fiber cloth is as follows: The glass fiber cloth is heated at 500-700°C for 0.5-1.5h, cooled to room temperature, washed with deionized water to obtain pretreated glass fiber cloth, trihydroxymethylaminomethane, dopamine hydrochloride and deionized water are mixed and stirred evenly to obtain dopamine impregnation solution, hexagonal boron nitride and deionized water are mixed to obtain hexagonal boron nitride impregnation solution, the pretreated glass fiber cloth is immersed in the dopamine impregnation solution, immersed at 25-30°C for 14-18h, the glass fiber cloth is taken out, dried at 45-55°C, added to the hexagonal boron nitride impregnation solution, immersed at 25-30°C for 1-3h, taken out after impregnation, and dried at 45-55°C to obtain dopamine / boron nitride modified glass fiber cloth.

5. The method for preparing a glass fiber prepreg and PU composite material according to claim 2, characterized in that: The preparation method of polyurethane prepolymer is: Polybutylene adipate diol, polyoxypropylene diol and diphenylmethane diisocyanate are vacuum dried at 95-105° C. for 0.5-1.5 h, mixed, stirred evenly, and reacted at 70-80° C. for 2-4 h to obtain a polyurethane prepolymer.

6. The method for preparing a glass fiber prepreg and PU composite material according to claim 2, characterized in that: The preparation method of pentaerythritol acrylate is: Acrylic acid, pentaerythritol and toluene are mixed and stirred evenly, p-toluenesulfonic acid and hydroquinone / anhydrous copper sulfate complex are added, reflux reaction is carried out at 110-130°C for 3-5 hours, cooled, saturated brine is added, allowed to stand for stratification, filtered, washed with sodium hydroxide solution and deionized water, and distilled under reduced pressure to obtain pentaerythritol acrylate.

7. The method for preparing a glass fiber prepreg and PU composite material according to claim 6, characterized in that: The preparation of pentaerythritol acrylate includes 14.2-14.6 parts of acrylic acid, 13.4-13.8 parts of pentaerythritol, 1.0-1.4 parts of p-toluenesulfonic acid, and 1.0-1.4 parts of hydroquinone / anhydrous copper sulfate compound, calculated by mass.

8. The method for preparing a glass fiber prepreg and PU composite material according to claim 2, characterized in that: The preparation method of silica-modified titanium dioxide filler is: Titanium dioxide, ethanol, ammonia water and deionized water are mixed, and ultrasonically dispersed for 20 to 40 minutes to obtain an alkaline titanium dioxide suspension. Ethanol and tetraethyl orthosilicate are mixed, stirred evenly, and slowly added dropwise to the alkaline titanium dioxide suspension. The mixture is reacted at 75 to 85° C. and 150 to 250 rpm for 5 to 7 hours, centrifuged, washed with deionized water, and dried at 50 to 70° C. to obtain a silica-modified titanium dioxide filler.

9. The method for preparing a glass fiber prepreg and PU composite material according to claim 8, characterized in that: The preparation of the silica-modified titanium dioxide filler includes 9 to 11 parts of titanium dioxide, 1.85 to 1.90 parts of ammonia water, and 0.75 to 0.80 parts of ethyl orthosilicate, in parts by mass.

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