Modified glass fiber based on lubricant and application of modified glass fiber in epoxy pultrusion plate

Abstract

The invention discloses a modified glass fiber based on a lubricant and application of the modified glass fiber in an epoxy pultrusion plate, and relates to the technical field of glass fibers. The invention discloses a lubricant and a modified glass fiber based on the lubricant. Fatty alcohol-polyoxyethylene ether, polyvinylpyrrolidone, triethanolamine borate and paraffin are used for enhancing the lubricating property. The waterborne polyurethane emulsion is added, so that a continuous and tough protective film is formed, and the wear resistance and mechanical damage resistance of the glass fiber are remarkably improved. The surface of the glass fiber is firstly subjected to low-temperature plasma treatment, so that the surface of the glass fiber becomes slightly rough, and the surface area is increased; then, nano silicon dioxide is formed on the surface of the glass fiber by adding tetraethyl orthosilicate, so that the surface roughness and the acid and alkali resistance of the glass fiber are further improved. And then amino branched polyamide is used for carrying out surface modification treatment on the glass fiber, so that the compatibility of the glass fiber and polyamide resin is enhanced, and the mechanical property of the pultrusion plate is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of glass fibers, in particular to a lubricant-based modified glass fiber and application thereof in epoxy pultruded boards. Background Art

[0002] As an important glass fiber reinforced epoxy resin composite product, epoxy pultruded board has excellent mechanical properties and corrosion resistance, and is widely used in wind turbine blades, aerospace, automobile manufacturing and other fields.

[0003] When glass fiber is used as a reinforcing material for epoxy pultruded boards, the insufficient interfacial compatibility between the glass fiber and the epoxy resin can lead to insufficient bonding between the fiber and the resin, affecting the overall performance of the composite material. Furthermore, glass fiber is susceptible to mechanical damage during the pultrusion process, resulting in a decrease in strength and toughness. Lubricants can improve the fluidity and dispersibility of glass fiber during the pultrusion process, reduce friction and damage between fibers, improve fiber integrity, and enhance the performance of epoxy pultruded boards. Choosing a suitable lubricant that effectively improves the performance of glass fiber while not negatively impacting the mechanical properties of epoxy pultruded boards is a pressing issue that needs to be addressed.

[0004] In order to solve the above problems, the present invention provides a lubricant-based modified glass fiber and its application in epoxy pultruded board. Summary of the Invention

[0005] The purpose of the present invention is to provide a method to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A lubricant-based modified glass fiber comprises the following steps:

[0008] S1: Take an aqueous polyurethane emulsion, add deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly, and obtain a lubricant;

[0009] S2: Tetraethyl orthosilicate and ethanol were mixed and uniformly stirred, and sodium hydroxide solution was added dropwise to adjust the pH value to obtain a tetraethyl orthosilicate solution; the plasma-treated glass fiber was immersed in the tetraethyl orthosilicate solution and reacted for 3-4 hours, and then removed and dried to obtain glass fiber A;

[0010] S3: Take amino-branched polyamide, deionized water, and ethanol, stir evenly, add glass fiber A, heat to 60-62°C, react for 15-20 minutes, filter, and dry to obtain glass fiber B;

[0011] S4: Immerse the glass fiber B in the lubricant, take it out, and dry it to obtain a modified glass fiber.

[0012] More optimally, in S1, the method for preparing the lubricant comprises the following steps:

[0013] Step 1: Take fatty alcohol polyoxyethylene ether, polyvinyl pyrrolidone, triethanolamine borate, paraffin, and deionized water, stir evenly to obtain a composite solution;

[0014] Step 2: Take aqueous polyamide and deionized water, stir them evenly to obtain a polyamide solution;

[0015] Step 3: Take a coupling agent, add deionized water, stir evenly, add a pH adjuster until the pH of the aqueous solution is 5-7, stir evenly, and obtain a coupling agent solution;

[0016] Step 4: Take the aqueous polyurethane emulsion, add deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain the lubricant.

[0017] More optimally, the composite solution contains the following components, calculated by weight: 6-8 parts of fatty alcohol polyoxyethylene ether, 3-5 parts of polyvinyl pyrrolidone, 1-2 parts of triethanolamine borate, 2-2.5 parts of paraffin, and 100-105 parts of deionized water.

[0018] More optimally, the mass ratio of the aqueous polyamide to deionized water is (10-15):100.

[0019] More optimally, the pH adjuster is any one or more of acetic acid, citric acid, and succinic acid.

[0020] More optimally, the coupling agent is coupling agent Y-9669 or coupling agent A-187.

[0021] More optimally, the method for preparing the plasma-treated glass fiber is as follows: taking the glass fiber, alternately rinsing the surface with deionized water and acetone, and drying to obtain the cleaned glass fiber; placing the cleaned glass fiber in a low-temperature plasma reaction device, filling it with argon, and discharging at a power of 80-85W for 3-4 minutes to obtain the plasma-treated glass fiber.

[0022] More optimally, the preparation method of the amino-branched polyamide is: take diethylenetriamine, heat it at 50-55°C for 2-3 hours, add succinic anhydride, raise the temperature to 140°C, continue heating and stirring for 3-4 hours, and cool to obtain the amino-branched polyamide.

[0023] The invention discloses an application of modified glass fiber in epoxy pultruded board.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention prepares a lubricant and a modified glass fiber based on the lubricant. Fatty alcohol polyoxyethylene ether, polyvinyl pyrrolidone, triethanolamine borate, and paraffin wax are used to enhance lubrication properties. The addition of an aqueous polyurethane emulsion forms a continuous, tough protective film, significantly improving the glass fiber's wear resistance and resistance to mechanical damage.

[0026] 2. The present invention first subjects the glass fiber surface to low-temperature plasma treatment, making it slightly rougher and increasing its surface area. Tetraethyl orthosilicate is then added to form nano-silica on the glass fiber surface, further increasing its surface roughness and acid and alkali resistance. The glass fiber is then surface-modified using amino-branched polyamide, improving its compatibility with lubricants. The amino groups are also loaded onto the glass fiber, forming chemical bonds with the polyamide resin used as the pultruded board substrate, enhancing the compatibility between the glass fiber and the polyamide resin, thereby improving the mechanical properties of the pultruded board. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] The sources and models of the substances involved in the present invention are not particularly limited, and illustratively include: coupling agent Y-9669: can be purchased from Maitu; coupling agent A-187: can be purchased from Maitu; glass fiber: diameter: 11-13 μm, length 3-20 mm; water-based polyamide: can be purchased from Wenzhou Guoshibang Polymer Materials Co., Ltd., GSB; water-based polyurethane emulsion: can be purchased from Nanjing Chuhai New Materials Technology Co., Ltd., model: PU667.

[0029] Example 1: Preparation of a lubricant-based modified glass fiber, comprising the following steps:

[0030] Step 1: Preparation of lubricant:

[0031] Take 6 g of fatty alcohol polyoxyethylene ether, 3 g of polyvinyl pyrrolidone, 1 g of triethanolamine borate, 2 g of paraffin, and 100 mL of deionized water, stir well to obtain a composite solution;

[0032] The composite solution contains the following components, calculated by weight: 7 parts of fatty alcohol polyoxyethylene ether, 4 parts of polyvinyl pyrrolidone, 1.5 parts of triethanolamine borate, 2.3 parts of paraffin wax, and 102 parts of deionized water;

[0033] Take 12 g of water-based polyamide and 100 mL of deionized water, stir evenly to obtain a polyamide solution;

[0034] The mass ratio of water-based polyamide and deionized water is 12:100;

[0035] Take 5g of coupling agent Y-9669 and 3g of coupling agent A-187, add 50mL of deionized water, stir evenly, add pH adjuster until the pH of the aqueous solution is 6, stir evenly to obtain a coupling agent solution;

[0036] The pH adjuster is citric acid;

[0037] Take 25g of aqueous polyurethane emulsion, add 100mL of deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain a lubricant;

[0038] Step 2: Preparation of modified glass fiber, including the following steps:

[0039] S1: Preparation of amino-branched polyamide:

[0040] Take 103g of diethylenetriamine, heat it at 52℃ for 2.5h, add 80g of succinic anhydride, raise the temperature to 140℃ and continue heating and stirring for 3.5h, then cool to obtain amino-branched polyamide;

[0041] S2: Plasma treatment:

[0042] The glass fiber was cut into 3-20 mm fibers, and the surface was rinsed twice with deionized water and acetone alternately, and dried to obtain cleaned glass fiber. The cleaned glass fiber was placed in a low-temperature plasma reaction device, filled with argon gas at a pressure of 0.1 MPa, and discharged at a power of 80 W for 3 minutes to obtain a plasma-treated glass fiber.

[0043] S3: Modification treatment:

[0044] 20 g of tetraethyl orthosilicate and 100 mL of ethanol were mixed and uniformly stirred, and sodium hydroxide solution was added dropwise to adjust the pH to 11 to obtain a tetraethyl orthosilicate solution; the plasma-treated glass fiber was immersed in the tetraethyl orthosilicate solution and reacted for 3.5 hours, then removed and dried to obtain glass fiber A;

[0045] Take 2g of amino-branched polyamide, 80mL of deionized water, and 20mL of ethanol, stir evenly, add 1g of glass fiber A, heat to 61℃, react for 18min, filter, and dry to obtain glass fiber B;

[0046] The glass fiber B is immersed in the lubricant, taken out, and dried to obtain a modified glass fiber.

[0047] Example 2: Preparation of a lubricant-based modified glass fiber, comprising the following steps:

[0048] Step 1: Preparation of lubricant:

[0049] Take 6 g of fatty alcohol polyoxyethylene ether, 3 g of polyvinyl pyrrolidone, 1 g of triethanolamine borate, 2 g of paraffin, and 100 mL of deionized water, stir well to obtain a composite solution;

[0050] The composite solution contains the following components, calculated by weight: 6 parts of fatty alcohol polyoxyethylene ether, 3 parts of polyvinyl pyrrolidone, 1 part of triethanolamine borate, 2 parts of paraffin wax, and 100 parts of deionized water;

[0051] Take 10 g of water-based polyamide and 100 mL of deionized water, stir evenly to obtain a polyamide solution;

[0052] The mass ratio of water-based polyamide and deionized water is 10:100;

[0053] Take 5g of coupling agent Y-9669 and 3g of coupling agent A-187, add 50mL of deionized water, stir evenly, add pH adjuster until the pH of the aqueous solution is 5, stir evenly to obtain a coupling agent solution;

[0054] The pH adjuster is citric acid;

[0055] Take 25g of aqueous polyurethane emulsion, add 100mL of deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain a lubricant;

[0056] Step 2: Preparation of modified glass fiber, including the following steps:

[0057] S1: Preparation of amino-branched polyamide:

[0058] Take 103g of diethylenetriamine, heat at 50℃ for 2h, add 80g of succinic anhydride, raise the temperature to 140℃ and continue heating and stirring for 3h, then cool to obtain amino-branched polyamide;

[0059] S2: Plasma treatment:

[0060] The glass fiber was cut into 3-20 mm fibers, and the surface was rinsed twice with deionized water and acetone alternately, and dried to obtain cleaned glass fiber. The cleaned glass fiber was placed in a low-temperature plasma reaction device, filled with argon gas at a pressure of 0.1 MPa, and discharged at a power of 80 W for 3 minutes to obtain a plasma-treated glass fiber.

[0061] S3: Modification treatment:

[0062] 20 g of tetraethyl orthosilicate and 100 mL of ethanol were mixed and stirred evenly, and sodium hydroxide solution was added dropwise to adjust the pH to 11 to obtain a tetraethyl orthosilicate solution; the plasma-treated glass fiber was immersed in the tetraethyl orthosilicate solution, reacted for 3 h, removed, and dried to obtain glass fiber A;

[0063] Take 2g of amino-branched polyamide, 80mL of deionized water, and 20mL of ethanol, stir evenly, add 1g of glass fiber A, heat to 60℃, react for 15min, filter, and dry to obtain glass fiber B;

[0064] The glass fiber B is immersed in the lubricant, taken out, and dried to obtain a modified glass fiber.

[0065] Example 3: Preparation of a lubricant-based modified glass fiber, comprising the following steps:

[0066] Step 1: Preparation of lubricant:

[0067] Take 6 g of fatty alcohol polyoxyethylene ether, 3 g of polyvinyl pyrrolidone, 1 g of triethanolamine borate, 2 g of paraffin, and 100 mL of deionized water, stir well to obtain a composite solution;

[0068] The composite solution contains the following components, calculated by weight: 8 parts of fatty alcohol polyoxyethylene ether, 5 parts of polyvinyl pyrrolidone, 2 parts of triethanolamine borate, 2.5 parts of paraffin wax, and 105 parts of deionized water;

[0069] Take 15g of water-based polyamide and 100mL of deionized water, stir evenly to obtain a polyamide solution;

[0070] The mass ratio of water-based polyamide and deionized water is 15:100;

[0071] Take 5g of coupling agent Y-9669 and 3g of coupling agent A-187, add 50mL of deionized water, stir evenly, add pH adjuster until the pH of the aqueous solution is 7, stir evenly to obtain a coupling agent solution;

[0072] The pH adjuster is succinic acid;

[0073] Take 25g of aqueous polyurethane emulsion, add 100mL of deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain a lubricant;

[0074] Step 2: Preparation of modified glass fiber, including the following steps:

[0075] S1: Preparation of amino-branched polyamide:

[0076] Take 103g of diethylenetriamine, heat at 55℃ for 3h, add 80g of succinic anhydride, raise the temperature to 140℃ and continue heating and stirring for 4h, then cool to obtain amino-branched polyamide;

[0077] S2: Plasma treatment:

[0078] The glass fiber was cut into 3-20 mm fibers, and the surface was rinsed twice with deionized water and acetone alternately, and dried to obtain cleaned glass fiber. The cleaned glass fiber was placed in a low-temperature plasma reaction device, filled with argon gas at a pressure of 0.1 MPa, and discharged at a power of 80 W for 4 minutes to obtain a plasma-treated glass fiber.

[0079] S3: Modification treatment:

[0080] 20 g of tetraethyl orthosilicate and 100 mL of ethanol were mixed and stirred evenly, and sodium hydroxide solution was added dropwise to adjust the pH to 11 to obtain a tetraethyl orthosilicate solution; the plasma-treated glass fiber was immersed in the tetraethyl orthosilicate solution, reacted for 4 hours, removed, and dried to obtain glass fiber A;

[0081] Take 2g of amino-branched polyamide, 80mL of deionized water, and 20mL of ethanol, stir evenly, add 1g of glass fiber A, heat to 62℃, react for 20min, filter, and dry to obtain glass fiber B;

[0082] The glass fiber B is immersed in the lubricant, taken out, and dried to obtain a modified glass fiber.

[0083] Comparative Example 1: The glass fiber surface is not subjected to low-temperature plasma treatment, and the rest is the same as Example 1:

[0084] Step 1: Preparation of lubricant:

[0085] Take 6 g of fatty alcohol polyoxyethylene ether, 3 g of polyvinyl pyrrolidone, 1 g of triethanolamine borate, 2 g of paraffin, and 100 mL of deionized water, stir well to obtain a composite solution;

[0086] The composite solution contains the following components, calculated by weight: 7 parts of fatty alcohol polyoxyethylene ether, 4 parts of polyvinyl pyrrolidone, 1.5 parts of triethanolamine borate, 2.3 parts of paraffin wax, and 102 parts of deionized water;

[0087] Take 12 g of water-based polyamide and 100 mL of deionized water, stir evenly to obtain a polyamide solution;

[0088] The mass ratio of water-based polyamide and deionized water is 12:100;

[0089] Take 5g of coupling agent Y-9669 and 3g of coupling agent A-187, add 50mL of deionized water, stir evenly, add pH adjuster until the pH of the aqueous solution is 6, stir evenly to obtain a coupling agent solution;

[0090] The pH adjuster is citric acid;

[0091] Take 25g of aqueous polyurethane emulsion, add 100mL of deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain a lubricant;

[0092] Step 2: Preparation of modified glass fiber, including the following steps:

[0093] S1: Preparation of amino-branched polyamide:

[0094] Take 103g of diethylenetriamine, heat it at 52℃ for 2.5h, add 80g of succinic anhydride, raise the temperature to 140℃ and continue heating and stirring for 3.5h, then cool to obtain amino-branched polyamide;

[0095] S2: Cleaning:

[0096] Take glass fiber, cut it into fibers of 3-20 mm, rinse the surface twice with deionized water and acetone alternately, and dry it to obtain cleaned glass fiber;

[0097] S3: Modification treatment:

[0098] 20 g of tetraethyl orthosilicate and 100 mL of ethanol were mixed and stirred evenly, and sodium hydroxide solution was added dropwise to adjust the pH to 11 to obtain a tetraethyl orthosilicate solution; the cleaned glass fiber was immersed in the tetraethyl orthosilicate solution and reacted for 3.5 hours, then removed and dried to obtain glass fiber A;

[0099] Take 2g of amino-branched polyamide, 80mL of deionized water, and 20mL of ethanol, stir evenly, add 1g of glass fiber A, heat to 61℃, react for 18min, filter, and dry to obtain glass fiber B;

[0100] The glass fiber B is immersed in the lubricant, taken out, and dried to obtain a modified glass fiber.

[0101] Comparative Example 2: No tetraethyl orthosilicate was added, and the rest was the same as in Example 1:

[0102] Step 1: Preparation of lubricant:

[0103] Take 6 g of fatty alcohol polyoxyethylene ether, 3 g of polyvinyl pyrrolidone, 1 g of triethanolamine borate, 2 g of paraffin, and 100 mL of deionized water, stir well to obtain a composite solution;

[0104] The composite solution contains the following components, calculated by weight: 7 parts of fatty alcohol polyoxyethylene ether, 4 parts of polyvinyl pyrrolidone, 1.5 parts of triethanolamine borate, 2.3 parts of paraffin wax, and 102 parts of deionized water;

[0105] Take 12 g of water-based polyamide and 100 mL of deionized water, stir evenly to obtain a polyamide solution;

[0106] The mass ratio of water-based polyamide and deionized water is 12:100;

[0107] Take 5g of coupling agent Y-9669 and 3g of coupling agent A-187, add 50mL of deionized water, stir evenly, add pH adjuster until the pH of the aqueous solution is 6, stir evenly to obtain a coupling agent solution;

[0108] The pH adjuster is citric acid;

[0109] Take 25g of aqueous polyurethane emulsion, add 100mL of deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain a lubricant;

[0110] Step 2: Preparation of modified glass fiber, including the following steps:

[0111] S1: Preparation of amino-branched polyamide:

[0112] Take 103g of diethylenetriamine, heat it at 52℃ for 2.5h, add 80g of succinic anhydride, raise the temperature to 140℃ and continue heating and stirring for 3.5h, then cool to obtain amino-branched polyamide;

[0113] S2: Plasma treatment:

[0114] The glass fiber was cut into 3-20 mm fibers, and the surface was rinsed twice with deionized water and acetone alternately, and dried to obtain cleaned glass fiber. The cleaned glass fiber was placed in a low-temperature plasma reaction device, filled with argon gas at a pressure of 0.1 MPa, and discharged at a power of 80 W for 3 minutes to obtain a plasma-treated glass fiber.

[0115] S3: Modification treatment:

[0116] Take 2g of amino-branched polyamide, 80mL of deionized water, and 20mL of ethanol, stir evenly, add 1g of plasma-treated glass fiber, heat to 61°C, react for 18min, filter, and dry to obtain glass fiber B;

[0117] The glass fiber B is immersed in the lubricant, taken out, and dried to obtain a modified glass fiber.

[0118] Comparative Example 3: No amino-branched polyamide was used to modify the surface of the glass fiber, and the rest was the same as in Example 1:

[0119] Step 1: Preparation of lubricant:

[0120] Take 6 g of fatty alcohol polyoxyethylene ether, 3 g of polyvinyl pyrrolidone, 1 g of triethanolamine borate, 2 g of paraffin, and 100 mL of deionized water, stir well to obtain a composite solution;

[0121] The composite solution contains the following components, calculated by weight: 7 parts of fatty alcohol polyoxyethylene ether, 4 parts of polyvinyl pyrrolidone, 1.5 parts of triethanolamine borate, 2.3 parts of paraffin wax, and 102 parts of deionized water;

[0122] Take 12 g of water-based polyamide and 100 mL of deionized water, stir evenly to obtain a polyamide solution;

[0123] The mass ratio of water-based polyamide and deionized water is 12:100;

[0124] Take 5g of coupling agent Y-9669 and 3g of coupling agent A-187, add 50mL of deionized water, stir evenly, add pH adjuster until the pH of the aqueous solution is 6, stir evenly to obtain a coupling agent solution;

[0125] The pH adjuster is citric acid;

[0126] Take 25g of aqueous polyurethane emulsion, add 100mL of deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain a lubricant;

[0127] Step 2: Preparation of modified glass fiber, including the following steps:

[0128] S1: Plasma treatment:

[0129] The glass fiber was cut into 3-20 mm fibers, and the surface was rinsed twice with deionized water and acetone alternately, and dried to obtain cleaned glass fiber. The cleaned glass fiber was placed in a low-temperature plasma reaction device, filled with argon gas at a pressure of 0.1 MPa, and discharged at a power of 80 W for 3 minutes to obtain a plasma-treated glass fiber.

[0130] S2: Modification treatment:

[0131] 20 g of tetraethyl orthosilicate and 100 mL of ethanol were mixed and uniformly stirred, and sodium hydroxide solution was added dropwise to adjust the pH to 11 to obtain a tetraethyl orthosilicate solution; the plasma-treated glass fiber was immersed in the tetraethyl orthosilicate solution and reacted for 3.5 hours, then removed and dried to obtain glass fiber A;

[0132] The glass fiber A is immersed in a lubricant, taken out, and dried to obtain a modified glass fiber.

[0133] Preparation of epoxy pultruded board:

[0134] The modified glass fibers prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were respectively taken, and a prepreg process was adopted, with 65 wt% glass fiber and 35 wt% polyamide resin, molded into sheets by hot pressing rollers, and then compositely molded at 0° and 90° horizontal and vertical angles to obtain epoxy pultruded boards.

[0135] experiment:

[0136] The epoxy pultruded boards prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for bending strength according to ASTM D790. The obtained data are shown in the following table:

[0137] Lubricant penetration state Bending strength / MPa Example 1 good 283 Example 2 good 280 Example 3 good 285 Comparative Example 1 good 276 Comparative Example 2 good 261 Comparative Example 3 good 258

[0138] Conclusion: From the comparison of the data in the table, it can be seen that the comparative example does not perform low-temperature plasma treatment on the surface of the glass fiber, and the surface area of the glass fiber is small. Therefore, the surface load of silica and amino-branched polyamide is less, the compatibility of the modified glass fiber with the lubricant is reduced, and the compatibility of the glass fiber with the polyamide resin is reduced, resulting in a decrease in the mechanical properties of the epoxy pultruded board. Comparative Example 2 does not add tetraethyl orthosilicate, and fails to form nano-silica on the surface of the glass fiber. Its surface roughness and acid and alkali resistance are reduced, resulting in a decrease in the mechanical properties of the epoxy pultruded board. Comparative Example 3 does not use amino-branched polyamide to perform surface modification treatment on the glass fiber, and the compatibility of the glass fiber with the polyamide resin is reduced, resulting in a decrease in the mechanical properties of the epoxy pultruded board. Examples 1 to 3 of the present invention first perform low-temperature plasma treatment on the surface of the glass fiber, making the surface of the glass fiber more slightly rough and increasing the surface area of the glass fiber; then, nano-silica is formed on the surface of the glass fiber by adding tetraethyl orthosilicate, further increasing its surface roughness and acid and alkali resistance. Finally, amino-branched polyamide is used to modify the surface of the glass fiber, making the modified glass fiber more compatible with the lubricant. At the same time, amino groups are loaded on the glass fiber, and the amino groups form chemical bonds with the polyamide resin, the base material of the pultruded board, thereby enhancing the compatibility of the glass fiber and the polyamide resin, thereby enhancing the mechanical properties of the epoxy pultruded board. The present invention prepares a lubricant and a modified glass fiber based on the lubricant. Fatty alcohol polyoxyethylene ether, polyvinyl pyrrolidone, triethanolamine borate, and paraffin are used to enhance the lubrication performance. Aqueous polyurethane emulsion is added to form a continuous and tough protective film, which significantly improves the wear resistance and mechanical damage resistance of the glass fiber. At this time, the lubricant of the glass fiber is well impregnated, meeting the industrial application standards.

[0139] 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 invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A lubricant-based modified glass fiber, characterized in that: The following steps are involved: S1: Take an aqueous polyurethane emulsion, add deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly, and obtain a lubricant; S2: Tetraethyl orthosilicate and ethanol were mixed and uniformly stirred, and sodium hydroxide solution was added dropwise to adjust the pH value to obtain a tetraethyl orthosilicate solution; the plasma-treated glass fiber was immersed in the tetraethyl orthosilicate solution and reacted for 3-4 hours, and then removed and dried to obtain glass fiber A; S3: Take amino-branched polyamide, deionized water, and ethanol, stir evenly, add glass fiber A, heat to 60-62°C, react for 15-20 minutes, filter, and dry to obtain glass fiber B; S4: Immerse the glass fiber B in the lubricant, take it out, and dry it to obtain a modified glass fiber.

2. The lubricant-based modified glass fiber according to claim 1, characterized in that: In S1, the preparation method of the lubricant comprises the following steps: Step 1: Take fatty alcohol polyoxyethylene ether, polyvinyl pyrrolidone, triethanolamine borate, paraffin, and deionized water, stir evenly to obtain a composite solution; Step 2: Take aqueous polyamide and deionized water, stir them evenly to obtain a polyamide solution; Step 3: Take a coupling agent, add deionized water, stir evenly, add a pH adjuster until the pH of the aqueous solution is 5-7, stir evenly, and obtain a coupling agent solution; Step 4: Take the aqueous polyurethane emulsion, add deionized water, stir evenly, add the composite solution and polyamide solution, stir evenly, add the coupling agent solution, stir evenly to obtain the lubricant.

3. The lubricant-based modified glass fiber according to claim 2, characterized in that: The composite solution contains the following components, calculated by weight: 6-8 parts of fatty alcohol polyoxyethylene ether, 3-5 parts of polyvinyl pyrrolidone, 1-2 parts of triethanolamine borate, 2-2.5 parts of paraffin, and 100-105 parts of deionized water.

4. The lubricant-based modified glass fiber according to claim 2, characterized in that: The mass ratio of the water-based polyamide to deionized water is (10-15):

100.

5. The lubricant-based modified glass fiber according to claim 2, characterized in that: The pH adjuster is any one or more of acetic acid, citric acid, and succinic acid.

6. The lubricant-based modified glass fiber according to claim 2, characterized in that: The coupling agents are coupling agent Y-9669 and coupling agent A-187.

7. The lubricant-based modified glass fiber according to claim 1, characterized in that: The preparation method of the plasma-treated glass fiber comprises: taking a glass fiber, washing the surface of the glass fiber alternately with deionized water and acetone, and drying the surface to obtain the cleaned glass fiber; placing the cleaned glass fiber in a low-temperature plasma reaction device, filling it with argon gas, and discharging it at a power of 80-85W for 3-4 minutes to obtain the plasma-treated glass fiber.

8. The lubricant-based modified glass fiber according to claim 1, characterized in that: The preparation method of the amino-branched polyamide is as follows: diethylenetriamine is heated at 50-55° C. for 2-3 hours, succinic anhydride is added, the temperature is raised to 140° C., the mixture is heated and stirred for 3-4 hours, and the mixture is cooled to obtain the amino-branched polyamide.

9. The modified glass fiber prepared according to the lubricant-based modified glass fiber according to any one of claims 1 to 8.

10. Use of the modified glass fiber according to claim 9 in epoxy pultruded board.