A self-lubricating sizing agent for silicon carbide fiber weaving and preparation method thereof

Abstract

The present invention relates to a self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The technical scheme is as follows: the raw material components of the self-lubricating sizing agent are: 25 to 34 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 6 to 9 parts by mass of active auxiliary agent, 13 to 19 parts by mass of fatty alcohol polyoxyethylene ether, 2 to 5 parts by mass of yttrium nitrate, 35 to 47 parts by mass of silica sol and 1.5 to 4.5 parts by mass of mixed regulator; the raw materials of the self-lubricating sizing agent are vacuum-mixed and uniformly kneaded, then steam-autoclaved in an oil bath at 100 to 110°C for 3 to 4 hours, rapidly cooled to 40 to 50°C, and then high-shear emulsified at 1150 to 1200 r / min for 2.5 to 3 hours to obtain the self-lubricating sizing agent for silicon carbide fiber weaving. The invention has low cost, simple process and is environmentally friendly. The wear resistance, breaking strength and shear performance of the manufactured product are improved, the phenomenon of hairy and broken wires is significantly improved, and the stability of the product in three-dimensional texture is comprehensively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of self-lubricating sizing agents, and specifically relates to a self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. Background Art

[0002] Silicon carbide fiber has the advantages of high temperature oxidation resistance, high hardness, high strength, high thermal stability, corrosion resistance and low density. It is one of the ideal high temperature resistant, enhanced and stealth materials for aerospace. With the rapid development of modern radio technology and radar detection systems, stealth technology, as an effective means to improve the survival, penetration and especially deep strike capabilities of weapon systems, has become a hot spot for military powers to compete for high-tech armaments. For stealth materials used in special environments, in addition to basic conditions such as reducing detectability, the materials are also required to have good thermal stability and corrosion resistance. SiC / SiC not only has excellent mechanical properties, antioxidant properties and longer high temperature service life, but also has good wave absorbing properties, which can meet the stealth requirements of high temperature parts of weapons and equipment such as the surface of hypersonic aircraft, engine tail nozzles, and cruise missile noses, and has broad application prospects.

[0003] However, continuous silicon carbide fiber is a ceramic fiber. During the production and subsequent transportation, friction and wear will occur, resulting in fuzz, which not only affects the smooth progress of subsequent processes but also reduces the overall performance of silicon carbide fiber. In addition, the preform woven from continuous silicon carbide fiber is constantly subjected to mechanical friction during the weaving process, and the fiber bundle is prone to repeated friction, causing the silicon carbide fiber bundle to fuzz, split, or even break. Furthermore, the opening is unclear during the weaving warp opening stage, resulting in defects in the final fabric, unstable dimensional structure, and other conditions, which reduces the comprehensive mechanical properties of the fiber three-dimensional texture. It can be seen that the performance damage and structural defects of continuous silicon carbide fibers during the weaving process have affected its processability and limited the scope of application of the fiber.

[0004] The sizing process is a method to improve the weaving performance of continuous silicon carbide fibers. Sizing is used to improve the wear resistance, bundling and antistatic properties of continuous silicon carbide fibers, reduce the friction coefficient of continuous silicon carbide fibers, reduce the amount of hair during processing and application, and meet the requirements of continuous silicon carbide fiber performance in the later three-dimensional texture forming process such as weaving, laying, and winding. Sizing plays a vital role in improving the mechanical properties of continuous silicon carbide fibers, so the research on the preparation of continuous silicon carbide fibers and the formulation of sizing agents has attracted the attention of technicians.

[0005] The patented technology of "a continuous silicon carbide fiber sizing agent and its application" (CN116180451A) uses waterborne polyurethane modified epoxy resin, acrylate modified polyurethane, emulsifier and softener as raw materials to prepare a continuous silicon carbide fiber sizing agent. The silicon carbide fiber sizing agent prepared by this method has fewer activated components and the sizing uniformity cannot be effectively guaranteed.

[0006] The patented technology of "A sizing agent for silicon carbide or silicon nitride fibers, its preparation method and application" (CN109853238A) uses polyvinyl alcohol, modified silicone oil, alkylphenol polyoxyethylene ether, benzoic acid and deionized water as raw materials to prepare a sizing agent for silicon carbide or silicon nitride fibers. The sizing agent for silicon carbide or silicon nitride fibers prepared by this method has a high degree of crosslinking, and the hardness of the bundles after sizing is high, but the bundling is poor.

[0007] The patented technology of "a fluorine-containing silicon carbide fiber sizing agent and its preparation method and application" (CN117684396A) uses polyfluoroethylene compounds, polyvinyl pyrrolidone, silane coupling agent and polyethylene glycol octylphenyl ether as raw materials to prepare a fluorine-containing silicon carbide fiber sizing agent. The fluorine-containing silicon carbide fiber sizing agent prepared by this method is relatively unfriendly to the environment, and a large amount of harmful gases are discharged during the degumming process.

[0008] The patented technology of "an epoxy resin sizing agent for continuous silicon carbide fibers and its preparation method and application" (CN110130108A) uses deionized water, epoxy resin, dispersant and leveling agent, wetting agent, emulsifier and preservative as raw materials to prepare the epoxy resin sizing agent for continuous silicon carbide fibers. The epoxy resin sizing agent for continuous silicon carbide fibers prepared by this method has poor binding force and the degree of activation of the epoxy resin is low. Summary of the invention

[0009] The present invention aims to overcome the defects of the prior art and has the purpose of providing a low-cost, simple-process and environmentally friendly self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The prepared self-lubricating sizing agent for silicon carbide fiber weaving has improved wear resistance, breaking strength and shear performance, can improve the phenomenon of broken wires, comprehensively improve the stability of the product during three-dimensional texturing, and has good biodegradability.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is:

[0011] The raw material components of the self-lubricating sizing agent are: 25 to 34 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 6 to 9 parts by mass of active auxiliary agent, 13 to 19 parts by mass of fatty alcohol polyoxyethylene ether, 2 to 5 parts by mass of yttrium nitrate, 35 to 47 parts by mass of silica sol and 1.5 to 4.5 parts by mass of mixed regulator; the raw materials of the self-lubricating sizing agent are vacuum-mixed to be uniform, and then steam hot-pressed in an oil bath at 100 to 110° C. for 3 to 4 hours, rapidly cooled to 40 to 50° C., and then high-shear emulsified at 1150 to 1200 r / min for 2.5 to 3 hours to obtain the self-lubricating sizing agent for silicon carbide fiber weaving.

[0012] The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 30-40 parts by weight of polypropylene carbonate type polyol, 15-20 parts by weight of isophorone diisocyanate, 1-2 parts by weight of dibutyltin dilaurate, 1-2 parts by weight of 2,2-dihydroxymethylpropionic acid, 2-5 parts by weight of di-n-butylamine-toluene solution, 5-8 parts by weight of acetone, 4-6 parts by weight of bisphenol A type epoxy resin E-44, 3-5 parts by weight of a mixed solution of triethylamine and acetone, 5-10 parts by weight of deionized water and 3-5 parts by weight of ethylenediamine are prepared. The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 90-120°C for 2-3 hours, and naturally cooled to room temperature; nitrogen is introduced, isophorone diisocyanate is added, and the reaction is carried out for 1.5-2.5 hours; dibutyltin dilaurate and 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 2-3 hours; then the di-n-butylamine-toluene solution is added, and the temperature is kept at 70-90°C in an oil bath for 0.5-1 hour; acetone is added, and stirred for 0. 5 to 1h; then continue to add the bisphenol A epoxy resin E-44, stir for 4 to 5h, naturally cool to 25 to 30°C, add the mixed solution of triethylamine and acetone, and stir for 1 to 1.5h; then add the deionized water under the high-speed shear emulsification condition of 1150 to 1200r / min, end the high-shear emulsification, and let it stand for 0.1 to 0.2h; finally add the ethylenediamine, and carry out polycondensation reaction for 0.5 to 1h to obtain an epoxy resin modified waterborne polyurethane emulsion.

[0013] The active auxiliary agent is one or more of acrylate, sodium sulfonate, tung oil-based glycol, and calcium carboxylate.

[0014] The Y(NO3)3·6H2O content of the yttrium nitrate is ≥99.8wt%.

[0015] The concentration of the silica sol is 0.1 mol / L or 0.15 mol / L.

[0016] The mixed regulator is prepared by mixing 2 to 5 parts by mass of anhydrous ethanol, 2 to 5 parts by mass of hydrochloric acid and 3 to 5 parts by mass of polyacrylamide.

[0017] The rapid cooling rate is 50-60°C / min.

[0018] The vacuum degree of the vacuum kneading is ≤0.0001MPa.

[0019] The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and nitrogen, or a mixed atmosphere of ethanol and argon; the pressure of the steam hot pressing is 1-1.5 MPa.

[0020] Due to the adoption of the above technical solution, the present invention has the following positive effects compared with the prior art:

[0021] 1. The epoxy resin modified waterborne polyurethane emulsion used in the present invention can be stored stably for a long time, can effectively avoid the problem of unstable preparation in practical applications, is not easy to produce colloidal precipitates, improves sizing uniformity, optimizes the weaving performance of silicon carbide fibers, and solves the problems of uniformity and stability of the self-lubricating sizing agent used for silicon carbide fiber weaving.

[0022] 2. The present invention adopts an organic-inorganic hybrid method and utilizes inorganic quantum dot interface doping to introduce Si-O structure into the self-lubricating sizing agent used for silicon carbide fiber weaving. The Si-O bond can produce hydrogen bonds with the groups on the surface of the silicon carbide fiber, so that the silicon carbide quantum dots show hydrophilic properties, effectively improve the bundling and flexibility of the silicon carbide fiber, effectively avoid damage to the silicon carbide fiber, and significantly improve the phenomenon of silicon carbide fiber breakage.

[0023] 3. After high-temperature debinding, the present invention has Si-O bonds on the surface of silicon carbide quantum dots, and the Si-OH on the surface of silicon carbide quantum dots replaces the Si-O-Si bridging oxygen bonds inside silicon oxide, making it easy for the matrix to infiltrate the silicon carbide fibers, thereby enhancing the bonding force of the silicon carbide fibers and greatly improving the shear strength of the silicon carbide fibers.

[0024] 4. The self-lubricating sizing agent for silicon carbide fiber weaving prepared by the present invention does not contain any components that are unfriendly to the environment or harmful to the human body, and does not generate harmful gases when used at high temperatures, thereby significantly improving the atmospheric environment and the working environment of operators.

[0025] 5. The raw materials used in the present invention are easily available and have low production costs. Water is used as a solvent during the preparation process and no volatile organic matter is added, which is beneficial to environmental protection. The preparation method is simple, stable and uniform, and it is easier to form a film and adhere to the silicon carbide fiber. At the same time, it is easy to desize, is environmentally friendly, has stable performance, and is easy to implement and promote on the production line.

[0026] 6. The present invention reduces the friction coefficient of silicon carbide fiber through sizing treatment, thereby effectively improving the wear resistance of brittle continuous silicon carbide fiber, making it have certain self-lubricating properties, and at the same time improving the phenomenon of fuzz and broken fibers after friction of silicon carbide fiber, improving the mechanical properties and processing properties of silicon carbide fiber, thereby improving the weavability and weaving efficiency of continuous silicon carbide fiber and the product quality of silicon carbide fabric.

[0027] 7. The present invention adds suitable self-lubricating additives and different formulas to the products for sizing the fibers. The wear resistance is characterized by friction testing and observing the changes in the fiber friction coefficient and wear rate. The tests of the fiber sizing rate, tensile strength and stiffness show that the fiber fabric exhibits excellent weaving performance. It can effectively reduce the friction coefficient, further improve the wear resistance of continuous silicon carbide fibers, give silicon carbide fibers certain self-lubricating properties, enhance their mechanical properties, and improve the weavability of silicon carbide fibers. At the same time, the sizing materials in the self-lubricating sizing agent used for silicon carbide fiber weaving are all degradable, easy to mix evenly with water, have good film-forming properties, environmental friendliness, and simple sizing operation. Sizing can be done at low temperatures and desizing is easy.

[0028] The properties of silicon carbide fibers sized with the self-lubricating sizing agent for silicon carbide fiber weaving prepared by the present invention were tested: the sizing rate was 1.56-1.70%; the tensile strength was 2.19-2.67 MPa; the stiffness was 8.89-9.02 cm; the wear rate was 1.25-1.43%; and the friction coefficient was 0.12-0.138.

[0029] The properties of the fiber which was not sized by the self-lubricating sizing agent for silicon carbide fiber weaving prepared by the present invention were tested: the tensile strength was 1.35 MPa; the stiffness was 8.65 cm; the wear rate was 2.85%; and the friction coefficient was 0.53.

[0030] Therefore, the present invention has the advantages of low cost, simple process and environmental friendliness. The prepared self-lubricating sizing agent for silicon carbide fiber weaving has improved wear resistance, breaking strength and shear performance, and the phenomenon of fuzzy and broken fibers is significantly improved, thereby comprehensively improving the stability of the product during three-dimensional texturing and having good biodegradability. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with specific implementation modes, which is not intended to limit the protection scope of the present invention.

[0032] A self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The preparation method of this specific embodiment is:

[0033] The raw material components of the self-lubricating sizing agent are: 25 to 34 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 6 to 9 parts by mass of active auxiliary agent, 13 to 19 parts by mass of fatty alcohol polyoxyethylene ether, 2 to 5 parts by mass of yttrium nitrate, 35 to 47 parts by mass of silica sol and 1.5 to 4.5 parts by mass of mixed regulator; the raw materials of the self-lubricating sizing agent are vacuum-mixed to be uniform, and then steam hot-pressed in an oil bath at 100 to 110° C. for 3 to 4 hours, rapidly cooled to 40 to 50° C., and then high-shear emulsified at 1150 to 1200 r / min for 2.5 to 3 hours to obtain the self-lubricating sizing agent for silicon carbide fiber weaving.

[0034] The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 30-40 parts by weight of polypropylene carbonate type polyol, 15-20 parts by weight of isophorone diisocyanate, 1-2 parts by weight of dibutyltin dilaurate, 1-2 parts by weight of 2,2-dihydroxymethylpropionic acid, 2-5 parts by weight of di-n-butylamine-toluene solution, 5-8 parts by weight of acetone, 4-6 parts by weight of bisphenol A type epoxy resin E-44, 3-5 parts by weight of a mixed solution of triethylamine and acetone, 5-10 parts by weight of deionized water and 3-5 parts by weight of ethylenediamine are prepared. The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 90-120°C for 2-3 hours, and naturally cooled to room temperature; nitrogen is introduced, isophorone diisocyanate is added, and the reaction is carried out for 1.5-2.5 hours; dibutyltin dilaurate and 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 2-3 hours; then the di-n-butylamine-toluene solution is added, and the temperature is kept at 70-90°C in an oil bath for 0.5-1 hour; acetone is added, and stirred for 0. 5 to 1h; then continue to add the bisphenol A epoxy resin E-44, stir for 4 to 5h, naturally cool to 25 to 30°C, add the mixed solution of triethylamine and acetone, and stir for 1 to 1.5h; then add the deionized water under the high-speed shear emulsification condition of 1150 to 1200r / min, end the high-shear emulsification, and let it stand for 0.1 to 0.2h; finally add the ethylenediamine, and carry out polycondensation reaction for 0.5 to 1h to obtain an epoxy resin modified waterborne polyurethane emulsion.

[0035] The active auxiliary agent is one or more of acrylate, sodium sulfonate, tung oil-based glycol, and calcium carboxylate.

[0036] The concentration of the silica sol is 0.1 mol / L or 0.15 mol / L.

[0037] The mixed regulator is prepared by mixing 2 to 5 parts by mass of anhydrous ethanol, 2 to 5 parts by mass of hydrochloric acid and 3 to 5 parts by mass of polyacrylamide.

[0038] The rapid cooling rate is 50-60°C / min.

[0039] The vacuum degree of the vacuum kneading is ≤0.0001MPa.

[0040] The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and nitrogen, or a mixed atmosphere of ethanol and argon; the pressure of the steam hot pressing is 1-1.5 MPa.

[0041] In this specific implementation mode:

[0042] The Y(NO3)3·6H2O content of the yttrium nitrate is ≥99.8wt%.

[0043] This will not be described in detail in the embodiments.

[0044] Example 1

[0045] A self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The preparation method of this embodiment is:

[0046] The raw material components of the self-lubricating sizing agent are: 25 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 6 parts by mass of active auxiliary agent, 13 parts by mass of fatty alcohol polyoxyethylene ether, 2 parts by mass of yttrium nitrate, 35 parts by mass of silica sol and 1.5 parts by mass of mixed regulator. The raw materials of the self-lubricating sizing agent are vacuum-mixed and uniformly mixed, and then steam hot-pressed in a 100°C oil bath for 3 hours, rapidly cooled to 40°C, and then high-shear emulsified at 1150r / min for 2.5 hours to obtain a self-lubricating sizing agent for silicon carbide fiber weaving.

[0047] The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 30 parts by mass of polypropylene carbonate type polyol, 15 parts by mass of isophorone diisocyanate, 1 part by mass of dibutyltin dilaurate, 1 part by mass of 2,2-dihydroxymethylpropionic acid, 2 parts by mass of di-n-butylamine-toluene solution, 5 parts by mass of acetone, 4 parts by mass of bisphenol A type epoxy resin E-44, 3 parts by mass of a mixed solution of triethylamine and acetone, 5 parts by mass of deionized water and 3 parts by mass of ethylenediamine are prepared. The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 90° C. for 2 hours, and naturally cooled to room temperature; nitrogen is introduced, and the isophorone diisocyanate is added, and the reaction is continued for 1.5 hours; the dibutyltin dilaurate and the 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 2 hours; then the di-n-butylamine-toluene solution is added, and the mixture is kept warm in an oil bath at 70° C. for 0.5 hours; the acetone is added, and the mixture is stirred for 0.5 hours; then the bisphenol A type epoxy resin E-44 is added, and the mixture is stirred for 4 hours, and the mixture is naturally cooled to 25° C., and the mixture of triethylamine and acetone is added, and the mixture is stirred for 1 hour; then the deionized water is added under high-speed shear emulsification conditions of 1150 r / min, the high-shear emulsification is completed, and the mixture is allowed to stand for 0.1 hours; finally, the ethylenediamine is added, and the polycondensation reaction is carried out for 0.5 hours to obtain an epoxy resin modified waterborne polyurethane emulsion.

[0048] The active auxiliary agent is acrylate.

[0049] The concentration of the silica sol is 0.1 mol / L.

[0050] The mixed regulator is prepared by mixing 2 parts by mass of anhydrous ethanol, 2 parts by mass of hydrochloric acid and 3 parts by mass of polyacrylamide.

[0051] The rapid cooling rate is 50°C / min.

[0052] The vacuum degree of the vacuum kneading is 0.0001 MPa.

[0053] The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and nitrogen; the pressure of the steam hot pressing is 1 MPa.

[0054] The properties of the silicon carbide fiber sized with the self-lubricating sizing agent for silicon carbide fiber weaving prepared by this embodiment were tested: the sizing rate was 1.56%; the tensile strength was 2.67 MPa; the stiffness was 8.90 cm; the wear rate was 1.34%; and the friction coefficient was 0.32.

[0055] Example 2

[0056] A self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The preparation method of this embodiment is:

[0057] The raw material components of the self-lubricating sizing agent are: 34 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 9 parts by mass of active auxiliary agent, 19 parts by mass of fatty alcohol polyoxyethylene ether, 5 parts by mass of yttrium nitrate, 47 parts by mass of silica sol and 4.5 parts by mass of mixed regulator. The raw materials of the self-lubricating sizing agent are vacuum-mixed and uniformly mixed, and then steam hot-pressed in an oil bath at 110°C for 4 hours, rapidly cooled to 50°C, and then high-shear emulsified at 1200r / min for 3 hours to obtain a self-lubricating sizing agent for silicon carbide fiber weaving.

[0058] The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 40 parts by mass of polypropylene carbonate type polyol, 20 parts by mass of isophorone diisocyanate, 2 parts by mass of dibutyltin dilaurate, 2 parts by mass of 2,2-dihydroxymethylpropionic acid, 5 parts by mass of di-n-butylamine-toluene solution, 8 parts by mass of acetone, 6 parts by mass of bisphenol A type epoxy resin E-44, 5 parts by mass of a mixed solution of triethylamine and acetone, 10 parts by mass of deionized water and 5 parts by mass of ethylenediamine are prepared. The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 120° C. for 3 hours, and naturally cooled to room temperature; nitrogen is introduced, and the isophorone diisocyanate is added, and the reaction is continued for 2.5 hours; the dibutyltin dilaurate and the 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 3 hours; then the di-n-butylamine-toluene solution is added, and the mixture is kept warm in a 90° C. oil bath for 1 hour; the acetone is added, and the mixture is stirred for 1 hour; then the bisphenol A type epoxy resin E-44 is added, and the mixture is stirred for 5 hours, and the mixture is naturally cooled to 30° C., and the mixture of triethylamine and acetone is added, and the mixture is stirred for 1.5 hours; then the deionized water is added under the high-speed shear emulsification condition of 1200 r / min, the high-shear emulsification is terminated, and the mixture is allowed to stand for 0.2 hours; finally, the ethylenediamine is added, and the polycondensation reaction is carried out for 0.8 hours to obtain an epoxy resin modified waterborne polyurethane emulsion.

[0059] The active auxiliary agent is sodium sulfonate.

[0060] The concentration of the silica sol is 0.15 mol / L.

[0061] The mixed regulator is prepared by mixing 3 parts by mass of anhydrous ethanol, 3 parts by mass of hydrochloric acid and 4 parts by mass of polyacrylamide.

[0062] The rapid cooling rate is 60°C / min.

[0063] The vacuum degree of the vacuum kneading is 0.00003MPa.

[0064] The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and argon; the pressure of the steam hot pressing is 1.2 MPa.

[0065] The properties of the silicon carbide fiber sized with the self-lubricating sizing agent for silicon carbide fiber weaving prepared by this embodiment were tested: the sizing rate was 1.72%; the tensile strength was 2.23 MPa; the stiffness was 8.99 cm; the wear rate was 1.43%; and the friction coefficient was 0.135.

[0066] Example 3

[0067] A self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The preparation method of this embodiment is:

[0068] The raw material components of the self-lubricating sizing agent are: 28 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 7 parts by mass of active auxiliary agent, 14 parts by mass of fatty alcohol polyoxyethylene ether, 3 parts by mass of yttrium nitrate, 37 parts by mass of silica sol and 2 parts by mass of mixed regulator. The raw materials of the self-lubricating sizing agent are vacuum kneaded uniformly, then steam hot-pressed in an oil bath at 105°C for 3.5 hours, rapidly cooled to 45°C, and then high-shear emulsified at 1180r / min for 2.5 hours to obtain a self-lubricating sizing agent for silicon carbide fiber weaving.

[0069] The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 35 parts by mass of polypropylene carbonate type polyol, 18 parts by mass of isophorone diisocyanate, 1.5 parts by mass of dibutyltin dilaurate, 1.5 parts by mass of 2,2-dihydroxymethylpropionic acid, 3 parts by mass of di-n-butylamine-toluene solution, 6 parts by mass of acetone, 5 parts by mass of bisphenol A type epoxy resin E-44, 4 parts by mass of a mixed solution of triethylamine and acetone, 6 parts by mass of deionized water and 4 parts by mass of ethylenediamine are prepared. The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 100° C. for 2.5 hours, and naturally cooled to room temperature; nitrogen is introduced, and the isophorone diisocyanate is added, and the reaction is continued for 2 hours; the dibutyltin dilaurate and the 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 2.5 hours; then the di-n-butylamine-toluene solution is added, and the mixture is kept warm in an oil bath at 80° C. for 0.5 hours; the acetone is added, and the mixture is stirred for 0.5 hours; then the bisphenol A type epoxy resin E-44 is added, and the mixture is stirred for 4.5 hours, and the mixture is naturally cooled to 25° C., and the mixture of triethylamine and acetone is added, and the mixture is stirred for 1.8 hours; then the deionized water is added under high-speed shear emulsification conditions of 1180 r / min, the high-shear emulsification is completed, and the mixture is allowed to stand for 0.2 hours; finally, the ethylenediamine is added, and the polycondensation reaction is carried out for 1 hour to obtain an epoxy resin modified waterborne polyurethane emulsion.

[0070] The active auxiliary agent is tung oil-based glycol.

[0071] The concentration of the silica sol is 0.1 mol / L.

[0072] The mixed regulator is prepared by mixing 3 parts by mass of anhydrous ethanol, 4 parts by mass of hydrochloric acid and 5 parts by mass of polyacrylamide.

[0073] The rapid cooling rate is 55°C / min.

[0074] The vacuum degree of the vacuum kneading is 0.00005MPa.

[0075] The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and nitrogen; the pressure of the steam hot pressing is 1.5 MPa.

[0076] The properties of the silicon carbide fiber sized with the self-lubricating sizing agent for silicon carbide fiber weaving prepared by this embodiment were tested: the sizing rate was 1.65%; the tensile strength was 2.39 MPa; the stiffness was 8.93 cm; the wear rate was 1.25%; and the friction coefficient was 0.122.

[0077] Example 4

[0078] A self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The preparation method of this embodiment is:

[0079] The raw material components of the self-lubricating sizing agent are: 30 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 8 parts by mass of active auxiliary agent, 17 parts by mass of fatty alcohol polyoxyethylene ether, 4 parts by mass of yttrium nitrate, 41 parts by mass of silica sol and 4 parts by mass of mixed regulator. The raw materials of the self-lubricating sizing agent are vacuum kneaded uniformly, then steam hot-pressed in a 100°C oil bath for 3 hours, quickly cooled to 40°C, and then high-shear emulsified at 1150r / min for 2.5 hours to obtain a self-lubricating sizing agent for silicon carbide fiber weaving.

[0080] The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 32 parts by mass of polypropylene carbonate type polyol, 19 parts by mass of isophorone diisocyanate, 2 parts by mass of dibutyltin dilaurate, 1 part by mass of 2,2-dihydroxymethylpropionic acid, 4 parts by mass of di-n-butylamine-toluene solution, 6 parts by mass of acetone, 4 parts by mass of bisphenol A type epoxy resin E-44, 5 parts by mass of a mixed solution of triethylamine and acetone, 9 parts by mass of deionized water and 5 parts by mass of ethylenediamine are prepared. The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 110° C. for 3 hours, and naturally cooled to room temperature; nitrogen is introduced, and the isophorone diisocyanate is added, and the reaction is continued for 2.5 hours; the dibutyltin dilaurate and the 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 3 hours; then the di-n-butylamine-toluene solution is added, and the mixture is kept warm in an oil bath at 85° C. for 0.5 hours; the acetone is added, and the mixture is stirred for 0.5 hours; then the bisphenol A type epoxy resin E-44 is added, and the mixture is stirred for 4 hours, and the mixture is naturally cooled to 28° C., and the mixture of triethylamine and acetone is added, and the mixture is stirred for 1.3 hours; then the deionized water is added under high-speed shear emulsification conditions of 1160 r / min, the high-shear emulsification is completed, and the mixture is allowed to stand for 0.1 hours; finally, the ethylenediamine is added, and the polycondensation reaction is carried out for 0.6 hours to obtain an epoxy resin modified waterborne polyurethane emulsion.

[0081] The active auxiliary agent is calcium carboxylate.

[0082] The concentration of the silica sol is 0.15 mol / L.

[0083] The mixed regulator is prepared by mixing 4 parts by mass of anhydrous ethanol, 3 parts by mass of hydrochloric acid and 4 parts by mass of polyacrylamide.

[0084] The rapid cooling rate is 50°C / min.

[0085] The vacuum degree of the vacuum kneading is 0.00008MPa.

[0086] The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and argon; the pressure of the steam hot pressing is 1.3 MPa.

[0087] The properties of the silicon carbide fiber sized with the self-lubricating sizing agent for silicon carbide fiber weaving prepared by this embodiment were tested: the sizing rate was 1.62%; the tensile strength was 2.19 MPa; the stiffness was 8.89 cm; the wear rate was 1.324%; and the friction coefficient was 0.138.

[0088] Example 5

[0089] A self-lubricating sizing agent for silicon carbide fiber weaving and a preparation method thereof. The preparation method of this embodiment is:

[0090] The raw material components of the self-lubricating sizing agent are: 32 parts by mass of epoxy resin modified waterborne polyurethane emulsion, 9 parts by mass of active auxiliary agent, 15 parts by mass of fatty alcohol polyoxyethylene ether, 4 parts by mass of yttrium nitrate, 45 parts by mass of silica sol and 3 parts by mass of mixed regulator. The raw materials of the self-lubricating sizing agent are vacuum kneaded uniformly, then steam hot-pressed in an oil bath at 110°C for 4 hours, rapidly cooled to 50°C, and then high-shear emulsified at 1200r / min for 3 hours to obtain a self-lubricating sizing agent for silicon carbide fiber weaving.

[0091] The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 38 parts by mass of polypropylene carbonate type polyol, 16 parts by mass of isophorone diisocyanate, 1 part by mass of dibutyltin dilaurate, 2 parts by mass of 2,2-dihydroxymethylpropionic acid, 2.5 parts by mass of di-n-butylamine-toluene solution, 7 parts by mass of acetone, 5 parts by mass of bisphenol A type epoxy resin E-44, 4 parts by mass of a mixed solution of triethylamine and acetone, 8 parts by mass of deionized water and 4 parts by mass of ethylenediamine are prepared. The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 95° C. for 2.5 hours, and naturally cooled to room temperature; nitrogen is introduced, and the isophorone diisocyanate is added, and the reaction is continued for 1.5 hours; the dibutyltin dilaurate and the 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 2.5 hours; then the di-n-butylamine-toluene solution is added, and the mixture is kept warm in an oil bath at 80° C. for 1 hour; the acetone is added, and the mixture is stirred for 1 hour; then the bisphenol A type epoxy resin E-44 is added, and the mixture is stirred for 5 hours, and the mixture is naturally cooled to 30° C., and the mixture of triethylamine and acetone is added, and the mixture is stirred for 1.6 hours; then the deionized water is added under high-speed shear emulsification conditions of 1170 r / min, the high-shear emulsification is completed, and the mixture is allowed to stand for 0.15 hours; finally, the ethylenediamine is added, and the polycondensation reaction is carried out for 0.9 hours to obtain an epoxy resin modified waterborne polyurethane emulsion.

[0092] The active auxiliary agent is acrylate.

[0093] The concentration of the silica sol is 0.1 mol / L.

[0094] The mixed regulator is prepared by mixing 5 parts by mass of anhydrous ethanol, 5 parts by mass of hydrochloric acid and 5 parts by mass of polyacrylamide.

[0095] The rapid cooling rate is 60°C / min.

[0096] The vacuum degree of the vacuum kneading is 0.00001 MPa.

[0097] The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and nitrogen; the pressure of the steam hot pressing is 1-1.4 MPa.

[0098] The properties of the silicon carbide fiber sized with the self-lubricating sizing agent for silicon carbide fiber weaving prepared by this embodiment were tested: the sizing rate was 1.70%; the tensile strength was 2.55 MPa; the stiffness was 9.02 cm; the wear rate was 1.28%; and the friction coefficient was 0.123.

[0099] Compared with the prior art, this specific implementation has the following positive effects:

[0100] 1. The epoxy resin modified waterborne polyurethane emulsion used in this specific embodiment can be stored stably for a long time, can effectively avoid the problem of unstable preparation in practical applications, is not easy to produce colloidal precipitates, improves sizing uniformity, optimizes the weaving performance of silicon carbide fibers, and solves the problems of uniformity and stability of the self-lubricating sizing agent used for silicon carbide fiber weaving.

[0101] 2. This specific implementation adopts an organic-inorganic hybrid method and utilizes inorganic quantum dot interface doping to introduce Si-O structure into the self-lubricating sizing agent used for silicon carbide fiber weaving. The Si-O bond can produce hydrogen bonds with the groups on the surface of the silicon carbide fiber, so that the silicon carbide quantum dots show hydrophilic properties, effectively improve the bundling and flexibility of the silicon carbide fiber, effectively avoid damage to the silicon carbide fiber, and significantly improve the phenomenon of silicon carbide fiber breakage.

[0102] 3. In this specific embodiment, after high-temperature debinding, Si-O bonds exist on the surface of silicon carbide quantum dots, and Si-OH on the surface of silicon carbide quantum dots replaces Si-O-Si bridging oxygen bonds inside silicon oxide, making it easy for the matrix to infiltrate and penetrate silicon carbide fibers, thereby enhancing the bonding force of silicon carbide fibers and greatly improving the shear strength of silicon carbide fibers.

[0103] 4. The self-lubricating sizing agent for silicon carbide fiber weaving prepared in this specific embodiment does not contain any ingredients that are unfriendly to the environment or harmful to the human body, and does not produce harmful gases when used at high temperatures, which significantly improves the atmospheric environment and the working environment of operators.

[0104] 5. The raw materials used in this specific implementation are easy to obtain and have low production costs. Water is used as a solvent during the preparation process and no volatile organic matter is added, which is beneficial to environmental protection. The preparation method is simple, stable and uniform, and it is easier to form a film and adhere to the silicon carbide fiber. At the same time, it is easy to desize, is environmentally friendly, has stable performance, and is easy to implement and promote on the production line.

[0105] 6. This specific embodiment reduces the friction coefficient of silicon carbide fibers through sizing treatment, thereby effectively improving the wear resistance of brittle continuous silicon carbide fibers, making them have certain self-lubricating properties, and at the same time improving the fuzziness and broken wire phenomena that occur after friction of silicon carbide fibers, thereby improving the mechanical properties and processing properties of silicon carbide fibers, thereby improving the weavability and weaving efficiency of continuous silicon carbide fibers and the product quality of silicon carbide fabrics.

[0106] 7. This specific embodiment adds suitable self-lubricating additives and different formulas to the product to perform sizing treatment on the fiber. The wear resistance is characterized by friction testing and observing the changes in the fiber friction coefficient and wear rate. The tests of the fiber sizing rate, tensile strength and stiffness show that the fiber fabric exhibits excellent weaving performance. It can effectively reduce the friction coefficient, further improve the wear resistance of continuous silicon carbide fibers, give silicon carbide fibers certain self-lubricating properties, enhance their mechanical properties, and improve the weavability of silicon carbide fibers. At the same time, the sizing materials in the self-lubricating sizing agent used for silicon carbide fiber weaving are all degradable, easy to mix evenly with water, have good film-forming properties, environmental friendliness, and simple sizing operation. Sizing can be done at low temperatures and desizing is easy.

[0107] The properties of silicon carbide fibers sized with the self-lubricating sizing agent for silicon carbide fiber weaving prepared by this specific embodiment were tested: the sizing rate was 1.56-1.70%; the tensile strength was 2.19-2.67 MPa; the stiffness was 8.89-9.02 cm; the wear rate was 1.25-1.43%; and the friction coefficient was 0.12-0.138.

[0108] The properties of the fiber that was not sized by the self-lubricating sizing agent for silicon carbide fiber weaving prepared by the specific embodiment were tested: the tensile strength was 1.35 MPa; the stiffness was 8.65 cm; the wear rate was 2.85%; and the friction coefficient was 0.53.

[0109] Therefore, this specific embodiment has low cost, simple process and environmental friendliness. The prepared self-lubricating sizing agent for silicon carbide fiber weaving has improved wear resistance, breaking strength and shear performance, and the phenomenon of lint and broken wires is significantly improved, thereby comprehensively improving the stability of the product in three-dimensional texturing and having good biodegradability.

Claims

1. A method for preparing a self-lubricating sizing agent for silicon carbide fiber weaving, characterized in that: The raw material components of the self-lubricating sizing agent are: 25 to 34 parts by weight of epoxy resin modified waterborne polyurethane emulsion, 6 to 9 parts by weight of active auxiliary agent, 13 to 19 parts by weight of fatty alcohol polyoxyethylene ether, 2 to 5 parts by weight of yttrium nitrate, 35 to 47 parts by weight of silica sol and 1.5 to 4.5 parts by weight of mixing regulator; The raw materials of the self-lubricating sizing agent are vacuum-mixed and then subjected to steam hot pressing reaction in an oil bath at 100-110° C. for 3-4 hours, rapidly cooled to 40-50° C., and then high-shear emulsified at 1150-1200 r / min for 2.5-3 hours to obtain a self-lubricating sizing agent for silicon carbide fiber weaving.

2. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The preparation method of the epoxy resin modified waterborne polyurethane emulsion is as follows: 30-40 parts by weight of polypropylene carbonate type polyol, 15-20 parts by weight of isophorone diisocyanate, 1-2 parts by weight of dibutyltin dilaurate, 1-2 parts by weight of 2,2-dihydroxymethylpropionic acid, 2-5 parts by weight of di-n-butylamine-toluene solution, 5-8 parts by weight of acetone, 4-6 parts by weight of bisphenol A type epoxy resin E-44, 3-5 parts by weight of a mixture of triethylamine and acetone, 5-10 parts by weight of deionized water and 3-5 parts by weight of ethylenediamine are prepared; The polypropylene carbonate type polyol is placed in a high-pressure reactor, dried at 90-120°C for 2-3 hours, and naturally cooled to room temperature; nitrogen is introduced, isophorone diisocyanate is added, and the reaction is carried out for 1.5-2.5 hours; dibutyltin dilaurate and 2,2-dihydroxymethylpropionic acid are added, and the reaction is continued for 2-3 hours; then the di-n-butylamine-toluene solution is added, and the temperature is kept at 70-90°C in an oil bath for 0.5-1 hour; acetone is added, and stirred for 0. 5 to 1h; then continue to add the bisphenol A epoxy resin E-44, stir for 4 to 5h, naturally cool to 25 to 30°C, add the mixed solution of triethylamine and acetone, and stir for 1 to 1.5h; then add the deionized water under the high-speed shear emulsification condition of 1150 to 1200r / min, end the high-shear emulsification, and let it stand for 0.1 to 0.2h; finally add the ethylenediamine, and carry out polycondensation reaction for 0.5 to 1h to obtain an epoxy resin modified waterborne polyurethane emulsion.

3. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The active auxiliary agent is one of acrylate, sodium sulfonate, tung oil-based glycol and calcium carboxylate.

4. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The Y(NO3)3·6H2O content of the yttrium nitrate is ≥99.8wt%.

5. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The concentration of the silica sol is 0.1 mol / L or 0.15 mol / L.

6. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The mixed regulator is prepared by mixing 2 to 5 parts by mass of anhydrous ethanol, 2 to 5 parts by mass of hydrochloric acid and 3 to 5 parts by mass of polyacrylamide.

7. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The rapid cooling rate is 50-60°C / min.

8. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The vacuum degree of the vacuum kneading is ≤0.0001MPa.

9. The method for preparing the self-lubricating sizing agent for silicon carbide fiber weaving according to claim 1, characterized in that: The atmosphere condition of the steam hot pressing is a mixed atmosphere of ethanol and nitrogen, or a mixed atmosphere of ethanol and argon; the pressure of the steam hot pressing is 1-1.5 MPa.

10. A self-lubricating sizing agent for silicon carbide fiber weaving, characterized in that The self-lubricating sizing agent for silicon carbide fiber weaving is a self-lubricating sizing agent for silicon carbide fiber weaving prepared according to the preparation method of the self-lubricating sizing agent for silicon carbide fiber weaving according to any one of claims 1 to 9.