Glass fiber impregnating compound for polyurethane wind turbine blade and preparation method of glass fiber impregnating compound

Abstract

The invention belongs to the technical field of glass fiber surface treatment, and particularly relates to a glass fiber impregnating compound for a polyurethane wind power blade and a preparation method thereof.The glass fiber impregnating compound for the polyurethane wind power blade comprises a coupling agent, a lubricant, hyperbranched polyether, a film-forming agent, a pH regulator and deionized water, and the film-forming agent is a polyurethane resin film-forming agent. According to the technical characteristics of a polyurethane pouring fabric, the impregnating compound suitable for producing glass fibers is obtained by selecting raw materials and optimizing the proportion of formula components, and after the glass fiber impregnating compound for the polyurethane wind power blade is used, a product can have better fatigue resistance, and the service life of the product is prolonged. And meanwhile, the product meets the technological requirements of blade manufacturers for producing polyurethane wind power blades.

Description

Technical Field

[0001] The present invention belongs to the technical field of glass fiber surface treatment, and particularly relates to a sizing agent for glass fiber used in polyurethane wind turbine blades and a preparation method thereof. Background Art

[0002] The designability and adjustability of polyurethane resin are very strong, and it has good adaptability to various fields and different application environments. In the early stage, polyurethane resin was mainly applied to functional materials such as coatings, foams, and adhesives; in terms of application to structural materials, it mostly focused on short fiber reinforced polyurethane resin, and a small amount was used in modified resins such as epoxy resin and unsaturated polyester resin. At present, the application field of polyurethane resin has gradually expanded to continuous fiber reinforced composites. Polyurethane has good toughness, strong impact resistance, low viscosity, can be rapidly cured at room temperature, and has almost no volatile substances, showing broad application prospects in the field of composites.

[0003] Polyurethane resin has characteristics such as good high resilience, wear resistance, oil resistance, low temperature resistance, and low price; the good resilience and deformation properties of polyurethane resin enable it to combine well with textile structure reinforcement materials, and the composite materials produced have high elongation at break and good toughness, endowing the composite materials with excellent mechanical properties.

[0004] With the advent of the era of wind power parity, the price competition of wind power complete machines has become increasingly fierce, and the price per unit kilowatt-hour of complete machines has reached new lows repeatedly. As the core component of wind power complete machines, the production price of blades has continued to decline, forcing blade manufacturers to continuously reduce manufacturing costs, which has promoted polyurethane resin to become another alternative matrix material that has attracted much attention in the wind power field. At present, there are already polyurethane wind turbine blades prepared using polyurethane. Compared with common epoxy resins, polyurethane resin has more excellent mechanical properties and fatigue resistance, fast curing speed, good processing performance, and better bonding force with glass fibers, which is of great significance for improving production efficiency and reducing production costs. The new polyurethane resin material exactly fits the development trend of large-scale and lightweight wind turbine blades, provides more possibilities for blade design, and helps to promote the development of clean energy. Thermosetting polyurethane resin itself has good toughness, and still has excellent performance in terms of static and fatigue properties under relatively high glass fiber content. At the same time, the resin system has low viscosity, can be rapidly infused without heating curing, and has good molding processability, making it an ideal material for the design and development of large wind turbine blades and high-efficiency manufacturing.

[0005] In the production process of wind power yarn for large wind turbine blades, it is necessary to coat a glass fiber sizing agent to achieve functions such as protection, lubrication, bundling, antistatic, and strengthening properties. During the wire drawing process, the lubricating component in the sizing agent can reduce the friction between the glass fiber roving and the oiler, bundling trough, and wire arranging device, avoiding problems with the roving tension caused by excessive friction coefficient, thereby reducing problems such as flying filaments, fraying of the filament bundle, and difficulty in unwinding the stuck roving bobbin. In addition, the sizing agent can also protect the fiber surface, prevent wear, and extend the service life of the fiber. Chinese Patent CN109095790A discloses a high-quality glass fiber sizing agent, which is composed of the following raw materials in parts by weight: 30-40 parts of polyorganosilicon polyurethane resin, 15-20 parts of modified starch, 8-13 parts of cyclodextrin-modified polyether, 2-6 parts of silane coupling agent, 1-4 parts of sodium citrate, 1-3 parts of film-forming aid, 5-8 parts of oregano oil, 3-6 parts of nano-crystalline cellulose particles, 2-5 parts of plant gum, 1-2 parts of antioxidant, 0.5-1 part of pH regulator, 2-4 parts of shell powder, 0.5-1 part of defoaming agent, and 70-85 parts of butyl acetate. Through the reasonable combination of various components, the present invention finally manufactures a sizing agent with excellent quality, which can effectively improve the physical and chemical properties of glass fiber textile yarn, enhance its strength, hardness and other properties, improve its processing quality, increase the yield rate, and has good popularization and application value.

[0006] Adding multiple components in the above patent makes the operation complex, increases the preparation difficulty of the sizing agent, and is prone to the phenomenon of stratification due to uneven mixing of raw materials. When used in the preparation of large wind power blades, there will be problems such as poor compatibility, difficult penetration, and uneven distribution, which is not conducive to enhancing the performance of glass fiber. Summary of the Invention

[0007] The purpose of the present invention is to provide a glass fiber sizing agent for polyurethane wind power blades, which has good compatibility with polyurethane resin and fast penetration; the composite material of glass fiber fabric reinforced with polyurethane resin produced by using the glass fiber sizing agent for polyurethane wind power blades has excellent mechanical properties; the present invention also provides a preparation method of the glass fiber sizing agent for polyurethane wind power blades.

[0008] The technical solution adopted by the present invention to solve its technical problems is: The glass fiber sizing agent for polyurethane wind power blades of the present invention includes a coupling agent, a lubricant, a hyperbranched polyether, a film-forming agent, a pH regulator, and deionized water, wherein the film-forming agent is a polyurethane resin film-forming agent.

[0009] Among them: The polyurethane resin film-forming agent mentioned above is a mixture of a first polyurethane resin film-forming agent and a second polyurethane resin film-forming agent; the molecular weight of the first polyurethane resin film-forming agent is 1500 - 4000, the particle size of the polyurethane resin particles in the first polyurethane resin film-forming agent is 0.6 - 3.6 μm, the molecular weight of the second polyurethane resin film-forming agent is 200 - 1000, the particle size of the polyurethane resin particles in the second polyurethane resin film-forming agent is 0.4 - 3.2 μm, and the mass ratio of the first polyurethane resin film-forming agent to the second polyurethane resin film-forming agent is 2.2 - 3.6:1.0 - 1.8.

[0010] The hyperbranched polyether mentioned above is a bisphenol A type hyperbranched polyether, the molecular weight of the bisphenol A type hyperbranched polyether is 1500 - 9000, and the bisphenol A type hyperbranched polyether is a hyperbranched polyether or hyperbranched block polyether with more than 8 branches with a bisphenol structure as the core.

[0011] The coupling agent mentioned above is a silane coupling agent, and the silane coupling agent is one or more of an amino silane coupling agent, an amide silane coupling agent, or a urea silane coupling agent.

[0012] The lubricant mentioned above is a mixture of PEG and a silicone oil lubricant, the mass ratio of PEG to the silicone oil lubricant is 1.5 - 4.5:1, and the pH regulator is one or more of formic acid, acetic acid, citric acid, or fluoboric acid.

[0013] In the glass fiber sizing agent for polyurethane wind turbine blades, the solid mass accounts for 5 - 15% of the total mass of the glass fiber sizing agent for polyurethane wind turbine blades. Taking the total solid mass of the glass fiber sizing agent for polyurethane wind turbine blades as 100%, the percentage of the solid mass of each component in the total solid mass of the glass fiber sizing agent for polyurethane wind turbine blades is as follows: Coupling agent 6 - 24% Film-forming agent 50 - 85% Lubricant 5 - 20% Hyperbranched polyether 2 - 10% pH regulator 1 - 5%.

[0014] The preferred percentage of the content of each component in the sizing agent mentioned above in the total solid mass of the sizing agent is as follows: Coupling agent 8 - 20% Film-forming agent 60 - 75% Lubricant 8 - 16% Hyperbranched polyether 3 - 8% pH regulator 1 - 5%.

[0015] The preparation method of the glass fiber sizing agent for polyurethane wind turbine blades includes the following steps: (1) First, add a pH regulator to deionized water and stir evenly, then add a coupling agent and stir evenly to obtain Solution A; (2) Add a polyurethane resin film-forming agent to deionized water and stir evenly to obtain Solution B; (3) Add hyperbranched polyether to deionized water and stir evenly to obtain Solution C; (4) Mix the lubricant with hot deionized water and stir evenly, then cool to room temperature to obtain Solution D; (5) Mix Solution A, Solution B, Solution C, Solution D and the remaining deionized water and stir evenly to obtain a glass fiber sizing agent for polyurethane wind turbine blades.

[0016] In the step (1) described above, the addition amount of deionized water is 30 - 40% of the total mass of the glass fiber sizing agent for polyurethane wind turbine blades.

[0017] In the step (2) described above, the mass ratio of the polyurethane resin film-forming agent to deionized water is 1:0.5 - 4, and in the step (3), the mass ratio of hyperbranched polyether to deionized water is 1:10 - 20.

[0018] In the step (4) described above, the mass ratio of the lubricant to hot deionized water is 1:7 - 15, and the temperature of the hot deionized water is 60 - 80 °C.

[0019] The sizing agent of the present invention can be applied in the production of glass fibers for polyurethane infusion.

[0020] The coupling agent selected in the present invention is a silane coupling agent with relatively strong reaction activity. Under the hydrolysis of the pH regulator, the formed silanol groups can react with the surface of the glass fiber to enhance the surface structural strength of the glass fiber and improve the performance of the glass fiber; in addition, the other end of the coupling agent has reactive functional groups such as amino groups that can react with the polyurethane resin. By reacting with the glass fiber and the resin matrix at both ends of the coupling agent respectively, a very special interface layer is formed. This interface layer directly affects the fatigue and static properties of the subsequent composite products. The dosage of the silane coupling agent and the combination of different silane coupling agents will directly affect the spatial network morphology of the interface layer. Therefore, the dosage and mixing ratio of the coupling agent are particularly important. The present invention controls the percentage of the solid mass of the silane coupling agent in the total solid mass of the sizing agent to be 6 - 24%, preferably 8 - 20%. Within this dosage range, the interface performance of the composite material is the best.

[0021] The coupling agent in the present invention is one or more of an amino silane coupling agent, an amide silane coupling agent or a urea silane coupling agent. The selected coupling agents all have good compatibility and reactivity with the polyurethane resin, and can effectively enhance the bonding strength and mechanical properties of the polyurethane resin. In the present invention, the amino silane coupling agent is preferably Momentive A - 1126, A - 1120, the amide silane coupling agent is preferably Momentive A - 1387, and the urea silane coupling agent is preferably Momentive A - 1160.

[0022] The polyurethane film-forming agent is the main component in the sizing agent. The amount of the film-forming agent directly affects the efficiency of the glass fiber drawing process and subsequent processes such as weaving. If the amount of the film-forming agent is too small, the fiber coating during the glass fiber drawing process will be poor and the amount of hairiness will be large. If the amount of the film-forming agent is too much, the air permeability and moisture absorption of the glass fiber will become poor, which will in turn affect the physical and mechanical properties of the fiber. Moreover, a thick film will be formed, reducing the fiber strength. When the glass fiber is under tension, it is not easy to disperse or the dispersion is uneven, resulting in poor conditions such as local hardness and slow local impregnation speed, affecting the performance of subsequent products. Therefore, it is necessary to determine a suitable dosage range of the film-forming agent to endow the glass fiber with good dispersibility, softness, slipperiness, etc. Through a large number of formulation tests, the optimal dosage of the film-forming agent is explored. In the present invention, the optimal dosage range of the solid mass of the film-forming agent accounting for the total solid mass of the sizing agent is 50 - 85%. Within the optimal dosage range of the film-forming agent, all aspects of the glass fiber have the best performance.

[0023] In the present invention, the film-forming agent is a mixture of polyurethane resin film-forming agents. The molecular weight of the first polyurethane resin film-forming agent is 1500 - 4000, and the particle size is 0.6 - 3.6 μm. Selecting a film-forming agent with a relatively large molecular weight can endow the fiber bundle with good adhesion and a certain stiffness, facilitating the drawing, forming, packaging, and transportation of glass fibers. The molecular weight of the second polyurethane resin film-forming agent is 200 - 1000, and the particle size is 0.4 - 3.2 μm. The small-molecule second polyurethane resin film-forming agent can be uniformly mixed with the first polyurethane resin film-forming agent to form a mixed and interlaced film-forming agent system. When the two are coated on the surface of the glass fiber and contact with the polyurethane resin, the second polyurethane resin film-forming agent is more likely to dissolve in the polyurethane resin, forming uniform "penetration points" on the surface of the glass fiber. These "penetration points" can promote the dissolution of the first polyurethane resin film-forming agent in the polyurethane resin, facilitating the rapid impregnation of the glass fiber in the polyurethane resin.

[0024] The pH regulator is used to adjust the pH value of the sizing agent so that the sizing agent can be stably stored without stratification.

[0025] The solid content of the glass fiber sizing agent for polyurethane wind turbine blades prepared in the present invention is 5 - 15%, and the pH value is 3 - 7.

[0026] The combustible content (LOI) of the glass fiber prepared by using the glass fiber sizing agent for polyurethane wind turbine blades of the present invention is generally controlled between 0.37 - 0.87%, preferably between 0.42 - 0.68%.

[0027] The beneficial effects of the present invention are as follows: During the preparation of the present invention, bisphenol A-based hyperbranched polyether is added. The bisphenol A-based hyperbranched polyether is a dendrimer-like macromolecule obtained by continuously branching outwards with bisphenol A as the core. This structure endows the hyperbranched polyether with unique chemical and physical properties. During the drying process of glass fiber production, the terminal hydroxyl groups of the bisphenol A-based hyperbranched polyether react with the active groups of some of the selected silane coupling agents. Part of the branched chains of the bisphenol A-based hyperbranched polyether bind to the surface of the glass fiber. Since the bisphenol A-based hyperbranched polyether has many branched chains and many reaction sites, the excess branched chains can cooperate with the active groups on another part of the silane coupling agent bound to the glass fiber surface to form a complex staggered combination. After reacting with the polyurethane resin, a complex crosslinked structure is obtained, making its structure more stable. While the polyurethane resin infiltrates the glass fiber, the interface between the glass fiber and the resin matrix in the composite material becomes closer, improving the fatigue and static properties of the glass fiber reinforced polyurethane resin composite material.

[0028] Compared with adding bisphenol A-based hyperbranched polyether to the sizing system of glass fiber for polyurethane wind turbine blades, when bisphenol A-based hyperbranched polyether is added to the resin system, while the resin penetrates the glass fiber, the bisphenol A-based hyperbranched polyether needs to compete with the more reactive polyurethane resin for the binding with the silane coupling agent on the glass fiber surface. The bisphenol A-based hyperbranched polyether acts as an additive in the resin system, resulting in a weaker interfacial bonding degree of the composite material than when bisphenol A-based hyperbranched polyether is added to the sizing system of glass fiber for polyurethane wind turbine blades. Binding part of the bisphenol A-based hyperbranched polyether to the glass fiber surface in advance during the glass fiber production process makes the glass fiber reinforced polyurethane resin composite material exhibit excellent performance in both fatigue tests and static tests. The glass fiber produced by using the sizing agent for glass fiber of polyurethane wind turbine blades of the present invention has good compatibility, processability, and fatigue resistance with the polyurethane resin. An appropriate combination of raw materials can ensure good impregnation of the glass fiber in the resin, unifying the softness and stiffness of the fiber.

[0029] According to the technical characteristics of polyurethane infusion fabric, through the selection of raw materials and the optimization of the proportion of formula components, a sizing agent suitable for the production of glass fiber is obtained. After using the sizing agent for glass fiber of polyurethane wind turbine blades, the product can have better fatigue resistance, and at the same time, the product meets the process requirements of blade manufacturers for the production of polyurethane wind turbine blades. Detailed Embodiments

[0030] The following further describes the present invention in conjunction with embodiments.

[0031] The sources of various additives used in the present invention are as follows: The manufacturers of the coupling agents Momentive A-1160 and Momentive A-1387 are Momentive Performance Materials Inc. The manufacturer of the hyperbranched block polyether D3203 is Deshi Energy Technology Group Co., Ltd.; The manufacturers of the first polyurethane resin film-forming agent HY-2648 and the second polyurethane resin film-forming agent HY-642 are Taishan Fiberglass Co., Ltd.; The silicone oil lubricant is lubricant BPMX200-500CST, and its manufacturer is Shanghai Kayin Chemical Co., Ltd.; The manufacturer of the lubricant PEG400MO is Nanjing Weier Pharmaceutical Group Co., Ltd.

[0032] Example 1 A preparation method of a glass fiber sizing agent for polyurethane wind turbine blades, comprising the following steps: (1) Add 30 kg of room temperature deionized water to the first preparation barrel, and add 0.14 kg of acetic acid while stirring; while ensuring uniform stirring and no air bubbles are stirred in, add 0.60 kg of Momentive A-1160 to the first preparation barrel and stir until there are no oil flowers on the water surface and the solution is clear and not turbid, then add 0.375 kg of Momentive A-1387, and stir in the same way until there are no oil flowers on the water surface and the solution is clear and not turbid to obtain solution A; (2) Add 5 kg of room temperature deionized water to the second preparation barrel, add 3.32 kg of the first polyurethane resin film-forming agent HY-2648, stir until it becomes a homogeneous and non-layered emulsion, and then add 1.58 kg of the second polyurethane resin film-forming agent HY-642, and stir until it becomes a homogeneous and non-layered emulsion to obtain solution B; (3) Add 2.8 kg of room temperature deionized water to the third preparation barrel, add 0.28 kg of Deshi hyperbranched block polyether D3203, and stir until there are no oil flowers on the water surface and the solution is clear and not turbid to obtain solution C; (4) Add 0.18 kg of lubricant BPMX200-500CST and 0.504 kg of lubricant PEG400MO to the fourth preparation barrel, then add 4.9 kg of 70 °C deionized water to this preparation barrel, stir until it becomes a homogeneous emulsion without precipitation, and cool to room temperature to obtain solution D; (5) Add solution A, solution B, solution C, and solution D to the fifth preparation barrel in sequence, and then add 50.321 kg of deionized water, and stir evenly to obtain 100 kg of a glass fiber sizing agent for polyurethane wind turbine blades.

[0033] Example 2 A preparation method of a glass fiber sizing agent for polyurethane wind turbine blades, comprising the following steps: (1) Add 30 kg of deionized water at room temperature to the first preparation tank, and add 0.14 kg of formic acid while stirring. While ensuring uniform stirring and no air bubbles are incorporated, add 0.375 kg of Momentive A-1160 to the first preparation tank, and stir until there are no oil streaks on the water surface and the solution is clear and not turbid. Then add 0.60 kg of Momentive A-1387, and stir in the same way until there are no oil streaks on the water surface and the solution is clear and not turbid to obtain Solution A; (2) Add 5 kg of deionized water at room temperature to the second preparation tank, add 3.32 kg of the first polyurethane resin film-forming agent HY-2648, stir until it becomes a homogeneous and non-layered emulsion, then add 1.58 kg of the second polyurethane resin film-forming agent HY-642, and stir until it becomes a homogeneous and non-layered emulsion to obtain Solution B; (3) Add 2.8 kg of deionized water at room temperature to the third preparation tank, add 0.28 kg of Deshi hyperbranched block polyether D3203, and stir until it becomes a homogeneous solution without precipitation to obtain Solution C; (4) Add 0.18 kg of lubricant BPMX200-500CST and 0.504 kg of lubricant PEG400MO to the fourth preparation tank, then add 4.9 kg of deionized water at 70 °C to this preparation tank, stir until it becomes a homogeneous emulsion without precipitation, and cool to room temperature to obtain Solution D; (5) Add Solution A, Solution B, Solution C, and Solution D to the fifth preparation tank in sequence, and then add 50.361 kg of deionized water and stir evenly to obtain 100 kg of glass fiber sizing agent for polyurethane wind turbine blades.

[0034] Example 3 A preparation method of a glass fiber sizing agent for polyurethane wind turbine blades, comprising the following steps: (1) Add 30 kg of deionized water at room temperature to the first preparation tank, and add 0.14 kg of acetic acid while stirring. While ensuring uniform stirring and no air bubbles are incorporated, add 0.375 kg of Momentive A-1160 to the first preparation tank, and stir until there are no oil streaks on the water surface and the solution is clear and not turbid. Then add 0.60 kg of Momentive A-1387, and stir in the same way until there are no oil streaks on the water surface and the solution is clear and not turbid to obtain Solution A; (2) Add 5 kg of deionized water at room temperature to the second preparation tank, add 3.18 kg of the first polyurethane resin film-forming agent HY-2648, stir until it becomes a homogeneous and non-layered emulsion, then add 1.58 kg of the second polyurethane resin film-forming agent HY-642, and stir until it becomes a homogeneous and non-layered emulsion to obtain Solution B; (3) Add 5 kg of deionized water at room temperature to the third preparation tank, add 0.42 kg of Deshi hyperbranched block polyether D3203, and stir until it becomes a homogeneous solution without precipitation to obtain Solution C; (4) Add 0.18 kg of lubricant BPMX200 - 500 CST and 0.504 kg of lubricant PEG400 MO into the fourth preparation barrel, then add 4.9 kg of deionized water at 70 °C into this preparation barrel, stir until a homogeneous emulsion without precipitation is obtained, and cool to room temperature to obtain solution D; (5) Add solution A, solution B, solution C and solution D into the fifth preparation barrel in sequence, then add 48.121 kg of deionized water and stir evenly to obtain 100 kg of fiberglass sizing agent for polyurethane wind turbine blades.

[0035] Example 4 A preparation method of fiberglass sizing agent for polyurethane wind turbine blades, comprising the following steps: (1) Add 30 kg of deionized water at room temperature into the first preparation barrel, add 0.14 kg of citric acid while stirring; while ensuring uniform stirring and no air bubbles are incorporated, add 0.375 kg of Momentive A - 1160 into the first preparation barrel, stir until there are no oil flowers on the water surface and the solution is clear and not turbid, then add 0.60 kg of Momentive A - 1387, and stir in the same way until there are no oil flowers on the water surface and the solution is clear and not turbid to obtain solution A; (2) Add 5 kg of deionized water at room temperature into the second preparation barrel, add 3.04 kg of the first polyurethane resin film - forming agent HY - 2648, stir until a homogeneous and non - stratified emulsion is obtained, then add 1.58 kg of the second polyurethane resin film - forming agent HY - 642, and stir until a homogeneous and non - stratified emulsion is obtained to obtain solution B; (3) Add 6 kg of deionized water at room temperature into the third preparation barrel, add 0.56 kg of Deshi hyperbranched block polyether D3203, stir until a homogeneous solution without precipitation is obtained to obtain solution C; (4) Add 0.18 kg of lubricant BPMX200 - 500 CST and 0.504 kg of lubricant PEG400 MO into the fourth preparation barrel, then add 4.9 kg of deionized water at 70 °C into this preparation barrel, stir until a homogeneous emulsion without precipitation is obtained, and cool to room temperature to obtain solution D; (5) Add solution A, solution B, solution C and solution D into the fifth preparation barrel in sequence, then add 47.121 kg of deionized water, stir evenly to obtain 100 kg of fiberglass sizing agent for polyurethane wind turbine blades.

[0036] Comparative Example 1 In step (1), add 0.975 kg of Momentive A - 1160, do not add Momentive A - 1387, and the remaining steps are the same as those in Example 1 to obtain the sizing agent.

[0037] Comparative Example 2 In step (1), MOMENTIVE A - 1160 is not added, and 0.975 kg of MOMENTIVE A - 1387 is added. The remaining steps are the same as in Example 1 to obtain a sizing agent.

[0038] Comparative Example 3 In step (2), 4.76 kg of the first polyurethane resin film - forming agent HY - 2648 is added, and the second polyurethane resin film - forming agent HY - 642 is not added. The remaining steps are the same as in Example 3 to obtain a sizing agent.

[0039] Comparative Example 4 In step (2), the first polyurethane resin film - forming agent HY - 2648 is not added, and 4.76 kg of the second polyurethane resin film - forming agent HY - 642 is added. The remaining steps are the same as in Example 3 to obtain a sizing agent.

[0040] Comparative Example 5 In step (3), DECHEMA hyperbranched block polyether D3203 is not added. The remaining steps are the same as in Example 1 to obtain a sizing agent.

[0041] Comparative Example 6 In step (3), DECHEMA hyperbranched block polyether D3203 is not added. The remaining steps are the same as in Example 1 to obtain a sizing agent. When the sizing agent is applied to glass fibers, 0.28 kg of DECHEMA hyperbranched block polyether D3203 is added.

[0042] The polyurethane glass fiber sizing agents for wind turbine blades prepared in Examples 1 - 4 and the sizing agents prepared in Comparative Examples 1 - 6 are applied to glass fibers, and relevant performance tests are carried out. In this invention, the composite materials are tested by the tension - tension fatigue test method. Isocyanate - type polyurethane resins such as Covestro DESMODUR 44CP20 and polyol - type curing agents such as Covestro's Baydur 78BD085 are used, and the RTM molding process is combined with a stepped temperature - rise curing of (40 - 60) °C / (1 - 3) h+(70 - 100) °C / (2 - 5) h to prepare corresponding composite material specimens for detection.

[0043] The performance data of the composite materials in Examples 1 - 4 and Comparative Examples 1 - 6 are shown in Table 1:

[0044] Note: The fibers used in the tests are all 2400 tex fibers, the resins are Covestro's Baydur 78BD085 and DESMODUR 44CP20, the 90° tensile strength test standard is ISO527 - 5, and the fatigue performance test standard is ISO13003.

[0045] As can be seen from Table 1, the amount of fuzz on the yarn using a single coupling agent is relatively large, and the impregnation rate of the yarn using a single polyurethane resin film-forming agent significantly slows down. The 90° tensile strength and fatigue performance of Examples 1-4 are significantly better than those of Comparative Examples 1-6.

Claims

1. A sizing agent for glass fiber used in polyurethane wind turbine blades, characterized in that, It includes a coupling agent, a lubricant, a hyperbranched polyether, a film-forming agent, a pH regulator and deionized water. Among them, the film-forming agent is a polyurethane resin film-forming agent.

2. The sizing agent for glass fiber used in polyurethane wind turbine blades according to claim 1, wherein, The polyurethane resin film-forming agent is a mixture of a first polyurethane resin film-forming agent and a second polyurethane resin film-forming agent; the molecular weight of the first polyurethane resin film-forming agent is 1500 - 4000, the particle size of the polyurethane resin particles in the first polyurethane resin film-forming agent is 0.6 - 3.6 μm, the molecular weight of the second polyurethane resin film-forming agent is 200 - 1000, the particle size of the polyurethane resin particles in the second polyurethane resin film-forming agent is 0.4 - 3.2 μm, and the mass ratio of the first polyurethane resin film-forming agent to the second polyurethane resin film-forming agent is 2.2 - 3.6:1.0 - 1.

8.

3. The sizing agent for glass fiber used in polyurethane wind turbine blades according to claim 1, characterized in that, The hyperbranched polyether is a bisphenol A type hyperbranched polyether. The molecular weight of the bisphenol A type hyperbranched polyether is 1500 - 9000. The bisphenol A type hyperbranched polyether is a hyperbranched polyether or hyperbranched block polyether with more than 8 branches with a bisphenol structure as the core.

4. The sizing agent for glass fiber used in polyurethane wind power blades according to claim 1, characterized in that, The coupling agent is a silane coupling agent, and the silane coupling agent is one or more of an amino silane coupling agent, an amide group silane coupling agent or a urea group silane coupling agent.

5. The sizing agent for glass fiber used in polyurethane wind power blades according to claim 1, wherein, The lubricant is a mixture of PEG and a silicone oil lubricant, and the mass ratio of PEG to the silicone oil lubricant is 1.5 - 4.5:

1. The pH regulator is one or more of formic acid, acetic acid, citric acid or fluoboric acid.

6. The sizing agent for glass fibers used in polyurethane wind turbine blades according to claim 1, characterized in that, In the glass fiber sizing agent for polyurethane wind turbine blades, the solid mass accounts for 5 - 15% of the total mass of the glass fiber sizing agent for polyurethane wind turbine blades. Based on 100% of the total solid mass in the glass fiber sizing agent for polyurethane wind turbine blades, the percentage of the solid mass of each component in the total solid mass of the glass fiber sizing agent for polyurethane wind turbine blades is as follows: Coupling agent 6 - 24% Film-forming agent 50 - 85% Lubricant 5 - 20% Hyperbranched polyether 2 - 10% pH regulator 1 - 5%.

7. A method for preparing a glass fiber sizing agent for polyurethane wind turbine blades according to any one of claims 1-6, characterized in that, It includes the following steps: (1) First add the pH regulator to the deionized water and stir evenly, then add the coupling agent and stir evenly to obtain solution A; (2) Add the polyurethane resin film-forming agent to the deionized water and stir evenly to obtain solution B; (3) Add the hyperbranched polyether to the deionized water and stir evenly to obtain solution C; (4) Mix the lubricant and hot deionized water and stir evenly, then cool to room temperature to obtain solution D; (5) Mix solution A, solution B, solution C, solution D and the remaining deionized water and stir evenly to obtain the glass fiber sizing agent for polyurethane wind turbine blades.

8. The preparation method of the glass fiber sizing agent for polyurethane wind power blades according to claim 7, characterized in that, In step (1), the addition amount of deionized water is 30 - 40% of the total mass of the glass fiber sizing agent for polyurethane wind turbine blades.

9. The preparation method of the glass fiber sizing agent for polyurethane wind power blades according to claim 7, characterized in that, In step (2), the mass ratio of the polyurethane resin film-forming agent to the deionized water is 1:0.5 - 4. In step (3), the mass ratio of the hyperbranched polyether to the deionized water is 1:10 - 20.

10. The preparation method of the glass fiber sizing agent for polyurethane wind power blades according to claim 7, characterized in that, In step (4), the mass ratio of the lubricant to the hot deionized water is 1:7 - 15, and the temperature of the hot deionized water is 60 - 80 °C.

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