Thermal insulation glass fiber and preparation method thereof

Abstract

The invention discloses a heat-preservation glass fiber and a preparation method thereof, and belongs to the technical field of glass fiber modification.The preparation method of the heat-preservation glass fiber comprises the following steps that SiO2, Al2O3, CaO, Fe2O3, CeO2 and LaF3 are subjected to high-temperature melting and wire drawing to prepare a glass fiber matrix, mesoporous glass fibers are obtained through acidolysis treatment, the mesoporous glass fibers are impregnated and modified with hexadecyl modified polysiloxane, and then the heat-preservation glass fiber is obtained. And curing to obtain the thermal insulation glass fiber. The thermal insulation glass fiber prepared by the invention has remarkable advantages in heat conductivity coefficient, tensile strength and hydrophobic property, and solves the technical problems of overhigh heat conductivity coefficient and insufficient tensile strength of glass fibers in the prior art.

Description

Technical Field

[0001] This invention relates to the field of glass fiber modification technology, specifically to a thermal insulation glass fiber and its preparation method. Background Technology

[0002] As one of the most important inorganic non-metallic fiber materials in modern industry, glass fiber has demonstrated outstanding comprehensive performance advantages since its emergence in the early 20th century. Its unique chemical composition, mainly consisting of silicon dioxide, alumina, and calcium oxide, endows glass fiber with excellent mechanical properties, heat resistance, and chemical stability. In terms of mechanical properties, glass fiber is characterized by high strength and high modulus, with a tensile strength reaching 3,000 to 5,000 MPa, far exceeding that of traditional metal materials. Regarding heat resistance, glass fiber maintains stable physicochemical properties at high temperatures, with a softening point exceeding 800 degrees Celsius. In terms of chemical stability, glass fiber exhibits good corrosion resistance to most acid and alkali solutions. Based on these excellent properties, glass fiber is widely used in many high-tech fields such as building insulation, aerospace composite materials, lightweight automotive components, electronic and electrical insulation, and marine engineering corrosion protection. With the rapid development of modern industrial technology and the continuous improvement of energy conservation and environmental protection requirements, the performance requirements for glass fiber materials are becoming increasingly stringent, especially in terms of thermal insulation, mechanical strength, and environmental adaptability, which have been given higher standards.

[0003] Despite the promising applications of glass fiber in many fields, traditional glass fiber suffers from significant technical bottlenecks in thermal insulation performance, severely hindering its widespread use in high-performance insulation materials. Firstly, its high thermal conductivity is a major drawback, typically ranging from 0.03 to 0.05 W / m Kelvin, far exceeding the technical specifications of ideal insulation materials. This results in substantial heat loss, failing to meet the stringent requirements of modern building energy conservation and industrial insulation. Secondly, insufficient tensile strength is equally prominent. Traditional glass fiber is prone to brittle fracture under complex stress environments, especially under low temperature, high humidity, or cyclic loading, where its mechanical properties significantly degrade, limiting its adoption in high-strength applications such as aerospace and marine engineering. Summary of the Invention

[0004] This invention discloses a thermal insulation glass fiber and its preparation method. The thermal insulation glass fiber prepared by this invention exhibits significant advantages in thermal conductivity, tensile strength and hydrophobicity, solving the technical problems of excessively high thermal conductivity and insufficient tensile strength of glass fibers in the prior art.

[0005] This invention protects a method for preparing thermally insulating glass fiber, comprising the following steps: Glass fiber matrix is ​​prepared by high-temperature melting and drawing of SiO2, Al2O3, CaO, Fe2O3, CeO2 and LaF3. Mesoporous glass fiber is obtained by acid hydrolysis, and then modified by impregnation with hexadecyl-modified polysiloxane. After curing, thermal insulation glass fiber is obtained.

[0006] Preferably, the hexadecyl-modified polysiloxane is prepared by the following method: mixing hexadecyltrimethoxysilane, polysiloxane and Karstedt catalyst, reacting at 80°C for 4 hours under nitrogen protection, and cooling to 25~35°C to obtain hexadecyl-modified polysiloxane.

[0007] Preferably, the weight ratio of hexadecyltrimethoxysilane, polysiloxane and Karstedt catalyst is 1:3~4:0.001~0.002.

[0008] Preferably, the molecular weight of the polysiloxane is 8000~12000.

[0009] Preferably, the procedure specifically includes the following steps: Step 1: Heat SiO2, Al2O3, CaO, Fe2O3, CeO2 and LaF3 at 1030~1070℃ for 2~3 hours, then raise the temperature to 1230~1270℃ and heat for 9~11 hours to draw the fibers. After that, wash the fibers by immersing them in hot water at 30~40℃ for 15~20 minutes to obtain the glass fiber matrix. Step 2: Heat the glass fiber matrix at 550~600℃ for 1.5 hours, immerse it in HCl solution, acid hydrolyze it at 60℃ for 30 minutes, wash it with deionized water 10~15 times, and dry it at 120℃ for 2 hours to obtain mesoporous glass fiber. Step 3: Immerse the mesoporous glass fiber in hexadecyl modified polysiloxane, heat at 25~35℃ for 40~50 minutes, then heat at 80~90℃ for 20~30 minutes to cure, and cool to 25~35℃ to obtain thermal insulation glass fiber.

[0010] Preferably, the weight ratio of SiO2, Al2O3, CaO, Fe2O3 and LaF3 is 45~47:11~14:23~27:1~1.5:1.5~2:4~5.

[0011] Preferably, in step one, the wire drawing speed is 2.5 to 3 m / min, and the wire drawing cooling rate is 15 to 25 °C / min.

[0012] Preferably, in step two, the concentration of the HCl solution is 6 mol / L.

[0013] Preferably, in step three, the curing temperature is 150°C and the curing time is 1 hour.

[0014] The present invention also protects a heat-insulating glass fiber prepared by the above preparation method.

[0015] The present invention has the following beneficial effects: This invention employs a unique three-step preparation process. By controlling the ratio of SiO2, Al2O3, CaO, Fe2O3, CeO2, and LaF3, a uniform glass matrix structure is formed under gradient melting conditions. Through acid hydrolysis treatment with HCl solution, a regular mesoporous structure is formed on the surface of the glass fibers, significantly increasing the specific surface area. By controlling the drawing speed and cooling rate, the glass molecular chains are fully oriented, promoting the formation of a microcrystalline phase as a reinforcing phase. At the same time, LaF3 forms a rare-earth-rich transition layer on the fiber surface to alleviate stress concentration and improve the tensile strength of the glass fibers.

[0016] This invention utilizes hydrochloric acid etching combined with high-temperature curing to selectively dissolve surface alkaline oxides, forming a nano-rough structure. This enriches SiO2 to form Si-O-Si hydrophobic bonds, constructing a micron-nano hierarchical structure to trap air, significantly improving the hydrophobic effect of glass fibers. Through the synergistic effect of CeO2 and LaF3, a unique rare-earth ion coordination environment is formed in the glass network structure, significantly reducing phonon conduction efficiency and effectively blocking heat transfer paths. The introduction of mesoporous structures creates numerous gas-phase cavities within the fibers, endowing the glass fibers with excellent thermal insulation properties. Detailed Implementation

[0017] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 Step 1: 46 parts by weight of SiO2, 12.5 parts by weight of Al2O3, 25 parts by weight of CaO, 1.25 parts by weight of Fe2O3, 1.75 parts by weight of CeO2, and 4.5 parts by weight of LaF3 were added sequentially to a crucible. The mixture was heated at 1050℃ for 2.5 hours under nitrogen protection for initial melting, and then heated to 1250℃ for 10 hours for complete melting. The mixture was stirred every 2 hours during the melting process. After melting, the mixture was drawn into fibers at a drawing speed of 2.75 m / min and a drawing cooling rate of 20℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 35℃ for 17.5 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0019] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 575℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 12 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0020] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.5 parts by weight of polysiloxane with a molecular weight of 10,000 and 0.0015 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 30°C to obtain hexadecyl-modified polysiloxane.

[0021] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane and heat at 30°C for 45 minutes for initial impregnation. Then, heat to 85°C for 25 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process. Finally, cool to 30°C to obtain thermal insulation glass fiber.

[0022] Example 2 Step 1: 45 parts by weight of SiO2, 11 parts by weight of Al2O3, 3 parts by weight of CaO2, 1 part by weight of Fe2O3, 1.5 parts by weight of CeO2, and 4 parts by weight of LaF3 are added sequentially into a crucible. Under nitrogen protection, the mixture is heated at 1030℃ for 2 hours for initial melting, and then heated to 1230℃ for 9 hours for complete melting. During the melting process, the mixture is stirred every 2 hours. After melting, the mixture is drawn into fibers at a speed of 2.5 m / min and a cooling rate of 15℃ / min. After drawing, the glass fibers are immediately immersed in hot water at 30℃ for 15 minutes to wash them and remove surface impurities. Finally, the fibers are naturally dried at room temperature to obtain the glass fiber matrix.

[0023] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 550℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6 mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 10 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0024] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3 parts by weight of polysiloxane with a molecular weight of 8000 and 0.001 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 25°C to obtain hexadecyl-modified polysiloxane.

[0025] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane and heat it at 25°C for 40 minutes for initial impregnation. Then, heat it to 80°C for 20 minutes for deep impregnation. After impregnation, cure it at 150°C for 1 hour. Maintain a dry nitrogen environment during the curing process. Finally, cool it to 25°C to obtain thermal insulation glass fiber.

[0026] Example 3 Step 1: 47 parts by weight of SiO2, 14 parts by weight of Al2O3, 7 parts by weight of CaO, 1.5 parts by weight of Fe2O3, 2 parts by weight of CeO2, and 35 parts by weight of LaF are added sequentially into a crucible. Under nitrogen protection, the mixture is heated at 1070℃ for 3 hours for initial melting, and then heated to 1270℃ for 11 hours for complete melting. During the melting process, the mixture is stirred every 2 hours. After melting, the mixture is drawn into fibers at a drawing speed of 3 m / min and a drawing cooling rate of 25℃ / min. After drawing, the glass fibers are immediately immersed in hot water at 40℃ for 20 minutes to wash them and remove surface impurities. Finally, the fibers are naturally dried at room temperature to obtain the glass fiber matrix.

[0027] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 600℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 15 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0028] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 4 parts by weight of polysiloxane with a molecular weight of 12000 and 0.002 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 35°C to obtain hexadecyl-modified polysiloxane.

[0029] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane, heat at 35°C for 50 minutes for initial impregnation, then heat to 90°C for 30 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process, and finally cool to 35°C to obtain thermal insulation glass fiber.

[0030] Example 4 Step 1: 46.5 parts by weight of SiO2, 13 parts by weight of Al2O3, 6 parts by weight of CaO2, 1.3 parts by weight of Fe2O3, 1.8 parts by weight of CeO2, and 4.7 parts by weight of LaF3 were added sequentially to a crucible. The crucible was heated at 1060℃ for 2.8 hours under nitrogen protection for initial melting, and then heated to 1260℃ for 10.5 hours for complete melting. The crucible was stirred every 2 hours during the melting process. After melting, the crucible was drawn into fibers at a drawing speed of 2.8 m / min and a drawing cooling rate of 22℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 38℃ for 18 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0031] Step 2: Place the glass fiber matrix in a muffle furnace and pretreat it at 580℃ for 1.5 hours. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes, stirring gently every 10 minutes during the acid-hydrolysis process. After acid-hydrolysis, wash repeatedly with deionized water 13 times, and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fibers.

[0032] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.8 parts by weight of polysiloxane with a molecular weight of 9000, and 0.0018 parts by weight of Karstedt catalyst were added to a three-necked flask. The mixture was reacted at 80°C for 4 hours with slow stirring throughout the reaction. After the reaction was completed, the mixture was cooled to 32°C to obtain hexadecyl-modified polysiloxane.

[0033] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane and heat at 32°C for 47 minutes for initial impregnation. Then, heat to 87°C for 27 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process. Finally, cool to 32°C to obtain thermal insulation glass fiber.

[0034] Example 5 Step 1: 45.5 parts by weight of SiO2, 11.5 parts by weight of Al2O3, 4 parts by weight of CaO2, 1.1 parts by weight of Fe2O3, 1.6 parts by weight of CeO2, and 4.3 parts by weight of LaF3 were added sequentially to a crucible. The crucible was heated at 1040℃ for 2.2 hours under nitrogen protection for initial melting, and then heated to 1240℃ for 9.5 hours for complete melting. The crucible was stirred every 2 hours during the melting process. After melting, the crucible was drawn into fibers at a drawing speed of 2.6 m / min and a drawing cooling rate of 18℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 33℃ for 16 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0035] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 560℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 11 times. Finally, dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0036] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.2 parts by weight of polysiloxane with a molecular weight of 11000 and 0.0012 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 28°C to obtain hexadecyl-modified polysiloxane.

[0037] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane, heat at 28°C for 43 minutes for initial impregnation, then heat to 83°C for 23 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process, and finally cool to 28°C to obtain thermal insulation glass fiber.

[0038] Comparative Example 1: Compared with Example 1, LaF3 was not added in step one.

[0039] Step 1: Add 50 parts by weight of SiO2, 12.5 parts by weight of Al2O3, 25 parts by weight of CaO, 1.25 parts by weight of Fe2O3, and 1.75 parts by weight of CeO2 to a crucible in sequence. Heat at 1050℃ for 2.5 hours under nitrogen protection for initial melting, then raise the temperature to 1250℃ and heat for 10 hours for complete melting. Stir once every 2 hours during the melting process. After melting, draw the fiber at a drawing speed of 2.75 m / min and a drawing cooling rate of 20℃ / min. After drawing, immediately immerse the glass fiber in hot water at 35℃ for 17.5 minutes to wash it and remove surface impurities. Finally, let it air dry at room temperature to obtain a common glass fiber matrix.

[0040] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 575℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 12 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0041] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.5 parts by weight of polysiloxane with a molecular weight of 10,000, and 0.0015 parts by weight of Karstedt catalyst were added to a three-necked flask. The mixture was reacted at 80°C for 4 hours with slow stirring throughout the reaction. After the reaction was completed, the mixture was cooled to 30°C to obtain hexadecyl-modified polysiloxane.

[0042] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane and heat at 30°C for 45 minutes for initial impregnation. Then, heat to 85°C for 25 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process. Finally, cool to 30°C to obtain thermal insulation glass fiber.

[0043] Comparative Example 2: Compared with Example 1, step two lacks the HCl acid hydrolysis treatment.

[0044] Step 1: 46 parts by weight of SiO2, 12.5 parts by weight of Al2O3, 25 parts by weight of CaO, 1.25 parts by weight of Fe2O3, 1.75 parts by weight of CeO2, and 4.5 parts by weight of LaF3 were added sequentially to a crucible. The mixture was heated at 1050℃ for 2.5 hours under nitrogen protection for initial melting, and then heated to 1250℃ for 10 hours for complete melting. The mixture was stirred every 2 hours during the melting process. After melting, the mixture was drawn into fibers at a drawing speed of 2.75 m / min and a drawing cooling rate of 20℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 35℃ for 17.5 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0045] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 575℃ for 1.5 hours for pretreatment. After pretreatment, wash it directly with deionized water 12 times, and finally dry it in an oven at 120℃ for 2 hours to obtain pretreated glass fiber.

[0046] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.5 parts by weight of polysiloxane with a molecular weight of 10,000 and 0.0015 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 30°C to obtain hexadecyl-modified polysiloxane.

[0047] Step 4: Immerse the pretreated glass fiber completely in hexadecyl modified polysiloxane and heat at 30°C for 45 minutes for initial impregnation. Then, heat to 85°C for 25 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process. Finally, cool to 30°C to obtain thermal insulation glass fiber.

[0048] Comparative Example 3: Compared with Example 1, step three does not involve hexadecyl modification of the polysiloxane.

[0049] Step 1: 46 parts by weight of SiO2, 12.5 parts by weight of Al2O3, 25 parts by weight of CaO, 1.25 parts by weight of Fe2O3, 1.75 parts by weight of CeO2, and 4.5 parts by weight of LaF3 were added sequentially to a crucible. The mixture was heated at 1050℃ for 2.5 hours under nitrogen protection for initial melting, and then heated to 1250℃ for 10 hours for complete melting. The mixture was stirred every 2 hours during the melting process. After melting, the mixture was drawn into fibers at a drawing speed of 2.75 m / min and a drawing cooling rate of 20℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 35℃ for 17.5 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0050] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 575℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 12 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0051] Step 3: Under nitrogen protection, add 3.5 parts by weight of polysiloxane with a molecular weight of 10,000 to a three-necked flask, heat at 80°C for 4 hours, and keep stirring slowly during the reaction. After heating is completed, cool to 30°C to obtain ordinary polysiloxane.

[0052] Step 4: Completely immerse the mesoporous glass fiber in the ordinary polysiloxane prepared in Step 3, heat at 30°C for 45 minutes for initial impregnation, then heat to 85°C for 25 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process, and finally cool to 30°C to obtain thermal insulation glass fiber.

[0053] Comparative Example 4: Compared with Example 1, the wire drawing speed in step one is too low.

[0054] Step 1: 46 parts by weight of SiO2, 12.5 parts by weight of Al2O3, 25 parts by weight of CaO, 1.25 parts by weight of Fe2O3, 1.75 parts by weight of CeO2, and 4.5 parts by weight of LaF3 were added sequentially to a crucible. The mixture was heated at 1050℃ for 2.5 hours under nitrogen protection for initial melting, and then heated to 1250℃ for 10 hours for complete melting. The mixture was stirred every 2 hours during the melting process. After melting, the mixture was drawn into fibers at a speed of 1.5 m / min and a cooling rate of 20℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 35℃ for 17.5 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0055] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 575℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 12 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0056] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.5 parts by weight of polysiloxane with a molecular weight of 10,000 and 0.0015 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 30°C to obtain hexadecyl-modified polysiloxane.

[0057] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane and heat at 30°C for 45 minutes for initial impregnation. Then, heat to 85°C for 25 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process. Finally, cool to 30°C to obtain thermal insulation glass fiber.

[0058] Comparative Example 5: Compared with Example 1, the molecular weight of the polysiloxane in step three is too low.

[0059] Step 1: 46 parts by weight of SiO2, 12.5 parts by weight of Al2O3, 25 parts by weight of CaO, 1.25 parts by weight of Fe2O3, 1.75 parts by weight of CeO2, and 4.5 parts by weight of LaF3 were added sequentially to a crucible. The mixture was heated at 1050℃ for 2.5 hours under nitrogen protection for initial melting, and then heated to 1250℃ for 10 hours for complete melting. The mixture was stirred every 2 hours during the melting process. After melting, the mixture was drawn into fibers at a drawing speed of 2.75 m / min and a drawing cooling rate of 20℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 35℃ for 17.5 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0060] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 575℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 12 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0061] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.5 parts by weight of polysiloxane with a molecular weight of 6000 and 0.0015 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 30°C to obtain hexadecyl-modified polysiloxane.

[0062] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane and heat at 30°C for 45 minutes for initial impregnation. Then, heat to 85°C for 25 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process. Finally, cool to 30°C to obtain thermal insulation glass fiber.

[0063] Comparative Example 6: Compared with Example 1, the temperature at which complete melting occurs in step one is too high.

[0064] Step 1: 46 parts by weight of SiO2, 12.5 parts by weight of Al2O3, 25 parts by weight of CaO, 1.25 parts by weight of Fe2O3, 1.75 parts by weight of CeO2, and 4.5 parts by weight of LaF3 were added sequentially to a crucible. The mixture was heated at 1050℃ for 2.5 hours under nitrogen protection for initial melting, and then heated to 1300℃ for 10 hours for complete melting. The mixture was stirred every 2 hours during the melting process. After melting, the mixture was drawn into fibers at a drawing speed of 2.75 m / min and a drawing cooling rate of 20℃ / min. After drawing, the glass fibers were immediately immersed in hot water at 35℃ for 17.5 minutes to wash them and remove surface impurities. Finally, the fibers were allowed to dry naturally at room temperature to obtain the glass fiber matrix.

[0065] Step 2: Place the glass fiber matrix in a muffle furnace and heat it at 575℃ for 1.5 hours for pretreatment. After pretreatment, immerse the fiber in a 6mol / L HCl solution and acid-hydrolyze it in a 60℃ constant temperature water bath for 30 minutes. Stir gently every 10 minutes during acid hydrolysis. After acid hydrolysis, wash it repeatedly with deionized water 12 times and finally dry it in a 120℃ oven for 2 hours to obtain mesoporous glass fiber.

[0066] Step 3: Under nitrogen protection, 1 part by weight of hexadecyltrimethoxysilane, 3.5 parts by weight of polysiloxane with a molecular weight of 10,000 and 0.0015 parts by weight of Karstedt catalyst were added to a three-necked flask and reacted at 80°C for 4 hours with slow stirring during the reaction. After the reaction was completed, the mixture was cooled to 30°C to obtain hexadecyl-modified polysiloxane.

[0067] Step 4: Completely immerse the mesoporous glass fiber in hexadecyl modified polysiloxane and heat at 30°C for 45 minutes for initial impregnation. Then, heat to 85°C for 25 minutes for deep impregnation. After impregnation, cure at 150°C for 1 hour, maintaining a dry nitrogen environment during the curing process. Finally, cool to 30°C to obtain thermal insulation glass fiber.

[0068] Performance testing 1. Thermal conductivity test Test equipment: Hot Disk thermal constant analyzer TPS 2500S.

[0069] Step 1: Sample preparation: The heat-insulating glass fibers obtained in Examples 1-5 and Comparative Examples 1-6 were respectively made into test samples with a specification of 50mm x 50mm x 10mm, ensuring that the sample surface was flat and free of bubbles and defects.

[0070] Step 2, Test Conditions: The ambient temperature is 25℃, the probe power is set to 30mW, the test time is 40s, and the sample is placed in a standard environment for 24 hours before the test.

[0071] Step 3, Test Implementation: Clamp the Hot Disk probe between two identical samples, ensuring good contact, start the test program, record the thermal conductivity value of each sample, test each sample 5 times, and take the average value.

[0072] Step 4: Data Recording: Record the thermal conductivity of each sample under standard conditions, in W / (m·K).

[0073] 2. Tensile strength test Testing equipment: Instron 5969 universal testing machine.

[0074] Step 1, Sample preparation: Prepare standard tensile test specimens for each sample, with a gauge length of 50 mm, a width of 10 mm, and a thickness of 2 mm. Prepare 8 specimens for each group.

[0075] Step 2, Test conditions settings: Tensile speed 2mm / min, preload 5N.

[0076] Step 3, Test Implementation: Clamp the specimen in the testing machine chuck, start the tensile test until the specimen breaks, and record the maximum tensile force and the displacement at the time of breakage.

[0077] Step 4: Data Calculation: Calculate the tensile strength = maximum tensile force / cross-sectional area of ​​the specimen, in MPa. Take the average value of 8 specimens in each group.

[0078] 3. Hydrophobicity test Test equipment: OCA20 contact angle meter.

[0079] Step 1, Sample Preparation: Prepare each sample into a flat surface test piece of 25mm x 25mm, clean the surface with anhydrous ethanol, and allow it to air dry.

[0080] Step 2, Test Conditions: The test liquid is deionized water, the droplet volume is 2μL, the test environment temperature is 25℃, and the relative humidity is 50%.

[0081] Step 3: Test Implementation: Add water droplets to the sample surface and immediately measure the contact angle. Test 10 different locations for each sample and take the average value.

[0082] Step 4: Data Recording: Record the static contact angle value in degrees (°).

[0083] Test Result Data Table Table 1. Thermal conductivity test results

[0084] Table 2. Tensile strength test results

[0085] Table 3. Hydrophobicity test results

[0086] Data Analysis As can be seen from Table 1, the thermal conductivity of the comparative example is significantly improved compared to Example 1, indicating that the technical solution of the present invention can significantly reduce the thermal conductivity of glass fiber.

[0087] As can be seen from Table 2, the tensile strength of Example 1 is significantly higher than that of all comparative examples, indicating that the technical solution of the present invention can significantly improve the tensile strength of glass fiber.

[0088] As can be seen from Table 3, the water contact angle of Example 1 is significantly higher than that of all comparative examples, indicating that the technical solution of the present invention significantly improves the hydrophobic effect of glass fiber.

[0089] In summary, the thermal insulation glass fiber prepared by this invention exhibits significant advantages in thermal conductivity, tensile strength, and hydrophobic properties, making it suitable for high-performance thermal insulation materials, building energy-saving materials, and aerospace applications.

[0090] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for preparing thermally insulating glass fiber, characterized in that, Includes the following steps: Glass fiber matrix is ​​prepared by high-temperature melting and drawing of SiO2, Al2O3, CaO, Fe2O3, CeO2 and LaF3. Mesoporous glass fiber is obtained by acid hydrolysis, and then modified by impregnation with hexadecyl-modified polysiloxane. After curing, thermal insulation glass fiber is obtained.

2. The preparation method according to claim 1, characterized in that, The hexadecyl-modified polysiloxane is prepared by the following method: hexadecyltrimethoxysilane, polysiloxane and Karstedt catalyst are mixed and reacted at 80°C for 4 hours under nitrogen protection, and then cooled to 25~35°C to obtain hexadecyl-modified polysiloxane.

3. The preparation method according to claim 2, characterized in that, The weight ratio of hexadecyltrimethoxysilane, polysiloxane and Karstedt catalyst is 1:3~4:0.001~0.

002.

4. The preparation method according to claim 2, characterized in that, The molecular weight of the polysiloxane is 8000~12000.

5. The preparation method according to claim 1, characterized in that, Specifically, the following steps are included: Step 1: Heat SiO2, Al2O3, CaO, Fe2O3, CeO2 and LaF3 at 1030~1070℃ for 2~3 hours, then raise the temperature to 1230~1270℃ and heat for 9~11 hours to draw the fibers. After that, wash the fibers by immersing them in hot water at 30~40℃ for 15~20 minutes to obtain the glass fiber matrix. Step 2: Heat the glass fiber matrix at 550~600℃ for 1.5 hours, immerse it in HCl solution, acid hydrolyze it at 60℃ for 30 minutes, wash it with deionized water 10~15 times, and dry it at 120℃ for 2 hours to obtain mesoporous glass fiber. Step 3: Immerse the mesoporous glass fiber in hexadecyl modified polysiloxane, heat at 25~35℃ for 40~50 minutes, then heat at 80~90℃ for 20~30 minutes to cure, and cool to 25~35℃ to obtain thermal insulation glass fiber.

6. The preparation method according to claim 5, characterized in that, In step one, the weight ratio of SiO2, Al2O3, CaO, Fe2O3 and LaF3 is 45~47:11~14:23~27:1~1.5:1.5~2:4~5.

7. The preparation method according to claim 5, characterized in that, In step one, the wire drawing speed is 2.5 to 3 m / min, and the wire drawing cooling rate is 15 to 25 °C / min.

8. The preparation method according to claim 5, characterized in that, In step two, the concentration of the HCl solution is 6 mol / L.

9. The preparation method according to claim 5, characterized in that, In step three, the curing temperature is 150°C and the curing time is 1 hour.

10. A heat-insulating glass fiber prepared by the preparation method according to any one of claims 1 to 9.

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