| High-silica glass fiber has been widely used in spacecraft anti-ablation materials and high temperature insulation materials and so on.The application prospect is broad.The production of high silica glass fiber yarn from binary sodium silicate glass fiber and it has the advantages of low production cost and low environmental pollution.However,the binary sodium silicate glass fiber has very poor chemical stability.It is easily eroded by environmental media and difficult to store.The tensile strength of the raw silk in the air will be rapidly lost,and the fibers will be bonded to each other,which cannot be retreated or woven.The Current sizing agents are not effective in protecting the properties of binary sodium silicate glass fibers.The purpose of this project is to develop a glass fiber sizing agent that can effectively protect the production of binary sodium silicate glass fibers and maintain mechanical properties.The research contents are studied from the following aspects:(1)The mechanism of strength loss of binary sodium silicate glass fiber was systematically analyzed.In water,the mechanism of the strong loss of binary sodium silicate glass fiber includes two forms of glass fiber internal structure network,Na~+dissolution by H~+dissolution,and glass fiber network formation body.The siloxane skeleton is directly eroded and destroyed by water molecules.In the acid,H~+continuously undergoes ion exchange reaction with the network outer body Na~+in the internal structure of the glass fiber,so that the glass fiber network structure changes from compact to loose,and the strength decreases.In the alkali,OH~-directly dissolves and destroys the internal structure network of the glass fiber A bulk silica skeleton is formed,and the surface layer of the glass fiber comes off layer by layer,causing a loss of strength.The decrease in the strength of the glass fiber in the atmosphere is mainly caused by the erosion of the binary sodium silicate glass fiber by water vapor.(2)Based on the strength loss mechanism of binary sodium silicate glass fiber,a solution polymerization process is adopted,with methacrylic acid,methyl methacrylate,and ethyl acrylate as monomers,and absolute ethanol as the polymerization reaction solvent.Benzoyl oxide was used as an initiator to prepare a binary sodium silicate glass fiber sizing agent.(3)The structure of the synthesized infiltrants was characterized by infrared spectroscopy.The results showed that:during the polymerization of the solution,the polymerization monomers copolymerized;DSC tests showed that the glass transition temperature of the synthetic infiltrants was 39.15?.And then we system tests the glass transition temperature,viscosity,solids content,mechanical properties,water resistance(swelling rate and dissolution rate),hygroscopicity of the sizing agent.The results show that the sizing agent has stable performance.(4)The binary sodium silicate glass fiber was drawn with the prepared sizing agent,and the breaking strength and elongation of the fiber were measured for 60 consecutive days.The results show that the sizing agent can meet the requirements for the drawing process and strength retention of binary sodium silicate glass fibers,and the mechanical properties of glass fibers are stable.(5)The results of spinning and weaving tests for glass fibers show that glass fibers have spinnability and weavability which drawn with homemade sizing agents.(6)The effect of temperature and humidity on the mechanical properties of glass fibers was studied.After testing the changes in the mechanical properties of fibers under different temperature and humidity conditions,it was found that the mechanical properties of binary sodium silicate glass fibers are greatly affected by temperature,and the relative humidity has no significant effect on their mechanical properties.When the temperature is 25?and the relative humidity is 60%,the binary sodium silicate glass fiber has the best long-term storage effect.There are 32 figures,36 tables and 80 references. |
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