Preparation and property of epoxy based nano-SiO_2/TiO_2/polyimide hybrid enhanced size for carbon fibers

An epoxy based nano-SiO2/TiO2/polyimide hybrid enhanced sizing for carbon fiber was prepared by in-situ modification of SiO2/TiO2 precursor in PAA collosol with silane couple agent(WD50) and proper surfactant through sol-gel technique,and during the preparation the ultrasonic cavitation and compounding technologies were utilized.The properties of PAA-SiO2-TiO2 hybrid sizing and micromorphology of its film formed on carbon fiber surface were analyzed by FTIR,DSC,particle size instrument and STM.The results indicated that nanoscale SiO2·TiO2 particles dispersed in the hybrid sizing film homogeneously,and a layer of nano particles was formed on carbon fiber surface after sizing by the hybrid enhanced size,the surface of the carbon fiber looked more rough and its interfacial property was improved.Mechanical test demonstrated that both tensile strength and interlaminar shear strength of the carbon fiber sized with this product were significantly enhanced.