Preparation and Mechanism of Nano-TiO<sub>2</sub> Coatings on Poly(<i>p</i>-phenylene-benzobisoxazole) (PBO) Fiber

Abstract

nanoTiO2/PBO composite fiber was prepared with a chemical method by depositing nanoTiO2 on the surface of PBO fiber which was treated by silane coupling agent. The process parameters on the preparation of nanoTiO2/PBO composite fiber were optimized according to the interfacial adhesion between the composite fiber and epoxy resin, and the coating mechanism of nanoTiO2/PBO composite fiber was also discussed. The results show that the uniform nanoTiO2/PBO composite fiber with high interfacial adhesion can be prepared on the PBO fiber which was pretreated by silane coupling agent with a concentration of 1.5 % for 35 min at room temperature, in which the nanoTiO2 aqueous solution with a concentration of 1.0wt% was ultrasonic dispersed for 1h in alkaline environment (pH 11), and then the PBO fiber was immersed in the dispersed solution at 60 °C for 6 h to prepare nanoTiO2/PBO composite fiber. The single fiber pull-out strength of the prepared composite fiber was increased by 85.28 % compared with that of the untreated PBO fiber. Silane coupling agent was a bridge of PBO and nanoTiO2, hydrogen bond association and like dissolves like were attributed to the improvement of interfacial adhesion between nanoTiO2 and PBO fiber.