A Comparison of Two Different Surface Modifications on the Properties of Poly (p-phenylene benzobisoxazole) Fibers

Abstract

Abstract Poly (p-phenylene benzobisoxazole) (PBO) fibers were modified by coupling agent 3-Glycidoxypropyltrimethoxysilane (KH-560) and polyphosphoric acid (PPA) respectively. The influence of two treatments on the properties of PBO was investigated, including surface morphology, water absorption and breaking strength retention ratio. The results indicate that the surface roughness of PBO fibers can be increased by both KH-560 and PPA. With the increase of PPA mass fraction, the retention rate of breaking strength of PBO fibers gradually was decreased, and the water absorption rate was gradually increased. Notably, KH-560 can effectively improve the water absorption rate without deteriorating mechanical properties of PBO fibers simultaneously. Compared to treatment by PPA, KH-560 has a milder effect on the performance of PBO fibers, which makes it easier to control the degree of surface modification.