Morphology and properties of filter paper prepared by highly fibrillated poly(p-phenylene benzobisoxazole) fiber

Abstract

Poly(p-phenylene benzobisoxazole) fiber is a kind of rigid-rod polymer fiber and has a fibrillar structure. It can be fibrillated through a refining process. In this study, the highly fibrillated poly(p-phenylene benzobisoxazole) fiber, which consists of poly(p-phenylene benzobisoxazole) fibrils, was prepared by refining and fractionalizing. It was found that the poly(p-phenylene benzobisoxazole) fibril has a specific surface area of 41.5 m2/g, and the diameter can be tens of nanometers. Poly(p-phenylene benzobisoxazole) fibrils can be prepared into the paper by a wet-laid formation process. It was found that the average pore size of poly(p-phenylene benzobisoxazole) paper was 0.64 μm. The filtration efficiency of poly(p-phenylene benzobisoxazole) paper was 99.96% for particles with a size of 150 nm. After being heated at 400°C for 5 min, the poly(p-phenylene benzobisoxazole) paper could still retain a complete structure and have a filtration efficiency of 99.58%. It is suggested that poly(p-phenylene benzobisoxazole) paper has a potential application in high-efficiency particulate air filters used in air and gas treatment systems in some industrial facilities to resist heated air with a temperature of 400°C.