The Anti-compaction Behavior of Aramid Fiber Based Polyvinylidene Fluoride Composite Separation Membranes

Poly( p -phenylene terephthalamide) (PPTA), as the raw polymer material of Aramid fiber-1414, has high modulus and high strength which is commonly used in the reinforced composites. However, the general blending often accompany the microphase incompatibility in polymer matrix. In this study, PPTA molecules were incorporated into poly(vinylidene fluoride) (PVDF) membrane matrix through in situ polycondensation of p -phenylene diamine (PPD) and terephthaloyl chloride (TPC) in PVDF solution and PPTA/PVDF molecular composite membranes were prepared via the subsequent nonsolvent induced phase separation (NIPS) process. The anti-compaction properties of resulted PPTA/PVDF molecular composite membranes were systematically investigated including the variations of bursting pressure and membrane thickness, porosity, pure water flux under different pressures. The results suggested that membrane comprehensive anticompaction properties were improved with the increasing of PPTA content in PVDF membrane matrix. Combining the variation trends of membrane anti-compaction properties with morphologies, the compaction-deformation evolution processes of two membrane pore types (sponge-like and finger-like pores) were proposed at the end.