열전환 된 폴리벤즈옥사졸 중공사막

Abstract

Preparation of polybenzoxazole asymmetric hollow fiber membrane from hydroxyl poly(amic acid) (HPAAc) precursor has been studied by non-solvent induced phase separation (NIPS) for CO2 capture. HPAAc hollow fiber membranes were converted to hydroxyl containing polyimide (tHPI) and finally convert to polybenzoxazole (PBO) by thermal imidization and rearrangement processes, respectively. Polymer solution for hollow fiber membrane spinning (dope solution) consists of polymer/ solvent/ non-solvent/ additives and salt. In spinning process, there are parameters to control thickness and morphology of hollow fibers which critically affect to performances such as dope flow rate, bore fluid rate, salt and viscosity. The evaluation factors of gas permeation are CO2 permeance (PCO2/L, GPU) and permselectivity(αCO2/N2). We can expect wall thickness of hollow fiber according to different dope flow rate with fixed bore fluid or various bore fluid rate with constant dope flow rate. Dope solution with salt indicates high viscosity for well formed morphology and outer dense layer. Defect-free is one of the significant elements to show high permselectivity as well.