Preparation and characterization of PSf hollow fiber membrane from PSf–HBPE–PEG400–NMP dope solution

Hyperbranched polyester (HBPE) was synthesized by melt polycondensation and the molecular weight of prepared HBPE was 5480 g/mol. Porous hollow fiber membranes were prepared via non-solvent induced phase separation (NIPS) from dope solutions composed of polysulfone (PSf), N-methyl-2-pyrrolidone (NMP), polyethylene glycol 400 (PEG400) and HBPE. Membrane morphologies, permeation performance, transient pure water contact angle and mechanical property of the prepared membranes were measured to investigate the effects of HBPE on membrane structures and properties. The addition of HBPE led to the coexistence of finger-like and sponge-like structures in the membranes. When the HBPE content increased from 0 to 3.0 wt%, there was a sharp decrease in contact angle. At the same time, the porosity, mean effective pore size, pure water flux and the breaking strength of membranes increased with the HBPE content.