Preparation and characterization of poly(vinyl butyral) hollow fiber membrane via thermally induced phase separation with diluent polyethylene glycol 200

Hydrophilic poly(vinyl butyral) (PVB) microporous hollow fiber membranes were prepared via thermally induced phase separation (TIPS), polyethylene glycol with molecular weight 200(PEG200) was used as diluent. The phase diagram of PVB/PEG200 system indicated L-L phase separation. The effects of preparation condition such as take-up speed, bore liquid flow rate, air-gap, and water bath temperature on the properties of the membrane were investigated. The results showed that PVB hollow fiber membrane prepared at air-gap 5 mm had a little greater tensile strength, breaking strength and elongation than those prepared at air-gap zero, and the former had a little greater rejection but smaller water permeate. The increase of the take-up speed led to the decrease of inner diameters and thickness, the increase of the bore liquid flow rate led to the increase of inner diameter and outer diameter, but the decrease of thickness.