Influence of polystyrene on PDMS IPNS blend membrane performance

In this work, a series of pervaporation blend membranes with polydimethylsiloxane (PDMS)/polystyrene (PS) were prepared by using the sequential interpenetrating polymer network (IPNs) technique with various amount of PS (10-70 wt.%). The blend IPN membranes were supported by Teflon (polytetrafluoroethylene) ultrafiltration membrane. Effect of PS contents in PDMS IPNs on crosslinked density, molecular weight, network-chain segment concentration, water swelling properties, and tensile properties were investigated. Results revealed that the degree of crosslink density and tensile strength of the PDMS IPNs blend membrane depending on wt.% of PS added and scan electron microscope image confirmed that the PDMS/PSt IPN membranes have continuous microphase structures. The synthesized IPNs blend membrane was used for ethanol recovery from aqueous solution by pervaporation, and exhibited enhanced separation performance compared with PDMS membranes. The maximum separation factor of IPNs blend membrane were obtained at 50°C, and the total flux increased exponentially along with the increase of temperature. The PDMS/PS membrane synthesized by 50 wt.% PS gave the best pervaporation performance with a selectivity (α) of 7.6, permeation rate of 214 g/m 2 h with a 10 wt.% ethanol (EtOH) concentration at 60°C