Selective separation of water from aqueous alcohol mixtures through functionalized syndiotactic poly(styrene-co-4-methylstyrene) membranes by pervaporation

The pervaporation performances of a series of functionalized syncliotactic poly(styrene-co-4-methylstyrene) (SPSM) membranes for various alcohol mixtures were investigated. The syndiotactic polystyrene copolymers, poly(styrene-co-4-methylstyrene) (SPSM), were prepared by styrene with 4-methylstyrene using a Cp*Ti(OCH3)(3)/methyl aluminoxane (metallocene/MAO) catalyst. The effect of functionalization on the thermal properties and polymer structure of the SPSM membranes were also investigated. The crystallinity of the functionalized SPSM membrane is lower than that of the unfunctionalized SPSM membranes. The water molecules preferentially permeate through the SPSM membranes. Compared with unfunctionalized SPSM membranes, the functionalized SPSM membrane effectively increases the membrane formation performances and the pervaporation performances. The optimun pervaporation performance (a separation factor of 510 and permeation rate of 220 g/m(2)h) was obtained by the bromination of SPSM (SPSMBr) membrane with a 90 wt % aqueous ethanol solution. (C) 2002 Wiley Periodicals, Inc.