DIENE-N-(2,4,6-TRIBROMOPHENYL)MALEIMIDE COPOLYMER MEMBRANES FOR PERVAPORATION OF ETHANOL-WATER MIXTURES

Alternating copolymers of butadiene or isoprene with N-(2,4,6-tribromo phenyl)maleimide and the copolymer of chloroprene containing 42.7 mole % N-(2,4,6-tribromophenyl)maleimide structure units were synthesized by radical copolymerization. Along with copolymerization, the Diels-Al der addition of comonomers proceeded. DSC revealed some crosslinking o f the copolymers occurring even at room temperature. Homogeneous membr anes were prepared from the copolymers by solution casting and tested in pervaporation of variously concentrated aqueous ethanol. Separation factors of the membranes related to the preferentially transported wa ter increased with increasing content of ethanol in solutions to be se parated. In contrast to hydrophilic maleimide groups, the incorporated diene units lowered separation efficiency due to their affinity to et hanol.