(552b) Novel Polysiloxaneimide/Polyetherimide/Non-Woven Fabric Composite Membranes for Hydrophobic Pervaporation

In this study, synthesis of polysiloxaneimide (PSI) was carried out and novel multi-layer composite membrane using PSI as selective top layer was prepared for pervaporation. The PSI was synthesized from 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA) and amino modified siloxane (dual-end type). Physiochemical characterization of the PSI with FTIR, NMR, XRD and GPC confirmed the success in synthesis. As for the composite membrane, non-woven fabric layer covered by crosslinked porous polyetherimide (PEI) layer was used as support. The PSI layer was formed by non-solvent induced phase inversion. Effects of preparation conditions in terms of support layer structure, PSI dope solution composition and post treatment on the pervaporation properties of the composite membranes were investigated. Pervaporation test for recovering ethanol from its aqueous solution (5wt.%) at 60^oC showed that the highest separation factor obtained with composite membrane was ~3 with corresponding flux being ~0.5kg/m²-hr. Based on the information accrued from pervaporation, FESEM, EDX etc., the problems existing with this new type of membrane and its fabrication methods were analyzed.