EFFECTS OF FUNCTIONAL-GROUP AND OPERATING TEMPERATURE ON THE SEPARATION OF PYRIDINE-WATER MIXTURE BY PERVAPORATION

Modified polyacrylonitrile (PAN) membranes were prepared by emulsion o r emulsifier-free emulsion polymerization technique. Separation capaci ty was determined at several operating temperatures (25, 40, 55 and 70 degrees C) to dehydrate 56wt% pyridine aqueous solution through modif ied PAN membranes having different functional groups. All these PAN-ba sed membranes were selective toward water to different degrees dependi ng on the nature of functional groups present in the membranes. Pervap oration characteristics of PAN-based membranes are so different and cl assified into three categories depending on the type of the functional groups in PAN copolymers. Among PAN-based membranes, the in situ comp lex membranes show the best separation capacity over the operating tem peratures.