PERMEATION AND SEPARATION OF A BENZENE CYCLOHEXANE MIXTURE THROUGH BENZOYLCHITOSAN MEMBRANES/

Benzoylchitosans (BzCses) with a different degree of benzoylation were synthesized as membrane materials having a good durability for the se paration of benzene/cyclohexane (Bz/Chx) mixtures. Characteristics of BzCs membranes such as contact angle, crystallinity and degree of swel ling were significantly influenced by the degree of benzoylation. The BzCs membranes showed a high benzene-permselectivity for a Bz/Chx mixt ure of 50 wt% benzene in pervaporation and a difference of the benzene -permselectivity for the BzCs membranes with different degree of benzo ylation corresponded to a difference in the physical structure of the membranes based on the characteristics of these membranes. When a Bz/C hx mixture of 50 wt% benzene was permeated through the BzCs membranes, permeation rate increased and benzene-permselectivity slightly decrea sed with increasing degree of benzoylation. These results are discusse d from the viewpoints of chemical and physical structures of the BzCs membranes with different degree of benzoylation. (C) 1998 Elsevier Sci ence B.V.