PROPERTY OF THERMOSENSITIVE AND REDOX-ACTIVE POLY(N-CYCLOPROPYLACRYLAMIDE-CO-VINYLFERROCENE) AND POLY(N-ISOPROPYLACRYLAMIDE-CO-VINYLFERROCENE)

Thermo-sensitive and redox-active polymers were prepared by the copoly merisation of N-cyclopropyl (NCPAM) or N-isopropyl acrylamide (NIPAM) with varying content of vinyl ferrocene (VFc(II)) Aqueous solution of the copolymer showed LCST (lower critical solution temperature) depend ing on the ferrocene content in copolymers. LCST of the aqueous soluti on of these copolymers was decreased with increasing ferrocene content in the copolymers. The oxidation of ferrocene has lead to a significa nt increase in LCST due to a transition from hydrophobic to hydrophili c property of ferrocene moiety in copolymers. The transition could be made reversibly by redox reaction using cerium sulfate as an oxidant a nd L-ascorbic acid as a reductant. Changes in the cloud point temperat ure accompanying the transition increased with increasing the amount o f ferrocene in copolymer. (C) 1997 Elsevier Science Ltd.