Styryl-Telechelic Polyisobutylenes. II. Amphiphilic Sequential Copolymers of Styryl-Telechelic Polyisobutylenes with Vinyl Acetate or N-Vinyl-2-pyrrolidone

Styryl-telechelic polyisobutylenes (i.e., linear and three-arm star polyisobutylenes capped with polymerizable p-styryl endgroups St-PIB-St and St-PIB-St) have been copolymerized with vinyl ace State VAc or N-vinyl-2-pyrrolidone VP by conventional free radical techniques. The products obtained with St-PIB-St/VAc systems were soluble, most likely branched block copolymers of isobutylene IB and VAc, whereas those prepared with St-PIB-St/VP or St-PIB-St/VP Stcombinations were networks consisting of PIB and poly(N-vinyl-2-pyrrolidone) PVP sequences. That the copolymerization of St-PIB-St with VAc results in soluble products and that with VP yields networks is due to the very different reactivities of styrene with VAc and with VP. Hydrolysis of VAc units in PID-PV Ac block copolymers gave vinyl alcohol V A units, i.e., these products are branched block copolymers consistion of random VAc/VA composition of these soluble aphiphilic materials was determined from conversion and molecular weight data and by 1H-NMR soectroscopy; their mechanical properties were examined by stress - strain measurements. The composition of amphiphilic PVP-PIB networks was calculated from conversion and elemental analysis data. These gels were founds to bind both water -soludle dyes (methyl orange) and hydrocarbons (benzene). The first binding constant K1 that characterizes the binding of methyl orange by these PVP-PIB networks is one order of magnitude larger than that characteristic of the binding of this dye by cross - linked PVP or by serum albumin.