Well-Defined Polymers Bearing Pendent Alkene Functionalities via Selective RAFT Polymerization

A facile synthetic approach for the preparation of well-defined copolymers bearing pendent alkene functionalities was established by selective reversible addition-fragmentation chain transfer (RAFT) (co)polymerization. A divinyl monomer, 4-(3'-buten-l'-oxy)-2,3,5,6-tetrafluorostyrene (1), with a styrenyl group and a pendent alkene group was synthesized. Because of a very high reactivity of the styrenyl group relative to the alkene group in 1, functional fluorocopolymers with both well-defined structures and pendent alkene groups were prepared by RAFT polymerization of 1 and copolymerization of 1 with pentafluorostyrene (PFS). Alkene-functionalized diblock copolymers were also prepared by RAFT copolymerizations of 1 with PFS or styrene, extending from a poly(styrene-alt-maleic anhydride) macrochain transfer agent. Hydrolysis and aminolysis of these copolymers resulted in amphiphilic diblock fluorocopolymers with alkene-functionalized hydrophobic segments, which were shown to form internally functionalized micelles in THF-water.