A polarity-activation strategy for the high incorporation of 1-alkenes into functional copolymersvia RAFT copolymerization

Abstract

A new synthetic methodology for the preparation of copolymers having high incorporation of 1-alkene together with multifunctionalities has been developed by polarity-activated reversible addition-fragmentation chain transfer (RAFT) copolymerization. This approach provides well-defined alternating poly(1-decene-alt-maleic anhydride), expanding the monomer types for living copolymerizations. Although neither 1-decene (DE) nor maleic anhydride (MAn) has significant reactivity in RAFT homopolymerization, their copolymers have been synthesized by RAFT copolymerizations. The controlled characteristics of DE-MAn copolymerizations were verified by increased copolymer molecular weights during the copolymerization process. Ternary copolymers of DE and MAn, with high conversion of DE, could be obtained by using additive amounts (5 mol %) of vinyl acetate or styrene (ST), demonstrating further enhanced monomer reactivities and complex chain structures. When ST was selected as the third monomer, copolymers with block structures were obtained, because of fast consumption of ST in the copolymerization. Moreover, a wide variety of well-defined multifunctional copolymers were prepared by RAFT copolymerizations of various functional 1-alkenes with MAn. For each copolymerization, gel permeation chromatography analysis showed that the resulting copolymer had well-controlled Mn values and fairly low polydispersities (PDI = 1.3–1.4), and 1H and 13C NMR spectroscopies indicated strong alternating tendency during copolymerization with high incorporation of 1-alkene units, up to 50 mol %. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3488–3498, 2008