AAB-Sequence Living Radical Chain Copolymerization of Naturally Occurring Limonene with Maleimide: An End-to-End Sequence-Regulated Copolymer

摘要

Sequence control in chain-growth polymerization is still one of the most challenging topics in synthetic polymer chemistry in contrast to natural macromolecules with completely sequence-regulated structures like proteins and DNA. Here, we report the quantitative and highly selective 1:2 sequence-regulated radical copolymerization of naturally occurring (+)-d-limonene (L) and a maleimide (M) in fluoroalcohol giving chiral copolymers with high glass transition temperatures (220−250 °C) originating from the specific rigid cyclic structures of the monomers. Furthermore, the combination with a reversible addition−fragmentation chain transfer (RAFT) agent (C−S) via the controlled/living radical polymerization resulted in end-to-end sequence-regulated copolymers [C-(M-M-L)_n-M-S] with both highly sequenced chain ends and main-chain repeating units as well as controlled molecular weights.