Preparation of ABC triblock copolymers of N-alkyl substituted acrylamides by RAFT polymerization

Abstract

Reversible addition-fragmentation chain transfer (RAFT) polymerization of N-alkyl substituted acrylamides has been carried out by the use of a trithiocarbonate (2-dodecylsulfanylthiocarbonyl-sulfanyl-2-methyl propionic acid) as the RAFT reagent. The N-alkyl groups of the acrylamide monomers are important in the RAFT process. N-alkyl monosubstituted polyacrylamides are found to be active macro-chain transfer agents, while N,N-disubstituted monomers can react easily with them to form a sequent block. We have designed a synthetic pathway to successfully prepare ABC triblock copolymers of N-alkyl substituted acrylamides with low polydispersities (PDI < 1.20) by a three-step RAFT polymerization process.Key words: block copolymers, RAFT polymerization, N-alkyl substituted acrylamides, thermosensitive polymers.