Synthesis of RAFT Block Copolymers in a Multi-Stage Continuous Flow Process Inside a Tubular Reactor

Abstract

This work describes a multi-stage continuous flow polymerisation process for the synthesis of block copolymers using the RAFT polymerization method. The process retains all the benefits and versatility of the RAFT method and has been adapted for a series of monomer combinations, including acrylates, acrylamides, and vinyl monomers. It resulted in polymers with molecular weights between 13500 and 34100 g mol–1, and dispersities typically between 1.21 and 1.58. Different architectures were prepared (including combinations of hydrophilic and hydrophobic blocks) which are soluble in a range of different solvents including aqueous and organic media.

RAFT Polymerization – Then and Now

“…In this context we (190)(191)(192)(193)(194)(195) and others (196,197) have examined RAFT polymerization in continuous flow reactors. Recent research at CSIRO in this area has involved developing processes for monomer degassing prior to polymerization (192), block copolymer synthesis (193), RAFT end-group removal (191,194,195), and sequential RAFT polymerization and end-group removal by, for example, thermolysis (194) or aminolysis (Scheme 23) (195). Scheme 23.…”

Continuous Flow Synthesis of RAFT Block Copolymers

“…[17] Several monomer combinations including acrylates, acrylamides, and vinyl monomers were studied.…”

“…Experimental configuration of the two-stage continuous flow process for the synthesis of RAFT di-block copolymers. Reproduced from ref [17]. with permission from CISRO Publishing.…”

Highly efficient reversible addition-fragmentation chain-transfer polymerization in ethanol/water via flow chemistry

“…Iwasaki and co‐workers even tried to keep the system running for several days to produce polymers with stable molecular weight and molar mass dispersity via free radical polymerization, which exhibited great potential for industrial productions . Others have reported the synthesis of both homopolymers and block copolymers via RAFT polymerization in continuous systems . Moreover, ‘click’ reaction and photo‐initiated RAFT polymerization were also successfully performed in flow systems .…”