Synthesis and characterization of telechelic polymethacrylates via RAFT polymerization

The reversible addn.-fragmentation chain transfer (RAFT) polymn. technique has been employed to synthesize linear a,w -telechelic polymers with either hydroxyl or carboxyl end groups. Me methacrylate, Bu methacrylate, and Bu acrylate were polymd. with RAFT polymn. The polymns. exhibited the usual characteristics of living processes. Telechelic polymethacrylates were obtained from a hydroxyl monofunctional RAFT polymer with a two-step chain-end modification procedure of the dithioester end group. The procedure consisted of an aminolysis followed by a Michael addn. on the resulting thiol. The different steps of the procedure were followed by detailed anal. It was found that this route was always accompanied by side reactions, resulting in disulfides and hydrogen-terminated polymer chains as side products next to the hydroxyl-terminated telechelic polymers. Telechelic poly(Bu acrylates) with carboxyl end groups were produced in a single step procedure with difunctional trithiocarbonates as RAFT agents. The high yield in terms of end group functionality was confirmed by a new crit.-liq.-chromatog. method, in which the polymers were sepd. based on acid-functionality and by mass spectrometry analysi