Synthesis of telechelics and block copolymers via“living” radical polymerization

Abstract

Hydroxy-telechelic poly(methyl methacrylate)s of molecular weights below 5000 were obtained by atom transfer radical polymerization (ATRP) of methyl methacrylate followed by end-capping with allyl alcohol via atom transfer radical addition (ATRA). As initiators for the ATRP, monofunctional initiators with an additional hydroxy group in the molecule or bifunctional initiators were employed. The successful synthesis of the hydroxy-telechelic PMMA was proved by determination of their molecular weight using MALDI-TOF-MS. The efficiency of the end-capping reaction was determined by 1H NMR spectroscopy using the allyl N-(4-tolyl)carbamate as end-capping agent. Block copolymers comprising a poly(ethylene oxide) (PEO) block and a poly(methyl methacrylate) (PMMA) block were prepared by ATRP using a macroinitiator on the PEO basis. The dormant species of the macroinitiator consists of the phenyl chloroacetate moiety which shows a high rate of initiation. The successful synthesis of the poly(ethylene oxide)-block-poly(methyl methacrylate) was proved by 1H NMR spectroscopy; the ratios of EO/MMA repeating units in the feed and the copolymer were nearly equal.