Simultaneous reversible addition fragmentation chain transfer and ring‐opening polymerization |
| |
| Authors: | Maude Le Hellaye Catherine Lefay Thomas P Davis Martina H Stenzel Christopher Barner‐Kowollik |
| |
| Institution: | 1. Centre for Advanced Macromolecular Design (CAMD), School of Chemical Sciences and Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia;2. Cooperative Research Centre for Polymers (CRC‐P), 8 Redwood Drive, Notting Hill, Victoria 3168, Australia |
| |
| Abstract: | The simultaneous ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) and 2‐hydroxyethyl methacrylate (HEMA) polymerization via reversible addition fragmentation chain transfer (RAFT) chemistry and the possible access to graft copolymers with degradable and nondegradable segments is investigated. HEMA and ε‐CL are reacted in the presence of cyanoisopropyl dithiobenzoate (CPDB) and tin(II) 2‐ethylhexanoate (Sn(Oct)2) under typical ROP conditions (T > 100 °C) using toluene as the solvent in order to lead to the graft copolymer PHEMA‐g‐PCL. Graft copolymer formation is evidenced by a combination of size‐exclusion chromatography (SEC) and NMR analyses as well as confirmed by the hydrolysis of the PCL segments of the copolymer. With targeted copolymers containing at least 10% weight of PHEMA and relatively small PHEMA backbones (ca. 5,000–10,000 g mol?1) the copolymer grafting density is higher than 90%. The ratio of free HEMA‐PCL homopolymer produced during the “one‐step” process was found to depend on the HEMA concentration, as well as the half‐life time of the radical initiator used. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3058–3067, 2008 |
| |
| Keywords: | ε ‐caprolactone NMR one‐step synthesis reversible addition fragmentation chain transfer (RAFT) ring‐opening polymerization (ROP) 2‐hydroxyethyl methacrylate (HEMA) |
|
|
