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Advantages of block copolymer synthesis by RAFT-controlled dispersion polymerization in supercritical carbon dioxide
journal contribution
posted on 2016-10-14, 11:43 authored by James Jennings, Mariana Beija, Jeremy T. Kennon, Helen WillcockHelen Willcock, Rachel K. O'Reilly, Stephen Rimmer, Steven M. HowdleReversible addition-fragmentation chain transfer (RAFT)-controlled block copolymer synthesis using dispersion polymerization in supercritical carbon dioxide (scCO2) shows unprecedented control over blocking efficiency. For PMMA-b-PBzMA and PMMA-b-PSt the blocking efficiency was quantified by measuring homopolymer contaminants using the techniques of GPC deconvolution, gradient polymer elution chromatography (GPEC), and GPC dual RI/UV detection. A new, promising method was also developed which combined GPC deconvolution and GPEC. All techniques showed that blocking efficiency was significantly improved by reducing the radical concentration and target molecular weight. Estimated values agreed well with (and occasionally exceeded) theory for PMMA-b-PBzMA. The heterogeneous process in scCO2 appeared to cause little or no further hindrance to the block copolymerization procedure when reaction conditions were optimized. High blocking efficiencies were achieved (up to 82%) even at high conversion of MMA (>95%) and high molecular weight. These data compare favorably to numerous published reports of heterogeneous syntheses of block copolymers.
Funding
[The authors] thank the EPSRC for the PhD studentship (J.J.) and postdoctoral support (M.B.).
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Materials
Published in
MacromoleculesVolume
46Issue
17Pages
6843 - 6851Citation
JENNINGS, J. ... et al., 2013. Advantages of block copolymer synthesis by RAFT-controlled dispersion polymerization in supercritical carbon dioxide. Macromolecules, 46 (17), pp.6843-6851.Publisher
© American Chemical SocietyVersion
- VoR (Version of Record)