22857.pdf (1.37 MB)

Advantages of block copolymer synthesis by RAFT-controlled dispersion polymerization in supercritical carbon dioxide

Download (1.37 MB)
journal contribution
posted on 14.10.2016 by James Jennings, Mariana Beija, Jeremy T. Kennon, Helen Willcock, Rachel K. O'Reilly, Stephen Rimmer, Steven M. Howdle
Reversible 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

Macromolecules

Volume

46

Issue

17

Pages

6843 - 6851

Citation

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 Society

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/

Publication date

2013

ISSN

0024-9297

eISSN

1520-5835

Licence

Exports

Logo branding

Keyword(s)

Licence

Exports