Chapter 11. RAFT Polymerization: Adding to the Picture

  1. Prof. Dr. Michael Buback2 and
  2. A. M. van Herk3
  1. Ezio Rizzardo,
  2. Ming Chen,
  3. Bill Chong,
  4. Graeme Moad,
  5. Melissa Skidmore and
  6. San H. Thang

Published Online: 31 MAY 2007

DOI: 10.1002/9783527610860.ch11

Radical Polymerization: Kinetics and Mechanism, Volume 248

Radical Polymerization: Kinetics and Mechanism, Volume 248

How to Cite

Rizzardo, E., Chen, M., Chong, B., Moad, G., Skidmore, M. and Thang, S. H. (2007) RAFT Polymerization: Adding to the Picture, in Radical Polymerization: Kinetics and Mechanism, Volume 248 (eds M. Buback and A. M. van Herk), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany. doi: 10.1002/9783527610860.ch11

Editor Information

  1. 2

    Institute of Physical Chemistry, Georg-August-University Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany

  2. 3

    Laboratory for Polymer Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands

Author Information

  1. CSIRO Molecular and Health Technologies, Bag 10 Clayton South, Victoria 3169, Australia

Publication History

  1. Published Online: 31 MAY 2007
  2. Published Print: 13 APR 2007

ISBN Information

Print ISBN: 9783527320561

Online ISBN: 9783527610860

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Keywords:

  • molecular weight;
  • radical polymerization;
  • RAFT agents;
  • facticity

Summary

Factors affecting the choice of RAFT agent [RSC(Z)=S] for a given polymerization are discussed. For polymerization of methyl methacrylate (MMA), tertiary cyanoalkyl trithiocarbonates provide very good control over molecular weight and distribution and polymerizations show little retardation. The secondary trithiocarbonate RAFT agents with R=CHPh(CN) also gives good control but an inhibition period attributed to slow reinitiation is manifest. Radical induced reduction with hypophosphite salts provides a clean and convenient process for removal of thiocarbonylthio end groups of RAFT-synthesized polymers. Two methods providing simultaneous control over stereochemistry and molecular weight distribution of chains formed by radical polymerization are reported. Polymerization of MMA in the presence of scandium triflate provides a more isotactic PMMA. A similar RAFT polymerization with trithiocarbonate RAFT agents also provides control and avoids issues of RAFT agent instability seen with dithiobenzoate RAFT agents in the presence of Lewis acids. RAFT polymerization of tetramethylammonium methacrylate at 45 8C provides a more syndiotactic PMMA of controlled molecular weight and distribution (after methylation; mm:mr:rr 2:21:77 compared to 3:35:62 when formed by bulk polymerization of MMA).