Controlled dispersion polymerization in supercritical carbon dioxide by RAFT

POLY 647

Andrew M. Gregory,, Kristofer J. Thurecht,, and Steven M. Howdle, School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
This work reports on controlled radical polymerization in supercritical carbon dioxide (scCO2) using free RAFT (Reversible Addition Fragmentation Chain Transfer) agents to produce well-defined, dispersed microspheres. The excellent mass transport properties of scCO2 has facilitated effective interphase transfer of the RAFT agent producing high molecular weight polymers whereby the theoretical molecular weight is close to experimental. Furthermore, molecular weight polydispersity was always less than 1.30 but typically less than 1.20. Further proof of the RAFT process was observed through the living nature of the polymers produced: poly(methyl methacrylate) was successfully reinitiated with methyl methacrylate and styrene to produce chain extension and block copolymers. These chain extension experiments showed controlled molecular weight increases while preserving the particulate morphology of the polymer precursor.

General Papers: Functional Materials
1:00 PM-4:40 PM, Thursday, August 23, 2007 Westin Boston Waterfront -- Grand Ballroom A, Oral

Division of Polymer Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007