Preparation of silicone-graft copolymers by homogeneous radical copolymerization in supercritical carbon dioxide

Copolymerizations of 1,1-dihydroperfluorooctyl methacrylate (FOMA; M-1) and methacryloxypropyl-terminated polydimethylsiloxane [M-PDMS (M-n = 5.9 K); M-2] and homopolymerization of M-PDMS in supercritical CO2 are described. T he homopolymerization of M-PDMS proceeded homogeneously without difficulty to produce oligomers (M-n = 30 K), The copolymerizations of FOMA and M-PDMS also proceeded homogeneously over a wide monomer feed ratio, The ratio of M-PDMS incorporated into the copolymer obtained was almost equal to the mon omer feed ratio even up to the high conversion. The reactivity ratio r(1) w as determined to be 1.66. DSC examination of the copolymers indicated a mic rophase-separated morphology consisting of poly-FOMA (PFOMA) and PDMS domai ns for all copolymer compositions. (C) 2000 John Wiley & Sons, Inc.