Novel graft stabilizers for the free radical polymerization of methyl methacrylate in supercritical carbon dioxide

This paper reports the free radical polymerization of methyl methacrylate (MMA) in supercritical carbon dioxide (scCO(2)) using novel graft copolymer stabilizers. The stabilizers are formed by the thermal ring-opening reaction of poly(methyl vinyl ether-alt-maleic anhydride) with 1H,1H,2H,2H-perfluorohexan-1-ol (1) or 1H,1H,2H,2H-perfluorooctan-1-ol (2). These stabilizers are effective at low concentrations (0.1-2 wt % with respect to MMA) for the dispersion polymerization of MMA leading to high yields of poly(methyl methacrylate) (PMMA) with reasonable molecular weights, narrow molecular weight distribution, and narrow particle size distribution. The increase of graft chain length by only two carbon units has a substantial effect on the stabilizers' activity.