Dispersion polymerization of methyl methacrylate in superctitical carbon dioxide using a silicone-containing fluoroacrylate stabilizer

Free radical dispersion polymerization of methyl methacrylate (MMA) was carried out in supercritical carbon dioxide (scCO₂) using poly{(heptadecafluorodecyl acrylate)-co-3-[tris(trimethylsilyloxy)silyl]propyl methacrylate) (p(HDFDA-co-SiMA)) as stabilizer. Dry, fine powdered spherical poly(methyl methacrylate) (pMMA) particles with well-defined sizes were produced. The resulting high yield of spherical and relatively uniform micron-size pMMA particles was formed utilizing various amounts of p(HDFDA-co-SiMA) random copolymer. The particle diameter was shown to be dependent on the weight percent of the stabilizer added to the system. The effects of varying the concentration of stabilizer (1-7 wt%), reaction time (4-12 h) and pressure (15-35 MPa) upon the polymerization yield, molar mass and morphology of pMMA were investigated.