Emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of methyl methacrylate with dimethyl ditelluride as the catalyst

Abstract

Emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of methyl methacrylate (MMA) using poly(methacrylic acid) (PMAA)–methyltellanyl (TeMe) (PMAA₃₀-TeMe) (degree of polymerization of PMAA, 30) was carried out at 60 °C with 1000 rpm stirring. The emulsion TERP of MMA did not successfully proceed with maintaining a living manner because of a low chain transfer rate constant relative to propagation rate constant. Moreover, even in the coexistence of (TeBu)₂, the emulsion TERP of MMA also did not proceed with living nature. On the other hand, it in the coexistence of (TeMe)₂ proceeded with good control/livingness. The difference was caused by the different in the solubility in water between (TeBu)₂ and (TeMe)₂. Because (TeBu)₂ is difficult to dissolve in the aqueous phase, it did not work as a catalyst in the aqueous phase, resulting in a homogeneous nucleation. On the other hand, because (TeMe)₂, which is more hydrophilic than (TeBu)₂, works as an efficient catalyst in the aqueous phase, resulting in the self-assembly nucleation.