Emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene: poly(dimethylaminoethyl methacrylate) macro-TERP agent

Abstract

Emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene was successfully carried out using poly(dimethylaminoethyl methacrylate) (PDM)–n-butyl tellanyl (TeBu) as control agent and 4,4′-azobis(2-amidinopropane) hydrochloride (V-50) as initiator. Emulsion TERP with inefficient stirring, in which the styrene phase floated as a layer on an aqueous phase, proceeded smoothly and almost finished within 30 h. The molecular weight distribution (MWD) shifted to higher molecular weight with increasing conversion, and M_w/M_n values were relatively small (∼2.0). The MWD control became better with decreasing PDM chain length of the control agent. The inefficient stirring caused better MWD control in the emulsion TERPs using all control agents compared to those with efficient stirring, in which the styrene phase was dispersed as droplets.