Coagulum formation and elimination in emulsion copolymerization of tribromostyrene with styrene

Coagulum formation in emulsion polymerization of tribromostyrene and also in its copolymerization with styrene has been shown to be due to thermal polymerization. The latter takes place in the monomer reservoirs, even in the absence of radical generating initiators, converting them into sticky particles which then form the undesired coagulum. The coagulum formation phenomenon can thus be remedied by reducing the thermal initiation level through a semi-batch emulsion polymerization method, by lowering the polymerization temperature, and reduction of the collision frequency of monomer/polymer particles.