“Gradient” polymer prepared by complex-radical terpolymerization of styrene, maleic anhydride, and N-vinyl pyrrolidone via gamma ray irradiation by use of a RAFT method: 2. Used in dispersion polymerization of styrene as a stabilizer

The radiation-induced dispersion polymerization of styrene in an ethanol–water mixture has been investigated using a novel “gradient” copolymer consisting of styrene–maleic anhydride (St–MA) and maleic anhydride–N-vinyl pyrrolidone (MA–NVP) complexes as a stabilizer. The influence of parameters such as the molar mass, the concentration and the molecular architecture of the “gradient” copolymers on the colloidal dispersion has been studied. Mono-dispersed polystyrene particles could be obtained in the range of 400–700 nm.