Synthesis of styrene-methyl methacrylate graft and block-graft copolymers via combination of atom transfer radical polymerization and stable free radical polymerization

Styrene (St)-methyl methacrylate (MMA) graft and block-graft copolymers were prepared by combination of atom transfer radical polymerization (ATRP) and stable free radical polymerization (SFRP). In the first step, MMA and comonomer 2-phenyl-2-[(2,2,6,6-tetramethylpiper-idino)oxy]ethyl methacrylate were polymerized in the presence of ethyl-2-bromo isobutyrate by ATRP in order to give suitable macroinitiator for the following SFRP step of St. Alternatively, first SFRP of St was carried out by using a dual initiator, 2-phenyl-2-[(2,2,6,6-tetramethylpiperidino)oxy]ethyl 2-bromopropanoate, yielding macroinitiator to be used in ATRP of MMA and the comonomer. The corresponding block copolymer was used as a polyfunctional macroinitiator in SFRP of St to yield final block-graft copolymer. The obtained graft and block-graft copolymers were characterized by ¹H-NMR, UV-Vis and GPC measurements.