Controlled Synthesis of Block Copolymers by Mechanistic Transformation from Atom Transfer Radical Polymerization to Iniferter Process

A straightforward transformation protocol combining two distinct living polymerization methods for the controlled synthesis of block copolymers is described. In the first step, bromo-terminated poly(methyl methacrylate) is prepared by atom transfer radical polymerization (ATRP). Then, a bromide end group is substituted with a triphenylmethyl (trityl) functionality under visible light irradiation using dimanganese decacarbonyl (Mn-2(CO)(10)) photochemistry. The resulting polymers with trityl end groups are used as macroiniferter for the polymerization of styrene and tert-butyl acrylate (tBA) to yield desired block copolymers with narrow molecular weight distribution. Moreover, the amphiphilic copolymers with acrylic acid functionalities are obtained by the hydrolyzation of poly(tert-butyl acrylate) containing block copolymers with trifluoroacetic acid.