Synthesis of Star-Shaped Polystyrenes via Nitroxide-Mediated Stable Free-Radical Polymerization

摘要

High molecular weight star-shaped pl>lystyrenes were prepared via thl coupling of 2,2,6,6.tetramethyl-1-piperidinyloxy (TEMPO) terminated polystyrene oli gomers with divinylbenzene (DVB) in m-xylene at 138 °C.. The optimum ratio of thl coupling solvent (m-xylene) to divinylbenzene was determined to be 9 to 1 based or volume. Linear polystyrene oligomers(M_n = 19,300 g/mol, M_n = 1.10) were pre pared in bulk styrene using benzoyl peroXide in the presence of TEMPO at approXi mately 130 °C under an inert atmosphere. Coupling of the TEMPO-terminated oli gomers under optimum condition