Diblock and triblock functional copolymers by controlled radical polymerization

Controlled polystyrenes with different molar mass values were synthesized s tarting from benzoyl peroxide and TEMPO (2,2,6,6-tetramethylpiperidinyl-1-o xy). The polystyrene homopolymers served as initiators for the block copoly merization of phthalimide methylstyrene (PIMS) to synthesize polystyrene-b- poly(PIMS) diblock copolymers. Diblock copolymers with well defined structu res as well as controlled and narrow molar mass distribution were obtained from the lower-mass polystyrene homopolymers. The lower-mass copolymers wer e found to Be active as initiators in the synthesis of the polystyrene-b-po ly(PIMS)-b-polystyrene triblock copolymers, In each reaction step, the effe cts of conversion and reaction time on the molar mass characteristics of th e prepared block copolymers were investigated. The diblock and triblock cop olymers were modified using hydrazine as the reagent in order to obtain the corresponding functional amino block copolymers. (C) 1999 John Wiley & Son s, Inc. J Polym Sci A: Polym Chem 37: 1237-1244, 1999.