Novel synthesis of branched polystyrenes by quasi-living radical copolymerization using photofunctional inimer

Branched polystyrenes were prepared by quasi-living radical copolymerization of N,N-diethylaniinodithiocarbamoylmethylstyrene (inimer: DTCS) with styrene under UV irradiation. DTCS monomers play an important role in this copolymerization system as an inimer capable of initiating living radical polymerization of the vinyl group. Two monomers (DTCS and styrene) showed equal reactivity toward both propagating species, and the copolymer composition was the same as the comonomer feed. This result means that both the branching and chain length of the hyperbranched molecules can be controlled statistically by the feed monomer ratios. The compact nature of the branched macromolecules is demonstrated by viscosity measurements compared to the linear analogues. (C) 2001 Society of Chemical Industry.