Synthesis of alternating hyperbranched copolymers using photofunctional inimer via living radical mechanism

Copolymerizations of N,N-diethylaminodithiocarbamoylmethylstyrene (inimer: DTCS) with maleic anhydride (MA) were carried out under UV light irradiation. DTCS monomers play an important role in this copolymerization system as an inimer that is capable of initiating living radical polymerization of the vinyl group. Reactivity ratios (r1=0 and r2=0.15) were estimated by the curve-fitting procedure (DTCS [M1]; MA [M2]). These reactivities showed strong alternation and the propagating copolymer radicals proceeded always with homopolymerization of 1:1 complexes formed between the donor and acceptor monomers. Examination of the 1H nuclear magnetic resonance (NMR) of copolymerization products confirmed the presence of hyperbranched structure.