Synthesis and characterization of comb-branched polyelectrolytes. 1. Preparation of cationic macromonomer of 2-(dimethylamino)ethyl methacrylate by atom transfer radical polymerization

The synthesis of water-soluble macromonomers of 2-(dimethylamino)ethyl meth acrylate (DMAEMA) by atom transfer radical polymerization (ATRP) was studie d in detail. The survival of the unsaturated groups in the initiators durin g the macromonomer preparation as well as the initiator efficiency depended on the nature of initiator and type of ligand used. The kinetics of the AT RP of DMAEMA catalyzed by allyl 2-bromoisobutyrate (ABIB)/copper bromide (C uBr)/N,N,N',N',N "-pentamethyldiethylenetriamine (PMDETA) system at differe nt conditions indicated that the low initiator efficiency of the ATRP syste m could not be improved by increasing temperature or changing solvents. It was found that ABIB/CuBr/tris(2-di(butylacrylate)amine (BA(6)-TREN) and all yl trichloroacetamide (ATCA)/CuBr/BA(6)-TREN gave high initiator efficienci es and excellent control over the molecular weights and molecular weight di stributions in the ATRP of DMAEMA. H-1 NMR studies confirmed that each poly DMAEMA. chain had a polymerizable allyl end group. These allyl-terminated p olyDMAEMAs after quaternized were proven to be reactive in the copolymeriza tion with acrylamide.