Synthesis and aqueous solution characterization of catalytically active homopolymers, block copolymers and networks containing imidazole

Imidazole-containing polymers were prepared and characterized in terms of their hydrolytic activity. Unlike similar materials synthesized in the 1960s, the polymers are of precise molecular weight and controlled structure (random or block) afforded by the group transfer polymerization (GTP) chemistry used in the synthetic procedure. The size and composition of the copolymers were determined by gel permeation chromatography (GPC) and proton nuclear magnetic resonance spectroscopy, respectively. Aqueous solutions of the polymers were evaluated in terms of their ability to hydrolyze 4-nitrophenyl acetate. The effects of pH, polymer concentration, substrate concentration, polymer size, and structure were investigated and discussed with reference to the nucleophilicity of imidazole and the self-assembly of the block copolymers into micelles. A series of model networks based on imidazole homopolymers were also prepared and characterized in terms of their aqueous degree of swelling.