Troponoid-Mediated Radical Polymerization in Aqueous Medium

Abstract

A new strategy, troponoid-mediated radical polymerization, has been applied to the radical polymerization of N-vinylpyrrolidone (NVP), 2-hydroxyethyl acrylate (HEA), and N, N-dimethyl acrylamide (DMA) in aqueous media. The observed living characteristics including the linear increase in molecular weight with monomer conversion and the formation of block copolymers demonstrate the effectiveness of troponoids in controlling radical polymerization in water, but the broader dispersity (Đ) implied that the polymerization is partially controlled. Tropone (TP) and its derivatives, tropolone (TP-OH), 2-chlorotropolone (TP-Cl), and 2-methoxytropolone (TP-OMe) were employed to optimize the reaction conditions. The versatility of this approach is further highlighted by the synthesis of PDMA-b-PVP and PHEA-b-PVP block copolymers. Mechanistic insights and kinetic parameters were elucidated through NMR analysis, chain extension experiments, UV/Vis spectroscopy, and computational simulation.