Synthesis of Well-Defined Sulfonated Polystyrene and Block Copolymers with n-Butyl Acrylate by Controlled Radical Polymerization

摘要

Ionomers such as sulfonated polystyrene and its block copolymers are used in a wide range of applications such as proton exchange membranes for fuel cells, additives in composites, gas separators, and polymer catalysts, etc. These molecules are usually synthesized by post sulfonation of polystyrene using sulfonating agents such as acetyl sulfate or sulfur trioxide. However, introduction of sulfonic acid groups on the styrene segments is not easy to control, especially at high sulfonation levels, due to the side-reactions between the polymers and the sulfonating agents. Controlled radical polymerization is one of the methods used to overcome this limitation because it enables direct homo- and co-polymerization of sulfonated styrene. Several researchers have reported synthesis of well-defined sulfonated polystyrene by the polymerization of sodium styrenesulfonate in aqueous nitroxide mediated radical polymerization (NMRP) and atom transfer radical polymerization (ATRP). Okamura et al.