Polymerization of vinylpyridinium salts. X. Copolymerization studies of cationicanionic monomer pairs

Abstract The mechanism of the spontaneous polymerization of vinylpyridinium salts in aqueous and acidic solution has been actively investigated in recent years. Recent reports have suggested that these reactions are free radical in nature. In order to investigate the involvement of free radical initiation in the spontaneous polymerization reactions, an investigation of ion pair copolymers between the cationic 4‐vinylpyridinium moiety and the anionic vinylsulfonate, 2‐acrylamido‐2‐methylpro‐panesulfonate, and p ‐styrenesulfonate has been undertaken. The results of spontaneous polymerization suggest that for 4‐vinylpyridinium vinylsulfonate, only the cationic moiety is polymerized, whereas for 4‐vinylpyridinium 2‐acrylamido‐2‐methylpropanesulfonate, two homopolymers or a block copolymer apparently result, and for 4‐vinylpyridinium p ‐styrenesulfonate, an alternating copolymer appears to be obtained.