Quaternary ammonium polyelectrolytes .6. Kinetic studies on the quaternization reactions of chloromethylated polystyrene with 4,4'-bipyridil and of poly(4-vinylpyridine) with ethylchloroacetate

Kinetic studies on the quaternization of chloromethylated polystyrene with 4,4'-bipyridil in dimethylsulfoxide and N,N-dimethylformamide, as well as on the quaternization of poly(4-vinylpyridine) with ethylchloroacetate in formamide, N,N-dimethylformamide, and methanol, were performed. For most solvents, kinetic studies of the reactions between model compounds, such as benzylchloride and 4-methylpyridine, with 4,4'-bipyridil and ethylchloroacetate, respectively, were also performed. Both the kinetic behaviors and the kinetic parameters were determined. Analytical and H-1-NMR methods were used, the latter only for the reaction of poly(4-vinylpyridine) and 4-methylpyridine with ethylchloroacetate in deuterated methanol. In the case of polymers, different kinetic behaviors were observed for the same quaternization reaction, depending on the nature of the solvent. Thus, the reaction of chloromethylated polystyrene with 4,4'-bipyridil in dimethylsulfoxide followed a normal second-order kinetics, while in N,N-dimethyiformamide the acceleration phenomenon appeared. The reactions of poly(4-vinylpyridine) with ethylchloroacetate in N,N-dimethylformamide and methanol were accompanied by an acceleration phenomenon, but in formamide a slight deceleration occurred. These behaviors were assigned to polymer-solvent interactions and were observed to change during the reaction.