Copolymers of 2‐vinylpyridine, methyl acrylate, and dichlorostyrene: Polymerization and properties in solution

Copolymerization studies have been made on the three two‐component systems formed by the monomers methyl acrylate, 2‐vinylpyridine, and dichlorostyrene, and values of the monomer reactivity ratios were determined. Terpolymers were prepared from mixtures of these same monomers, and their compositions were compared with those predicted from the kinetic data for the copolymerizations. Measurements of dissymmetry of scattered light, molecular weight, and viscosity were made on solutions in acetic acid and in methyl ethyl ketone of a terpolymer containing 37 mole per cent methyl acrylate, 47 mole per cent 2‐vinylpyridine, and 16 mole per cent dichlorostyrene. The molecular weight of the terpolymer is essentially the same in the two solvents but the polymer chain is more extended in acetic acid than in methyl ethyl ketone. In nitromethane solutions of the terpolymer the η sp / c values increase sharply with decreasing concentration. This increase is eliminated if the solutions also contain 0.01 mole per liter of a substituted quaternary ammonium iodide. These facts indicate that the polymer behaves as a polyelectrolyte in nitromethane, presumably because of reaction between the aci ‐form of the solvent and the vinylpyridine groups.