Effect of solvent in radical polymerization of butadiene 1‐carboxylic acid

Abstract

AbstractThe radical polymerization and copolymerization of butadiene 1‐carboxylic acid (Bu‐1‐Acid) were studied in a variety of the electron‐donor solvents such as dimethylformamide (DMF), tetrahydrofuran (THF), methyl ethyl ketone (MEK), acetonitrile (ACN), and benzene (BZ) using AIBN as an initiator at 50°C. Under these conditions, the polymerization rate of Bu‐1‐Acid increased in the order, DMF < THF < MEK < ACN < BZ in the various solvents. In copolymerization with styrene [M2] and acrylonitrile [M2], the monomer reactivity ratio r1 increased and r2 decreased in the same order. Moreover, it was found that Alfrey‐Price Q‐e value of Bu‐1‐Acid increased depending on solvent in the order DMF < THF < MEK < ACN < BZ. These variations were correlated to the electron‐donating power (Δvcm−) of the solvents used and are discussed on the basis of the solvation of Bu‐1‐Acid into the solvent. Also, it was found that the microstructures of these polymers were always trans‐1,4 and did not change with the solvent used.