Terpolymerization of acrylamide, acrylic acid, and acrylonitrile: Synthesis and properties

Free-radical solution terpolymerization of acrylamide, acrylic acid, and acrylonitrile was carried out in a mixture of dimethylformamide and water (60 : 40,v/v) at 85°C using benzoyl peroxide as the initiator. The polymers were characterized by elemental analysis, IR, 1H-NMR, TGA, and viscosity measurements. Elemental analysis data were used to evaluate the terpolymer composition. The reactivity ratios were determined by Fineman–Ross and Kelen–Tudos methods. The reactivity ratios (r) for the copolymerization of (1) acrylic acid + acrylonitrile with (2) acrylamide was found to be r1 = 0.86 ± 0.09 and r2 = 1.93 ± 0.03, respectively, by the Kelen–Tudos method. The Fineman–Ross method yielded a value of r1 = 0.86 ± 0.05 and r2 = 1.94 ± 0.09, respectively. The activation energy values for various stages of decomposition were calculated from TGA analysis. Voluminosity (VE) and the shape factor (ν) were also computed from the viscosity measurements in different ratios of the solvent mixture.