Percipitation copolymerization of acrylamide and acrylic acid: Determination of reactivity ratio by various methods

Abstract Copolymers of acrylamide ( AM ) and acrylic acid ( AA ) were prepared by precipitation polymerization method at 65 °C in the ethyl acetate as solvent. Copolymer composition was determined by elemental analysis. Monomer reactivity ratios were determined in low conversions. Mayo-Lewis, Finemann-Ross, Inverted Finemann-Ross, Ezrielev-Brokhina-Roskin, Kelen-Tudos, Extended Kelen-Tudos and Mao-Huglin methods, as linear methods, and Tidwell-Mortimer, as nonlinear method, were applied to calculate r AM and r AA r reactivity ratios. Monomer reactivity ratios of AM and AA were obtained 0.46 and 0.28, respectively. Comparing of reactivity ratios of AM and AA in this work by other solvents showed that hydrogen bonding and ionic strength are important parameters that can affect the reactivity ratios of monomers. Moreover, microstructure of copolymers was determined using reactivity ratios and conditional probability based on the kinetic model for free-radical polymerization.