Studies on aqueous polymerization of acrylonitrile. Cerium(IV)/acetaldehyde redox system

The thermal polymerization of acrylonitrile initiated by the cerium(IV)/acetaldehyde (A) redox system was carried out at 25°C, and the rate of monomer disappearance, –d[M]/dt, was followed by gravimetry and the rate of cerium(IV) disappearance –d[Ce(IV)]/dt by titrimetry. –d[M]/dt was found to be directly proportionsl to [M]3/2, [A]1/2, and [Ce(IV)]1/2. –d[Ce(IV)]/dt was found to be directly proportional to [Ce(IV)] and [A]. A reaction scheme is given together with the kinetic expressions. The activation energy for the overall rate was found to be 67,24kJ.mol−1 (16,06kcal.mol−1), and the value of the second order rate constant kr, was obtained as 2,481.mol−1s−1.