Polymerization of acrylonitrile

Abstract

Polymerization of acrylonitrile in homogeneous medium in dimethyl formamide at 50°C and 60°C (to be inserted in all places where temperatures are mentioned) in precipitation medium in toluene at 50°C and 60°C, and in bulk at 35° to 55°C, all initiated by α, α'-azobis-isobutyronitrile has been studied. Transfer constants with their activation energies for polyacrylonitrile radicals and dimethyl formamide or toluene have been evaluated. By measurements of rates and degrees of polymerization, rates of initiation have been evaluated in homogeneous and precipitation media. Values of K, A',k_p/k_t^½ and their respective activation energies have been evaluated. The abnormalities of exponents for initiator and monomer concentrations in the rate equation are discussed. The applicability of normal homogeneous medium kinetics is examined. Apparent values of k_p/k_t^½ in bulk have been evaluated at temperatures ranging from 35°C to 55°C.