| Abstract: | In the presence of triphenyl phosphite (TPP), the radical polymerization of acrylonitrile (AN) with α,α′-azobisisobutyronitrile (AIBN) as the initiator was carried out at 50°C, and the effects of TPP on the polymerization were kinetically investigated. The rate of polymerization was found to be proportional to the first order of the AIBN concentration and the AN concentration, respectively, at all concentrations of TPP. However, the rate of polymerization was proportional to the reciprocal of the TPP concentration at low concentrations, but to the first order of the TPP concentration at high concentrations. On assuming two termination reactions, i.e., the usual unimolecular termination by occlusion of the polymer radical and a bimolecular termination between the propagating radical and TPP, and the formation of the weak n-π complex between AN and TPP which accelerates propagation step, the rate of polymerization and the degree of polymerization were kinetically discussed. The equations derived were in good agreement with the experimental results. |
