The polymerization of acrylonitrile in aqueous nitric acid solution with sodium nitrite as initiator has been studied. The rate of polymerization can be expressed by following equation:Rp = Ae10.800/RT [AN]2.3 [NaNO2]0.17-1.0[HNO3]1.0-0.67In the copolymerization of acrylonitrile and methyl acrylate

the reactivity ratios was found to be 0.96 and 1.17

respectively

indicating a free radical mechanism.According to the results of polymerization kinetics and infra-red analysis

it is suggested that the initiation mechanism of acrylon trile in aqueous nitric acid solution by sodium nitrite is analogous to thesecondary initiation by electrolysis or corrosion of metals.