Kinetics of gamma-radiation induced polymerisation of 4-vinyl pyridine

Gamma-radiation initiated polymerisation of 4-vinyl pyridine has been studied at various dose rates and temperatures. The polymerisation is initiated by a free radical mechanism. The values (ksub(p)/ksub(t)sup(1/2)), energy of activation (Esub(A)) and chain transfer constant (ksub(trans)/ksub(p)) determined are 2.3 x 10-3, 11.0 kcal/mole and 1.5 x 10-2, respectively. An auto acceleration is observed at approx. 10% conversion. Auto acceleration and the increase in molecular weight with conversion are explained as due to chain transfer to the monomer leading to an unsaturated terminal end group, which is being utilised for the polymer growth. (author)