Effect of starting structure on the lifetime of a polymer under load in the presence of ultraviolet radiation

An investigation of the behavior of the coefficents A_j and _j in the radiation lifetime equation _j=A_je–_j with variation of the starting structure of polycaprolactam has revealed the structure-sensitivity of _j and the structure-insensitivity of A_j. This and the fact that _j is proportional to the structure-sensitive coefficient in the equation for the lifetime without irradiation, together with the previous experimental data, provide a basis for the development of a theory of the mechanism of polymer fracture in the presence of UV radiation and throw light on the physical significance of the coefficients A_j and _j.A. F. Ioffe Physicotechnical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 4, pp. 636–641, July–August, 1969.