Physicochemical processes along the early stages of the thermal degradation of isotactic polypropylene l. Evolution of the y relaxation under oxidative conditions

摘要

The evolution of the y relaxation along the early stages of the thermo-oxidation of two isotactic polypropylenes (i-PP) has been studied. It has been found that regardless of their different thermal stability, they show a similar disappearing of the y relaxation as soon as the induction period ends. The features of that disappearance and its correlation with some chemical and structural changes on oxidising are discussed.