Radiation‐induced oxidative degradation of isotactic polypropylene

摘要

AbstractGas evolution, oxygen consumption, and change of mechanical properties were studied for the γ‐ray irradiation of isotactic polypropylene from60Co under various conditions, such as vacuum, air, and oxygen at room temperature. For irradiation under vacuum,G(H2) = 2.9 andG(CH4) = 0.09; theGvalues for other gases were very small. In the presence of oxygen,G(H2) was the same, and theGvalues for other hydrocarbons were two times those under vacuum. The G values of oxidative products and oxygen consumption wereG(CO2) = 2.5,G(CO) = 1.1, and G(O2) = 50 at oxygen pressure of 500 torr and were dependent on oxygen pressure. With irradiation under vacuum at 2–3 Mrad, mechanical properties scarcely changes immediately after irradiation but degrade gradually with storage time in air at room tempera