Accession Number : AD0729573

Title :   The Effects of Nitrous Oxide and Ethylene on the Gas Yields and Gel Formation from gamma-Irradiated Polypropylene,

Corporate Author : DEFENCE STANDARDS LABS MARIBYRNONG (AUSTRALIA)

Personal Author(s) : Pinkerton,D. M.

Report Date : 25 NOV 1970

Pagination or Media Count : 14

Abstract : Isotactic and atactic polypropylene have been gamma-irradiated in a vacuum, in nitrous oxide, and in ethylene, and also in the presence of mixtures of these two gases. The gamma-irradiation of the isotactic polypropylene in a vacuum gives a H2 yield which is non-linear with dose, whereas the CH4 yield is linear with dose. Yields of H2 and CH4 from atactic polypropylene obey a linear relationship with the dose delivered. Both N2O and ethylene depress the G(H2) obtained from vacuum irradiations of isotactic polypropylene, the former due to electron scavenging and the latter to hydrogen atom scavenging. Compared to vacuum irradiations, N2O enhances, and ethylene suppresses completely, the crosslinking yield in isotactic polypropylene. In mixtures, the results are consistent with ethylene participating in the energy transfer reaction in preference to the N2O and so inhibiting the additional crosslinking that N2O causes through the dehydrogenation reaction. A tentative reaction sequence is proposed. (Author)

Descriptors :   (*POLYMERS, RADIATION CHEMISTRY), (*CROSSLINKING(CHEMISTRY), *RADIATION CHEMISTRY), GAMMA RAYS, NITROGEN OXIDES, ETHYLENES, FREE RADICALS, AUSTRALIA

Subject Categories : Radiation and Nuclear Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE