In addition to hydrogen, there are at least seventy-three radiolysis products from the x irradiation of PMH. Thirtyfour of these products are in the C1 to C11 range with a total G approximates 4.9 and with individual G values ranging from 0.001 to 1.2. Thirty-nine are in the C12 to C24 range with a total G approximates 2.1 and with individual G values ranging from 0.003 to 0.23. Twerty-six of the Products in the C1 to C10 range were identified, of which the major ones are methane, isobutane, isobutylene, neopentane, 2,2,4-trimethylpentane, and 2,4,4-trimethylpentene-1. Since authentic hydrocarbon samples of the types expected from radiolysis of PMH are not available, identification of products in the C11 to C24 range was not possible. In the C1 to C11 range, the processes that lead to a product which can be related to some portion of the carbon skeieton of the parent hydrocarbon predominate. Also, the processes that lead to products of carbon content less than the parent hydrocarbon predominate over those that lead to products of carbon content equal to or greater than the parent hydrocarbon. Molecularweight measurements and gas chromatographic evidence indicate very strongly that the highest-molecular-weight products, at least in the earliermore » stages of radiolysis, are those of C/sub 24/ carbon content. In addition to the identification of unsaturated products in the C1 to C11 range, evidence for unsaturation in the C12 to C24 range was obtained from H2 uptake measurements and infrared spectra.« less