Nature of the side chain branches in low density polyethylene: volatile products from gamma radiolysis

Measurements of the yields of low molecular weight hydrocarbons after γ-irradiation of low density polyethylene (LDPE) in the solid and liquid phases have confirmed that the main products are ethane and butane. Alkene yields were small, contrary to some previous reports. Irradiation at 150°C doubled the total yield of hydrocarbons, but the relative proportions of different hydrocarbons did not change markedly. The compatibility of these results with ¹³C n.m.r. determinations of the distributions of short chain branches in the same samples of LDPE is considered.