POLYETHYLENE HYDROPEROXIDE DECOMPOSITION PRODUCTS

The decomposition products from pre-oxidized, linear low-density polyethylene have been identified and quantified for films exposed in the absence of oxygen to ultra-violet irradiation, heat or gamma-irradiation. Films were pre-oxidized under controlled conditions by gamma-irradiation in air. Vacuum decomposition products were then analyzed by infrared derivatization techniques to allow the quantification of carboxylic acid, ketone, ester, gamma-lactone, alcohol, hydroperoxide and unsaturation products. From the relative proportion of these products it is possible to compare the mechanisms of the three initiation methods. These mechanisms are compared and contrasted with previously proposed mechanisms for polyethylene degradation.