MOLECULAR-WEIGHT AND ANTIOXIDANT EFFECTS ON THE STRUCTURE OF IRRADIATED LINEAR LOW-DENSITY POLYETHYLENE

Linear copolymers of ethylene and butene-1 with uniform chemical microstructure and very narrow molecular weight distribution are used to study the effects of ionizing radiation. The well characterized copolymers are irradiated at room temperature with gamma-rays from a Co-60 source. To follow the evolution of the molecular structure with the radiation doses, changes in molecular weight averages M(n) and M(w) are measured by membrane osmometry, light scattering and GPC. The influence of the original linear polymer molecular weight is examined in the range of 50,000-100,000. The effects of antioxidant are explored irradiating samples with and without additive.