Positron annihilation lifetime in situ study of deformed polyolefin elastomers

Abstract

The positron annihilation lifetime spectroscopy was used to investigate the free volume hole size of ethylene octane copolymers as a function of deformation in the range from 0 to 110% in steps of 10%. For each degree of deformation a series of 5-6 positron annihilation lifetime spectra was collected in situ. All spectra of a given series were analysed simultaneously. They were resolved into three exponential components, of lifetimes parameters ¿i and intensities Ii. The variations of ¿3 reflect three deformation regions, the elastic range, strain softening range, and plastic region.