Inelastic neutron scattering spectra of polyethylene

Abstract

High quality inelastic neutron scattering (INS) spectra of randomly oriented polycrystalline polyethylene and highly oriented polyethylene are presented. For the polycrystalline sample, comparison with the best available dispersion curves shows that these reproduce the INS spectrum qualitatively, apart from the energy of the maximum in the in-plane C—C bending mode ν₅. For the oriented samples, comparison with two sets of calculated INS spectra show fair agreement although neither reproduces the observed spectra exactly.