Comparison of the local chain motion of a number of polymers in the melt observed by quasielastic incoherent neutron scattering experiments

Abstract

Incoherent quasielastic neutron scattering results are reported for a number of polymer melts at temperatures well away from their glass transitions. The data are discussed in terms of the Rouse model, which is shown apparently to fit the scattering results over an unexpectedly wide range of frequency and momentum transfer. This effect is explained in terms of contributions to the observed scattering from interchain propagating modes.

Differences between results are broadly explained by variation between polymers of their local backbone flexibility and by hindering effects of side groups. Values of monomeric friction coefficients are calculated from these results and give good agreement with those obtained from viscoelastic data.