A Small Angle X-Ray Scattering Study of Melt Separation in Crosslinked Low Density Polyethylene

Abstract

Studies of the sol-gel separation process, believed to occur in chemically crosslinked low density polyethylene at temperatures just above the melting point, have been carried out using small angle x-ray scattering. Analyses of the results demonstrate that two phases do indeed exist after the lamellae disappear. Scattering that occurs is symptomatic of isolated scattering entities. Comparison with theoretically predicted scattering envelopes show that the sol exists as small droplets which are disc-like at a temperature immediately above the melting point, but that they become spherical as temperature is increased, ultimately disappearing when miscibility returns.