A combined raman imaging and transmission electron microscopy study of blends of a deuterated linear polyethylene and a low-density polyethylene

Abstract

Abstract Local compositional variations in blends are examined using micro-Raman im- aging. Raman images are compared with morphologies detected by transmission electron microscopy (TEM). In isothermally crystallized blends, with morpholo- gies composed of clusters of crystals rich in deuterated linear polyethylene (DLPE) in a matrix of quenched material, the results from both techniques are comparable. These results show that compositional variations of about 30% can be detected by Raman imaging on a scale as small as 2 fim. In rapidly quenched blends exhibiting morphological phase structures on a scale of 1–2 f Am in the electron microscope, the Raman images were homogeneous to within the level of uncertainty in composition. However, the scale of the morphological phase structures examined is close to the limit of resolution of Raman imaging. It is shown that if there are compositional differences between the morphological phases, then these must be less than 3% in the samples studied.