SAXS MEASUREMENTS OF INTERFACIAL THICKNESS IN AMORPHOUS POLYMER BLENDS CONTAINING A DIBLOCK COPOLYMER

Small-angle X-ray scattering measurements were performed in order to e stimate the interfacial thickness of melt blended poly(styrene)/poly(m ethyl methacrylate)samples, with and without the corresponding poly(st yrene-b-methyl methacrylate) copolymer. The analysis of the scattering profile was based on deviations from Porod's law using the Koberstein /Morra/Stein (J. Appl. Crystallogr. 1980, 13, 34) graphical method in which the desmearing procedure is avoided. The interfacial thickness w as found to increase regularly with the addition of the copolymer, up to 33% when 10 wt % copolymer was added to the homopolymer blend. Thes e results are in agreement with existing theories.