Small-Angle X-ray Scattering from Blends of PE and SBS. Observation of a Novel Kind of Deviation from Porod's Law

In a study of technical blends from poly(ethylene) and poly(styrene)-poly(butadiene) star block copolymers, reproducibility of the blending process and of the structural analysis is tested. A peculiar and reproducible deviation in the angular interval of the scattering curve is observed, which is governed by a decay according to Porod's law. The notion of a faint electron-density undulation in space with a wavelength of 5 nm, an amplitude of 1 e.u. nm^-3 and a range of 40 nm could explain the triangular peak observed in a plot which otherwise linearizes the scattering curve in the Porod regime.