Small-angle x-ray scattering from bulk block polymers in disordered state. Estimation of χ-values from accidental thermal fluctuations

Abstract

Small-angle X-ray scattering (SAXS) from accidental thermal concentration fluctuations of block polymers in bulk and in the disordered state was studied for a polystyrene–polyisoprene diblock polymer as a function of temperature. It was shown that the experimental SAXS profiles are predictable by Leibler’s theory based on the random phase approximation. Temperature dependence of χ-parameter between polystyrene and polyisoprene was estimated by fitting the experimental and theoretical SAXS profiles. An effect of glass transition on the thermal concentration fluctuations was also predicted. © 1985 The Society of Polymer Science, Japan.