A modulated differential scanning calorimetry and small-angle x-ray scattering study of the interfacial region in structured latices

Abstract

The interfacial structure of poly(styrene) (PS)-poly(methyl acrylate) (PMA) structured latices has been investigated by means of modulated-temperature differential scanning calorimetry (M-TDSC) and small-angle x-ray scattering (SAXS). The differential of heat capacity, dCp/dT, signal from M-TDSC was used to quantify the weight fraction of interface in these latices. For PS-PMA (50:50 by weight) structured latices in which the PS component had different crosslink densities (0, 1, 3, 5 and 10 mol% of crosslinking agent), the weight fraction of interface was about 13%. With increasing crosslink density, the fraction of interface increased only slightly. A core-shell model has been used to analyse SAXS data for these PS-PMA latices. M-TDSC can only provide information about the weight fraction of interface, but the combination of M-TDSC and SAXS can provide much more information on the morphology of such structured latices.