Investigation of phase separation mechanisms of thermoset polymer blends by time-resolved SAXS

Phase separation induced by crosslinking was studied by time-resolved small angle X-ray scattering in thermoset blend based on unsaturated polyester, styrene and low molar weight saturated polyester as low profile additive. The scattering intensities were analyzed using the Cahn–Hilliard–Cook theory. Combining DSC and DMA experiments allowed us to conclude that phase separation proceeded via spinodal decomposition frozen in the early stage. Apparent diffusion coefficients Dapp were estimated.