Spinodal decomposition of the polymer blend deutereous polystyrene (d-PS) and polyvinylmethylether (PVME) studied with high resolution neutron small angle scattering

Decomposition of a polymer blend in the miscibility gap has been studied by small angle scattering of neutrons, using a double crystal diffractometer. It covers a range of 10^-5 to 10^-3 Å^-1, which connects the region of elastic light scattering and, at the upper end, the region of conventional neutron small angle scattering instruments. The decomposed structure in the miscibility gap can be described by a characteristic length R which increases with time, t^1/3 between 7 and 25 min. At longer times, the growth follows a more linear power law. This behaviour is consistent with predictions of the domain growth for liquid mixtures and is estimated by using the self diffusion constant, viscosity, and the surface energy of the polymer.