Phase and microphase separation in polymer blends

Abstract
When two different polymers are mixed, they usually demix because of the slight repulsive interaction that exists between their monomers. This is general and may be related to phase separation in two component mixtures. When the same polymer blend is cross-linked in the one phase region, elastic forces develop and do not let this to occur. There results a microphase separation, with coexistence of regions of finite extent and different compositions. We discuss these phenomena as well as the kinetics of the decomposition.