Stress-induced ordering in microphase-separated multicomponent networks

Polymer blends, mixtures, or block copolymers can be cross-linked in a homogeneous state forming a multicomponent network. Upon cooling such network, the repulsion between different components may lead to a microphase separation into regions rich in each of these components. The main difference of the microphase separation in multicomponent networks from, say, that in block copolymers is that there are quenched random elastic forces acting on the microphase regions from the cross-links of the network. We demonstrate that these forces destroy the long-range order of microstructures in undeformed or isotropically swollen network. The system is broken into correlation regions significantly larger than the period of microstructures. The long-range orientational order appears upon anisotropic deformation of the network.