Laminar heterogeneous coatings obtained from mixtures of epoxy-oligomer and polymethylphenylsiloxane in binary solvents☆

Abstract Regularities were examined of the layer separation of incompatible polymer mixtures (oligoepoxide and polymethylphenylsiloxane) during evaporation of a general binary solvent from moderately thin layers. A phase diagram was plotted for an oligoepoxide-polymethylphenylsiloxane-acetone-toluene system. As a consequence of nonequilibrium ply separation the structure of laminar heterogeneous coatings depends to a large extent not only on the composition and thermodynamic characteristics of separating phases, but also on solvent volatility, layer thickness and the presence of a hardening agent.