Prediction of the phase structure in polymer blends: What is needed for success?

Rules for prediction of the phase structure in immiscible polymer blends fr om the knowledge of their composition, component properties and the flow fi eld in a mixing or processing device are discussed. The reliability of qual itative prediction of the dependence of phase structure on system parameter s is used as a criterion of plausibility of the rules. No general reliable rule for prediction of the phase structure type (continuity of phases) is a vailable in the literature. Dependence of the droplet break-up frequency on its size, contribution of simultaneous collisions of three or more droplet s to coalescence and the effect of complex flow field on coalescence must b e better described for a reliable qualitative prediction of the dependence of the droplet size on the system parameters.