The production of polymer blends by means of melt-mixing technologies presents itself today as a well established way for the development of polymeric materials. Morphology formation depends on the properties of each component, such as the melt viscosity, melt elasticity, and surface tension. The homogeneity and, as a result, the morphology of polymer blends are basically determined by the thermodynamic interactions of the components. The formation of morphology in heterogeneous polymer blends is determined by the mixing mechanisms that take place during melt-mixing, which can be characterized as dispersion and distribution processes. Morphology refinement and coupling reactions at the interface lead to improved phase adhesion. Elongational flow is especially needed to sufficiently deform the high viscous rubber phase that results in a morphology transformation from a cocontinuous morphology of the non-cross-linked rubber thermoplastic blend into the island-matrix morphology of the dynamic vulcanizate.