Micro- and nanostructured polymer blends: State of the art, challenges, and future prospects

Polymer blending has been identified as the most versatile and economical method to produce new multiphase polymeric materials that are able to satisfy the complex demands for performance. Over the past few decades the number of polymer blends has grown tremendously. In fact the design and development of these multiphase polymer blend materials are strongly dependent on two major parameters: the control of the interface and the control of the morphology. In general, the term morphology refers to the shape and organization on a scale above the atomic level (e.g., the arrangement of polymer molecules into amorphous or crystalline regions) and the manner in which they are organized into more complex units. On the other hand, morphology of a polymer blend indicates the size, shape, and spatial distribution of the component phases with respect to each other. Since it is well established that most of the properties — mechanical, optical, rheological, dielectrical, and barrier properties — of polymer blends are strongly influenced by the type and fineness of the phase structure, the study of the control of the morphology of polymer blends has emerged as an area of continuous interest to polymer material scientists in the last few decades (1–5).