Formation of composition gradient or step from melted polymer blend of poly(ethylene oxide) and polypropylene

In the melted blend of poly(ethylene oxide) (PEO) and polypropylene (PP), layer phase separation of gradient or step structure along the thickness of the sample was obtained by the temperature gradient formation. In the step structure, an extremely clear boundary was observed. Such a clear structure had not been obtained in previously examined blends and was considered to be based on the insolubility of the two crystalline polymers. On the point of widening the structural area which can be controlled, this procedure offers examples which may be useful in the search for functions or in the original inventions needed for applied research.