Three-Dimensional Orientation of a Crystalline Polymer via Epitaxial Growth from a Magnetically Oriented Nucleating Agent

The three-dimensional orientation of a crystalline polymer can be achieved via epitaxial growth from a nucleating agent under a modulated rotating magnetic field. Microcrystals with three different principal values of magnetic susceptibility tensors can be aligned three-dimensionally by modulated rotation under a static magnetic field. In this study, such magnetic processing is applied to poly(l-lactic acid) (PLLA) containing zinc citrate (ZnCit) as a nucleating agent under a PLLA melt. The X-ray diffraction patterns of the magnetically processed film showed that the PLLA crystals and ZnCit microcrystals are aligned three-dimensionally. The present method has potential not only for the orientation control of PLLA, which is required for optimizing the ability, but also for the investigation of epitaxy in a pair of crystalline polymers and nucleating agents.