Three-dimensional analyses of spherulite morphology in poly(oxyethylene) and its blends with amorphous poly(d, l-lactic acid) using X-ray computerized tomography

Here, we report on the three-dimensional structural analyses of huge spherulites of poly(oxyethylene) (PEG) using X-ray computerized tomography (CT) in blends of PEG and amorphous poly(d, l-lactic acid). Large spherulite formation is characteristic of PEG, and its direct observation using X-ray CT is reported here for the first time. Slit-shaped cracks that were straight or curved were clearly observed using X-ray CT. Furthermore, scanning electron microscopic observation revealed that the cracks were parallel to bundles of lamellar crystallites. From these observations, we conclude that a set of radial cracks observed by X-ray CT is a signature of a huge spherulite. Several aspects that are representative of an axialite structure are presented, and they are in good agreement with the intuitively proposed structural model for axialite long ago, although the size scale is much larger in our study.