Morphological analyses evidencing corrugate-grating lamellae assembly in banded spherulites of Poly(ethylene adipate)

Abstract

The classical model of continuous helix-twist lamellae versus a novel corrugate-grating assembly in accounting for long-debated issues of periodic optical banding in poly(ethylene adipate) (PEA) polymer spherulites is critically assessed, by comparing and checking against a series of scientific evidence based on experimental data of scanning electron microscopy (SEM), ultrathin microbeam small-angle & wide-angle X-ray scattering (SAXS/WAXD), and optical microscopy. Analyses show that grating-structured model fits perfectly with all results. The novel proposition of grating-structured lamellae with a crossbar pitch fits perfectly with the experimental optical band spacing, and the interior morphology dissection is fully supported by the literature-reported microbeam X-ray data.