Effect of Submicron Structures on the Mechanical Behavior of Crystalline Polymers

We investigated changes in hierarchical structures of crystalline polymers during tensile testing by means of time-resolved ultra small-angle, small-angle, and wide-angle X-ray scattering (USAXS, SAXS, and WAXS, respectively). We discovered the enhancement of density fluctuation on the submicron scale by USAXS, which led to the generation of voids and necking. The spatial inhomogeneity of the stress fields associated with density or crystallinity fluctuation on the submicron scale induced the inhomogeneous flow during stretching.