In sharp contrast with their amorphous counterparts, crystalline polymers provide a wealth of information on chain conformation, the packing chains in unit-cells, existence or not mirror symmetric conformations, lamellae, folds linking stems, and so forth. Three illustrations these insights are presented here: (a) orientation polymer (b) complete structural analysis alpha phase isotactic polypr...

Isotactic polypropylene (iPP) melts are industrial semicrystalline polymers whose processing typically involves strong shear flows. The study of the rheological response iPP melts, well beyond linear viscoelastic limit, is limited by edge fracture, which manifests in rotational rheometers. In this work, we used a reflection polariscope under to detect onset rate at fracture observed for various...

When a minor semicrystalline phase is dispersed in an immiscible blend with another polymer the form of isolated droplets, its crystallization behavior dominated by nucleation. In particular, nucleation can occur bulk volume (homogeneous nucleation), at surface possible nucleating foreign impurities, or interface matrix polymer. Dispersed poly(butene-1) (PB) and polycaprolactone (PCL) droplet p...

Flow-induced structure formation is investigated with in situ wide-angle X-ray diffraction with high acquisition rate (30 Hz) using isotactic polypropylene in a piston-driven slit flow with high wall shear rates (up to ≈900 s(-1) ). We focus on crystallization within the shear layers that form in the high shear rate regions near the walls. Remarkably, the kinetics of the crystallization process...