Synchrotron X-Ray Mapping on Flow-Induced Crystallized Polymers

Polymer crystallization under shear is a critical area of polymer research due to its significant impact on industrial processing techniques including injection molding and 3D printing. Under shear conditions, polymers become anisotropic and can develop complex structures such as shish-kebabs. Traditionally, the effect of shear on polymer structure has been studied using pressure-driven flow, which inherently includes pressure drop and shear gradient effects. In our research, we utilize a tangential flow setup in a rotational rheometer, allowing precise control over shear gradient, and sample size suitable for X-ray mapping. By employing synchrotron X-ray techniques at APS and CHESS, we capture a comprehensive view of the structural evolution under these conditions. This presentation will discuss our use of X-ray mapping to examine various responses in resin alignment in PEEK and its composites, the impact of melting temperature on the flow-induced crystallization of iPP, and how X-ray mapping enhances our understanding of iPP orientation as predicted by mold flow simulations.