Real-time X-Ray Scattering Study of Morphological Evolution of Melt Extruded Semicrystalline Polymer

Niah Johnson

Co-Presenters: Individual Presentation

College: Hennings College of Science Mathematics and Technology

Major: BS.CHEMISTRY/EXP

Faculty Research Mentor: Ree, Brian  

Abstract:

Material extrusion has gained significant attention in materials science as a prominentmanufacturing strategy, particularly in polymer processing, due to its design flexibility, highproduction speed, compatibility with a wide range of materials, production of high-valuereplacement and repair parts, environmentally friendly manufacturing with minimal waste, andcontinuous improvement with decreasing costs. Its applicability spans polymers, metals, alloys,ceramics and composites with polymers being the most extensively used in products likeconsumer-grade goods as well as high-performance engineering components. Despite thewidespread adoption of extrusion-based techniques, the morphological evolution of polymersduring processing remains understudied and insufficiently understood.In this study, the real time morphological evolution of semicrystalline poly(ε-caprolactone)(PCL) was investigated using synchrotron wide-angle X-ray scattering (WAXS) during meltextrusion under varying bed temperatures. Quantitative analysis allowed the generation of high-resolution two-dimensional maps of key morphological parameters, describing relativecrystallinity and lattice parameters with both spatial and temporal exactness. A recently developedmodel was instituted to resolve crystallization kinetics into primary and secondary processes.The results show that synchrotron X-ray scattering provides a highly sensitive and precisemethod for characterizing the morphological evolution of melt-extruded PCL. Given the fastcrystallization kinetics of PCL compared to many other conventional polymers, this approachoffers critical insight into the relationship between processing parameters, morphologicaldevelopment, and the structural properties of extruded filaments in fused filament fabrication.