An in-situ SAXS/WAXD study on the effect of molecular weight distribution and entanglement state on structure evolution in extrusion-based additive manufacturing; part II

To value the directionality in for example patient-specific braces and exoskeletons, extrusion-based Additive Manufacturing (AM) strategies and molecular materials design demand alignment first. Properties transverse to the weld interfaces are the everlasting Achilles heel due to the lack of molecular mixing and entangling across the weld interfaces. Contrary, shear and elongational flow-induced shish-kebab morphology, provides design opportunities in the spatial deposition of strength. Our last experiment (2021035145) proved that standard molecular weight designs cannot tie in both requirements. Molecular designs that promote shish-kebab morphology have poor interfacial strength, while shish-kebab structures are lost in molecular designs that provide interfacial strength. A new so-called reactor blend did meet both structural requirements but turned out to be difficult to print in reality. Learning from the soon-published data, we have developed two new blends being discriminative by a reactor-induced disentangled state. The disentangled state facilitates high interfacial strength and good printability. To conclude our study, complement our tensile thermal analysis data, and develop the ultimate polymer formulation for extrusion-based AM, we aim to follow in-situ shish-kebab formation and potential melting as a function of time and spatial position as the AM process proceeds by in situ SAXS/WAXD measurements.