Establishing structure-processing-property relationships in 3D printed thermoplastic : pi-conjugated blends

Polymer processing displays at its core structure-processing-property relationships which are key for understanding the materials’ behavior and properties. As useful and promising additive manufacturing is shown to be, there is still a gap in our understanding of how the process will impact the printed material at the molecular level. To contribute tackling this challenge, our research group is currently developing strategies to investigate the structure-processing-property relationships at play upon the additive manufacturing of polymeric materials, more specifically, pi-conjugated polymers, which are well known for their optoelectronic properties. Herein, as a proof-of-concept, blends prepared form polycaprolactone (PCL) and poly(3-hexylthiophene-2,5-diyl) (P3HT) are evaluated for their printing capabilities in the context of hot-melt extrusion additive manufacturing. Our work consisting in the establishment of systematic correlations between the printability, print fidelity, and optoelectronic properties of these polymer blends via rheology, metrology and spectroscopy will be presented. Our conclusions highlight the challenges and opportunities involved in the additive manufacturing of functional polymer materials to enable the preparation of freeform materials with built-in functionalities.