Renewable and biodegradable materials have been used extensively to replace petroleum feedstocks due to the growing global environmental concerns. We report the utilization of lignin (the second most abundant renewable material) to prepare 3D-printed and fiber reinforced composites with two of the most widely used polymers, polypropylene (PP) and polyethylene (PE). Both PP and PE have high melt viscosity and crystallize quickly causing processing difficulties. Adding lignin enabled tuning of the materials’ 3D-printing and melt-spinning characteristics. The application of high shear-flow and external stress during processing, particularly melt-spinning, resulted in a significant increase in molecular alignment and tensile strength. We discovered that miscible amorphous lignin chains were intercalated and confined between the PP and PE crystalline chains. The alignment of PP and PE induced orientation of the amorphous lignin chains. Rheological properties, kinetics of crystallization, crystal structure and molecular orientation under different stretching conditions were comprehensively investigated to elucidate their 3D-printability, melt-spinnability, and mechanical performance. The results obtained from this study suggest a better route to valorize different lignin sources.

Confinement and alignment of miscible amorphous lignin in polypropylene and polyethylene by 3D-printing and melt-spinning

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.