(649a) Invited Talk: Networked Structure and Properties of Lignin-Based Thermoplastics

Our recent study demonstrates a significant performance enhancement in formulations of lignin-based thermoplastics. Lignin, a biomass-derived polyphenolic material, is highly branched in structure and amorphous in nature. Its chemical structure depends on biomass type and method of extraction. In this work we have investigated network formation in lignin or its plasticized derivatives to formulate various melt-processible plastics. Understanding network formation in lignin polyblends is critical for tailoring their mechanical properties. In this work, the lignin phase was crosslinked by a reactive melt-mixing route both in the presence and absence of plasticizers. It was observed that the reactivity, processibility, and mechanical properties of lignin-modified polymer resins depend on the chemical architecture of lignin. The lignin-derived polymer formulations obtained had ultimate elongation >100% and mechanical strength >15 MPa. Depending on the melt-mixing temperature and sequence, the plasticizer and reinforcing agents offer synergistic compatibility in the polyblend.  Successful use of lignin bioplastics can significantly enhance biorefinery and pulping industry economics.