Lignin and Cellulose Nanofibers Enhanced Corn-Based Thermoplastic Composites

Abstract

The goal of this project is to develop biobased thermoplastics and composites using corn as the main raw material. Corn contains mainly starch, zein, and oil. Thermoplastic starch/zein blends were prepared through internal mixing and extrusion. Lignin was used as a compatibilizer to refine the phase structure of the blend and increase the mechanical properties of the product. Scanning electron microscopy study showed that the incorporation of lignin significantly reduced the domain size of the zein phase in the blends. Modulus and tensile strength of the blend were increased greatly. Thermogravimetric analysis showed that the thermal stability of the blends was slightly improved after the incorporation of lignin. Cellulose nanofibrils (CNFs), a biobased nanomaterial, were also tested as a reinforcement for the blend. The incorporation of CNFs further enhanced the modulus and strength of the blends, suggesting a strong synergy between lignin and CNFs in reinforcing the corn-based thermoplastics.