Hybrid Polylactic Acid (PLA) Composites: Impact of Varying the Cellulose Material (CM) Source

Thermoplastic composites are of significant interest in a variety of industries ranging from automotive to construction as they present a recyclable, low cost, and lightweight alternative material without sacrificing performance. Additionally, hybrid composites which contain more than one type of reinforcement (<i>e.g.,</i> natural fibers and cellulose materials (CM)) have gained increasing attention where target properties are enhanced via composite formulations. Herein, three different fibers (<i>i.e.,</i> creafill, flax, and wheat straw) are mixed with three different CM and incorporated into polylactic acid (PLA) via melt compounding. PLA was chosen as the matrix material for all hybrid composites due to its industrial compostability and its demonstrated applicability in 3D printing. The mechanical and thermomechanical properties of the resulting thermoplastic, hybrid composites are reported where the composite strength and modulus exhibit marked increases compared to the non-hybrid composites. In addition, by matching the fiber and CM, the material demonstrates further improvements; the mechanism for property enhancement is explored as a function of CM. Finally, these hybrid composites are formulated and targeted for automotive and tooling applications.