Characterization of Mycelium Biocomposites Under Simulated Weathering Conditions

Expanded polystyrene (EPS); commonly known as Styrofoam; has been utilized for various packaging and shipping applications; despite being notoriously difficult to recycle; resulting in microplastics and other environmental concerns. Research efforts have focused on evaluating mycelium-based materials for packaging applications due to their unique mechanical properties and biodegradability. Mycelium is the root system of fungi and composed of natural polymers including cellulose; protein; lignin; and chitin; it typically grows on a substrate made of agricultural waste products or dead organic materials. To replace EPS; mycelium biocomposites must be robust to various weather environments. As a natural biocomposite; this material is known to be affected by the environment; so it is critical to understand how temperature and humidity affect its properties. The purpose of this study is to evaluate the effect of various real-world environmental conditions on the properties of a commercially available mycelium biocomposite. Extreme conditions such as freezing temperatures; high heat and high humidity were examined. Unlike previous studies; we focus on both the mechanical properties as determined by hardness and impact testing as well as chemical; thermal and morphological characteristics to provide a complete picture of the transformation in the biocomposite. These results can help further our understanding of natural biocomposites as environmentally-friendly replacements for EPS and other synthetic plastics for a broad range of applications.