Uncovering the Mechanical, Thermal, and Chemical Characteristics of Biodegradable Mushroom Leather with Intrinsic Antifungal and Antibacterial Properties
Jenniffer Bustillos, Archana Loganathan, Richa Agrawal, Brittany A. Gonzalez, Marcos González Pérez, Sharan Ramaswamy, Benjamin Boesl, Arvind Agarwal
Abstract
is investigated. The biodegradable leather proves to be thermally stable up to 250 °C. The mechanically robust macrostructure combines a tensile strength of 1.2 MPa and ductility (101% strain at break) attributed to the natural balance of chitin (0.3) and proteins (0.7) constituting the mycelium fibers. The chitin-protein system results in an intrinsic scratch-resistant structure with exciting damping properties in a low frequency range. Enhanced damping capabilities within 5-20 Hz (tan δ: 0.1-0.20) are attributed to the macrostuctural alignment of the mycelium under cyclic tension. Whereas, increasing frequencies >20 Hz induce micromolecular interactions between chitin and proteins within the fibers. Exposure of the bioleather to acidic (pH 4, 5) and basic (pH 8, 9) media demonstrated the selective dissolution of proteins (basic) and chitin (acid) components within the mycelium, opening an opportunity for tunable mechanical response. Reducing the protein content induced an increase in stiffness and strength (pH 8 and 9), while reducing its chitin component showed variable ductility (pH 4 and 5). Owing to the entirely natural composition of the mushroom leather, intrinsic antifungal and antibacterial properties found in the mycelium resist fungal invasion and bacterial growth. Thus, this study displays the unique morphology-property relationship of a biodegradable mushroom leather, proving its potential as a fully sustainable and environmentally friendly alternative.