High-Strength and Biodegradable Mycelial Leather Materials Cross-linked with Dialdehyde Carboxymethyl Cellulose

In recent years, mycelium, a green and biodegradable material, has garnered strong interest from researchers for developing leather materials. Due to its high biodegradability, biocompatibility, and renewability, it is regarded as a promising alternative to animal leather. In this study, mycelia were procured via solid fermentation from Ganoderma species using readily available agricultural wastes as nutrient sources. Subsequently, mycelium-based leather (ML) was fabricated using a series of processes, including deacetylation, plasticizing, cross-linking, and hot pressing. The results showed that homemade dialdehyde carboxymethyl cellulose (DCMC) can impart the mycelium with a higher tensile strength compared to glyoxal or glutaraldehyde, approximately 772 and 276% higher, respectively. This can be attributed to its nanoscale dimensions and high reactivity, which are conducive to the penetration of DCMC into the mycelium and further cross-linking between DCMC and mycelium. The prepared DCMC heat-pressing treated ML (DCMC-HT-ML) demonstrated heat resistance up to 250 °C and showed a tensile strength of 2.18 MPa and elastic modulus of 17.24 MPa, 581 and 698% higher than the pristine ML (P-ML), respectively. Notably, the results of landfill degradation experiments indicated that DCMC-HT-ML showed no discernible difference in biodegradability compared to P-ML. This study provided a facile approach for preparing degradable ML and highlighted that mycelium is a potential alternative to next-generation green leather materials.