Mycelium-Based Composites: A New Approach to Sustainable Materials

The use of plastics is facing, nowadays, some drawbacks as the use of fossil resources and its recycling. New approaches are being studied for the use of sustainable materials, by replacing plastics with natural materials, with a low ecological impact and low carbon footprint. The mycelium-based materials are a potential alternative to plastics and are totally recyclable. The growth of natural resources, as mycelium-based materials, is increasing its relevance as an alternative production process. The present study allowed the analysis of the viability of different fungi species to grow under controlled conditions and the selection of the best substrate according to the fastest and more consistent mycelium growth. Four types of fungal mycelium were used, namely Pleurotus ostreatus, Hypsizygus ulmarius, Ganoderma lucidum and Trametes versicolor, on three substrates (coffee grounds, pinewood waste and mixed wood waste). The mycelial growth was analyzed both morphologically and thermomechanically by means of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle with water tests. Mycelium growth varied with the fungus species and with the selected substrates. Microstructures of hyphae of the mycelium were obtained with different diameters, numbers of bonds between them and densities. The mycelium-based materials presented a stable behavior with increased temperature, undergoing degradation in terms of mass values above 270 °C.