# Mycelium-Based Thermal Insulation for Domestic Cooling Footprint Reduction: A Review
## 4 Mechanical, Physical, and Chemical Characterization of Mycelium-Based Composites
The results show that MBC has low thermal conductivity (0.057-0.085 W\(\cdot\)m\({}^{-1}\)K\({}^{-1}\)), high mechanical strength (0.145-0.452 MPa), low density (156-373 Kg/m\({}^{3}\)), and good moisture buffer capacity of 1.632 g/m\({}^{2}\cdot\)%RH. The authors' findings suggest that mycelium-based composites (MBCs) have potential applications as insulation materials within interior walls and integral components of building envelope systems designed for vapor permeability [34]. The production of mycelium-derived composites from spent mushroom substrate (SMS) and sawdust (SD) is a promising way to recycle lignocellulosic by-products and create eco-friendly materials. The growth and binding capabilities of two fungi, _Ganoderma lucidum_, and _Tranetes versicolor_, were examined across various substrates. The results showed that T. versicolor could grow on both SMS and SD, while G. lucidum could only grow on SD. Both fungi generated lightweight substances exhibiting reduced thermal conductivity compared to traditional insulation materials [21]. An additional research endeavor investigates the creation of bio-composites using rice husks and sawdust, employing _Pleurotus ostreatus_ fungus as a binding agent for insulation, packaging, and construction applications. The authors employ a Box-Behnken experimental approach to enhance the bio-composites' attributes by optimizing substrate type, water content, and incubation time. They then compare anticipated values for the physical, mechanical, thermal, and fire safety properties of the bio-composites. The outcomes reveal that the bio-composites are lightweight, porous, hydrophilic, moderately robust, rigid, thermally insulative, and capable of self-extinguishing [35]. An investigation delves into using fungal mycelium as a natural bonding agent for crafting biodegradable composite materials using wood sawdust. The researchers analyze and contrast the material properties of composites originating from the two fungi in their pressed and unpressed forms. They find that hot pressing affects the composites' morphology, hydrophobicity, and mechanical properties in different ways depending on the fungal species. They observe that T. versicolor produces a homogeneous layer of aerial hyphae that melts during hot pressing. At the same time, T. pubescent creates a more heterogeneous network of hyphae that retains its structure after hot pressing. They also measure the composites' water contact angle, density, porosity, thermal conductivity, and compressive strength. They report that both fungi produce strongly hydrophobic mycelium composites, with T. versicolor being more hydrophobic than T. pubescent. They also find that hot pressing reduces the composites' density, porosity, and thermal conductivity while increasing their compressive strength. They deduce that the mechanical attributes of mycelium composites subjected to hot pressing are on par with, or potentially exceed, those of Expanded Polystyrene [23]. Another research investigates the mechanical and morphological properties of bio-foams produced from Oyster mushrooms and biomass substrates, namely sawdust and teak leaves. The paper aims to find a way to utilize agricultural waste and mushroom production to create biodegradable material. The paper uses two types of spawn: _Pleurotus sajor-caju_ (Grey Oyster mushroom) and _Pleurotus djamor_ (Pink Oyster mushroom) to inoculate the substrates and grow the biofoam. The paper tests the hardness, springiness, water adsorption, and morphology of the biofoam using scanning electron microscopy (SEM). The paper finds that teak leaves biofoam is more springy but less complicated than sawdust biofoam and that teak leaves biofoam has less water absorption than sawdust biofoam. The paper also observes that teak leaves biofoam has a dense filamentous and tubular structure, while sawdust biofoam has a more porous structure [36]. A research paper assesses the viability of utilizing mycelium as an alternative material for the sustainable construction industry.