Abstract

Increases in the world’s population and subsequent urbanization has driven consumption levels of building materials higher. In order to meet this need, and maintain the sustainability of resources, novel, ecofriendly insulation materials must be developed. These types of insulation materials should possess excellent thermal, acoustic and electrical insulating properties. In this study, four bio-based mycelium-substrate composites were developed by creating combinations of two mushroom species (T. versicolor and P. ostreatus) and two different growth substrates derived from waste stream sources (paper and bagasse). To test these mycelium-substrate composites for thermal, acoustic and electrical insulating properties, three low-cost novel testing systems were developed. The test materials included paper, bagasse, T. versicolor-paper composite (TP), T. versicolor-bagasse composite (TB), P. ostreatus-paper composite (PP), and P. ostreatus-bagasse composite (PB). The ability of commercial insulation, TP, PP and PB to reduce heat flow across a temperature gradient over 40 minutes was found to be significantly better, as compared to no insulation, with thermal conductivity values of 0.0407, 0.0461, 0.0356, and 0.0336 W/(mK), respectively. These mycelium-substrate composites performed similarly to commercial insulation. The average percent reductions in sound were 0%, 22.97%, 7.97%, 11.08%, 25.24%, 16.08%, 28.76%, and 32.36% for no insulation, commercial insulation, paper, bagasse, TP, TB, PP and PB respectively. The average amperage for each test material was 0 amps in response to 50 V. These results warrant further investigation of these bio-based mycelium-substrate composites in order to determine their potential applications.