Development of a myco-material based on textile and agro-industrial waste for thermal insulation

Abstract

The European Union is promoting the increased use of thermal insulation to ensure energy conservation in the coming years. This will drive increased demand for materials suitable for such applications. However, the rise in the production of goods combined with the prevalent use of non-renewable resources in thermal insulation pose environmental challenges, leading to increased pollution and solid waste accumulation. In response, this study focuses on developing and characterizing a sustainable, biodegradable mycelium-based composite for thermal insulation. The bio-composite, cultivated from Pleurotus Pulmonarius fungus in agro-industrial and textile waste, offers a promising approach. In this work, two distinct combinations of substrates were utilized: one comprising 70% grass cuttings and dry leaves, along with 30% recycled ground textile, predominantly polyester; the other consisting of 70% sugarcane bagasse and 30% ground textile waste. Additionally, an extra 20% of the substrate weight of Pleurotus Ostreatus grain spawn was added to each combination to facilitate mycelium growth. The mycomaterials were tested for tensile and compression analysis (ASTM D3039 and ASTM D695 standards, respectively) and a thermal conductivity assessment (ISO 8301) was done. The materials showed better performance at compression tests than tensile test. Also, results demonstrate the superior performance of sugarcane bagasse mycelium composites over the dry leaves/grass cutting counterparts in thermal conductivity, tensile and compression tests. The inclusion of synthetic fibres to the mycelium composite may have compromised the mechanical and thermal properties of the samples as polyester fibres have a higher thermal conductivity than the natural components included in the sample. The fibres being synthetic, the mycelium could not feed on it, thus impeding binding and proliferation in some sections of the material.