Using an Invasive Plant (Japanese Knotweed) for Mycelium-Based Thermal Insulation Composites.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Sustainable Construction

Background:

• Mycelium-based composites (MBCs) offer a sustainable alternative to conventional insulation.
• Hemp is a common feedstock for MBCs but faces sourcing challenges.
• Invasive plant species represent an underutilized resource for biomaterial production.

Purpose of the Study:

• To compare the physical and thermal properties of MBCs made from hemp and invasive Japanese knotweed.
• To evaluate Japanese knotweed-derived MBCs as a potential sustainable insulation material.
• To benchmark performance against Polyisocyanurate (PIR) insulation.

Main Methods:

• Fabrication of MBCs using hemp shives and Japanese knotweed biomass.
• Characterization of thermal conductivity using an internally developed method.
• Assessment of physical properties including bulk density and water absorption.
• Comparison with Polyisocyanurate (PIR) insulation standard.

Main Results:

• MBCs from Japanese knotweed exhibited thermal conductivity comparable to hemp-based MBCs and PIR.
• Japanese knotweed MBCs showed higher bulk density (166 vs. 128 kg/m³).
• Significantly higher water absorption was observed in Japanese knotweed MBCs (7.5% vs. 3.5% volume uptake).

Conclusions:

• While Japanese knotweed is a promising feedstock for thermally efficient MBCs, its suboptimal physical properties limit its viability for insulation.
• Further research is needed to improve the physical characteristics of knotweed-based MBCs for practical applications.
• Invasive species management can be integrated with sustainable material development.