Thermal Insulation Board Based on Miscanthus Residual Fibers

Juan Pablo Cárdenas R1, Rodrigo Navia2, 3, Gonzalo Valdés1, Nima Zarrinbakhsh4, Manjusri Misra4, 5 and Amar K. Mohanty4, 5
1Departamento de Ingenieria en Obras Civiles, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile
2Scientific and Technological Bioresource Nucleus, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile
3Departamento de Ingeniería Química, Universidad de La Frontera, Av. Francisco Salazar 01145, Temuco, Chile
4Bioproducts Discovery and Development Centre, Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, N1G 2W1, Ontario, Canada,
5School of Engineering, Thornbrough Building, University of Guelph, Guelph, N1G 2W1, Ontario, Canada

Buildings are known for their high energy consumption, and therefore as relevant actors as climate change contributors. This is the reason why one of the most important challenges in the future is the reduction of their energy demand throughout the life cycle. Insulation materials are a key factor to reduce the energy demand during the operational stage of a building. These materials are however commonly fabricated from petrochemicals with high energy consumption, causing significant detrimental effects on the environment during the production and discarding stage. In this context, insulation materials based on natural fibers appear as an excellent alternative, due to abundant availability, potential low cost, low energy consumption during the production stage and high biodegradation rate at the end of life. In this research, a block type insulation based on Miscanthus residual fibers was developed. Taguchi method was applied to investigate the effect on thermal conductivity of three control factors in two levels, namely boiling time; NaOH concentration and blending time; in a L-4(23) orthogonal array. Furthermore, flexural strength and density were determined and compared with expanded polystyrene block insulation. The results show that NaOH concentration was the principal factor influencing the thermal conductivity with 47.1% followed by the blending time with 28.4% and boiling time with 24.5%. The thermal conductivity values were between 0.079 – 0.116 W/mK. In addition, flexural strength results were similar to those of the standard expanded polystyrene type IX. Finally, optimum conditions of the process were determined to obtain a final block, which was morphologically analyzed using scanning electron microscopy (SEM), while the thermal behavior was studied by thermogravimetric analysis (TGA).

The authors would like to acknowledge the partial financial support of Facultad de Ingenieria y Ciencias, Universidad de La Frontera, Temuco, Chile and the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), Canada/University of Guelph-Bioeconomy for Industrial Uses Research Program Theme (Project # 200283 and 200359) to carry out this research work.


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