Sustainable Mineral Wool Binder Using Algal Biomatter and Nanocellulose

Stone wool, with its high insulation properties and fire resistance, effectively reduces the energy consumption in buildings and helps further mitigate climate change. However, conventional binders such as phenol-formaldehyde resins used to provide mechanical strength to the stone wool system typically include components that are harmful in uncured form. These binders generally also require high temperatures to cure properly, leading to high energy consumption and possibly also emissions that may require post-treatment. Here, we aim to develop a non-toxic and fully degradable binder system for stone wool. We designed a green biobinder system consisting of whole biological materials that not only store carbon through photosynthesis but also prevent waste during manufacturing. Our green biobinder system uses algal biomatter and bacterial nanocellulose as key structural and adhesive components while the addition of other biopolymers is evaluated in terms of the final stone shots/biobinder mechanical properties. We investigate the rheological properties of biobinders at different concentrations and evaluate the effects of different thermal processing of the biobinders on the mechanical properties of composite bars. Furthermore, we use scanning electron microscopy to study the morphology of biobinder in the composite systems and Fourier transform infrared spectroscopy to analyze the complex bonding interactions of the biobinders. With a better understanding of the performance driving from each biomatter, this innovative approach of using whole biological materials as alternatives to mineral wool binders presents great potential for reducing the environmental impacts of insulation products throughout the full life cycle.