Recycling alginate composites for thermal insulation

Thermal insulation materials represent one the most straightforward, yet effective, technologies for improving the energy efficiency of buildings (and not only) – one of the key strategies for reducing carbon emissions. Natural-based materials and downcycled industrial and agricultural waste, thanks to their potentially reduced environmental footprint, have already made their way up to the market with the aim of limiting the ever-growing waste stream generated by the industrial sector. Research efforts on the topic are currently mainly focused on developing new insulation solutions, in which waste is reconverted as a new valuable resource. Carbohydrates, such as alginate, cellulose or chitosanare currently extensively studied base materials for thermal insulation systems, in the form of aerogels or as low-impact binding agents in waste-filled panels. Unfortunately, little or no attention has been paid to the end-of-life fate of these recycled materials; disposal (or incineration) still represents the only available option. This unprofitable scenario is even more critical in the case of polysaccharide-based composites specifically developed to reuse industrial waste. 

This was the starting point of our work, mainly conducted at the laboratories of the Engineering and Architecture department of the University of Trieste, in collaboration with TomoLab at Elettra. We developed a recycling process for an alginate-based thermal insulation foam, in which the original material is fully recovered and the thermal and acoustic insulation performances are maintained. The original foam is produced via a patented process in which alginate is used as the host poly-anionic matrix for industrial fiberglass waste. 

Read more on the Elettra website

Image: SEM and μCT image of oCAF

Credit: Figure reprinted from Carbohydrate Polymers, 251, Matteo Cibinel, Giorgia Pugliese, Davide Porrelli, Lucia Marsich, Vanni Lughi, Recycling alginate composites for thermal insulation, 116995, Copyright 2021, with permission from Elsevier.