Project Portugal 2030

Summary

The main objective of the aeroZwaste project is the development of aerogels from plastic wastes, for use as acoustic insulators through a sustainable, straightforward and scalable method. The issue of plastic disposal is pressing, and effective management of plastic wastes is of outmost importance to prevent the pollution of various ecosystems. While mechanical recycling has proven to be a suitable process for handling plastic waste, it is important to note that plastics cannot be recycled indefinitely. Most plastics undergo degradation during mechanical recycling, particularly polyesters, which limits their application compared to virgin plastics. Moreover, degradation induced by mechanical recycling can led to the formation of harmful by-products. This is particularly relevant if the intention is to use the recycled materials in food contact applications. Thus, a fundamental question arises: how to transform polyester plastics, which have undergone several recycling cycles, into a useful and value-added material, thus promoting their circularity and avoiding their disposal in the environment? The aeroZwaste project intends to give an answer to this problematic, aiming to bring polyester wastes to a new life by using them in the production of aerogels, which are materials with high added value, with recognized importance in the field of thermal and acoustic insulation. Additionally, the project seeks to extend the aerogel production methodology to include EPS of ETICS waste, whose mechanical recycling is not straightforward, due to necessary preliminary separations. The aeroZwaste project aims to produce aerogels using a simple dissolution/precipitation method at room temperature, followed by drying. Preliminary results on aerogel production from rPET by this method demonstrated its feasibility. Furthermore, the project aims to reinforce aerogels with nanofibrous mats also derived from plastic waste. A significant advancement will be made by introducing non-toxic, bio-based solvents in the dissolution/precipitation steps, rendering the process more environmentally friendly. Additionally, employing molecular modeling studies to better understand polymer-solvent-non-solvent interactions will be pivotal, enhancing comprehension of gel formation processes and their impact on aerogel properties. The aeroZwaste project adopts a multidisciplinary approach, drawing from fundamental and applied chemistry, chemical engineering, and civil engineering. To achieve the main project objective, several specific objectives are outlined: 1. Selection of optimal green solvents to facilitate the dissolution and precipitation of considered plastics (rPET and EPS). 2. Investigation of polymer-solvent-non-solvent interactions at the molecular level. 3. Optimization of aerogel production process. 4. Preparation of nanofibrous mats via electrospinning, utilizing plastic wastes to reinforce the aerogels. 5. Assessment of the scale-up process for aerogel production. 6. Evaluation of aerogels as thermoacoustic insulators. The project plan for implementation includes an interconnected layout of task/subtask topics which are easily associated with the abovementioned objectives, allowing a simple appraisal of their fulfilling.