Innovative Surface Treatments Of Synthetic Fabrics For The Mitigation Of Microplastic Pollution

Microplastics have been recently identified as one of the most concerning new class of pollutants, extensively found in various environments. They have been defined as plastic fragments smaller than 5 mm, coming from several sources. The most unexpected source of microplastic pollution is certainly the washing processes of synthetic textiles, that was estimated as a major contributor to the emission of microplastics into global oceans. Due to the mechanical and chemical stresses that fabrics undergo during a washing process in a laundry machine, microfibres detach from the yarn and, through the wastewater, end up in the marine environment. Sampling of marine sediments showed that polyester, acrylic, polypropylene, and polyamide fibres contaminate shores on a global-scale. Their impact on marine flora and fauna is unpredictable and quite dangerous since they can adsorb organic pollutants and be ingested by marine organisms, potentially reaching the human food web. In this work, innovative surface treatments of synthetic fabrics were developed to mitigate the release of microplastics during their washing. The aim was to create a protective coating on the fabric surface, which can protect clothes during washing processes, then reducing the amount of microfibres released. Instead of using conventional synthetic textile auxiliaries, these treatments involve the usage of alternative polymers, selected for their biocompatibility and eco-sustainability. Two different strategies were explored to develop such surface treatments on polyamide 6.6. fabrics. The first one is based on the application of pectin, a natural polysaccharide, that was chemically modified by reaction with glycidyl methacrylate (GMA), whose vinylic groups were exploited to graft pectin on the surface of the polyamide fabric.1 The second treatment is based on the application of an electrofluidodynamic (EFD) method to deposit on the fabric a countinuous layer made of biodegradable polymers from biosources - i.e., polylactic acid (PLA) and polybutylene succinate adipate (PBSA).2,3 The treated fabrics underwent different analysis to evaluate the coating morphology and possible changes to fabric properties. Among the tecniques used there are scanning electron microscopy (SEM), attenuated total reflectance (ATR) Fourier Transform InfraRed (FTIR) spectroscopy and thermogravimetric analysis (TGA). Finally, washing tests were performed to evaluate the effectiveness of the finishing treatments in mitigating the release of microplastics during the washing of fabric and the outcomes revealed that all treatments decreased of more than 80% the release of microfibres with respect to untreated fabrics.