Nanofragmentation of Expanded Polystyrene Under Simulated Environmental Weathering (Thermooxidative Degradation and Hydrodynamic Turbulence)

Fragmentation of macroplastics into microplastics in the marine environment is probably one processes that have generated most drive for developing research field. Thus, it surprising level scientific knowledge on combinative effect oxidative degradation and mechanical stressors fragmentation relatively limited. Furthermore, has been hypothesized plastic continues nanoplastic size domains, but environmentally realistic studies are lacking. Here effects thermooxidative aging hydrodynamic conditions relevant shoreline expanded polystyrene (EPS) were tested laboratory simulations. The pre-degraded EPS was cut pieces subjected to mechanical, simulations during four-day stirring experiments. Subsamples filtered subsequently analyzed with light microscopy automated image analysis particle distribution determinations, polymer identification Raman spectroscopy, Scanning Electron Microscopy (SEM) distribution. fraction measured using nanoparticle tracking analysis. In addition, degree oxidation spectroscopically characterized Fourier transform infrared (FTIR) spectroscopy. results illustrate mesoplastic objects observed already after 2 days, more distinct 4 higher abundances smaller fractions, which imply release sizes or several steps. For fraction, day four shows a abundance released fragmented particles than two. conclusions nanofragmentation an important understudied process standardized test protocols both treatments mimicking environmental needed. Further testing common macro- materials assess rates fluxes fragmenting micro- fractions should be conducted.