Comparison of biodegradable polyesters degradation behavior in sand

Sandy beaches represent environmental compartments particularly vulnerable to litter pollution, and they reflectthe magnitude of pollution of adjacent compartments: water and coastal areas. The substitution of conventionalpolymers by biodegradable materials is generally considered as an alternative for reducing environmentalaccumulation of plastic debris. The present study is aimed to investigate the degradation of poly(lactic acid), poly(?-caprolactone), poly(butylenesuccinate adipate) and poly(3-hydroxybutyrate) buried in sand for 267 days,simulating them as beach litter. The analysed polyesters showed different degradation mechanisms and kinetics.PLA is mainly subjected to weathering by physical aging; after an initial faster degradation of the amorphousphase, PCL showed a decrease of its degradation rate; similarly to PCL, the degradation of PBSA started from theamorphous phase; PHB is clearly subjected to biological degradation. The degradation trend of the investigatedmaterials in sand decreased in the order PHB > PBSA > PCL > PLA. PLA, PCL and PBSA did not undergocomplete degradation in sand during the testing time.