Biodegradation of Polylactic Acid/Poly(Butylene Adipate-co-Terephtalate) Mulching Film Under Weathering Conditions

Biodegradable polymers have substituted conventional polymers in many applications for overcoming the accumulation of plastic waste and its disposal. However, many so-called biodegradable polymers still cause pollution especially in marine environment where the plastic degradation pathways could be different compared to those occurring in the land. An important source of marine plastic and microplastic pollution comes from the use of plastic in agriculture. In fact, soil plastic debris can be transported by rivers towards sea mouths, thus increasing the concerns about marine litter. The highest source of plastic pollution in agriculture derives from the use of films for mulching, greenhouses, tunnels and low tunnels. In recent years, biodegradable polymers are extensively used for mulching in agriculture, providing more benefits with respect to traditional plastic films. Thus, understanding the degradation processes of biodegradable mulching films under weathering conditions before their fragments could reach marine environment is essential to breakdown plastic pollution. This study analyzes the degradation processes of a commercial biodegradable polylactic acid (PLA)/ polybutylene adipate terephthalate (PBAT) polymer mulching film under weathering conditions occurring in the South Italy Adriatic zone.