Polyhydroxyalkanoates-based Cast Film as Bio-based Packaging for Fresh Fruit and Vegetables: Manufacturing and Characterization

The packaging sector is one of the main responsible of post-consumer plastic waste in the European Union. The increasing consumer pressure and the banning or limitation of some materials are pushing producers towards new solutions. Polyhydroxyalkanoates (PHA) are a class of compostable bioplastics, easily degraded in composting facilities as well as on soil and aquatic environment. Three different blends of P(3HB)(3HH), poly-3-hydroxybutyrate-co-3-hydroxyhexanoate, and of P(3HB)(4HB), poly-3-hydroxybutyrate-co-4-hydroxybutyrrate are studied to achieve a thin film suitable for the manufacturing of films for food packaging. The compounds were produced by twin-screw extrusion and then processed by cast film extrusion. The increasing percentage of P(3HB)(4HB) leads to a higher elongation at break, a lower maximum stress and elastic modulus. The OTR sensibly increases whereas the increase in WVTR is less remarked. The properties of the films confirm the possibility of employing these PHA-based films as packaging with low environmental footprint.