Tearing fracture of poly(lactic acid) (PLA)/ poly(butylene succinate-co-adipate) (PBSA) cast extruded films: Effect of the PBSA content

The development of bio-based film formulations that show mechanical properties comparable to current fossil films is a challenging technological goal. Poly(lactic acid) (PLA) is the most attractive bio-based polymer; however, its poor ductility limits its use for film application. To overcome this issue, in this work PLA was blended with a ductile poly(butylene succinate-coadipate) (PBSA) bio-based polymer, and cast extruded PLA/PBSA films were produced with differing PBSA amounts (20, 30 and 40 wt%). The mechanical properties of the film were evaluated both in machine and cross direction. The tearing resistance of the produced film was implemented with the essential work of fracture approach to explore the mode III out-of-plane fracture resistance

Antimicrobial and Gas Barrier Crustaceans and Fungal Chitin-Based Coatings on Biodegradable Bioplastic Films

Chitin nanofibrils (CN) can be obtained from crustaceans and fungal sources and can be used for preparing coatings for bioplastic films, that are fundamental for developing a safe and sustainable biodegradable food packaging. Coatings with different concentrations of CN from shrimps were applied on different bioplastic substrates, like Poly (butylene succinate-co-adipate)/Poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PBSA/PHBV) blend, Polybutylene succinate (PBS), and Polybutylene adipate terephthalate/Poly(lactic acid) (PBAT/PLA) blend, but the adhesion to the substrates was scarce. On the contrary, the fungal-based CN showed a better adhesion. Additionally, it was found that the use of an additive based on oligomeric lactic acid was useful to prepare a coating with an improved adhesion to bioplastics. The gas barrier properties to oxygen and water vapour of coated and un-coated films were measured, revealing an improvement of these properties thanks to applied coatings, especially towards the oxygen. Antimicrobial properties and biodegradation capacity were also evaluated revealing an antibacterial effect of the coatings that did not significantly interfere with their biodegradability. The results are discussed and interpreted considering the correlation between composition and macromolecular structures with the observed functional properties