Development of PHA-based formulations for sustainable packaging solutions and their biodegradation behaviour in compost and marine environments

Abstract

This thesis focuses on addressing the environmental impact of conventional plastics, by the development of biodegradable plastic materials with enhanced performance. From a biocircular economy perspective, the microbial polyhydroxyalkanoates, and specifically poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), are considered due to their biobased origin and biodegradability. However, PHBV exhibits some technical limitations such as brittleness and high costs that hinder its direct applicability. This research explores blending PHBV with ductile biopolyesters (PHBH, PBSA) and lignocellulosic fibers (cellulose, woodflour, almond shell) to improve mechanical properties and processability while keeping or even improving its biodegradability. Additionally, this thesis aims to widen the knowledge about factors impacting the biodegradation process of PHBV in natural and lab-simulated compost and marine environments over long periods (12-18 months). The resulting materials demonstrated to be promising biodegradable alternatives for various packaging applications, emphasizing the importance of incorporating biodegradability assessment in eco-design practices.