Composites Based On PHB-HV and Saw Dust Fibers for Terrestrial Applications: Processability and Degradability

Large-scale dependence on petroleum-derived plastics leads to serious pollution problems; the methodologies used for plastic waste disposal are challenging. In landfills, the degradation rates are tremendously slow. In this scenario, with the aim of decreasing plastic environmental impact, the use of bio-based and/or biodegradable polymers aliphatic polyesters, such as polyhydroxyalkanoates (PHAs), having similar physicochemical properties as conventional plastics can represent a valuable solution to the current plastic pollution problem [1]. However, the replacement of classical polymers with biodegradable plastics requires the knowledge of their biodegradability in controlled and uncontrolled environments to have a real positive environmental impact [2]. In the present work, composites based on poly(β-hydroxybutyrate-co-β-hydroxyvalerate (PHB-HV) and waste sawdust fibers (SD), derived from the wood industry, were produced by extrusion and characterized in terms of processability and rheological/mechanical properties. In view of their use in terrestrial applications, biodegradation tests were carried out on the developed composites under simulated composting conditions in accordance with standard methods and a preliminary evaluation of the degradability in soil of PHB-HV-SD-based molded specimens (pots with thickness of 1 mm) was also performed.