Biodegradable biocomposites based on PHA and naturall fibres for applications in different environments

Petrol plastic wastes accumulation in natural environments is raising and generating the interest for new materials with high sustainability, biodegradability and relevant performances. In this contest bio-composites produced with biodegradable, bio-based polymeric matrices and fibres of natural origin derived from by-products or over production are one of the most important categories of material that is being proposed on the market. In the present abstract we report our contribute to knowledge and advancement in research on biobased composites in particular produced with biopolymers such as polyhydroxyalkanoates (PHAs), biodegradable in different environments, with natural fibres from agro-food industrial waste (potatoes, beet, bran, legume fibers) and cellulosic fibres (Poseidonia oceanica fibers or sawdust). Composites based on PHAs and the natural fibres were produced by extrusion in presence of appropriate amounts of plasticizer and inorganic fillers. Thermal, rheological, mechanical and morphological characterizations of the developed composites were conducted. Biodegradability of the bio-composites was investigated in different environments: in controlled composting conditions , soil and marine water. The results showed that the presence of the fibres facilitated the disintegration of the PHA matrix and, consequently, accelerated its biodegradation. The developed composites resulted biodegradable in marine environment in a relatively short time and compostable. In order to deepen the study on bio composites properties, different predictive models (Cox, Curtis and Pukanszky) were applied to evaluate how the mechanical performance varies with the fibres load. Considering that PHAs present a secondary crystallization with consequent change of mechanical properties, an ageing study of the developed composites was carried out by monitoring the properties of tensile specimens over time