Manufacture of PHB-Based Biodegradable Composite Film and Evaluation of Mechanical Properties

Biodegradable plastics can be decomposed into water, carbon dioxide, and biomass by the action of living organisms, typically micro-organisms. Biodegradable plastics are commonly produced with renewable raw materials, micro-organisms, petrochemicals, or combinations of all three. These plastics have been considered as a promising solution to troubleshoot the plastic pollution problem bedeviling the world. Currently, most of biodegradable plastics such as PLA, PBS, PBAT, and PBSA, are degraded in well-managed industrial composting systems providing the specific environments. If products made from these plastics are discarded into conventional waste streams such as landfills, or find their way into the open environment such as rivers and oceans, the potential environmental benefits of the biodegradable plastics are not exploited and can actually exacerbate plastic pollution problems.<br/>Polyhydroxyalkanoates (PHAs) are a class of biodegradable polymers that produced from various micro-organisms. Specific types of PHAs include poly-3-hydroxybutyrate (PHB)s. PHBs have been shown to be biodegradable in less than about one year in various natural and biologically active environments even without the industrial composting systems. Furthermore, PHB’s properties are similar to those of conventional petroleum-based polymers (e.g. melting temperature, young’s modulus) such as polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET). On the other hand, the use of pure PHB has been restricted due mainly to its inherent brittleness, which renders it too frangible for most practical applications. In this study, we have developed a new component of PHB-based polymer composite films using various green additives to overcome the mechanical instability of PHB and optimize the film condition. As a result, the bioplastics films prepared show huge potential, offering 30 times increase of the elongation property with decreasing the melting temperature and the degree of crystallinity. In this presentation, some prototypes of PHB-based packaging (e.g. disposable label, bag) which LANL has developed, will be presented.