Mechanical and Thermal Characterization of Multiprocessed PHBs

Bioplastics like Polyhydroxybutyrate (PHB) have a promising time to come in the packaging market sector. To achieve circularity, mechanical recycling of these plastics also needs to be addressed. In this work, we investigate the properties at each stage from virgin PHB, to multiprocessed PHB recyclates (E1-E5). We found that the tensile strength of the recyclates remained roughly constant till the 4th reprocessing cycle (E5). Young's Modulus slightly increased as the cycles progressed. The thermal stability of the material was assured by the degradation temperature which did not change even after 4 reprocessing cycles. The melting temperature of PHB was ~177°C and did not vary with each cycle. We demonstrate quantitatively that the utilization of recycled PHB in packaging is a potential area of growth and importance for the Circular Economy.