End-of-life options of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)-based blends

In this study, the end-of-life options of PHBH and PBAT blends were investigated. The blends were fabricated and optimized in a twin-screw extruder and injection moulding techniques. PBAT with high ductility was added to a brittle polymer, PHBH _xx31n , to improve the ductility and toughness of the brittle polymer. The processed blends were tested for thermal and mechanical properties. It was discovered that the blend comprising PHBH and PBAT in an 80/20 ratio exhibits good tensile strength, tensile modulus, and elongation at break when compared to other blends. The blend exhibited lower thermal stability, with a degradation temperature that was lower when compared to neat PHBH and PBAT. The blends were also exposed to QUV radiation for degradation. The thermal stability of the blend was slightly improved with the increased exposure time. Visual analysis revealed photo-oxidative yellowing in the blends, and tensile properties were decreased with increased exposure time. FTIR spectroscopy displayed a carbonyl group at 1720 cm ^− 1 , confirming the degradation of the material. The results obtained by monitoring the integrity of the materials reveal that the material started biodegrading after 12 weeks and reached 90% in 180 days. The results demonstrate that the processed blends are compostable according to ASTM D5338, making composting a viable end-of-life disposal method for the blends.