Utilization of Bamboo Biochar as a Multi-Functional Filler of Flexible Poly(L-lactide)-b-Poly(ethylene glycol)-b-Poly(L-lactide) Bioplastic

Abstract

Abstract Biodegradable poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) triblock copolymer could potentially be used in bioplastic applications because it is more flexible than PLLA. However, investigations into modifying PLLA-PEG-PLLA with effective fillers are still required. In this work, bamboo biochar (BC) was used as an eco-friendly and cost-effective filler for the flexible PLLA-PEG-PLLA. The influences of BC addition on crystallization properties, thermal stability, hydrophilicity, and mechanical properties of the PLLA-PEG-PLLA were explored and compared to those of the PLLA. The PLLA-PEG-PLLA matrix and BC filler were found to have strong interfacial adhesion and good phase compatibility, while the PLLA/BC composites displayed weak interfacial adhesion and poor phase compatibility. For the PLLA-PEG-PLLA, the addition of BC induced a nucleation effect that was characterized by a decrease in the cold crystallization temperature and an increase in the crystallinity; however, this effect was not observed for the PLLA. When compared to pure PLLA-PEG-PLLA, the PLLA-PEG-PLLA/BC composites displayed greater thermal stability, tensile stress, and Young’s modulus. Based on the findings, the crystallizability, thermal stability, and mechanical properties of the flexible PLLA-PEG-PLLA bioplastic were all enhanced by the use of BC as a multi-functional filler.