Bend, Twist, and Turn: First Bendable and Malleable Toughened PLA Green Composites. (2nd June 2020) - Yeo, Jayven Chee Chuan
Abstract: The future of green electronics possessing great strength and toughness proves to be a promising area of research in this technologically advanced society. This work develops the first fully bendable and malleable toughened polylactic acid (PLA) green composite by incorporating a multifunctional polyhydroxybutyrate rubber copolymer filler that acts as an effective nucleating agent to accelerate PLA crystallization and performs as a dynamic plasticizer to generate massive polymer chain movement. The resultant biocomposite exhibits a 24‐fold and 15‐fold increment in both elongation and toughness, respectively, while retaining its elastic modulus at >3 GPa. Mechanism studies show the toughening effect is due to an amalgamation of massive shear yielding, crazing, and nanocavitation in the highly dense PLA matrix. Uniquely distinguished from the typical flexible polymer that stretches and recovers, this biocomposite is the first report of PLA that can be "bend, twist, turn, and fold" at room temperature and exhibit excellent mechanical robustness even after a 180° bend, attributes to the highly interconnected polymer network of innumerable nanocavitation complemented with an extensively unified fibrillar bridge. This unique trait certainly opens up a new horizon to future sustainable green electronics development. Abstract : A green, sustainable, and durable polylactic acid biocomposite with degradability, desirable strength, and ability to deform into anfractuous shapes such as twisting, bending, folding, and stretching would open to greater possibilities for future green electronic used in wider applications in prosthetics, robotics, health monitoring, and biomedical devices.