Polydopamine surface modified Ti3C2Tx/PLA biocomposites with enhanced mechanical, thermal, and tribological properties

The industry desires to create robust, resilient, thermally stable, and environmentally friendly composites. In this study, we created a poly (lactic acid) (PLA) composite via a straightforward method. The Ti 3 C 2 T X was surface-coated with polydopamine (PDA) via a bioinspired approach and was then reinforced in the PLA using melt blending. The PDA layer adorned on the Ti 3 C 2 T X provided several functional groups for the MXene nanosheets and strengthened the PLA-MXene interaction by hydrogen bonding. The well-dispersed PDA@Ti 3 C 2 T X in the PLA improved mechanical, thermal, and tribological properties. For PLA/PDA@Ti 3 C 2 T X -1, the tensile strength and elongation at the break of the nano-composite were 9.03% and 25.5% higher than pure PLA, respectively. The flexural strength and modulus were increased by 49.5% over pure PLA, reaching 148.8 and 6702 MPa, respectively. The nanocomposite toughness increased by up to 53.3%. The nanocomposites had 3.8% and 49.08% lower friction coefficient and specific wear rate, respectively, than pure PLA. The addition of Ti 3 C 2 T X and PDA@Ti 3 C 2 T X increased the thermal stability of PLA at lower temperatures and promoted carbonization. PLA/PDA@Ti 3 C 2 T X -1 showed the maximum char yield of 10 wt.% at 800°C, proving the highest thermal barrier effect due to MXene exfoliation during PDA and increased PLA dispersion state.