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 Ti3C2TX 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 Ti3C2TX provided several functional groups for the MXene nanosheets and strengthened the PLA-MXene interaction by hydrogen bonding. The well-dispersed PDA@Ti3C2TX in the PLA improved mechanical, thermal, and tribological properties. For PLA/PDA@Ti3C2TX-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 6702MPa, 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 Ti3C2TX and PDA@Ti3C2TX increased the thermal stability of PLA at lower temperatures and promoted carbonization. PLA/PDA@Ti3C2TX-1 showed the maximum char yield of 10wt.% at 800 degrees C, proving the highest thermal barrier effect due to MXene exfoliation during PDA and increased PLA dispersion state.