Enhancement of Mechanical, Thermal, and Barrier Behavior of Sustainable PECF Copolyester Nanocomposite Films Using Polydopamine-Functionalized MXene Fillers

The development of high-strength titanium carbide (Ti 3 C 2 T x ) MXene-PDA nanosheet-based sustainable poly(ethylene- co -1,4-cyclohexane dimethylene 2,5-furan dicarboxylic acid) (PECF) copolyester nanocomposites with superior tensile, thermal, and barrier properties is a promising avenue for advanced materials. However, achieving Ti 3 C 2 T x MXene-based polyester nanocomposites that exhibit exceptional thermal conductivity, and enhanced mechanical and barrier properties remains a significant challenge. In this study, we employed self-assembly technology through layer-by-layer (LBL) coating to create highly saturated Ti 3 C 2 T x MXene-PDA fillers that are uniformly dispersed and strongly bonded within the PECF matrix. This approach enabled the formation of dense nanocomposites with diverse functional properties. Specifically, MPP2 nanocomposites (0.3 wt %) demonstrated excellent mechanical performance, with a compressive tensile strength of 84 MPa and a modulus of 4.4 GPa, alongside remarkable O 2, CO 2, and H 2 O vapor barrier properties and superior thermal stability. Compared to pure PECF, the addition of Ti 3 C 2 T x MXene-PDA at a loading of 0.3 wt % resulted in substantial improvements: a 30% increase in tensile strength, a 109% increase in modulus, and significantly enhanced barrier properties for O 2 (27.3-times), CO 2 (24.7-times), and H 2 O vapor (5.0-times). These findings highlight the potential of Ti 3 C 2 T x MXene-PDA-reinforced PECF nanocomposites for high-performance applications, offering valuable insights for future materials development.