Synergistic Effect of Polydopamine Modified <scp> Ti ₃ C ₂ T _x </scp> ‐ <scp>MMT</scp> Hybrid Nanofillers on Mechanical and Tribological Properties of <scp>Poly(lactic acid)</scp> Composite

ABSTRACT Uniform dispersion of reinforcing nanomaterials in polymer matrices remains a key challenge in materials engineering, often limited by agglomeration and poor interfacial compatibility. This study presents a synergistic hybrid filler system comprising Ti 3 C 2 T X MXene and montmorillonite (MMT, Al 2 O 9 Si 3 ), designed to act as co‐dispersing agents to enhance exfoliation and distribution within Poly(lactic acid) (PLA). Dynamic light scattering revealed an optimal MXene: MMT ratio of 35:65, yielding a zeta potential of −45.5 mV, indicating high colloidal stability. To further strengthen interfacial interactions with PLA, the MXene‐MMT hybrid was simultaneously functionalized with polydopamine (PDA) to introduce reactive surface groups. Lyophilization preserved nanoscale dispersion, followed by masterbatch film preparation before melt blending, ensuring uniform nanofiller integration. PLA composites with 0.5, 1.0, and 1.25 wt.% filler loadings were fabricated and systematically assessed for structural, mechanical, tribological, and thermal properties. The PMM1 composite (1 wt.% polydopamine‐treated Ti 3 C 2 T X ‐MMT hybrid in PLA) showed notable improvements: Tensile strength (+10.07%), elongation at break (+44.31%), toughness (+99.38%), flexural strength (+52.46%), modulus (+61.26%), and storage modulus (+67.09%). Friction and wear rate decreased by 5.76% and 49.45%, respectively. A char yield of 8.52 wt.% at 800°C confirmed flame‐retardant potential. This multi‐step strategy presents a promising approach for developing high‐performance PLA nanocomposites suitable for industrial and biomedical applications.