Zn2+-Doped Carbon Dots as Multifunctional Nano-Regulators for Enhancing 3D Printability of PBAT

Poly(butyleneadipate-co-terephthalate) (PBAT), a highly promising biodegradable polymer, faces significant limitations in high-precision fused deposition modeling (FDM) 3D printing owing to its low melt strength, inadequate thermal conductivity, and insufficient mechanical properties. This article describes the rapid synthesis of Zn-ion-doped carbon quantum dots (Zn-CDs) using an efficient magnetic induction heating method. Zn-CDs/PBAT composite materials were successfully prepared by melt blending Zn-CDs with PBAT through twin-screw extrusion. Empirical evidence indicates that incorporating 0.5 wt % Zn-CDs into the composite material resulted in a tensile strength of 32.01 MPa and an elongation at break of 1302.37%. These values represent increases of 23.03% and 46.59%, respectively, compared to those of pure PBAT. Notably, the incorporation of Zn-CDs substantially decreased the melt viscosity of PBAT at elevated shear rates and established an effective three-dimensional heat conduction network, thereby significantly enhancing the processing fluidity and thermal conductivity of the material. Based on these excellent processing characteristics, we successfully achieved high-precision molding of PBAT on industrial-grade particle 3D printers for the first time. The results of the printing tests indicated that the interlayer adhesion of the Zn-CDs/PBAT printed components was 44.6% superior to that of pure PBAT. This improvement effectively addresses the challenges of inadequate interlayer adhesion and the propensity for deformation in products manufactured through 3D printing with pure PBAT. This study introduces an efficient strategy for developing high-performance, biodegradable 3D printing materials and highlights the significant potential of functionalized carbon quantum dots in polymer processing and modification.