High-Performance Polymer Blends: Manufacturing of Polyetherimide (PEI)-Polycarbonate (PC)-Based Filaments for 3D Printing.

The demand for high-performance polymers in 3D printing continues to grow due to their ability to produce intricate and complex structures. However, commercially available high-temperature 3D printing materials often exhibit limitations such as brittleness, warping, thermal sensitivity, and high costs, highlighting the need for advanced filament development. This study investigates the fabrication of polyetherimide (PEI) and polycarbonate (PC) blends via melt extrusion to enhance material properties for stable additive manufacturing. The addition of PC improved the processability of the blends, enabling successful extrusion at temperatures ranging from 290 to 310 °C. Differential scanning calorimetry (DSC) confirmed a shift in the softening temperature (T) of PEI, indicating effective blending. To further improve the properties of the PEI:PC blends, 1 wt% of a compatibilizer was incorporated, resulting in homogeneous microstructures as observed through scanning electron microscopy (SEM). The optimized PEI:PC (70:30) blend with compatibilizer (1 wt%) demonstrated a 49% higher storage modulus than neat PEI and a 40% greater storage modulus than ULTEM9085. Moreover, reduced melt viscosity facilitated consistent and stable printing, making these materials highly suitable for applications in aerospace and transportation, where performance and reliability are critical.