Synergistic enhancement of properties in FDM-printed PLA composites with KH570-modified SiO2 and CPE-PEG

To improve the toughness, thermal stability, and melt processability of polylactic acid (PLA), this study introduced chlorinated polyethylene-polyethylene glycol (CPE-PEG, 10 wt%) into the PLA matrix and investigated the effect of the content of nano-SiO2 surface-modified with the silane coupling agent KH570 (K-SiO2) on the composite properties. Composite filaments were prepared via single-screw extrusion, and standard specimens were printed using fused deposition modeling (FDM) technology. Comprehensive characterization indicated that the composite achieved optimal mechanical properties at a K-SiO2 content of 1.5 wt%; simultaneously, the material’s thermal stability and crystallization behavior were optimized. Rheological behavior demonstrated that K-SiO2 could regulate the melt viscoelasticity, broadening the FDM processing window. This study provides an effective strategy for developing high-performance PLA composites for FDM printing.