Comparison of Mechanical and Crystallization Properties of Polylactic Acid Modified by Organic–Inorganic Composite Fillers

ABSTRACT In this study, polylactic acid (PLA) was selected as the matrix, with Talc, Talc/poly(ethylene glycol) (PEG), and Talc/triethyl citrate (Tec) chosen as fillers. PLA/Talc, PLA/Talc/PEG, and PLA/Talc/Tec blends with varying filler contents were prepared to investigate the effects of composite fillers, particularly combinations of nucleating and plasticizing agents. The impacts of Talc, Talc/PEG, and Talc/Tec on overall properties of PLA were analyzed, and the mechanisms were also discussed. The mechanical properties of PLA varied with the type and content of fillers. The PLA/Talc system showed a decreasing trend in mean tensile strength with increasing filler content, whereas the PLA/Talc/PEG and PLA/Talc/Tec systems generally showed an increasing trend. With regard to crystallization performance, the order was PLA/Talc/PEG > PLA/Talc > PLA/Talc/Tec > PLA. The self‐nucleation temperature range (Domain II width) of PLA/Talc/PEG and PLA/Talc/Tec increased with filler content. Thermal stability was ranked as PLA/Talc/PEG > PLA/Talc > PLA > PLA/Talc/Tec. This research elaborated on how composite fillers affect PLA properties, providing valuable guidance for formulation design and industrial production.