Effect of matrix composition on the performance of calcium carbonate filled poly(lactic acid)/poly(butylene adipate- co -terephthalate) composites

The ratio of poly(lactic acid) (PLA), poly(butylene adipate- co -terephthalate) (PBAT), and calcium carbonate (CaCO 3 ) fillers in PLA/PBAT/CaCO 3 composites was set at 90/10/5, 70/30/5, and 30/70/5. The effect of nano- and micro-CaCO 3 on the melting and crystallization performance of the composites was investigated by differential scanning calorimetry. PLA crystallization was related to the PLA and PBAT ratio, cooling rate, and CaCO 3 particle size in PLA/PBAT/CaCO 3 composites. Nano-CaCO 3 prevented the crystallization of PLA in PLA/PBAT/CaCO 3 90/10/5 and 70/30/5 but did not prevent the crystallization of PLA in PLA/PBAT/CaCO 3 30/70/5. Unlike nano-CaCO 3 , micro-CaCO 3 did not prevent PLA crystallization regardless of the PLA and PBAT ratio. Nano- and micro-CaCO 3 enhance PLA90 and PLA70 to some extent, due to the aggregation and dissociation of the CaCO 3 filler in polylactic acid. But nano- and micro-CaCO 3 improved the mechanical properties of PLA30 several times, due to the good compatibility of the CaCO 3 filler and PBAT. The effect of nano-CaCO 3 and micro-CaCO 3 on the mechanical properties of PLA/PBAT/CaCO 3 composites had no significant difference.