Fine-tuning heat resistance and impact toughness of natural rubber-toughened PLA at Various degrees of PLA/PDLA stereocomplexation

•This work emphasizes on improving both the impact strength and heat resistance of PLA by blending with 15 wt% NR in a stereocomplex system.•The degrees of PLA/PDLA stereocomplexation was adjusted by varying the PLA:PDLA ratio from 100:0 to 50:50.•Well-dispersed NR domains could simultaneously act as excellent toughening and nucleating agents for PLA leading to 8-fold increase in toughness, faster crystallization, and higher% crystallinity.•Higher poly d-lactic acid (PDLA) contents led to higher heat resistance of PLA/NR, where the blend at 30 wt% PDLA could tolerate 100 ºC with the impact strength still more than 3 folds that of neat PLA.