Simultaneous improvement of impact strength and thermal resistance of PLA/PDLA stereocomplex with core-shell rubber blends
Pongsakorn Malayarom, Nilobol Somboonphong, Cattaleeya Pattamaprom
Abstract
This study investigated simultaneous improvement in both toughness and heat resistance of polylactic acid (PLA) by incorporating core-shell rubber (CSR), poly D-lactic acid (PDLA), and nucleating agents. CSR was found to provide almost 25 folds increase in the impact strength of PLA with a slight decrease in thermal resistance. PDLA at 5 wt% and three commercial nucleating agents including talc, LAK301, and NAV101 at 0.5–5 wt% were investigated to further improve the thermal properties of the PLA/CSR blend. It was found that heat resistance of the blend strongly correlated with the % PLA/PDLA stereocomplex crystals (Xc,sc). LAK301 was found to be the most effective in improving the heat resistance as it could induce the highest Xc,sc, followed by talc. Their optimal content was 1 wt%. On the other hand, NAV101 not only failed to improve but also worsened both the impact strength and thermal resistance of the blends.