Influence of calcium carbonate nanoparticles on mechanical behavior of poly(lactic acid)/poly(butylene succinate) blend

PLA/PBS blends in various blend ratio (70:30, 50:50, and 30:70 wt%) containing calcium carbonate nanoparticles (nano-CaCO 3 ) of 1 and 5 phr were prepared. Tensile tests with 3 strain rates and Izod impact test were carried out in order to investigate the influence of CaCO 3 nanoparticles on mechanical behavior of nanocomposites under different deformation rates. Morphology and compatibility of nanocomposites were studied using SEM and DSC. It is found that PBS/PLA 50/50 wt% blends exhibited the highest percentage of elongation at break due to co-continuous phases as seen in SEM. CaCO 3 nanoparticles were dispersed uniformly in polymer matrix although they showed agglomeration sizes in micro-scale. CaCO 3 nanoparticles of 1 phr increased toughness of polymer matrix as evident in higher elongation at break in all straining rates and higher impact strength. This indicates lubricating effect of CaCO 3 nanoparticles during the deformation of polymer samples. Nevertheless, adding CaCO 3 nanoparticles of 5 phr showed positive effect to improve mechanical properties for brittle polymer matrix since they offered better molecular mobility to withstand applied stresses. However, NPCC of 5 phr gave negative effect on ductile matrix or low strain rates. This would be attributed to loss of molecular mobility during the deformation from nano-CaCO 3 agglomeration.