Investigation of the effect of clay nanoparticles on the thermal behavior of PLA using a heat flux rapid scanning rate calorimeter

The effect of clay nanoparticles on the glass transition and melting behavior of PLA was examined using a heat flux, rapid scanning rate calorimeter. The samples were prepared by electrospinning through incorporation of clay in the electrospinning solution, which facilitated composites with high filler loadings (15-25 wt.%). Incorporation of clay increased the crystallization kinetics of PLA only at lower loading levels. The incorporation of 15.3 wt.% clay resulted in only a slight reduction in the overall degree of crystallinity (wc) in PLA, while a substantial reduction was observed with the incorporation of 25.0 wt.% clay. A significant reduction in the equilibrium melting temperature (Tm0) was observed for nanocomposites containing 15.3 wt.% clay compared to the neat PLA fiber; however, the extent of reduction was mitigated when increasing the clay loading further to 25 wt.%. The PLA nanocomposites with 15.3 wt.% clay exhibited the lowest Tg values in both semicrystalline and amorphous samples. Elucidating the differences in thermal behavior and morphology of these nanocomposites as a function of clay loading is crucial for optimizing their physical and mechanical properties.