Mechanical properties and thermal stability of poly(<scp>L</scp>‐lactide)/calcium carbonate composites

Abstract

Abstract Poly( L ‐lactide) (PLA) was melt‐mixed with micrometer‐sized and nanosized calcium carbonate (CaCO 3 ) particles before and after modification with calcium stearate. Adhesion between the CaCO 3 particles and the PLA matrix was assessed qualitatively by scanning electron microscopy observation of the fractured surface morphology of the composites. The effect of the incorporation of the CaCO 3 particles on the thermal stability of the PLA‐based composites was quantified by the temperatures corresponding to 5 and 50% of weight loss and the activation energy determined through thermogravimetric analyses of the composites. The tensile strength and modulus values of the composite were improved greatly without a significant loss in the elongation at break when the nanosized CaCO 3 was incorporated up to 30 wt %. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008