Thermal and Mechanical Properties of Polymeric Films Based on PLA / PBAT and Corn Starch and Babassu Mesocarp Starch by Flat Extrusion for Packaging

Abstract

The influence of different amounts (1, 3 and 5%) of commercial corn starch and of babassu mesocarp starch on a (polylactic acid)/poly (butylene co-terephthalate adipate) (PLA/PBAT) based blend obtained by flat extrusion was ascertained.  The thermal and mechanical properties were determined and the results obtained are independent of the type of starch employed but are dependent on its concentration, the nucleating effect of the different starches and on the mobility of the polymer chains that make up the blend. Thermogravimetric analysis indicated the presence of two defined stages of mass loss for all films under investigation. Tensile testing shows that films containing starch had similar behavior to that of PLA in the PLA/PBAT blend, presenting high values of tensile strength, elastic modulus and tensile strength and low values of strain at break.  The results suggest that babassu mesocarp starch is viable alternatives to the production of packaging films.