Thermal decomposition kinetics and lifetime prediction of a PP/PLA blend supplemented with iron stearate during artificial aging

Abstract

In this work, the effect of iron stearate (IS) on the thermal degradation of polypropylene (PP)/poly (lactic acid) (PLA) blend compatibilized by polypropylene-grafted-maleic anhydride during artificial aging for 21 days at 70 °C, with sampling every 7 days has been investigated. The thermogravimetric (TG) analysis revealed a two-stage degradation process for the blends (with and without IS), which corresponded to each polymer in the blends. For each degradation stage, the decomposition temperature shifts to a lower value for the system that contains IS. Broadly, the kinetic modeling proved that the activation energy (Ea) decreases with the addition of IS and the artificial aging progress. Moreover, the decomposition mechanisms are dependent on the incorporation of IS and artificial aging. Besides, the lifetimes of the investigated samples were assessed at different failure temperatures using the obtained kinetic triplets. Both IS and artificial aging progress reduce significantly the lifetimes of the PP/PLA blends.