PLA/SEBS Bioblends: Influence of SEBS Content and of Thermal Treatment on the Impact Strength and Morphology

摘要

The aim of this work is to evaluate the effect of SEBS content and of thermal treatment on the properties of poly(lactic acid)/styrene-ethylene butylene-styrene (PLA/SEBS) bioblends. X-Ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) results show that the thermal treatment leads to the crystallization of PLA matrix, resulting in the increase of the impact strength. The PLA/SEBS bioblends containing 5 and 10% of SEBS show the highest impact strength before and after the thermal treatment. From the rheological measurements under dynamic-oscillatory shear flow, it is observed that at low frequencies, PLA and PLA/SEBS bioblends containing 5 and 10% of SEBS exhibit a Newtonian behavior, whereas the bioblends containing 15 and 20% of SEBS present a shear thinning behavior. Cole-Cole and Han plots show that PLA/SEBS bioblends are immiscible. SEM results show that the PLA/SEBS bioblends are immiscible, and that the bioblends containing 15 and 20% of SEBS present the highest SEBS dispersed phase domains size. The thermal treatment has no effect on the morphology of PLA/SEBS bioblends, but improves the impact strength.