Modeling and analysis of nonlinear elastoplastic behavior of compatibilized polyolefin/polyester/clay nanocomposites with emphasis on interfacial interaction exploration

Analysis of mechanical properties of compatibilized polymer pairs comprising clay nanoplatelets was the subject of numerous works, however nonlinear elastoplastic behavior of such nanocomposites has rarely been addressed in the literature. Though localization of nanofiller within one or at the interface of two phases was occasionally dealt with, there often were serious complexities with the lack of knowledge about the interface region. This work focuses on modeling of stress-strain behavior of the compatibilized polyolefin/polyester/clay nanocomposites to give some more lights on the interfacial interaction in such complex system, and clay localization analysis. The use of two kinds of organomodified clays as well as two compatibilizers having different chemical affinity to polymers, and using different amount of compatibilizers led to localization of clay either in the polyester or at the polyolefin/polyester interface region, as confirmed by X-ray diffraction, transmission electron microscopy and uniaxial tensile strength measurements. The mechanical properties analyses revealed a rise in both Young's modulus and tensile strength of composites with clay loading. Application of Bergström-Boyce model brought about a deeper understanding of the effect of compatibilizer and organoclay on large deformation mechanical behavior of polyolefin/polyester/clay nanocomposites. Overall, theoretical analyses could appropriately predict nonlinear elastoplastic behavior of nanocomposites, even though some deviations were detected at yielding and necking regions.