Rheology and morphology of polypropylene/poly(ethylene-co-methacrylic acid)/clay nanocomposites

Abstract

In this study, ternary composites of polypropylene / ionomer / clay were investigated depending on the dispersion and localization of clay. The transition of property were observed by adding additive fillers. Fillers were localized inside of the dispersed phase under the critical mass ratio. However, over that composition, the clay particles formed stiff network structure in the dispersed phase and additional clays were localized at the interface between two phases. The interaction of ternary composites changed from polypropylene-ionomer to polypropylene-ionomer and ionomer-clay according to development of microstructure. The transition point of storage modulus (G) was observed due to the evolution of microstructure. Depending on the growth of rheological properties, the fractured morphology of the composites changed from phase separated morphology to compatibilized morphology due to dispersion of fillers and droplet size of dispersed phase changed. The interfacial interaction of the ternary composite was quantified depending on the structural development of dispersed phase by the rheological properties. Also, interfacial interaction at solid state were measured through peel adhesion strength increased by evolution of microstructure. Furthermore, the crystallinity of the composites was decreased when the clay particles were localized at the interface.