Tensile properties and morphological evolution of polypropylene and poly(ethylene‐co‐1‐octene) blends

Abstract Extruded sheet of isotactic polypropylene and poly(ethylene‐co‐1‐octene) blends extruded from a counterrotating twin‐screw extruder were studied by scanning electron microscopy, tensile test, and small‐angle X‐ray scattering. The average characteristic length (Λ_m) determined by the statistical computing from the SEM images increases linearly with increasing of dispersed phase concentration. When POE content is 50 wt% (double continuous phase), Λ_m is two or three times as big as that of other blends ratio. The analyses of SAXS data confirm this result. Comparison has been made between experimental data of tensile test and those predicted from several meso‐mechanical models such as parallel model, series model, Halpin's model, Mori‐Tanaka's model, and modified mixture model. The modified mixture model is an effective method for predicting Young's modulus in comparison with other models. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers