Simulation of mechanical properties of multilayered propylene–ethylene copolymer/ethylene 1-octene copolymer composites by equivalent box model and its experimental verification

Multilayered propylene–ethylene copolymer (PPE)/ethylene 1-octene copolymer (POE) composites were prepared by a microlayered coextrusion system. Static and dynamic tensile results showed that yield strengths and storage moduli of the multilayered samples were distinctly larger than those of conventional blends. The equivalent box model (EBM) proposed by Kolarik was used to explain the effect of morphology on mechanical properties. Experimental and theoretical results indicated that the excellent mechanical properties of multilayered composites were ascribed to the phase continuity. The effects of interfacial layers in multilayered composites on mechanical properties were also discussed. The existence of interfaces between POE and PPE layers not only led to the invalidation of EBM for prediction of mechanical properties of multilayered composites with larger number of layers, but also induced a new absorbing peak in loss modulus-temperature spectrum because of the shearing friction between POE and PPE layers through interfaces.