Quantifying Structural and Solid-State Viscoelastic Properties of Poly(propylene) (PP)/Poly(oxymethylene) (POM) Blend Films

Abstract

In this study, isotactic poly(propylene) (PP)/poly(oxymethylene) (POM) blend films, including of POM as minor phase in the range of 10-30 wt%, are prepared in a twin screw extruder equipped with a slit-die and cast film haul-off unit. It is found that the blend films show -characteristic immiscible matrix-droplet morphology. Short-term uniaxial tensile creep behaviors of films imply that the introducing of POM significantly improves the elastic modulus and decreases the total creep strain of PP/POM blends. Creep tests are also performed at various temperatures and long-term deformations of samples are predicted by applying of time-temperature superposition principle and the Findley model. It is found that the presence of POM domains into PP matrix enhances the creep resistance of PP especially at high temperatures. It is concluded that the PP-rich PP/POM blend films show much lower short and long-term creep strains compared to PP.