Morphological Studies and Thermo-Mechanical Behavior of Polypropylene/Sepiolite Nanocomposites

This article describes the effect of natural Sepiolite nanofibers on the properties of polypropylene (PP) in the absence/presence of compatibilizer (maleic anhydride grafted-polypropylene (PP-g-MA)). For this purpose, PP/Sepiolite and PP/PP-g-MA/Sepiolite nanocomposites were prepared by melt blending using twin-screw extruder. The morphology and dispersion of Sepiolite in PP composites characterized using scanning electron microscope (SEM) and transmission electron microscope (TEM) revealed that the dispersion of Sepiolite in PP matrix was better in the presence of PP-g-MA. Thermogravimetric analysis (TGA) was used to study the effect of Sepiolite on the thermal stability of PP in absence/presence of PP-g-MA. X-ray diffraction (XRD) and differential scanning calorimetric (DSC) techniques were employed to assess the effect of Sepiolite on the crystallinity of PP matrix. Dynamic mechanical analysis (DMA) was used to evaluate the viscoelastic properties of PP/Sepiolite nanocomposites in solid state. Mechanical properties evaluated as per ASTM methods showed similar to 65% increase in flexural modulus, 60%-70% increase in tensile modulus and 10%-20% increase in impact strength on addition of 10% Sepiolite in PP. Addition of compatibilizer has further improved the flexural modulus close to 85% when compared to neat PP without compromising other properties like impact strength and tensile strength. (C) 2015 Society of Plastics Engineers