Investigation into poly(propylene)/montmorillonite/calcium carbonate nanocomposites

A novel method was used to prepare poly(propylene)/montmorillonite/calcium carbonate nanocomposites by melt-mixing, using pristine montmorillonite (MMT), hexadecyltrimethylammonium bromide (C16), calcium carbonate (CaCO3) and a matrix in a twin-screw extruder. Two different sizes of calcium carbonate were used (nanosized CaCO3 and micron-sized CaCO3, the average sizes being 60 nm and 12 pm respectively). The nanocomposite structure was evidenced using X-ray diffraction (XRD), transmission electron microscopy (TEM) and high resolution electronic microscopy (HREM). Tensile tests and Izod notch impact tests suggested that the incorporation of nanosized CaCO3 into PP/ montmorillonite nanocomposites increased the mechanical properties of the composites, but the improvement in the microsized CaCO3-filled PP/montmorillonite nanocomposites was found to be minimal. The thermal stability and flammability properties were characterized by thermogravimetric analysis (TGA) and a cone calorimeter respectively.