Effect of Montmorillonite Content on Nucleation of Polypropylene

In this article, the effect of montmorillonite (MMT) concentration on the nucleation of polypropylene (PP) was investigated. The PP/MMT nanocomposites containing various content of MMT (0.075-3.0 wt%) were prepared by a melt blending process using an internal mixer, followed by compression molding into sheets. The nucleation effect of MMT was characterized by X-ray diffraction (XRD), wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) techniques. XRD results indicated that the PP nanocomposites loaded with less than 1.5 wt% of MMT formed an exfoliated structure. DSC results showed that the crystallization temperature (Tc) of PP/MMT nanocomposites were higher than that of neat PP. Tc also increased with increasing MMT content, indicating that MMT was effective in nucleating PP crystal. WAXD patterns revealed that the addition of MMT did not affect the crystal structure of PP. Mechanical property tests showed that the tensile and impact strengths of the PP/MMT nanocomposites were better than those of neat PP when the MMT content was lower than 1.5 wt%.