Masterbatches of polypropylene/clay obtained by in situ polymerization and melt-blended with commercial polypropylene

Abstract

In the present work, polypropylene nanocomposites were prepared from blends in the molten state of a commercial polypropylene and masterbatches of polypropylene/organophilic montmorillonite or polypropylene/organically modified sodic clay with different amounts of filler. The masterbatches were obtained by the method of in situ polymerization using fourth-generation Ziegler-Natta catalysts based on MgCl2/TiCl4 containing clay. We also evaluated the effect of adding maleated polypropylene on the properties of the blends. Materials were characterized by X-ray diffractometry, differential scanning calorimetry, dynamic-mechanical, and thermogravimetric analyses. Morphological stability of the blends was studied after annealing using the differential scanning calorimetry technique. The results showed an improvement in the mechanical properties of the blends compared to commercial polypropylene, and an increase of the clay basal spacing in the polymeric matrix was achieved, especially when maleated polypropylene is employed in the blend. Initial thermal degradation of the obtained nanocomposites increased by ∼80℃.