Characteristics of the structure of materials designed for the manufacture of piezoelectric composites based on polypropylene

Composites based on isotactic polypropylene (i-PP) modified by organophilized montmorillonite (MMT) have been obtained, as potential piezoelectric materials, by extrusion without addition of compatibilizer. The crystallinity of these products has been studied using X-ray diffraction. The morphology and mechanical properties have been determined by SEM and tensile tests, respectively. The formation of cellular structure was observed in the i-PP composites. Also, they exhibit an increase in the degree of crystallinity of the PP matrix when compared to virgin polymer. The parameters characterizing the mechanical properties of montmorillonite-filled i-PP are decreased, but the range of stresses for which Hooke's law applies is similar for i-PP composites containing 2.5 and 5 wt % MMT as well as for neat PP.