Evaluation of the Influence of a Smectite Clay in PP Composites

Abstract

In this work, the effect of the addition of an organophilic smectite clay on the properties of polypropylene (PP) was evaluated. The clay was a commercial natural montmorillonite treated with ammonium quaternary salt (Cloisite 20A®). The composites were prepared by extrusion, and contain 5 wt.% of clay. The materials were characterized by: tensile and impact strength, oxygen permeability tests, optical microscopy, thermal analysis and X-ray diffraction analysis. The mechanical properties of the PP were decreased due to the clay addition. The composites presented a microstructure predominantly intercaleted, with fine and homogeneous dispersion of the clay layers within the matrix. The composite showed an increase of about 30% in the oxygen barrier property of the PP, which is an interesting result when considering the application of the composite as a packaging material.