In this article, nanocomposites based on polypropylene containing montmorillonite, modified with two different intercalants (primary and quaternary amine), at three different coverage levels have been investigated. The specimens were prepared in a mini-extruder machine with a counter-rotating configuration. The effectiveness of intercalant type and clay coverage level on the dispersion was analyzed by different means, including Xray diffraction analysis, field emission gun scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. The flexural performance of the specimens was also examined.