A one-step preparation of compatibilized polypropylene-nanocomposites by reactive extrusion processing

We have developed a one‐step method for preparing nanocomposites based on powdered isotactic polypropylene (i‐PP) as a matrix polymer (melt‐flow index (MFI) = 7.2 g 10 min−1), oligo(i‐PP‐g‐MA) (MFI = 35–70 g 10 min−1) as a reactive compatibilizer and docecylamine‐surface‐modified montmorillonite clay (organo‐MMT). This method includes grafting maleic anhydride (MA) onto i‐PP chains in the melt state under the controlled thermal degradation conditions and intercalative compounding of the obtained oligo(i‐PP‐g‐MA) with i‐PP and organo‐MMT by reactive extrusion. The effect of extrusion parameters on MFI, composition and properties of the grafted i‐PPs, and mechanism of formation and properties of PP/oligo(PP‐g‐MA)s/organo‐MMT nanocomposites were investigated by FTIR, XRD, and thermal analysis (DSC, TGA, and DTA). The results indicate that the formation of nanostructured morphologies proceeds through the formation of strong H‐bonding and amidization/imidization reactions between the anhydride units of exfoliated grafted i‐PP chain and alkylamine within the organo‐MMT interlayers. © 2007 Wiley Periodicals, Inc. Adv Polym Techn 26:41–55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20082