POLYPROPYLENE BASED NANOCOMPOSITES. EFFECT OF TYPE OF ORGANO-MODIFIED MONTMORILLONITE

MARÍA FERNANDA HORST; CORA O. ROHLMANN; WALTER TUCKART; LIDIA M. QUINZANI; MARCELO D. FAILLA

Lima Peru

Simposio; 11° Simposio Latinoam. de Polímeros (SLAP'08) y 9° Congreso Iberoam. de Polímeros (CIP); 2008

Montmorillonite (MMT) is the clay most frequently used in the preparation of polymer nanocomposites (PNCs) due to its potential to exfoliate and the combination of the required stiffness, strength and dimensional stability. MMT is a layered silicate that exists naturally in a tactoid structure. The layers have a typical lateral dimension of 0.1-0.5 mm and a thickness plus interlayer spacing of about 1 nm. It is believed that the improved properties presented by PNCs are related with the large aspect ratio of exfoliated platelets. Nevertheless, complete exfoliation of platelets is rarely obtained and part of the clay remains pillared with a relatively large basal spacing due to the penetration of macromolecules in the interlaminar spaces. The use of MMT in PNCs requires an initial step of purification of the material followed by the interchange of the natural cations by organophilic ones (o-MMT). This step increases the interlayer spacing and improves the compatibilization with the polymer. Presently we discuss the effect of the o-MMT on the morphological, rheological and tribological properties of PP/PPg/o-MMT nanocomposites