Organoclay modification by insertion of hyperbranched aromatic polyamides

Hyperbranched (HB) aromatic polyamides (aramids) synthesized from A2 (p-phenylenediamine) + B3 (trimesic acid) reactants have been intercalated into three organically-modified montmorillonite-type clays (OMMT), namely Cloisite 30B®, Dellite 43B® and Dellite 72T®. Solution intercalation has been applied for the preparation of the OMMT/HB aramid pair. The presence of HB aramid has been found to increase the interlayer distances of some silicate layers and to reduce those of others. This phenomenon has been explained by the broad polydispersity of the HB aramid leading to a complex mixture of macromolecules which can interact with the organic compatibilizer of the clay in different ways and thus affect the arrangement of it inside the galleries. Purthermore, the swelling of the layered silicate in the solvent used has been found to be a key parameter, which strongly biases polymer intercalation. TGA measurements have evidenced the active role of clay in the degradation process of HB aramid and the higher thermal stability of clay/HB aramid systems, as compared to the pristine organoclays. Finally, the Cloisite 30B®/HB aramid system has been used as masterbatch to produce polyamide 6 (PA6)-based nanocomposites. WAXD and TEM characterization have evidenced the possibility to obtain fully exfoliated nanocomposites.