Structure and properties of polyamide-6/vermiculite nanocomposites prepared by direct melt compounding

Polyamide-6 (PA6)/vermiculite nanocomposites were fabricated through the direct melt compounding of maleic anhydride-modified vermiculite (MAV) with PA6 in a twin-screw extruder followed by injection molding. The structure and morphology of the nanocomposites were determined by X-ray diffraction and scanning and transmission electron microscopy techniques. The results revealed the formation of intercalated and exfoliated vermiculite platelets in the PA6 matrix. Tensile measurement showed that the tensile modulus and strength of the nanocomposites tended to increase with increasing vermiculite content. The thermal properties of the nanocomposites were determined by dynamic mechanical analysis, differential scanning calorimetry, and thermogravimetry measurements. The storage modulus of the PA6-MAV nanocomposites increased to almost twice that of the neat PA6. The thermal stability of the nanocomposites increased dramatically, and this was associated with the addition of vermiculite. The effect of the addition of maleic anhydride on the formation of the PA6-vermiculite nanocomposites was examined. (C) 2002 Wiley Periodicals, Inc.