Structure and properties of nanocomposites prepared by directly melt blending ethylene‐co‐vinylacetate and natural montmorillonite

Abstract The poly(ethylene‐co‐vinylacetate)/montmorillonite (EVA/MMT) nanocomposites were prepared by directly melt blending EVA and natural MMT in the presence of hexadecyl trimethylammonium bromide. The interlayer spacing of the silicate layers in EVA/MMT nanocomposites increased within 15 min of the blending time, and then remained unchanged with further increase in the blending time. The tensile and tear strength and Young's modulus of EVA/MMT nanocomposites increased with increasing blending time and reached the maximum value at 15 min, and then decreased. The tensile and tear strength and Young's modulus of EVA/MMT nanocomposites blended at 140°C were lower than those of the nanocomposites blended at 120°C. The thermal stability of EVA/MMT nanocomposites was improved compared with EVA. Furthermore, the thermal stability of EVA/MMT nanocomposites in nitrogen was higher than thermal stability of the nanocomposites in air because of the air destabilized the EVA and speeded up both deacylation and degradation. POLYM. COMPOS., 27:529–532, 2006. © 2006 Society of Plastics Engineers