Effect of sepiolite content on mechanical, thermal and flammability properties of ethylene vinyl acetate nanocomposite

Abstract

Polymer/clay nanocomposites are a new class of composite materials consisting of a polymer matrix with dispersed clay nanoparticles. Ethylene vinyl acetate (EVA)/Sepiolite and EVA/modified Sepiolite (M-Sepiolite) nanocomposites were prepared by melt extrusion using a counter-rotating twin-screw extruder followed by injection molding in order to examine the mechanical, morphological, thermal and flammability properties of the nanocomposites. Sepiolite was modified with silane treatment (M-Sepiolite). Sepiolite content was various in EVA with 1, 3, 5 and 7 wt%. The mechanical properties of EVA/Sepiolite and EVA/M-sepiolite nanocomposites were studied through tensile. Scanning electron microscopy (SEM) was used to investigate the phase morphology of nanocomposites. The thermal properties were determined using Thermogravimetric analysis (TGA) and flame retardancy of nanocomposites was conducted by characterization for limiting oxygen index. The mechanical, thermal and flame retardancy properties of EVA / Sepiolite nanocomposite increased with the increase sepiolite content due to good dispersion and well interface interaction between Sepiolite and EVA. The mechanical, thermal and flame retardancy properties the EVA/M-Sepiolite nanocomposite was better than the mechanical, thermal and flame retardancy properties of EVA/Sepiolite nanocomposite, where the modification of Sepiolite caused extremely good interface interaction, as well as good dispersion and better adhesion between Sepiolite and polymer matrix.