Effect of multi-walled carbon nanotube on mechanical and rheological properties of silane modified EPDM rubber

A novel mixing approach for achieving a good dispersion of multi-walled carbon nanotubes (MWCNTs) in ethylene- propylene diene monomer (EPDM) matrix has been investigated. In this approach EPDM was modified with vinyltrimethoxysilane (VTMS) during melt mixing. In addition the effect of MWCNT concentration on mechanical and rheological properties of modified EPDM has been studied. The formulated composites by this method exhibited significantly enhanced physical properties even at very low nanotube concentration. The grafting reaction was confirmed by Fourier transform infrared spectroscopy (FT-IR) peak at 1070 and 1250 cm-1according to Si-O and Si-C vibration. The state of dispersion of the fillers in the polymer matrix was evaluated through transmission electron microscopy (TEM) and scanning electron microscopy (SEM), In addition surface topology was studied with atomic force microscopy (AFM). The results showed that VTMS-grafted on the EPDM surface improved the dispersion of MWCNTs in the matrix. The rheological characteristics have been studied by rubber process analyzer (RPA). Some properties such as storage modulus (Ǵ) and complex viscosity (η^*) increased with increasing MWCNT content. It was found that at concentration of 2 wt.% MWCNT, the nanocomposites exhibited notably enhanced mechanical properties such as modulus and tensile strength.