Microstructure, mechanical, and rheological properties of natural rubber/ethylene propylene diene monomer nanocomposites reinforced by multi‐wall carbon nanotubes

Abstract

Nanocomposites based on natural rubber (NR)/ethylene propylene diene monomer (EPDM)/multi‐wall carbon nanotubes (MWCNT) have been prepared in an internal and a two roll‐mill mixer in two steps. The effect of carbon nanotubes (MWCNTs) and rubber composition were studied on microstructure, mechanical and rheological properties of the vulcanizated NR/EPDM/MWCNT nanocomposites. Ethylene propylene diene monomer grafted with maleic anhydride (EPDM‐g‐MAH) was prepared using a solution process. Grafting of maleic anhydride on EPDM confirmed by attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR). The effects of compatibilizer (EPDM‐g‐MAH) and functionalized carbon nanotubes (f‐MWCNTs) on mechanical properties of NR/EPDM/MWCNT nanocomposites was investigated as well. Dynamic mechanical thermal analysis (DMTA) results demonstrated the glass transition temperature (Tg) of nanocomposites were slowly enhanced with increasing the amount of MWCNTs. The microstructure of nanocomposites have been characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which showed that the observed MWCNTs were in both NR and EPDM phases. The rheological behavior has been evaluated by a rubber processing analyzer (RPA). The ozone resistance times of the nanocomposite samples indicated that by increasing the amount of MWCNTs ozone resistance was improved. POLYM. COMPOS., 39:E745–E753, 2018. © 2016 Society of Plastics Engineers