Reinforcement of Natural Rubber/Ethylene-Propylene-Diene Monomer (NR/EPDM) by Silane Functionalized Halloysite Nanotubes

We describe a nanocomposite made of halloysite nanotubes (HNTs, a naturally occurring tube-like nanoparticle), natural rubber (NR), ethylene-propylene-diene monomer (EPDM), and ethylene-propylene-diene monomer grafted with maleic anhydride (EPDM-g-MA). Diethoxydimethyl silane (DMS), a silane coupling agent, was used to modify highly hydrophilic HNT nanotubes to ensure proper dispersion of these nanoparticles in the hydrophobic NR/EPDM rubber matrix. After the silane modification, the functional groups on the surface of the HNTs were characterised and the degree of modification was determined using field emission scanning electron microscopy (FESEM). The maximal tensile strength, stress at 100% elongation (M100), and elongation at break are reached at 8 phr after the addition of DMS modified HNTs to NR/EPDM. Any additional growth causes the tensile strength, M100, and elongation at break to gradually decline.