Morphology, rheology and curing of (ethylene-propylene elastomer/hydrogenate acrylonitrile-butadiene rubber) blends reinforced by POSS and organoclay

Nanocomposites based on polyhedral silsesquioxanes POSS and modified montmorillonite MT reinforced ethylene-propylene elastomer/hydrogenated butadiene-acrylonitrile rubber blends (EPR/HNBR) are reported. The effect of the methacryloisobutyl MIB-POSS and octavinyl OV-POSS on the curing characteristics, viscoelastic properties, relaxation behavior and morphology of EPR/HNBR blends was determined. The rheometric characteristics, the viscosity of molded rubber blends and kinetic parameters of curing were determined using a RPA rheometer, in which the process of crosslinked network formation was monitored at various temperatures. The obtained results demonstrated a correlation between the calculated activation energies of crosslinking Ea and the viscoelastic properties of POSS functionalized EPR/HNBR composites, which can be particularly seen in OV-POSS functionalized EPR/HNBR sample. The increase in EPR glass transition temperature Tg confirmed the formation of OV-POSS crosslinks between phases of both rubbers. A relatively more homogeneous morphology, which was investigated by SEM, confirmed the influence of OV-POSS on the miscibility of both rubbers.