The reactive compatibilization of NBR/EVA blends with oxazoline-modified nitrile rubber

The reactive compatibilization of ethylene-vinyl acetate copolymer (EVA)/nitrile rubber (NBR) blends has been performed using partially hydrolyzed EVA (EVALVA) in combination with oxazoline-functionalized NBR (NBROX). The synthesis of the NBROX has been performed in solution. The presence of 5 wt% of EVALVA in combination with 2.5 wt% of NBROX resulted in a substantial improvement of tensile strength of NBR/EVA (50:50 wt%) vulcanized blends, with a little increase of the elongation at break. The morphologies of these blends were examined by the scanning electron microscopy. A finer morphology has been observed in vulcanized and non-vulcanized blends, compatibilized with the co-reactive EVALVA/NBROX copolymers. Blends of NBROX/EVALVA (50:50 wt%) resulted in insoluble material, constituted by both components, as indicated by Fourier transform infrared analysis. This result indicates the reaction of the co-reactive groups (hydroxyl and oxazoline) during blending.