Dynamic mechanical properties and structure of in situ cured polyurethane/hydrogenated nitrile rubber compounds: Effect of carbon black type

Abstract

AbstractA peroxide‐curable hydrogenated nitrile rubber (HNBR) was modified by in situ crosslinked polyurethane (PU) in a 1 : 1 weight ratio. PU was formed from solid PU precursors, polyester polyol, and blocked polyisocyanate incorporated in the HNBR during the curing of the latter. HNBR/PU blends containing carbon black (CB) of different types (N234, N330, and N550) were prepared in this work. Thirty parts of CB per hundred parts of polymer matrix (HNBR and PU) were used. The curing of PU was followed by differential scanning calorimetry (DSC). Information of the phase structure was derived from DSC and dynamic mechanical analysis (DMA) tests. DMA results suggested that a quasi‐interpenetrating network structure developed in the HNBR/PU blend. This was confirmed also by scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy inspections. The partition of CB between the PU and HNBR was assessed by TEM. It was established that CB was exclusively located in the HNBR phase. CB N234 proved to be more efficient reinforcement than N330 and N550. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012