Evaluation of carbon black distribution in different phases of compatible blend of EVA/NBR through electrical, mechanical and morphological test

The paper reveals the influence of different methods of carbon black (CB) incorporation in the compatible blend of 50/50 (wt %) Ethylene vinyl acetate (EVA) and Acrylonitrile butadiene elastomer (NBR) on different properties of vulcanized blend compounds. The partitioning of two types of CB in two different phases of the blend was estimated from dynamic mechanical analysis (DMA). The distribution of CBs due to preferential addition in different phases of the blend affects property variations in different degrees. From the analysis of SEM, TEM, AFM and electrical property measurements, it is found that mixing method significantly affects the electrical properties, morphology, and surface topography. The variation in AC conductivity and surface resistance study confirms the formation of different conductive network of CB with variation in mixing technique and it is supported by morphology analysis. The DMA have shown that CB has higher affinity towards less viscous EVA phase. This is further corroborated by the surface energy measurement, which in turn controls the electrical conductivity behaviour as well as mechanical properties of the blends.