The copolymer of acrylonitrile and butadiene - NBR is commonly used to manufacture gaskets and seals to be used in electrical transformers insulated by mineral oil. During operation those materials are constantly in contact with oil at temperatures that can reach 90 ºC, causing physical and chemicals changes in both gaskets and oil. In this paper the changes in elastomer mechanical properties after the compatibility test were studied (ASTM D 3455)[3]. This characterization was done by tension properties, hardness and dynamical mechanical analysis (DMA). The evaluation of thermal stability and composition of the NBR was carried out through thermogravimetry analysis (TG).
NBR gaskets; mineral oil compatibility; mechanical tests
