Abstract: The glass transition temperature and the tensile strength of poly (butadiene-co-acrylo-nitrile) filled with graphite powder, molybdenum disulfide powder and silica were measured. The results showed that the copolymer filled with graphite has the highest tensile strength and percentage of bound rubber as compared with the copolymers containing either of the other two fillers. T_g (U) of the copolymer was verified.