Mechanical performance and fracture surface analysis of fatty acid-coated iron oxide-reinforced nitrile butadiene composites

The addition of iron oxide nanoparticles (IONP) tends to agglomerate easily, and thus it is hard to obtain a uniform and well-dispersed particle nitrile rubber matrix (NBR). IONP was synthesized via the precipitation method, coated with fatty acid to produce coated IONP (C-IONP) before being compounded with NBR latex at 0 to 20 phr loading. The good interaction of C-IONP and NBR matrix was established by the formation of significant FTIR peaks at 1710 and 565 cm(-1) presented as C=O and Fe-O bands, respectively. Mechanical performance analysis by universal testing machine demonstrated that the tensile stress of NBR 15 and 20 increased dramatically as compared to neat NBR attributed to filler-filler interaction in C-IONP. Meanwhile, the lower tensile strength increment rate of NBR 5 and 10 than neat NBR was due to the presence of C-IONP which increased the strain by more than 700%, with well particle distribution.