Effect of carbon nanotubes on aging properties of hydrogenated nitrile rubber in the dilute oxygen medium

To solve the key problem of accelerated aging for packer rubber cylinder under high temperature. The hydrogenated nitrile rubber (HNBR) composites reinforced by multi-walled carbon nanotubes (MWCNTs) were prepared. Effect of MWCNTs on the aging performance of HNBR/MWCNTs composites was studied with dilute oxygen as a medium at 180 degrees C. Fourier-infrared spectroscopy, differential scanning calorimetry, dynamic thermomechanical analysis and transmission electron microscope were used to investigate the aging behavior of HNBR/MWCNTs composites. The tensile strength of HNBR composites with 3, 6, and 9 phr MWCNTs loading increased by 35%, 37%, and 39% respectively. After 15 days at 180 degrees C, HNBR composites with 3 phr of MWCNTs had a tensile strength retention rate of 91% and an elongation retention rate of 57%, while the blank HNBR composites had a tensile strength retention ratio of 72% and elongation retention ratio of 52%. The result of DSC shows that the presence of MWCNTs can enhance T-g of HNBR composite, the T-g increase rate (2 degrees C) for HNBR/MWCNTs composites was lower than that (3.2 degrees C) for the blank in 15 days at 180 degrees C. MWCNTs exhibited better reinforcement and excellent anti-aging performance. The possible anti-aging mechanism has been proposed.