Effects of acrylonitrile content and hydrogenation on fatigue behaviour of HNBR

Abstract

AbstractThe influence of acrylonitrile (ACN) content and hydrogenation on the fatigue properties of HNBR is investigated. HNBR blends consist of different quantities of acrylonitrile (24, 36, and 44 wt%) and per cent hydrogenation (91%, 96%, and 99%), and a composite of two blends of HNBR with 24 and 44 wt% ACN for an average of 36 wt% . A comprehensive experimental campaign is carried out with fatigue life and crack propagation testing at 120°C. Afterwards, fatigue damage is analysed thanks to both optical and scanning electron microscopy. The results of the three experimental approaches demonstrate that HNBR with median ACN content (36 wt%) and median hydrogenation (96%) has the best fatigue resistance. In general, the fatigue resistance decreases in the following order: for ACN—36 to 44 to 24 wt%, and for hydrogenation—96% to 99% to 91%. The composite blend also has lower fatigue resistance than a regular HNBR blend.