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Non-linear viscoelastic characteristics of carbon black (CB)-filled fluoroether rubber mixture samples are investigated by large amplitude oscillatory shear (LAOS) tests. Three analysis approaches based on LAOS tests are then used to discuss correlations between rheological behavior and CB-filling amount. Each non-linear viscoelastic parameter of the mixture presents a three-stage characteristic with increasing CB content, which are attributed to the alteration of CB-elastomer network structure, corresponding to the state where gum continuous phase, CB-elastomer mesophase, and excessive CB agglomerates predominate in the mixture compound, respectively. According to the findings in engineering experiments, a CB content of 35-40 phr is recommended, taking into account tensile, hardness, and aging properties. Excessive CB agglomerates are found to reinforce CB-elastomer networks at elevated temperatures. For cold-resistance properties, structural changes in CB-elastomer network are proven to exert little effect on [T.sub.g], but a higher CB content was found to slightly enhance the cold-resistance coefficient, probably due to the decrease in velocity fraction of gum rubber. Highlights * LAOS tests were utilized to study the influences of CB on fluoroelastomer; * Three-stage alteration was observed in the mixture with increasing CB content; * Correlation between CB content and the engineering properties was discussed. KEYWORDS carbon black-elastomer interaction, fluoroether rubber, large amplitude oscillatory shear, non-linear viscoelasticity, 1 | INTRODUCTION Fluoroether rubber is a special type of fluoroelastomer (FKM), in which the polymerization monomers contain a large proportion of perfluoroethers such as perfluoromethyl vinyl ether (PMVE), perfluoropropyl [...]

High fluorine content fluororubber (FKM) was used as the research object, the high temperature medium resistance of high fluorine content FKM vulcanizates in a variety of aero-engine lubricanting oils was investigated, and the changes in physical and mechanical properties of high fluorine content FKM vulcanizates caused by different types of lubricanting oils were studied. The results showed that the high fluorine content FKM vulcanizates could still maintain good compression resilience after aging in lubricating oil at 200 ℃ for 72 h, the volume change rate was lower than 12%, the mechanical properties declined slightly, and the Shore A hardness decreased significantly. The mechanical pro-perty attenuation and volume change rate of high fluorine content FKM vulcanizate were different for different kinds of oil. The corrosion of lubricating oil on high fluorine content FKM vulcanizate at high temperature included physical infiltration and che-mical corrosion.