Fluororubber And NBR

- Nov 09, 2020-

NBR and fluororubber are commonly used oil resistant rubber. The service temperature is 120 ℃ and the chemical stability is good. The price is much lower than that of fluororubber. The purpose of the combination of fluororubber and nitrile rubber is to greatly reduce the price of products, improve the processability of fluororubber, prepare low hardness fluororubber products, improve the fatigue resistance of fluororubber, and be in the intermediate state in terms of heat resistance and chemical medium resistance. It has been reported that FPM / NBR blends with good comprehensive properties and moderate price can be obtained by using DCP / TAIC as co curing system. In addition, through the study of the micro phase state of the blends, it was found that the blends were heterogeneous when NBR with high acrylonitrile content (48%) and high Mooney viscosity was blended with fluororubber with low Mooney viscosity. If fluororubber is a continuous phase, the heat resistance of NBR can be obviously improved by blending modification: even if fluororubber does not form continuous phase, NBR is also protected and heat resistance is improved. The morphology of the blends was observed by electron microscopy. It was found that when the ratio of FPM / NBR was 50 / 50, it was difficult to distinguish the marine phase from the island phase. Only when the volume fraction of FPM exceeds 60 phr, can fluororubber form continuous phase. In order to reduce the cost, the proportion of fluororubber should be reduced as much as possible, and continuous phase of fluororubber can be formed. Usually, compatibilizer can be added to the blend to solve the problem. The results showed that the compatibility of NBR and fluororubber could be improved by using Vamac as compatibilizer. At the same time, in order to improve the dispersion effect of the two kinds of adhesives, dispersant ear (ethylene methacrylate copolymer) can be added, which can also improve the aging resistance of FPM / NBR blends. The change (decrease) rate of tensile properties of FPM / NBR blends decreased with the increase of fluororubber content; when the FPM / NBR contained ear, the decrease rate decreased significantly with the increment of fluororubber.