(1) Mechanical properties under normal conditions
The general blending strength of 26-type fluorine rubber is 10-20Mpa; the elongation is 150-300%; the tear strength is between 20-40KN / m, but its elasticity is poor.
The coefficient of friction of fluorine rubber (0.8) is smaller than that of nitrile rubber (0.9 ~ 1.5).
(2) High temperature resistance
  The high temperature resistance of fluorine rubber and silicone rubber is currently the best among the existing rubbers. F26-41 fluorine rubber can work for a long time at 200 ~ 250 ℃, and it can also work for a short time at 300 ℃ (
(3) Corrosion resistance
Viton has excellent corrosion resistance. It has excellent stability to organic liquids, different fuel oils and lubricants. Good resistance to most inorganic acids, hydrocarbons, benzene and toluene. Only resistant to low molecular esters, ethers, ketones and some amines.
(4) Performance of heat-resistant water and superheated steam
The stability of rubber on hot water depends not only on the material of the body, but also on the compounding of the rubber. For fluororubbers, peroxide-cured fluororubbers are superior to amine and phenolic vulcanizates. It should be said that the performance of fluororubber is hot water and superheated steam in general, it is not as good as ethylene propylene rubber, the volume change does not exceed 10% after soaking in 180 ℃ × 24h hot water, and the physical properties do not change much.
(5) Compression set
Fluorine rubber is used for sealing at high temperature. Compression deformation is its key performance. Viton-type fluororubber is so widely used that it is inseparable from the improvement of its compression deformation. From the 1960s to 1970s, the American DuPont Company is committed to improving the resistance to compression deformation of fluoroelastomers, and has achieved significant results. Table 4 shows the improvement of compression deformation of DuPont's fluorine rubber.
(6) Low temperature resistance
The low temperature resistance of fluororubber is general, and the limit temperature for maintaining elasticity is -15 ~ -20 ℃. As the temperature decreases, its tensile strength becomes greater, and it appears tougher at low temperatures. When measuring a 2mm thick standard sample, its brittleness temperature is about -30 ° C; -45 ° C when thickness is 1.87mm; -53 ° C when thickness is 0.63mm; -69 ° C when thickness is 0.25mm. Generally, the operating temperature of fluororubber can be slightly lower than the brittle temperature. For example, the US military standard MIL-25879D stipulates that the use temperature is -40 ~ 205 ° C. The operating temperature limit of fluoroelastomers in aviation engines abroad is -35 ° C.
(7) Weathering resistance and ozone resistance
The performance of VitonA after 10 years of natural storage is still satisfactory. In the air with an ozone concentration of 0.01%, there was no obvious cracking after 45 days. Its weather resistance and ozone resistance are satisfactory.
(8) Electrical performance
Fluorine rubber's electrical insulation performance is not very good, it is only suitable for low frequency and low voltage use. Temperature has a great influence on its electrical properties. When it rises from 24 ° C to 184 ° C, its insulation resistance decreases by 35,000 times.
(9) Air permeability
The gas solubility of fluororubber is relatively large, its diffusion speed is relatively small, and its total air permeability is small. In fluororubber, the addition of filler fills the voids inside the rubber, so that the air permeability of the vulcanizate becomes smaller, which is very advantageous for vacuum sealing. If properly matched, fluororubber can solve the vacuum sealing of 10-7Pa.
(10) Fire resistance
Fluorine rubber can burn in case of fire.