Fluorine rubber has a high degree of chemical stability, is the best dielectric resistance of all elastomers at present. Type 26 fluororubber is resistant to petroleum-based oils, diester oils, silane oils, silicates oils, inorganic acids, most organic and inorganic solvents, pharmaceuticals, etc. It is only resistant to low molecular ketones, ethers, esters, amines, ammonia, hydrofluoric acid, chlorosulfonic acid, phosphoric acid hydraulic oils. The medium properties of type 23 fluorine adhesive are similar to those of type 26, and more unique. Its resistance to strong oxidizing inorganic acids such as fuming nitric acid and concentrated sulfuric acid is better than that of type 26, and its volume expansion is only 13%-15% after 27 days of immersion in 98% HNO3 at room temperature.
High temperature resistance
The high temperature resistance of fluorine rubber is the same as that of silicone rubber, which can be said to be the best elastomer. 26-41 fluorine glue can be used for a long time at 250℃, and for a short time at 300℃; 246 fluorine glue is more heat resistant than 26-41. The physical properties of 26-41 after air thermal aging at 300℃×100 hours are equivalent to those of 246 after hot air aging at 300℃×100 hours. The elongation at break can be maintained at about 100%, and the hardness is 90~95 degrees. Type 246 maintains good elasticity after 16 hours of aging in hot air at 350℃, and good elasticity after 110 minutes of aging in hot air at 400℃. After 110 minutes of aging in hot air at 400℃, the elongation of the rubber material containing spray carbon black, hot cracking carbon black or carbon fiber increases about 1/2~1/3, and the strength decreases about 1/2. Still maintain good elasticity. Type 23-11 fluorine adhesive can be used for a long time at 200℃ and for a short time at 250℃.
Fluorine rubber has excellent weather aging resistance and ozone resistance. VitonA, developed by DuPont, reportedly performed satisfactorily after ten years of natural storage, with no significant cracking after 45 days in air with an ozone concentration of 0.01%. The type 23 fluorine rubber has excellent weather aging resistance and ozone resistance.
Type 26 fluorine rubber has excellent vacuum properties. 246 fluorine rubber basic formula of vulcanized rubber vacuum vent rate is only 37×10-6 ml /(second * cm ^2). Type 246 fluorine rubber has been successfully used under vacuum conditions of 10-9 torn roots.
Fluorine rubber has excellent physical and mechanical properties. The strength of type 26 fluorine rubber is generally between 10~20MPa, the elongation at break is between 150~350%, and the tearing strength is between 3~4KN/m. The strength of type 23 fluorine rubber is between 15.0~25MPa, elongation is 200%~600%, and the tearing strength is between 2~7MPa. Generally, the compression permanent deformation of fluorine rubber at high temperature is large, but if compared with the same conditions, such as the compression permanent deformation of the same time at 150℃, butyl and chloroprene rubber are larger than 26 fluorine rubber, 26 fluorine rubber at 200℃×24 hours of compression deformation equivalent to butyl rubber at 150℃×24 hours of compression deformation.
Type 23 fluorine rubber has better electrical properties and lower hygroscopic property than other elastomers, so it can be used as a better electrical insulation material. Type 26 rubber can be used at low frequency and low pressure.
Low air permeability
The solubility of fluorine rubber to gas is relatively large, but the diffusion rate is relatively small, so the overall performance of air permeability is also small. It is reported that the permeability of type 26 fluoroprene rubber to oxygen, nitrogen, helium and carbon dioxide gas at 30℃ is comparable to that of butyl rubber and butadiene rubber, and better than neoprene rubber and natural rubber.
Low temperature performance
The low temperature performance of fluorine rubber is not good, which is due to its own chemical structure, such as 23-11 Tg> 0 ° C. The actual low temperature performance of fluorine rubber is usually expressed by brittleness temperature and compressive cold resistance coefficient. The formula of the rubber material and the shape of the product (such as thickness) have a relatively large influence on the brittleness temperature, such as the amount of filler in the formula increases, the brittleness temperature is sensitive to deteriorate, the thickness of the product increases, the brittleness mixing degree is also sensitive to deteriorate.
The radiation resistance of fluorine rubber is relatively poor among elastomers. Type 26 rubber shows crosslinking effect after radiation action, and type 23 fluorine rubber shows cracking effect. 246 type fluorine rubber in the air radiation at room temperature at 5×107 LUN dose of performance changes dramatically, in 1×107 LUN condition hardness increase 1~3 degrees, strength decreased below 20%, elongation decreased 30%~50%, so generally considered 246 type fluorine rubber can withstand 1×107 LUN, the limit is 5×107 LUN.