Views: 80 Author: Site Editor Publish Time: 2018-06-07 Origin: Site
Fluoroelastomer is a synthetic polymer elastomer containing fluorine atoms on the carbon atoms of the main chain or side chain.The introduction of fluorine atoms, giving rubber excellent heat resistance, oxidation resistance, oil resistance, corrosion resistance, and atmospheric aging resistance, in the aerospace, aviation, automobiles, oil, and household electrical appliances and other fields has been widely applied, is irreplaceable in defense cutting-edge industry key materials.Since 1943, polyolefin fluororubber, nitrite rubber, tetraproflon rubber, phosphonitrile fluororubber and perfluoroether rubber have been developed successively.
Fluoroelastomer(FKM) and epoxy acrylate elastomer(EACM) blends were prepared by melt blending through a twin-screw extruder. Morphology, thermal properties, dynamic mechanical properties were investigated and confirmed by transmission electron microscopy (TEM) and dynamic mechanical thermal analysis. The effects of the composition ratios on mechanical properties were studied. TEM showed that FKM/EACM blends exhibited a perfect co-continuous phase structure in a limited range of blending ratio, where EACM formed a network in FKM matrix. The morphology of FKM/EACM blends demonstrated a different network size with the change of EACM amount. A fine and complete network structure of EACM in FKM matrix was achieved at the mass ratio of FKM/EACM 80/20. Mechanical testing indicated a synergistic effect at the FKM/EACM 80/20 with maximal values for both the tensile strength and the tear strength.
Fluoroelastomer rubber has high chemical stability and is the best dielectric resistance of all elastomers at present .26 type fluorine rubber oil resistant base oil, double ester oils ethers, silicon oil, oil, silicate inorganic acid resistance, resistance to most organic and inorganic solvents, drugs, etc, is not only resistant to low molecular, ether, ester, ketone amine and ammonia, hydrofluoric acid, chlorosulfonic acid, phosphoric acid type of hydraulic oil.23 type fluorine rubber dielectric properties similar to 26 type, and even more unique, its strong oxidation resistance of the inorganic acid such as fuming nitric acid, sulfuric acid performance is better than 26 type, 98% HNO3 at room temperature the macerate in 27 days its volume expansion is only 13% ~ 15%.
2.High temperature resistance
Fluoroprene rubber has the same high temperature resistance as silicon rubber, which can be said to be the best elastomer at present.26-41 fluorine rubber can be use for a long time under 250 ℃, 300 ℃ under short-term use;Fluorochrome 246 has better heat resistance than 26-41.At 300 ℃, 100 hours after air thermal aging properties of 26-41 and 300 ℃ after hot air ageing type 246 x 100 hours, the performance of its elongation at failure can remain at around 100%, the hardness of 90 ~ 95 degrees.Type 246 in the 350 ℃ hot air aging after 16 hours to maintain good elasticity, after 400 ℃ hot air aging 110 minutes to maintain good elasticity, after 400 ℃ hot air aging 110 minutes, containing carbon black, cracking spray method of carbon black or carbon fiber sizing elongation increases about 1/2 ~ 1/3, intensity fell by about half, still keep good elasticity.23-11 type fluorine rubber can be use for a long time under 200 ℃, 250 ℃ under short-term use.
Fluoro rubber has excellent weather-aging resistance and ozone resistance.It is reported that the performance of VitonA developed by DuPont is still satisfactory after 10 years of natural storage, with no obvious cracking after 45 days in the air with the ozone concentration of 0.01%.Fluoro - 23 rubber weather - aging, ozone - resistant performance is also excellent.
However, fluoride rubbers are low polarizability materials with low surface energy and poor wettability, so it's very difficult for fluoride rubbers to wet, and the surface inertness has resulted in the poor adhesion of the polymer with various materials.
7.The low temperature performance
Low temperature properties of fluorine rubber is not good, this is due to its chemical structure, such as 23-11 of Tg > 0 ℃.The low temperature performance of fluorinated rubber is usually expressed by brittle temperature and compressive cold resistance coefficient.Sizing formula and the shape of the products, such as thickness of brittleness temperature influence is big, such as formulation of filler increase brittleness temperature sensitive to deteriorate, the thickness of the products increases, the brittle confusion degree also sensitive to deteriorate.
The radiation resistance of fluoro rubber is a poor one in the elastomer. After the radiation of type 26 rubber, fluoro rubber presents crosslinking effect, while type 23 fluoro rubber presents cracking effect.246 type fluorine rubber radiation in air at room temperature in the higher doses of 5 x 107 severe changes of performance under the condition of 1 x 107 shimron hardness increase 1 ~ 3 degrees, the strength drops below 20%, the elongation decreased 30% ~ 50%, so it is generally believed 246 type fluorine rubber can be resistant to 1 x 107 shimron, limit of 5 x 107 accessions.
Because the fluorine rubber has high vacuum and high temperature resistant, oil resistant, resistant to acid and alkali resistance, the characteristics of a variety of chemicals, has been applied in modern aircraft, missile, rocket, space travel, ships, nuclear power and other cutting-edge technology and automobile, shipbuilding, chemical, petroleum, telecommunication, apparatus, machinery and other industrial fields.Fluoro rubber seals, rubber tubes made of fluoro rubber, fluoroelastomer bellows, fluoroelastomer band, fluoroelastomer o-ring, fluoroelastomer rubber, fluoroelastomer buy,viton b fluoroelastomer (fkm).