Teflon [PTFE , F4] is to be able to bear one of corrosion function the best material in the world nowadays .Get the "plastic king" laudatory title therefore .Chemistry medium uses its energy over a long period of time in any kind, its many problem of creation fields such as chemical industry , petroleum , pharmacy having resolved our country. Teflon sealing element , washer , pad. The teflon sealing element , pad , seal washer are that the model moulds treating select and use suspension polymerization teflon resin be made from. Teflon and plastic is compared with each other other have be able to bear the chemistry corrosion and be able to bear the outstanding characteristic of temperature, it is encapsulant and filling material already quilt applying broadly.
Teflon molecular formula teflon is four fluorine ethenes polymers. English abbreviation is PTFE. The commodity is called "Teflon " (teflon). "King of being plastic" by good reputation. Teflon basic structure is. -CF2- CF2- CF2- CF2- CF2- CF2- CF2- CF2- CF2- CF2. Teflon applies to need the antiacid alkali and organic various menstruum's broadly, its self one of the raw material not having toxicity to person, but being put into use in procedure of production satisfies the bitter fluorine ammonium (PFOA) being considered may have a carcinogenesis.
Teflon (Teflon or PTFE) , popular name "plastic king ", Chinese commodity "iron fluorine dragon " ", exceptional fluorine dragon " ", "Tefulong" ", Thailand fluorine dragon " etc.It is accomplished because four fluorine ethene classics get together high polymer , have the good chemistry stability , is able to bear corrosivity , hermetic sealing , high lubrication the viscidity , electricity insulation and fine resisting do not age endurance. The long range works under the temperature being able to in 250 ℃ + till 180 ℃-, except six-zone-pass metal sodium and the liquid fluorine, ability other all chemicals, boil in chloroazotic acid getting change neither. Being used as engineering plastics , may manufacture the teflon tube , stick , belt , board , film and so on. Apply to function demanding the pipeline , container , pump , valve that higher being able to bear corrodes and making the radar , high frequency communication equipment and material , radio equipment and material and so on in general. Antisepsis picture preparing metal , glass , earthenware surface waits for the insulation dipping liquid dispersing various liquid work material available tier. Various gathering four fluorine circles , gathering four fluorine pads , gathering four fluorines checking root and so on is used for preservative pipeline flange of all kinds hermetic sealing broadly. Can be used to reel off raw silk from cocoons besides , also, teflon fibre fluorine silk tassel (abroad the commodity is called exceptional fluorine silk tassel).
At present, various classified collections tetrafluoroethylene product already, in the chemical industry, the machinery, the electron, the electric appliance, the war industry, astronautics, the link guaranteed with national economy domains in and so on bridge play the pivotal role.
The teflon (PTFE) exploitation conditions profession chemical industry, the petrochemical, the refinery, the chlorine alkali, the system acid, the phosphate fertilizer, the drugs manufacture, the agricultural chemicals, the chemical fiber, influence, the coking, the coal gas, the organic synthesis, colored smelting, the steel and iron, the atomic energy and the high net product production (for example ionic membrane electrolysis), sticks the thick material handling and the operation, hygienic processing Production departments and so on request highly strict food, drink.
Medium hydrofluoric acid , phosphoric acid , sulfuric acid , hydrogen nitrate , chlorhydric acid , various organic acid , organic solvent , strong oxidant and other strong various corrosivity chemistry medium.
Or temperature- 20 ~ 250 ℃, allows the shock chilling shock heating, cold hot alternative operation 0.1 ~ 6.4 Mpa (satisfy pressure- shouldering pressure till 64 kgf/cm2) -0.1 ~ 6.4 Mpa (Full vacua to 64 kgf/cm2 Teflon (PTFE) uses merit.
The thermostability uses the working temperature to amount to 250 ℃. Be able to bear the low temperature having fine machinery tenacity; Even if the temperature comes down to 196 ℃-, may keep 5%'s elongation rate. Be able to bear corrosion showing the inertia , ability to great majority chemicals and menstruum, strong acid strong base , water and various organic solvent. Be able to bear the climate the life-span ageing having plastic middle best .
High lubrication is that solid material is hit by friction coefficients minimum person.
Not gluing is that minimal surface tension, does not glue any matter in solid material.
Inertia the nothing is poisoned having physiology, the inner has no bad reaction as the manpower blood vessel and the visceral organ long range implantation body.
Relatively molecular big , low teflon mass being in number one hundred thousand, high reaching more than 10 million, general be in number million (polymerization degree are in 104 order of magnitude, but polyethylene is in 103 only). General crystal degree is 90 ~ 95%, the six-zone-pass temperature is 327 ~ 342 ℃. . The CF2 element has arranged according to sawtooth form in teflon molecule , comparatively, the hydrogen has faced slightly greatly, therefore the adjacent CF2 element can not choose completely according to opposing style alternating, but the warping chain , fluorine atom being to form a heliciform have almost covered entire high polymer chain surface because of fluorine atom radius 。This molecular structure has made an explanation various teflon function. Helix forming 13/6 when the temperature is lower than 19 ℃,; Untwisting, forms 15/7 a bit in 19 ℃ occurrence phase transitions , molecules helix.
346.94 and 484.88 kJ／mol, but teflon depolymerization generates 1 mol four fluorines ethenes though the carbon- carbon key and carbon- fluorine key fracture need to absorb an energy respectively in entire fluorine carbon compound needing an energy only 171.38 kJ. Therefore during the period of high temperature splitting decomposition, main depolymerization of teflon is four fluorine ethenes。The teflon weightlessness rate (%) during the period of 260 , 370 and 420 ℃ is 1 X 10-3 10-4 , 4 X sums every time hour respectively 9 X 10-2. It can be seen that teflon may be put into use in 260 ℃ long ranges. Since subsidiary outcome producing daedly poison time high temperature splitting decomposition protects and guards against teflon therefore fluorine phosgene and different butylene of entire fluorine etc., being going to pay attention to safety specially contact naked light.
Teflon keeps the good Mechanics function without exception within 196 ~ 260 ℃'s broader temperature range- , one of entire fluorine carbon high polymer characteristic are invariable in the low temperature fragile.
Be able to bear the chemistry corrosion and be able to bear the alkali metal outside , teflon waiting for nature getting rid of six-zone-pass being corroded hardly by any chemical reagent. The for example is in oil of vitriol , hydrogen nitrate , chlorhydric acid , boil even in chloroazotic acid, whose weight and the function nothing change equal, are insoluble in all menstruum also nearly , dissolve in entire alkane slightly above 300 ℃ (about 0.1 g／100g). Teflon not attracting tide , not burning, the equal pole stabilizes to oxygen , the ultraviolet ray , wait for nature therefore having outstanding being able to bear.
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