Polytetrafluoroethylene (PTFE) yog carbon thiab fluorine polymer. Cov khoom no muaj lub npe paub tshaj plaws: Teflon.
Cov khoom ntawm PTFE muaj xws li:
Zoo heev mechanical zog (<1%)
Chemical inertness corrosion kuj
Thaum tshav kub kub kuj
Tsawg coefficient ntawm kev sib txhuam
Cov khoom uas tsis yog nplaum (nrog rau qhov kub thiab txias ntawm 500 ° F (260 ° C))
Hnav tsis kam
Siab melting point
Cov khoom zoo heev ntawm PTFE muab nws ntau yam kev siv, thiab nws feem ntau yog siv los ua cov txheej tsis lo rau cookware. PTFE qhov zoo dua hnav tsis kam tso cai rau nws ua ke nrog ntau yam ntaub ntawv los ntawm emulsion polymerization los yog ncua kev kawm ntawv polymerization ua cov khoom siv thermal-resistant nrog cov khoom siv zoo heev, xws li rwb thaiv tsev hlau, khoom noj khoom haus-qib conveyor txoj siv sia, yoog raws cov ntaub tsis lo, thiab lwm yam.
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Polytetrafluoroethylene tau tshawb pom hauv xyoo 1938. Nws yog thawj zaug tshawb pom los ntawm American chemist Roy J. Plunkett (1910–1994) thaum nws tab tom sim ua cov pa roj carbon thiab fluorine compound refrigerant tshiab. Cov neeg nyob rau lub sijhawm yuav tsis xav txog cov khoom lag luam zoo li no. Cov catalysts txawv txawv yuav cuam tshuam rau txhua qhov ntawm lub ntiaj teb.
Xyoo 1941, DuPont tau txais daim ntawv pov thawj rau cov khoom no thiab tau sau npe ua lag luam raws li lub npe 'Teflon' xyoo 1944.
Niaj hnub no, polytetrafluoroethylene tau siv dav hauv ntau yam kev tsim khoom thiab lub neej. Hauv kev lag luam catering, PTFE coated cookware yog dav siv; Hauv kev lag luam khaub ncaws, cov khaub ncaws tiv thaiv khaub thuas sab saum toj los ntawm cov khoom lag luam xws li HELIKON thiab Carinthia txhua tus siv PTFE ua txheej txheej lossis txheej txheej. Txhawm rau ua kom muaj peev xwm tiv taus qhov txias txias ntawm -30 ° C; nyob rau hauv cov tub rog teb, PTFE cov ntaub ntawv uas tsis tshua muaj poob, zoo heev dielectric zog, zoo sib xws, ruaj khov tshuaj, thiab yuav luag tsis muaj noo noo nqus tau lug siv nyob rau hauv high zaus xov tooj cua radar panels. Hauv kev kho mob, cov ntaub ntawv PTFE kuj tau siv dav hauv cov khoom siv lub cev.
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PTFE sawv cev rau polytetrafluoroethylene, lub sij hawm tshuaj rau cov polymer (C2F4)n.
Cov khoom siv no feem ntau yog hais txog txhua yam khoom muaj npe ptfe hluavtaws fluoropolymer. Cov yam ntxwv tseem ceeb ntawm polytetrafluoroethylene yog raws li nram no:
Ua haujlwm kub siab tshaj plaws (° F / ° C): 500/260
Tensile Strength ntawm Break (PSI): 4,000
Dielectric qhov tsis tu ncua (kV/mil): 3.7
Loj: 2.16
Elongation thaum so: 350%
Ntug D Hardness: 54
Qhov dav siv ptfe polytetrafluoroethylene hluavtaws fluoropolymer nrog cov yam ntxwv saum toj no twb muaj ntau lub npe, cov hom tseem ceeb yog raws li nram no:
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Polytetrafluoroethylene yog cov kab hluav taws xob uas muaj cov pa roj carbon (C) thiab fluorine (F) atoms, nrog rau cov tshuaj formula (C2F4)n, qhov twg n yog tus naj npawb ntawm monomer units.
Cov qauv ntawm PTFE tuaj yeem hais tau raws li: -CF2-CF2-CF2-CF2-
Cov saw ntev ntawm PTFE molecules yog tsim los ntawm cov pa roj carbon atoms, txhua qhov txuas nrog ob lub fluorine atoms.
Fluorine atoms yuav luag npog qhov chaw ntawm cov pa roj carbon atoms ntawm kauv polymer saw. Cov pa roj carbon atoms tsim cov saw tseem ceeb ntawm cov saw hlau polymer. Cov fluorine atoms tsim ib daim thaiv zoo li cov qauv nyob ib ncig ntawm cov pa roj carbon atoms, uas zoo tiv thaiv cov pa roj carbon atoms sab hauv.
Qhov kev npaj tshwj xeeb ntawm atoms muab PTFE nws cov khoom tshwj xeeb. Cov qauv molecular no pab txhawb rau PTFE lub cev tsis muaj zog thiab tshuaj lom neeg.
Cov khoom siv Teflon yog dab tsi?
Teflon yog ib qho thermoplastic fluoropolymer, thiab Teflon acronym yog PTFE (polytetrafluoroethylene).
Teflon yog lub cim lag luam ntawm Chemours, txawm li cas los xij, PTFE kuj tuaj yeem yuav los ntawm cov tuam txhab uas tsis yog Chemours.
Teflon yog cov khoom siv nrov vim nws tsis tshua muaj kev sib txhuam, kub tsis kam, thiab tshuaj tiv thaiv.
Tau kawg, Teflon yog cov khoom siv hluav taws xob polymerized los ntawm tetrafluoroethylene thiab yog hom perfluorinated khoom. Nws lub npe tshuaj yog polytetrafluoroethylene (PTFE).
Teflon tshuaj qauv yog heev tshwj xeeb. Cov qauv molecular yog F (fluorine atoms) hloov tag nrho H (hydrogen atoms) ntawm C saw. Nyob rau tib lub sijhawm, vim tias lub vojvoog ntawm cov fluorine atom loj dua lub vojvoog ntawm cov pa roj carbon atom, qhov kev tawm tsam ntawm cov atoms loj heev, yog li nws yuav tsis zoo li hydrogen atoms, lawv tuaj yeem teem caij rau hauv lub dav hlau, yog li cov fluorine atoms yuav luag muab kauv mus qhwv cov pa roj carbon atoms, kom lub ntiaj teb sab nraud tuaj yeem sib cuag nrog cov fluorine atoms.
Nrog rau qhov muaj zog fluorine atom barrier, Teflon polymer qauv kuj ruaj khov piv rau lwm cov ntaub ntawv.
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PTFE yog ib qho polymerized los ntawm tetrafluoroethylene monomer. Nws yog pob tshab lossis opaque ciab zoo ib yam li PE. Nws qhov ceev yog 2.2g / cm3 thiab nws qhov nqus dej tsawg dua 0.01%.
Cov qauv tshuaj ntawm PTFE polymer zoo ib yam li PE, tshwj tsis yog tias tag nrho cov hydrogen atoms hauv polyethylene hloov los ntawm fluorine atoms. Vim lub zog siab thiab ruaj khov ntawm CF daim ntawv cog lus, nws muaj cov tshuaj tiv thaiv corrosion zoo heev thiab tuaj yeem tiv taus tag nrho cov acids muaj zog (xws li aqua regia) tshwj tsis yog cov hlau alkali molten, oxidizing media, thiab sodium hydroxide saum 300 ° C. Ntxiv nrog rau cov teebmeem ntawm cov oxidants muaj zog, txo cov neeg ua haujlwm thiab ntau yam organic solvents.
F atom nyob rau hauv PTFE molecule yog symmetrical, thiab ob lub ntsiab nyob rau hauv CF daim ntawv cog lus yog covalently bonded. Tsis muaj cov electrons dawb hauv cov molecule, ua rau tag nrho cov molecule nruab nrab. Yog li ntawd, nws muaj cov khoom zoo heev dielectric, thiab nws cov hluav taws xob rwb thaiv tsev tsis cuam tshuam los ntawm kev cuam tshuam ntawm ib puag ncig thiab zaus.
Teflon Physical Properties
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Nws lub ntim resistivity yog ntau dua 1017, nws cov dielectric poob yog me me, nws tawg voltage siab, nws arc kuj zoo, thiab nws muaj peev xwm ua hauj lwm nyob rau hauv ib tug hluav taws xob ib puag ncig ntawm 250 ° C. Vim tias tsis muaj hydrogen bonds hauv PTFE molecular qauv, cov qauv yog symmetrical, yog li nws cov crystallization Qib ntawm crystallization yog siab heev (feem ntau cov crystallinity yog 55% ~ 75%, qee zaum siab li 94%), uas ua rau PTFE tsis tshua muaj kub-resistant. Nws melting kub yog 324C, nws decomposition kub yog 415°C, thiab nws siab tshaj plaws siv kub yog 250°C. Nws yog nkig Qhov kub yog -190 ° C, thiab kub distortion kub (nyob rau hauv 0.46MPa tej yam kev mob) yog 120C.
Cov khoom siv Teflon muaj cov khoom siv zoo. Nws lub zog tensile yog 21 ~ 28MPa, khoov lub zog yog 11 ~ 14MPa, elongation yog 250% ~ 300%, thiab nws cov dynamic thiab zoo li qub kev sib txhuam coefficients tiv thaiv hlau yog ob qho tib si 0.04, uas zoo dua li nylon, polyformaldehyde, thiab polyethylene. Lub coefficient ntawm kev sib txhuam ntawm cov yas txias yog me me.
Pure PTFE muaj lub zog tsis muaj zog, hnav tsis zoo thiab tsis muaj kev nkag siab tsis zoo. Nws yog feem ntau yuav tsum tau ntxiv ib co inorganic hais rau PTFE polymer, xws li graphite, disulfide pawg, aluminium oxide, iav fiber, carbon fiber, thiab lwm yam. , thiab tseem tuaj yeem nthuav dav los ntawm kev koom tes nrog lwm cov polymers xws li polyphenylase (PHB), polyphenylene sulfide (PFS), polyethylene glycol (PEEK), polyethylene / propylene copolymer (PFEP), thiab lwm yam. nws damping kub ntau yam, txhim kho nws cov tsis kam mus rau variability.
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Cov txheej txheem tsim khoom siv chloroform ua cov khoom siv raw, siv cov dej tsis muaj hydrofluoric acid rau fluorinate chloroform, cov tshuaj tiv thaiv kub siab tshaj 65ºC, siv antimony pentachloride ua catalyst, thiab thaum kawg siv thermal cracking los tsim tetrafluoroethylene.
Aokai yog tsim los siv ncua kev kawm ntawv polymerization lossis emulsion polymerization.
Kev npaj ntawm monomer tetrafluoroethylene
Industrially, chloroform yog siv los ua raw khoom, anhydrous hydrofluoric acid yog siv los fluorinate chloroform, cov tshuaj tiv thaiv kub siab tshaj 65ºC, antimony pentachloride yog siv los ua catalyst, thiab thaum kawg tetrafluoroethylene yog tsim los ntawm thermal cracking. Tetrafluoroethylene kuj tuaj yeem tsim los ntawm kev ua haujlwm zinc nrog tetrafluorodichloroethane ntawm qhov kub thiab txias.
Kev npaj ntawm polytetrafluoroethylene
Hauv cov enamel lossis stainless hlau polymerization kettle, dej yog siv los ua qhov nruab nrab, poov tshuaj persulfate yog siv los ua tus pib, perfluorocarboxylic acid ammonium ntsev yog siv los ua cov dispersant, fluorocarbon yog siv los ua tus stabilizer, thiab tetrafluoroethylene yog redox polymerized kom tau cov hmoov zoo polyethylene. Tetrafluoroethylene.
Ntxiv ntau yam additives rau cov tshuaj tiv thaiv kettle, thiab cov tetrafluoroethylene monomer nkag mus rau hauv lub polymerization kettle nyob rau hauv lub roj theem. Kho qhov kub thiab txias hauv lub lauj kaub rau 25 ° C, tom qab ntawd ntxiv ib qho nyiaj ntawm activator (sodium metabisulfite) los pib polymerization los ntawm redox system. Thaum lub sij hawm txheej txheem polymerization, monomers txuas ntxiv, thiab lub siab polymerization yog tswj ntawm 0.49 ~ 0.78MPa. Cov dispersion tau tom qab polymerization yog diluted mus rau ib tug tej yam concentration nrog dej, thiab qhov kub yog hloov mus rau 15 ~ 20ºC. Tom qab sib sau ua ke nrog cov neeg kho tshuab nplawm, nws yog ntxuav nrog dej thiab qhuav, uas yog, Cov khoom no tau txais raws li cov khoom zoo granular resin.
Teflon txheej nws tus kheej muaj kev nyab xeeb: cov khoom siv Teflon nws tus kheej tsis muaj tshuaj lom, yuav tsis decompose, thiab yuav tsis ua rau muaj kev phom sij rau kev noj qab haus huv. Qhov no yog tej zaum vim nws cov qauv molecular yog qhov yooj yim insoluble hauv cov tshuaj tiag tiag, cia nyob ib leeg digested thiab absorbed los ntawm tib neeg lub cev.
Kawm paub ntxiv txog Teflon kev nyab xeeb
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Cov khoom tshwj xeeb ntawm PTFE ua rau nws siv dav hauv kev lag luam thiab kev lag luam marine xws li kev lag luam chemical, roj av, textile, zaub mov, papermaking, tshuaj, electronics thiab machinery.
Daim ntawv thov ntawm polytetrafluoroethylene (PTFE) nyob rau hauv anti-corrosion zog:
Vim yog qhov tsis xws luag hauv kev tiv thaiv corrosion ntawm roj hmab, iav, hlau alloys thiab lwm yam ntaub ntawv, nws yog ib qho nyuaj rau ua tau raws li qhov hnyav ib puag ncig qhov kub, siab thiab tshuaj lom neeg media coexist, thiab qhov tshwm sim poob yog heev txaus ntshai. Thaum PTFE cov khoom muaj kev tiv thaiv corrosion zoo heev, polytetrafluoroethylene siv cov ntaub ntawv tseem ceeb corrosion-resistant hauv roj av, tshuaj, textile thiab lwm yam lag luam.
Cov ntawv thov tshwj xeeb suav nrog: cov kav dej xa khoom, cov kav dej tso tawm, cov kav dej rau thauj cov roj corrosive, cov kav dej kub siab rau dov mills, siab, nruab nrab thiab qis-siab kav rau aircraft hydraulic systems thiab txias xovxwm tshuab, distillation yees, kub exchangers, kettles, yees thiab tso tsheb hlau luam. Kev ua tau zoo ntawm cov khoom siv tshuaj lom neeg cov khoom sib khi xws li hauv ob sab phlu thiab li qub muaj kev cuam tshuam zoo rau kev ua haujlwm thiab kev ua haujlwm ntawm tag nrho cov tshuab thiab cov khoom siv. PTFE cov khoom muaj cov yam ntxwv ntawm corrosion kuj, aging kuj, tsis tshua muaj kev sib txhuam coefficient thiab tsis-stickiness, dav kub ntau, thiab zoo elasticity, ua rau nws haum heev rau manufacturing seals nrog siab corrosion kuj yuav tsum tau thiab kev khiav hauj lwm kub siab tshaj 100 °. Xws li cov ntsaws ruaj ruaj rau grooved flanges ntawm cov cav tov, tshav kub exchangers, high-pressure nkoj, loj-inch hlab, li qub, thiab twj tso kua mis, seals rau iav tshuaj tiv thaiv pots, tiaj flanges, loj-inch flanges, shafts, piston rods, valve rods, Worm iav twj tso kua mis, khi pas nrig seals, thiab lwm yam.
2.Qhov kev sib txhuam qis ntawm polytetrafluoroethylene (PTFE) yog siv rau hauv daim ntawv thov load.
Kev sib txhuam ntawm qee yam khoom siv tsis haum rau lubrication, xws li nyob rau hauv cov xwm txheej uas lubricating roj yuav yaj los ntawm cov kuab tshuaj thiab ua tsis tau zoo, los yog hauv papermaking, pharmaceuticals, zaub mov, textiles, thiab lwm yam. Cov khoom lag luam hauv kev lag luam yuav tsum zam kom tsis txhob muaj cov roj lubricating, uas ua rau cov khoom siv PTFE yog cov khoom siv zoo tshaj plaws rau roj-dawb lubrication (cov khoom siv ncaj qha. Qhov no yog vim qhov sib txhuam coefficient ntawm cov khoom siv no yog qhov qis tshaj ntawm cov ntaub ntawv paub zoo. Nws cov kev siv tshwj xeeb muaj xws li bearings rau cov khoom siv tshuaj, papermaking machinery, thiab cov tshuab ua liaj ua teb, xws li piston rings, machine tool guide rails, and guide rings. Lawv tau dav siv nyob rau hauv pej xeem kev tsim kho tej yaam num raws li kev txhawb nqa slides rau txuas hniav, tunnel steel qauv ru tsev trusses, loj chemical pipelines, thiab cia tso tsheb hlau luam. Blocks, raws li zoo raws li siv raws li choj txhawb nqa thiab choj swivels, thiab lwm yam.
3.Kev siv ntawm polytetrafluoroethylene (PTFE) hauv kev siv hluav taws xob thiab hluav taws xob.
Qhov poob qis thiab me me dielectric tas li ntawm PTFE cov ntaub ntawv ua rau nws tuaj yeem ua rau hauv cov xov hlau enameled siv rau hauv micro motors, thermocouples, tswj cov cuab yeej, thiab lwm yam., PTFE hluav taws xob rwb thaiv tsev zaj duab xis Nws yog ib qho zoo tagnrho insulating khoom rau manufacturing capacitors, xov tooj cua insulating liners, insulated cables, motors thiab transformers. Nws kuj yog ib qho ntawm cov khoom siv tsis tseem ceeb rau cov khoom siv hluav taws xob xws li aerospace thiab aerospace. Kev siv cov fluorine yas zaj duab xis muaj permeability siab rau oxygen thiab siab permeability rau dej vapor. Qhov kev xaiv permeability ntawm me me permeability tuaj yeem siv los tsim cov pa oxygen sensors. Cov yam ntxwv ntawm fluoroplastics uas ua rau polar charge deviation nyob rau hauv qhov kub thiab siab siab tuaj yeem siv los tsim cov microphones, hais lus, qhov chaw ntawm cov neeg hlau, thiab lwm yam, thiab lawv cov refraction tsawg tuaj yeem siv tau. Cov yam ntxwv ntawm kev ua haujlwm siab tuaj yeem ua rau optical fibers.
4.Kev thov ntawm polytetrafluoroethylene (PTFE) hauv cov tshuaj kho mob.
Cov khoom siv PTFE nthuav dav yog qhov tsis muaj zog thiab muaj zog lom neeg yoog raws. Nws yuav tsis ua rau tsis lees paub los ntawm lub cev thiab tsis muaj kev phiv ntawm lub cev ntawm tib neeg lub cev. Nws tuaj yeem ua kom tsis muaj menyuam los ntawm txhua txoj kev. Nws cov qauv microporous tso cai rau siv ntau yam kev daws teeb meem, suav nrog cov hlab ntsha thiab thaj ua rau thaj rau cov ntaub so ntswg rov tsim dua tshiab thiab phais kev phais rau vascular, plawv, kev phais thiab orthopedic.
5.Application ntawm anti-stick zog ntawm polytetrafluoroethylene (PTFE).
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PTFE cov khoom muaj qhov tsawg tshaj plaws ntawm qhov nro ntawm cov khoom siv thiab tsis ua raws li cov khoom siv. Nws kuj muaj cov yam ntxwv ntawm qhov kub thiab txias tsis kam thiab tshuaj inertness, ua rau nws tsim nyog rau kev siv xws li kev tsim khoom. Cov lauj kaub uas tsis yog-stick yog dav siv hauv kev siv tshuaj tiv thaiv. Cov txheej txheem los tiv thaiv nplaum feem ntau suav nrog ob hom: txhim kho PTFE daim ntawv ntawm lub substrate thiab tso cov PTFE txheej los yog kua roj vanish composited nrog iav ntawm lub substrate los ntawm tshav kub shrinkage.
Kawm paub ntau ntxiv txog PTFE txheej
Txawm hais tias PTFE cov ntaub ntawv tseem muaj qhov teeb meem ntawm kev nyuaj siab hauv vuam, nrog rau kev nce qib ntawm cov thev naus laus zis, cov txheej txheem synthesis tshiab yuav daws tau cov ntsiab lus mob ntawm PTFE thiab siv PTFE rau ntau thaj chaw.
