Kub siab tshaj 77 ° C tsis haum rau cov khoom ntawm feem ntau elastomers thiab plastics, whereas PTFE withstands kub txog li 260 ° C.Txawm tias qis dua 77 ° C, yog tias cov kua qaub corrosive rau cov hlau thiab cov kuab tshuaj organic sib xyaw ua ke, cov ntaub ntawv thiab cov khoom ntawm PTFE feem ntau nyiam vim elastomers thiab lwm yam yas feem ntau tsis muaj kev tiv thaiv rau cov kuab tshuaj o thiab softening.
Los ntawm Chemical inertness, peb txhais tau tiasPTFEfluorocarbon resins tuaj yeem tiv tauj nrog lwm cov tshuaj uas tsis muaj tshuaj lom neeg tshwm sim.Feem ntau, PTFE fluorocarbon resins yog tshuaj inert.Txawm li cas los xij, cov lus no, zoo li txhua qhov kev qhia dav dav, yuav tsum tsim nyog yog tias nws yuav tsum ua kom raug.Qhov kev tsim nyog yuav tsis ua rau muaj kev tsis sib haum xeeb, txawm li cas los xij, yog tias ib tug nco ntsoov cov lus tseeb ntawm tus cwj pwm ntawm PTFE resins.
Cov lus piav qhia ib txwm muaj ntawm ntau yam kev sim cov ntaub ntawv tuaj yeem ua yuam kev, vim nws tuaj yeem sib sau ua ke hauv ntau hom kev coj tus cwj pwm "Chemical".Yog tias cov lus piav qhia kom meej, nws yuav tsum paub qhov txawv ntawm cov tshuaj tiv thaiv nruj thiab kev ua ntawm lub cev xws li nqus.Cov lus piav qhia yuav tsum ua kom tus neeg siv coj mus rau hauv tus account qhov kev sib raug zoo ntawm lub cev thiab tshuaj lom neeg uas yuav cuam tshuam rau ib qho kev thov.
Piv txwv li, PTFE resins yuav tsis cuam tshuam los ntawm immersion hauv aqua regia.Txawm li cas los xij, yog tias qhov ntsuas kub thiab qhov tshwm sim siab ntawm cov reagent no dhau los ua siab, qhov nqus ntawm cov khoom ntawm cov reagent mus rau hauv cov resin kuj yuav nce ntxiv.Cov kev hloov pauv tom qab, xws li kev poob siab tam sim ntawd, tuaj yeem ua rau lub cev puas tsuaj vim kev nthuav dav ntawm cov vapors absorbed hauv cov resin.Pom tseeb, tom qab ntawd, thaum peb tham txog cov khoom siv tshuaj lom neeg ntawm PTFE peb yuav tsum paub qhov txawv ntawm cov tshuaj tiv thaiv nruj heev, raws li peb tau hais txog "Chemical compatibility" thiab lub cev ua haujlwm, xws li "kev nqus" ua ke nrog kev siv tshuab thiab thermal.
Nyob rau hauv ib txwm siv kub, PTFE resins raug tawm tsam los ntawm ob peb cov tshuaj es tsis tabulate cov tshuaj uas lawv sib xws.Cov reactants no yog ib qho ntawm cov oxidizers hnyav tshaj plaws thiab txo cov neeg ua haujlwm paub.Elemental sodium nyob rau hauv kev sib cuag nrog fluorocarbons tshem tawm fluorine los ntawm polymer molecule.Cov tshuaj tiv thaiv no yog siv dav hauv cov tshuaj anhydrous rau etch qhov chaw ntawm PTFE kom cov resins tuaj yeem ua cov nplaum nplaum.Lwm cov alkali hlau (potassium, lithium, thiab lwm yam) hnov zoo li no.
Intimate blends ntawm finely faib hlau hmoov hmoov (xws li, txhuas los yog magnesium) nrog cov hmoov fluorocarbon resins tuaj yeem hnov mob hnyav thaum ignited, tab sis qhov kub ntawm qhov hluav taws kub yog deb tshaj qhov luam tawm pom zoo siab tshaj qhov kev pab kub rau PTFE resins.Cov oxidizers uas muaj zog heev, fluorine (F2) thiab lwm yam sib txuas (xws li, chlorine trifluoride, CIF3), tuaj yeem ua haujlwm los ntawm PTFE tsuas yog nrog kev saib xyuas zoo thiab paub txog qhov muaj peev xwm txaus ntshai.Fluorine yog absorbed rau hauv cov resins, thiab nrog xws li intimate kev sib cuag cov sib tov ua rhiab heev rau ib qhov chaw ntawm ignition xws li cuam tshuam.
Qee qhov xwm txheej ntawm lossis ze ntawm qhov kev pom zoo txwv qhov ntsuas kub ntawm 260 ° C rau TFE & PFA, thiab 204 ° C rau FEP, ob peb cov tshuaj nyob rau hauv siab tau tshaj tawm cov tshuaj tiv thaiv rau PTFE.Kev tawm tsam zoo ib yam li sodium etch tau raug tsim los ntawm qhov kub siab ntawm 80% NaOH lossis KOH, hlau hydrides xws li boranes (xws li, B2H6), aluminium chloride, ammonia (NH3), thiab qee yam amines (R-NH2) thiab imines ( R = NH).Tsis tas li ntawd, qeeb oxidative nres tau pom los ntawm 70% nitric acid nyob rau hauv siab ntawm 250 ° C.Kev ntsuam xyuas tshwj xeeb yog xav tau thaum muaj kev txo qis lossis oxidizing tej yam kev mob mus txog.
Li no, nrog rau kev zam raws li tau sau tseg, PTFE resins nthuav tawm ntau yam tshuaj lom neeg thiab thermal serviceability.Tab sis tus neeg yuav khoom lossis tus neeg tshwj xeeb ntawm cov khoom ntawm PTFE kuj yuav tsum paub thiab nkag siab txog nws cov kev txwv hauv kev hais txog cov tshuaj ib txwm muaj.Tsis zoo li qhov txwv ntawm cov hlau, cov no feem ntau tsis yog tshuaj lom neeg yuav lub cev hauv qhov xwm txheej.Qhov cuam tshuam ntawm qhov kub thiab txias, siab, thiab nqus ntawm cov tshuaj hauv PTFE, thiab lawv cov kev cuam tshuam, yog dab tsi nyob rau hauv lub sij hawm feem ntau txwv cov xwm txheej raws li PTFE yuav ua tau txaus siab.Txij li qhov no txawv ntawm yuav luag txhua yam khoom siv ntawm kev tsim kho, nws yuav tsum tau ua tib zoo xav txog cov lus piav qhia ntxaws ntxiv uas ua raws.
Post lub sij hawm: Oct-04-2019