Polytetrafluoroethylene yog ib qho hluavtaws fluoropolymer ntawm tetrafluoroethylene uas muaj ntau yam kev siv.Lub npe nrov tshaj plaws ntawm PTFE-raws li cov qauv yog polymer los ntawm Chemours.Melting point: 620.3 ° F (326.8 ° C); qauv: (C2F4) n; Qhov ceev: 2.2 g / cm³; IUPAC ID: poly (1,1,2,2-tetrafluoroethylene).
PTFE yog tsim los ntawm free-radical polymerization mechanism nyob rau hauv ib tug aqueous xov xwm los ntawm ntxiv polymerization ntawm TFE nyob rau hauv ib tug batch txheej txheem.Tus pib rau lub polymerization feem ntau yog cov dej-soluble peroxide xws li ammonium persulfate los yog disuccinic peroxide.Lub redox catalyst yog siv rau qhov kub thiab txias polymerization.PTFE yog tsim los ntawm kev ncua (los yog slurry) polymerization tsis muaj surfactant kom tau granular resins lossis nrog perfluorinated surfactant (emulsion polymerization) xws li ammonium perfluorooctanoate los tsim cov hmoov zoo thiab cov khoom tawg.Polymerization kub thiab siab feem ntau yog li ntawm 0 txog 100 C thiab 0.7 txog 3.5 MPa.
Granular PTFE yog tsim los ntawm polymerizing TFE ib leeg lossis los ntawm kev siv cov lej ntawm comonomers.Ib tug peroxide pib, me me los yog tsis muaj surfactant, thiab lwm yam additives tej zaum yuav muaj nyob rau hauv lub aqueous polymerization nruab nrab uas yog nquag nplawm thiab tej zaum buffered los ntawm cov tshuaj alkaline.Feem ntau ntawm cov polymer yog tsim nyob rau hauv cov roj theem nyob rau hauv cov duab ntawm stringy thiab irregularly zoo li hais tias.Cov khoom yog comminuted rau ntau qhov sib txawv, nyob ntawm seb cov khoom siv hmoov yuav tsum tau ua los ntawm cov txheej txheem fabrication.Piv txwv li, ib qho smoother nto yuav tsum tau me me particle loj thaum zoo txaus yog txhim kho los ntawm loj particle loj.
Fine hmoov PTFE yog tsim los ntawm polymerization ntawm TFE nyob rau hauv ib tug aqueous nruab nrab nyob rau hauv lub xub ntiag ntawm ib tug pib thiab surfactant.Lub polymerization tsis ua raws li cov qauv siv emulsion, tab sis qee qhov ntawm cov ntsiab lus, uas siv.Lub stability ntawm lub dispersion thaum lub sij hawm lub polymerization, kom tsis txhob ntxov ntxov coagulation, yog balanced tawm tsam qhov yuav tsum tau ua txhaum lub emulsion kom rov qab PTFE.Tsawg shear rate agitation yog khaws cia thaum lub sij hawm polymerization siv surfactant qib qis dua qhov tseem ceeb micelle concentration.Tus nqi ntawm polymerization thiab particle puab thiab loj yog cuam tshuam los ntawm cov concentration ntawm surfactant.Feem ntau ntawm cov khoom yog tsim nyob rau hauv thaum ntxov ib feem ntawm polymerization thiab loj hlob raws li lub voj voog mus.Molecular hnyav thiab muaj pes tsawg leeg hauv cov khoom tuaj yeem tswj tau siv cov khoom xyaw polymerization thiab cov xwm txheej.
Tib txheej txheem polymerization ua rau aqueous dispersions ntawm PTFE ua hmoov zoo.Lub dispersion yog concentrated thiab stabilized siv ntau yam ionic thiab nonionic surfactants.Ob peb txoj kev concentration tau tshaj tawm nrog rau electrodecantation, evaporation, thiab thermal concentration.Tshuaj additives kom phim lawv nrog cov txheej txheem fabrication los yog ib feem ntawm cov khoom yuav tsum tau hloov kho qhov kawg PTFE dispersion.
Filled compounds yog tsim los ntawm tag nrho peb hom PTFE siv cov khoom siv xws li iav fiber ntau, graphite, hlau hmoov, carbon fiber, thiab lwm yam.
Post lub sij hawm: Sep-24-2018