Yuav Ua Li Cas Thiaj Ua Tau Fluorocarbon Yas Thiab Nws Siv Hauv Kev Siv Tshuaj Lom Zem
Cov yas fluorocarbon yog ib pawg ntawm cov polymers uas muaj ntau cov carbon-fluorine (C-F) bonds. C-F bonds paub tias muaj zog heev thiab ruaj khov, muab cov yas no zoo heev tiv taus tshuaj lom neeg, tiv taus cua sov, thiab tsis lo. Vim lawv cov yam ntxwv tshwj xeeb, fluorocarbons siv dav hauv kev lag luam tshuaj lom neeg, petrochemical, tshuaj, semiconductor, thiab chaw soj nstuam tshawb fawb. Tsab xov xwm no tham txog cov txheej txheem tsim khoom ntawm fluorocarbon plastics (ob qho tib si lub tswv yim thiab kev lag luam) thiab lawv siv hauv kev siv tshuaj lom neeg.
1. Yas fluorocarbon yog dab tsi?
Lo lus "fluorocarbon plastic" feem ntau yog hais txog cov polymers uas muaj fluorinated, piv txwv li:
- PTFE (Polytetrafluoroethylene) - hu ua Teflon.
- FEP (Fluorinated Ethylene Propylene) - yooj yim dua rau kev ua dua li PTFE.
– PFA (Perfluoroalkoxy alkane) – tiv taus tshuaj lom neeg/kub siab, yooj yim dua rau kev ua.
- PVDF (Polyvinylidene fluoride) - ua haujlwm tau zoo hauv tshuaj lom neeg thiab muaj zog kho tshuab.
- ETFE (Ethylene tetrafluoroethylene) - muaj zog, tiv taus huab cua, yooj yim rau kev ua.
Ntawm txhua yam, PTFE feem ntau suav hais tias yog "tus qauv kub" rau kev tiv taus tshuaj lom neeg, tab sis nws nyuaj dua rau kev ua vim nws tsis yaj zoo li cov yas thermoplastic ib txwm muaj.
2. Cov ntsiab cai yooj yim ntawm kev ua cov yas fluorocarbon
Feem ntau, cov yas fluorocarbon yog ua los ntawm kev sib xyaw ua ke ntawm cov monomers uas muaj fluorine. Cov monomers feem ntau suav nrog:
- TFE (tetrafluoroethylene) rau PTFE.
- VDF (vinylidene fluoride) rau PVDF.
- Cov khoom sib xyaw ua ke ntawm monomer (piv txwv li TFE nrog HFP/hexafluoropropylene) rau FEP.
Kev ua kom cov polymerization ua tiav los ntawm kev txuas cov monomers rau hauv cov saw ntev siv lub initiator (reaction trigger). Hauv kev lag luam, cov txheej txheem no yuav tsum tau tswj hwm nruj vim tias qee cov fluorine monomers (tshwj xeeb tshaj yog TFE) muaj kev cuam tshuam ntau heev, yooj yim hlawv hauv qee qhov xwm txheej, thiab xav tau cov qauv kev nyab xeeb siab.
> Lus Cim Tseem Ceeb: Cov lus piav qhia hauv qab no yog rau cov ntaub ntawv txog kev xav/kev lag luam thiab tsis yog cov lus qhia siv tau rau hauv tsev. Kev tsim cov tshuaj fluoropolymer yog ua tiav hauv cov chaw tsim tshuaj uas muaj cov kab ke kaw, kev tswj siab/kub, thiab cov txheej txheem kev nyab xeeb nruj.
3. Cov theem dav dav ntawm cov txheej txheem tsim khoom (piv txwv li: PTFE)
3.1. Kev npaj cov monomers thiab cov tshuaj tiv thaiv
Yuav ua PTFE, cov khoom xyaw tseem ceeb yog TFE (C₂F₄). Hauv kev lag luam, TFE feem ntau yog muab los ntawm kev huv siab thiab khaws cia rau hauv qhov chaw nyab xeeb (kev tswj siab thiab kub) kom tiv thaiv kev tsis haum tshuaj.
PTFE polymerization feem ntau siv cov emulsion lossis suspension system hauv dej, vim tias:
- Dej pab tswj qhov kub ntawm cov tshuaj tiv thaiv (cov tshuaj tiv thaiv polymerization tsim cua sov).
- Pab tswj qhov loj ntawm cov khoom polymer.
- Txo qhov xav tau cov organic solvents.
3.2. Kev ua kom cov emulsion/suspension polymerization
Muaj ob txoj hauv kev tseem ceeb:
1. Kev sib xyaw ua ke ntawm cov khoom siv emulsion
TFE monomer raug dispersed hauv dej nrog kev pab los ntawm surfactant (emulsifier) los tsim cov khoom me me uas loj hlob mus rau hauv PTFE latex. Txoj kev no yog siv dav los tsim cov khoom PTFE zoo heev uas tsim nyog rau kev txheej lossis kev sib kis.
2. Kev ncua polymerization
Tsim cov khoom PTFE loj dua (granular). Cov khoom granular feem ntau siv rau kev molding thiab sintering.
Hauv ob txoj kev no, tus neeg pib ua kom muaj zog (piv txwv li, persulfate) yog siv los pib cov tshuaj tiv thaiv polymer. Cov tshuaj tiv thaiv no tshwm sim hauv lub tshuab ua kom muaj zog nrog kev tswj qhov kub kom meej kom ntseeg tau tias qhov nrawm ntawm cov tshuaj tiv thaiv ruaj khov thiab qhov zoo ntawm polymer zoo ib yam.
3.3. Kev sib cais thiab ntxuav cov polymers
Thaum polymerization tiav lawm, PTFE raug cais tawm ntawm cov dej nruab nrab. Yog tias nws nyob rau hauv daim ntawv latex, coagulation (coagulation) yog ua tiav, ces:
- ntxuav kom tshem tawm cov surfactant/initiator seem,
– lim thiab ziab.
Kev ntxuav zoo yog qhov tseem ceeb kom ntseeg tau tias cov khoom siv hluav taws xob, kev huv si, thiab kev ua haujlwm tshuaj lom neeg ntawm PTFE.
3.4. Kev ua cov khoom (molding thiab sintering)
PTFE yog qhov tshwj xeeb uas nws tsis tuaj yeem ua tiav los ntawm cov txheej txheem txhaj tshuaj ib txwm muaj xws li polyethylene, vim nws tsis ntws ua cov kua nplaum thaum lub sijhawm cua sov ib txwm muaj. Yog li ntawd, cov txheej txheem hauv qab no feem ntau siv:
- compression molding (hmoov compaction),
- ces sintering (tswj cua sov saum ib qho chaw hloov pauv) kom cov khoom me me sib xyaw ua ib qho khoom khov.
Rau lwm yam fluoropolymers xws li FEP thiab PFA, kev ua cov thermoplastic yooj yim dua (tuaj yeem extruded lossis txhaj tshuaj) ua rau nws tsim nyog rau cov kav dej, zaj duab xis thiab cov txheej cable.
4. Cov yam ntxwv uas txiav txim siab cov khoom ntawm cov yas fluorocarbon
Cov khoom zoo dua ntawm fluorocarbons tshwm sim los ntawm qhov tshwj xeeb ntawm C-F daim ntawv cog lus thiab cov qauv polymer:
- Kev tiv taus tshuaj lom neeg siab: tiv taus cov kua qaub muaj zog, cov hauv paus, qee cov tshuaj oxidants, thiab cov kuab tshuaj organic.
- Lub zog qis ntawm qhov chaw: tsis lo, nyuaj rau ntub (hydrophobic / oleophobic).
- Ruaj khov thaum kub siab: qee qib tuaj yeem ua haujlwm ntawm ntau pua degrees Celsius.
- Cov coefficient qis ntawm kev sib txhuam: zoo rau cov ntawv thov uas xav tau "sliding".
- Cov khoom dielectric zoo: tshwj xeeb tshaj yog PTFE.
- Kev tiv thaiv UV thiab huab cua: ETFE feem ntau siv rau kev siv sab nraum zoov.
Tiam sis kuj muaj cov kev txwv:
- Kim dua.
- Kev ua PTFE nyuaj dua.
– Thaum kub heev (ua kom sov dhau), cov fluoropolymers tuaj yeem lwj, tsim cov pa roj / cov khoom tsis zoo, yog li kev siv yuav tsum ua raws li cov lus qhia.
5. Kev siv cov yas fluorocarbon hauv kev siv tshuaj lom neeg
5.1. Cov kav dej, cov hoses, thiab cov ntaub thaiv rau cov tshuaj lom neeg corrosive
Hauv kev lag luam tshuaj lom neeg, cov kav dej hlau feem ntau xav tau cov ntaub thaiv kom tiv taus xeb. Cov tshuaj fluoropolymers siv ua:
- txheej ntawm cov tank cia kua qaub,
- cov yeeb nkab hloov cov kuab tshuaj,
- cov kav dej rau cov tshuaj lom neeg hnyav,
vim nws tiv taus ntau yam tshuaj xws li sulfuric acid, hydrochloric acid, NaOH, thiab qee cov organic solvents.
5.2. Cov gaskets, O-rings, thiab cov seals ntawm lub reactor
Cov ntsaws ruaj ruaj thiab cov gaskets yog cov khoom tseem ceeb hauv cov tshuab muaj siab / txaus ntshai. PTFE thiab nws cov kev hloov pauv tau siv dav dav li:
- flange gasket,
- lub valve ntim khoom,
- lub foob twj tso kua mis,
vim nws tsis yooj yim puas tsuaj los ntawm cov tshuaj lom neeg thiab tuaj yeem tswj tau kev ua tau zoo ntawm ntau qhov kub thiab txias.
5.3. Cov khoom siv hauv chav kuaj thiab cov cuab yeej siv
Hauv chav kuaj mob, cov fluoropolymers siv rau:
- cov fwj thiab cov thawv coj mus kuaj (tshwj xeeb tshaj yog cov uas muaj kev cuam tshuam ntau heev),
- cov kav dej rau chromatography,
- cov khoom siv valve, cov khoom siv sib txuas thiab cov khoom sib txuas,
vim nws txo qis kev ua qias tuaj thiab kev cuam tshuam nrog cov tshuaj lom neeg.
PTFE kuj tseem siv rau hauv cov hlau nplaum sib nqus ua ib txheej tiv thaiv inert.
5.4. Cov ntaub so ntswg thiab kev lim dej hauv cov txheej txheem tshuaj lom neeg
PVDF thiab PTFE siv dav rau:
- daim nyias nyias lim (microfiltration / ultrafiltration);
- cov ntxaij lim dej rau cov kuab tshuaj thiab cov pa roj,
- lub kaw lus purification,
vim nws ruaj khov hauv tshuaj lom neeg thiab muaj qee yam khoom ntawm qhov chaw uas txhawb nqa kev lim dej.
5.5. Kev lag luam semiconductor thiab tshuaj lom neeg ntub dej
Hauv kev tsim cov khoom siv semiconductor, ntau cov txheej txheem siv cov tshuaj ultrapure thiab corrosive heev. Fluoropolymers siv rau:
– cov kav dej tshuaj lom neeg ultrapure,
- cov tank thiab cov li qub,
- cov khoom uas yuav tsum txo qis "leaching" (kev tso tawm cov pa phem),
vim tias kev huv thiab kev tiv thaiv tshuaj lom neeg yog qhov tseem ceeb heev.
5.6. Txheej tsis lo thiab tiv thaiv xeb
Cov khoom tsis lo ntawm PTFE tsis yog siv rau hauv cov khoom siv hauv tsev xwb, tab sis kuj siv rau hauv:
- cov khoom siv ua haujlwm uas yooj yim ua rau muaj kev puas tsuaj (kev sib sau ua ke),
- cov chutes/hoppers rau cov hmoov tshuaj lom neeg,
- cov khoom uas xav tau kev sib txhuam tsawg,
yog li ntawd cov khoom tsis lo yooj yim thiab kev ntxuav yooj yim dua.
6. Piv txwv ntawm kev xaiv hom fluoropolymer rau cov kev xav tau tshuaj lom neeg
– PTFE: zoo tshaj plaws rau kev tsis muaj tshuaj lom neeg thiab kub siab; tsim nyog rau cov gaskets, linings, labware.
– PFA/FEP: yooj yim dua rau kev ua duab; tsim nyog rau cov raj xa dej uas yooj ywm, cov kav dej, thiab cov khoom siv precision.
- PVDF: muaj zog, tiv taus tshuaj lom neeg, feem ntau siv rau cov ntaub so ntswg, qee cov kav dej ua haujlwm, thiab cov ntawv thov uas xav tau lub zog kho tshuab siab dua.
- ETFE: muaj zog thiab tiv taus huab cua; tsim nyog rau cov chaw sab nraum zoov lossis cov kev xav tau siab.
Kev xaiv cov khoom siv feem ntau yuav xav txog: kev sib xyaw ua ke ntawm cov tshuaj lom neeg, qhov kub thiab txias ua haujlwm, qhov siab, qhov yuav tsum tau ua kom yooj ywm, thiab kev nyab xeeb thiab cov qauv kev cai lij choj.
7. Xaus Lus
Cov yas fluorocarbon yog ua los ntawm kev sib xyaw ua ke ntawm cov fluorinated monomers (xws li TFE lossis VDF) hauv cov txheej txheem kev lag luam uas tswj hwm nruj. Cov khoom siv tau los ntawm kev sib xyaw ua ke ntawm cov khoom zoo tshaj plaws: kev tiv taus tshuaj lom neeg siab, kev ruaj khov kub siab, cov khoom nplua, thiab kev ua haujlwm tsawg. Hauv kev siv tshuaj lom neeg, fluoropolymers ua lub luag haujlwm tseem ceeb hauv cov kav dej thiab cov ntaub thaiv kev xeb, cov gaskets reactor thiab cov ntsaws ruaj ruaj, cov khoom siv hauv chaw kuaj mob, cov ntaub lim dej, thiab txawm tias cov kab ke ultrapure hauv kev lag luam semiconductor.
Yog tias koj xav tau, kuv tuaj yeem hloov kho tsab xov xwm no kom muaj kev txawj ntse ntau dua (piv txwv li tsom mus rau qhov sib txawv ntawm emulsions vs. suspensions, lossis piv PTFE-PFA-FEP rau kev tiv thaiv rau cov npe tshuaj tshwj xeeb), lossis sau ua ib daim ntawv nrog cov lus hais thiab cov ntaub ntawv teev cia.
