Mokhoa oa ho Etsa Plastiki ea Fluorocarbon le Tšebeliso ea Eona Litšebelisong tsa Lik'hemik'hale
Lipolasitiki tsa fluorocarbon ke sehlopha sa lipolasitiki tse nang le palo e kholo ea litlamo tsa carbon-fluorine (C-F). Litlamo tsa C-F li tsejoa li le matla haholo ebile li tsitsitse, li fa mofuta ona oa polasetiki khanyetso e ntle ea lik'hemik'hale, khanyetso ea mocheso, le thepa e sa khomareleng. Ka lebaka la litšobotsi tsa tsona tse ikhethang, li-fluorocarbon li sebelisoa haholo liindastering tsa lik'hemik'hale, petrochemical, meriana, semiconductor le lilaboratori tsa lipatlisiso. Sengoloa sena se tšohla ts'ebetso ea tlhahiso ea lipolasitiki tsa fluorocarbon (ka bobeli ka khopolo le ka indasteri) le ts'ebeliso ea tsona lits'ebetsong tsa lik'hemik'hale.
1. Plastiki ea fluorocarbon ke eng?
Poleloana "polasetiki ea fluorocarbon" hangata e bolela li-polymer tse nang le fluorine, mohlala:
– PTFE (Polytetrafluoroethylene) – e tsejoang e le Teflon.
– FEP (Fluorinated Ethylene Propylene) – ho bonolo ho e sebetsana ho feta PTFE.
– PFA (Perfluoroalkoxy alkane) – e hanelang lik'hemik'hale/mocheso o phahameng, e bonolo ho e sebetsana.
– PVDF (Polyvinylidene fluoride) – e hanyetsa lik'hemik'hale hantle le matla a mechini.
– ETFE (Ethylene tetrafluoroethylene) – e matla, e hanela maemo a lehodimo, e bonolo ho e sebetsana.
Har'a tsohle, PTFE hangata e nkoa e le "tekanyetso ea khauta" bakeng sa ho hanyetsa lik'hemik'hale, empa ho thata haholo ho e sebetsana hobane ha e qhibilihe joaloka polasetiki e tloaelehileng ea thermoplastic.
2. Melao-motheo ea motheo ea ho etsa polasetiki ea fluorocarbon
Ka kakaretso, polasetiki ea fluorocarbon e etsoa ka ho polymerization ea li-monomer tse nang le fluorine. Li-monomer tse tloaelehileng haholo li kenyelletsa:
– TFE (tetrafluoroethylene) bakeng sa PTFE.
– VDF (vinylidene fluoride) bakeng sa PVDF.
– Metswako ya monomer (mohlala, TFE e nang le HFP/hexafluoropropylene) bakeng sa FEP.
Ho etsa polymerization ho etswa ka ho hokahanya di-monomer ka diketane tse telele ho sebediswa seqadi (reaction trigger). Diindastering, tshebetso ena e hloka taolo e tiileng hobane di-monomer tse ding tsa fluorine (haholoholo TFE) di arabela haholo, di kgona ho tuka tlasa maemo a itseng, mme di hloka maemo a phahameng a polokeho.
> Ntlha ea bohlokoa: Tlhaloso e latelang ke ea tlhahisoleseling ea khopolo-taba/ea indasteri eseng tataiso e sebetsang bakeng sa tšebeliso ea lapeng. Tlhahiso ea fluoropolymer e etsoa libakeng tsa lik'hemik'hale tse nang le litsamaiso tse koetsoeng, taolo ea khatello/mocheso, le litsamaiso tse tiileng tsa polokeho.
3. Mehato e akaretsang ea ts'ebetso ea tlhahiso (mohlala: PTFE)
3.1. Ho lokisoa ha li-monomer le mecha ea karabelo
Ho etsa PTFE, motsoako o ka sehloohong ke TFE (C₂F₄). Indastering, TFE hangata e fanoa ka bohloeki bo phahameng mme e bolokoa tlas'a maemo a sireletsehileng (khatello le taolo ea mocheso) ho thibela liketso tse sa laoleheng.
Hangata polymerization ea PTFE e sebelisa sistimi ea emulsion kapa ea ho emisoa ka metsing, hobane:
– Metsi a thusa ho laola mocheso oa karabelo (likarabelo tsa polymerization li hlahisa mocheso).
– E nolofatsa taolo ea boholo ba likaroloana tsa polymer.
– E fokotsa tlhoko ea li-solvents tsa tlhaho.
3.2. Ho etsa polymerization ea emulsion/suspension
Ho na le mekhoa e 'meli e meholo:
1. Polymerization ea emulsion
TFE monomer e qhalanngoa ka metsing ka thuso ea surfactant (emulsifier) ho etsa likaroloana tse nyane tse holang ho ba PTFE latex. Mokhoa ona o sebelisoa haholo ho hlahisa likaroloana tse ntle haholo tsa PTFE tse loketseng ho koaheloa kapa ho hasana.
2. Polymerization ea ho emisoa
E hlahisa dikarolwana tse kgolo tsa PTFE (tse nang le makumane). Dihlahiswa tse nang le makumane hangata di sebediswa bakeng sa ditshebetso tsa ho bopa le ho tjhesa.
Mekhoeng ena ka bobeli, sesebelisoa sa ho qala ka radical (mohlala, persulfate) se sebelisoa ho qala karabelo ea ho thehoa ha ketane ea polymer. Karabelo e etsahala ka har'a reactor e nang le khatello e nang le taolo e nepahetseng ea mocheso ho netefatsa sekhahla se tsitsitseng sa karabelo le boleng bo tsitsitseng ba polymer.
3.3. Karohano le ho hlatswa ha di-polymer
Hang ha polymerization e phethetswe, PTFE e arolwa ho metsi. Haeba e le ka sebopeho sa latex, ho a kwala (ho kwala) ho a etswa, ebe:
– e hlatswitswe ho tlosa masalla a surfactant/initiator,
– e sefiloeng le ho omisoa.
Boleng ba ho hlatsoa bo bohlokoa ho netefatsa thepa ea motlakase, bohloeki le ts'ebetso ea lik'hemik'hale ea PTFE.
3.4. Ho sebetsana le dihlahiswa (ho di bopa le ho di sila)
PTFE e ikhetha ka hore e ke ke ea sebetsoa ka mekhoa e tloaelehileng ea ho enta e kang polyethylene, kaha ha e phalle e le ho qhibiliha ho viscous tlas'a mocheso o tloaelehileng. Ka hona, mekhoa e latelang e sebelisoa hangata:
– ho bopa ka kgatello (ho tiisa phofo),
– ebe ho tjhesa (ho futhumala ho laolwang ho feta ntlha e itseng ya phetoho) e le hore dikarolwana di kopane ho ba ntho e tiileng.
Bakeng sa di-fluoropolymer tse ding tse kang FEP le PFA, ts'ebetso ya thermoplastic e bonolo (e ka ntshwa kapa ya entwa) e leng se etsang hore e lokele diphaephe, difilimi le dikoahelo tsa thapo.
4. Mabaka a khethollang thepa ea polasetiki ea fluorocarbon
Thepa e phahameng ea li-fluorocarbon e hlaha ka lebaka la litšobotsi tse ikhethang tsa tlamo ea C-F le sebopeho sa polymer:
– Ho hanyetsa lik'hemik'hale tse phahameng: ho hanela li-acid tse matla, metheo, li-oxidant tse itseng le li-solvents tsa organic.
– Matla a tlase a bokaholimo: ha a khomarele, ho thata ho a kolobisa (a sa rateng metsi/a sa rateng oleophoofolo).
– E tsitsitse mochesong o phahameng: mefuta e meng e ka sebetsa ho likhato tse makholo tsa Celsius.
– Koefficient e tlase ea khohlano: e ntle bakeng sa lits'ebetso tse hlokang "ho thella".
– Thepa e ntle ea dielectric: haholo-holo PTFE.
– Ho hanyetsa mahlaseli a kotsi a letsatsi le boemo ba leholimo: ETFE hangata e sebelisetsoa tšebeliso ea kantle.
Empa ho boetse ho na le mefokolo:
– E theko e boima haholo.
– Ts'ebetso ea PTFE e rarahane haholo.
– Maemong a mocheso o phahameng haholo (a futhumatsang haholo), li-fluoropolymer li ka senyeha, tsa hlahisa likhase/lihlahisoa tse kotsi, kahoo tšebeliso e tlameha ho latela litlhaloso.
5. Tšebeliso ea polasetiki ea fluorocarbon lits'ebetsong tsa lik'hemik'hale
5.1. Liphaephe, liphaephe le masela a koahelang lik'hemik'hale tse senyang
Indastering ea lik'hemik'hale, liphaephe tsa tšepe hangata li hloka lesela ho thibela ho bola. Li-fluoropolymer li sebelisoa e le:
– lesela la litanka tsa polokelo ea asiti,
– phaephe ea phetisetso ea solvent,
– liphaephe tsa lik'hemik'hale tse matla,
hobane e hanela lintho tse fapaneng tse kang sulfuric acid, hydrochloric acid, NaOH, le di-solvent tse itseng tsa tlhaho.
5.2. Li-gasket, masale a O, le litiiso holim'a reactor
Litiiso le li-gasket ke likarolo tsa bohlokoa lits'ebetsong tse nang le khatello/kotsi. PTFE le mefuta ea eona e sebelisoa haholo e le:
– gasket ea flange,
- ho paka li-valve,
- tiiso ea pompo,
hobane ha e senyehe habonolo ke lik'hemik'hale 'me e ka boloka ts'ebetso ho pholletsa le mocheso o pharaletseng.
5.3. Likarolo tsa laboratori le tsa lisebelisoa
Laboratoring, li-fluoropolymer li sebelisetsoa:
– libotlolo tsa mohlala le lijana (haholo-holo tse arabelang habonolo),
- ho kenya liphaephe bakeng sa chromatography,
– dikarolo tsa di-valve, di-fittings, le dihokelo,
hobane e fokotsa tšilafalo le liketso tse bakoang ke lik'hemik'hale.
PTFE e boetse e sebelisoa ka har'a li-stir bars tsa makenete e le lera le sireletsang le sa sebetseng.
5.4. Mele le ho sefa lits'ebetsong tsa lik'hemik'hale
PVDF le PTFE li sebelisoa haholo bakeng sa:
– lera la ho sefa (ho sefa ka tsela e nyane/ho sefa ka tsela e feteletseng),
– difiltara tsa dihlapolli le dikgase,
- sistimi ea tlhoekiso,
hobane e tsitsitse ka lik'hemik'hale 'me e na le litšobotsi tse itseng tsa bokaholimo tse tšehetsang ho sefa.
5.5. Indasteri ea ts'ebetso ea metsi ea semiconductor le lik'hemik'hale
Tlhahisong ea li-semiconductor, lits'ebetso tse ngata li sebelisa lik'hemik'hale tse hloekileng haholo le tse senyang haholo. Li-fluoropolymer li sebelisoa bakeng sa:
– liphaephe tsa lik'hemik'hale tse hloekileng haholo,
– litanka le li-valve,
– dikarolo tse lokelang ho fokotsa “ho dutla” (ho ntsha ditshila),
hobane bohloeki le ho hanyetsa lik'hemik'hale li bohlokoa haholo.
5.6. Seaparo se sa khomareleng le se thibelang mafome
Thepa e sa khomareleng ea PTFE ha e sebelisoe feela lisebelisoa tsa lapeng, empa hape le ho:
– lisebelisoa tsa ho sebetsana le lintho tse ka bakang litšila (ho bokellana ha tsona),
– li-chute/li-hopper bakeng sa phofo ea lik'hemik'hale,
– dikarolo tse hlokang khanyetso e tlase,
e le hore thepa e se ke ea khomarela habonolo 'me ho hloekisa ho be bonolo.
6. Mohlala oa ho khetha mofuta oa fluoropolymer bakeng sa litlhoko tsa lik'hemik'hale
– PTFE: e molemo ka ho fetisisa bakeng sa ho se sebetse hantle ha lik'hemik'hale le mocheso o phahameng; e loketse li-gasket, linings, labware.
– PFA/FEP: ho bonolo ho e bopa; e loketse diphaephe tse tenyetsehang, diphaephe le dikarolo tse nepahetseng.
– PVDF: e matla, e hanela lik'hemik'hale, e atisa ho sebelisoa bakeng sa lera, liphaephe tse itseng tsa ts'ebetso, le lits'ebetso tse hlokang matla a phahameng a mechini.
– ETFE: e matla ebile e hanela maemo a lehodimo; e loketse dibaka tsa kantle kapa ditlhoko tse phahameng tsa mechini.
Khetho ea thepa hangata e ela hloko: mahloriso a lik'hemik'hale, mocheso oa ts'ebetso, khatello, litlhoko tsa ho tenyetseha, le litekanyetso tsa polokeho le taolo.
7. Qetello
Lipolasitiki tsa fluorocarbon li etsoa ka ho etsa polymerization ea li-monomer tse nang le fluorine (tse kang TFE kapa VDF) ts'ebetsong ea indasteri e laoloang ka thata. Thepa e hlahisoang e na le motsoako oa thepa e phahameng: khanyetso e phahameng ea lik'hemik'hale, botsitso bo phahameng ba mocheso, thepa e thellang, le karabelo e tlase. Ts'ebelisong ea lik'hemik'hale, li-fluoropolymer li bapala karolo ea bohlokoa liphaepheng le li-linings tse thibelang ho bola, li-gasket tsa reactor le litiiso, likarolo tsa lisebelisoa tsa laboratori, li-membrane tsa ho sefa, esita le litsamaiso tse hloekileng haholo indastering ea semiconductor.
Haeba o lakatsa, nka fetola sengoloa sena hore se be sa botekgeniki haholoanyane (mohlala, ho tsepamisa maikutlo liphapang pakeng tsa emulsions khahlanong le li-suspensions, kapa ho bapisa PTFE–PFA–FEP bakeng sa ho hanyetsa lethathamo le itseng la lik'hemik'hale), kapa ho se kopanya e le pampiri e nang le litšupiso le bibliography.
