Amazinga okushisa angaphezu kuka-77°C awahambisani nezingxenye zama-elastomer amaningi namapulasitiki, kuyilapho i-PTFE imelana namazinga okushisa afinyelela ku-260°C.Ngisho nangaphansi kuka-77°C, uma ama-asidi agqwala ezinsimbini nasezincibilikisini eziphilayo kuhlangene, amalayini nezingxenye ze-PTFE kuvame ukuthandwa ngenxa yokuthi ama-elastomer namanye amapulasitiki avame ukuntula ukumelana nokuvuvukala kwe-solvent kanye nokuthamba.
Ngokungangeni kweKhemikhali, siqonde lokhoI-PTFEIzinhlayiya ze-fluorocarbon zingathintana ngokuqhubekayo nenye into ngaphandle kokusabela kwamakhemikhali okubonakalayo okwenzekayo.Ngokuvamile, i-PTFE fluorocarbon resins ayisebenzi ngamakhemikhali.Noma kunjalo, lesi sitatimende, njengawo wonke ama-generalizations, kufanele sifaneleke uma sizonemba ngokuphelele.Iziqu ngeke ziholele ekudidekeni, noma kunjalo, uma umuntu egcina engqondweni amaqiniso ayisisekelo mayelana nokuziphatha kwe-PTFE resins.
Isifinyezo esijwayelekile sencazelo yedatha yokuhlola ehlukahlukene singase sidukise, ngoba singase sihlangane ngokuyisisekelo izinhlobo ezihlukene zokuziphatha "Kwekhemikhali".Uma incazelo izoba sobala, kufanele ihlukanise phakathi kokusabela kwamakhemikhali ngokuqinile kanye nezenzo zomzimba njengokumuncwa.Incazelo kufanele ivumele umsebenzisi ukuthi acabangele ukuhlobana kwezakhiwo zomzimba namakhemikhali okungase kuthinte uhlelo oluthile.
Isibonelo, ama-PTFE resins ngeke athintwe ukucwiliswa ku-aqua regia.Kodwa uma izinga lokushisa kanye nokucindezela okuwumphumela kwalesi siphepho kuba phezulu, ukumuncwa kwezingxenye ze-reagent ku-resin nakho kuzokwanda.Ukushintshashintsha okulandelayo, njengokuncipha kwengcindezi kungazelelwe, kungase kube yingozi emzimbeni ngenxa yokwanda kwezihwamuko ezimuncwe kunhlaka.Ngokusobala-ke, uma sikhuluma ngezakhiwo zamakhemikhali ze-PTFE kufanele sihlukanise phakathi kokusabela kwamakhemikhali ngokuqinile, njengoba sizwakalise “ngokuhambisana kwamakhemikhali” nezenzo zomzimba, njengokuthi “ukumuncwa” kuhlanganiswe nokucindezeleka kwemishini nokushisa.
Ngaphakathi kwamazinga okushisa okusetshenziswa okuvamile, ama-resin e-PTFE ahlaselwa amakhemikhali ambalwa kunokuba adwebe amakhemikhali ahambisana nawo.Lawa ma-reactants aphakathi kwama-oxidizer anodlame kakhulu nama-ejenti anciphisayo aziwayo.I-sodium ye-elemental ekuxhumaneni okuseduze nama-fluorocarbons isusa i-fluorine ku-molecule ye-polymer.Lokhu kusabela kusetshenziswa kakhulu ezixazululweni ezingenamanzi ukuze kuqoshwe indawo engaphezulu ye-PTFE ukuze ama-resin akwazi ukunamathela.Ezinye izinsimbi ze-alkali (i-potassium, i-lithium, njll.) zenza ngendlela efanayo.
Izingxube ezisondelene zezimpushana zensimbi ezihlukaniseke kahle (isb., i-aluminium noma i-magnesium) nezinsalela eziyimpuphu ze-fluorocarbon zingasabela ngobudlova lapho zivutha, kodwa amazinga okushisa angaphezulu kakhulu kwezinga lokushisa eliphezulu elishicilelwe elinconyiwe lezinhlaka ze-PTFE.Ama-oxidizer anamandla ngokwedlulele, i-fluorine (F2) nezinhlanganisela ezihlobene (isb, i-chlorine trifluoride, i-CIF3), ingaphathwa yi-PTFE kuphela ngokunakekela okukhulu nokuqaphela izingozi ezingaba khona.I-fluorine imuncwa kuma-resin, futhi ngokuthintana okusondelene okunjalo ingxube iba bucayi emthonjeni wokuthungela njengomthelela.
Kwezinye izimo at noma eduze kwamazinga okushisa omkhawulo wesevisi ophakanyisiwe angu-260°C we-TFE & PFA, kanye no-204°C we-FEP, amakhemikhali ambalwa ekugxilweni okuphezulu abikwe asebenza ku-PTFE.Ukuhlasela okufana ne-sodium etch kuye kwakhiqizwa emazingeni okushisa aphezulu kangaka ngo-80% we-NaOH noma i-KOH, ama-hydrides ensimbi afana ne-boranes (isb, i-B2H6), i-aluminium chloride, i-ammonia (NH3), kanye nama-amine athile (R-NH2) kanye nemines ( R = NH).Futhi, ukuhlasela okuhamba kancane kwe-oxidative kuye kwabonwa ngu-70% we-nitric acid ngaphansi kwengcindezi engu-250°C.Ukuhlolwa okukhethekile kuyadingeka lapho izimo ezinjalo ezeqisayo zokunciphisa noma ze-oxidizing kusondela.
Ngakho-ke, ngaphandle kwalokho njengoba kuphawuliwe, ama-PTFE resins abonisa ububanzi obubanzi bamakhemikhali nokusebenza okushisayo.Kodwa umthengi noma isicacisi sezingxenye ze-PTFE futhi udinga ukwazi nokuqonda imikhawulo yayo maqondana nezimo ezijwayelekile zamakhemikhali.Ngokungafani nomkhawulo wezinsimbi, lezi ngokuvamile azithengwa ngamakhemikhali ngokwemvelo.Imiphumela yokushisa, ingcindezi, nokumuncwa kwamakhemikhali ku-PTFE, kanye nokusebenzisana kwawo, yilokho ngokuhamba kwesikhathi ngokuvamile okukhawulela izimo lapho i-PTFE izokwenza ngokugculisayo.Njengoba lokhu kuhluke cishe kunoma iyiphi enye impahla yokwakha, kudinga ukucatshangelwa ngokucophelela kwezincazelo ezinemininingwane eyengeziwe ezilandelayo.
Isikhathi sokuthumela: Oct-04-2019