Yintoni i-PTFE(Polytetrafluoroethylene)?

I-Polytetrafluoroethylene (PTFE) yipolymer yekhabhoni kunye nefluorine. Esi sixhobo sinegama eliqhelekileyo: iTeflon.

Iimpawu zePTFE ziquka:

• Iipropati ezigqwesileyo zoomatshini (<1%)

• Ikhemikhali inertness ukubola ukumelana

• Ukumelana nobushushu

• Ezona coefficients ezisezantsi zokukhuhlana

• Iimpawu ezingezizo intonga (zimelana namaqondo obushushu aqhubekayo angama-500°f (260°c))

• Ukunxiba ukuxhathisa

• Indawo yokunyibilika ephezulu

Iipropati ezigqwesileyo ze-PTFE zinika uluhlu olubanzi lwezicelo, kwaye iqhele ukusetyenziswa njenge-non-stick yokwambathisa kwi-cookware. I-PTFE yokumelana nokunxiba ngcono ivumela ukuba idityaniswe nezinto ezahlukeneyo nge-emulsion polymerization okanye i-polymerization processing yokumiswa ukuze yenze iimveliso zemizi-mveliso ezikwaziyo ukumelana ne-thermal ezineempawu ezigqwesileyo zoomatshini, ezifana nokugqunyelelwa kocingo, amabhanti okuhambisa okutya, amalaphu athambileyo angabambekiyo, njl.

Yintoni i-PTFE?

I-Polytetrafluoroethylene yafunyanwa ngo-1938. Yafunyanwa kuqala ngusokhemisti waseMelika u-Roy J. Plunkett (1910-1994) xa wayezama ukwenza ikhabhoni entsha kunye ne-fluorine compound efrijini. Abantu ngelo xesha bebengayi kucinga ngale mveliso iqhelekileyo. Ii-catalysts ezingaqhelekanga ziya kuchaphazela zonke iinkalo zehlabathi.

Ngo-1941, iDuPont yafumana ipatent yale mveliso yaza yabhalisa uphawu lwentengiso phantsi kwegama 'Teflon' ngo-1944.

Namhlanje, i-polytetrafluoroethylene isetyenziswa ngokubanzi kwiinkalo ezininzi zemveliso kunye nobomi. Kushishino lokutya, i-PTFE coated cookware isetyenziswa kakhulu; kwishishini lempahla, iimpahla eziphezulu ezibandayo ezisuka kwiimpawu ezifana ne-HELIKON kunye neCarinthia zonke zisebenzisa i-PTFE njengengubo okanye umaleko wangaphandle. , ukuze ufezekise ukukwazi ukumelana nokubanda okukhulu kwe -30 ° C; kwintsimi yomkhosi, izixhobo ze-PTFE ezinelahleko ephantsi, iipropathi ezigqwesileyo zedielectric, ukungaguquguquki okuhle, iipropathi zekhemikhali ezizinzileyo, kwaye phantse akukho kufunxa ukufuma zisetyenziswa ngokubanzi kwiiphaneli zeradar yamaza kanomathotholo aphezulu. Kwicandelo lezonyango, izinto ze-PTFE nazo zisetyenziswa ngokubanzi kumalungu omzimba okwenziwa.

Imele ntoni i-PTFE?

I-PTFE imele i-polytetrafluoroethylene, igama lekhemikhali le-polymer (C2F4)n.

Esi sixhobo sibhekisa ngokubanzi kuyo nayiphi na ibranded ptfe synthetic fluoropolymer. Iimpawu eziphambili zepolytetrafluoroethylene zezi zilandelayo:

• Elona qondo lobushushu bokusebenza (°F /°C): 500/260

• Amandla okuqina ngexesha lekhefu (PSI): 4,000

• Idielectric constant (kV/mil): 3.7

• Umlinganiselo: 2.16

• Ukwandiswa ngexesha lekhefu: 350%

• Unxweme D Ukuqina: 54

I-ptfe esetyenziswa kakhulu i-polytetrafluoroethylene synthetic fluoropolymer eneempawu ezingentla sele ineempawu ezingenakubalwa, iibrendi eziphambili zezi zilandelayo:

• I-TEFLON®: IiChemours

• FLUON®: AGC Ltd

• I-DYNEON®: 3M

• IPOLYFLON: iDaikin Industrial Co., Ltd.

• I-ALGOFLON: I-Solvay Ltd.

  
  

Ulwakhiwo lweMichiza ye-PTFE

I-Polytetrafluoroethylene yi-polymer yomgca eyenziwe nge-carbon (C) kunye ne-fluorine (F) athom, kunye ne-chemical formula (C2F4) n, apho i-n inani leeyunithi ze-monomer.

Ubume be-PTFE bunokuchazwa ngolu hlobo: -CF2-CF2-CF2-CF2-

Itsheyini elide leeathom ze-PTFE zenziwe ngeeathom zekhabhoni, nganye kuzo idityaniswe kwiiathom ezimbini zefluorine.

Iiathom zeFluorine ziphantse zigqume umphezulu weeathom zekhabhoni zekhonkco lepolymer elijikelezayo. Iiathom zekhabhoni zenza ikhonkco eliphambili letsheyini yepolymer. Iiathom zefluorine zenza i-shield-like structure ejikeleze iiathom zekhabhoni, ezikhusela kakuhle iiathom zekhabhoni zangaphakathi.

Olu lungiselelo lulodwa lweeathom lunika i-PTFE iimpawu zayo ezikhethekileyo. Olu lwakhiwo lwemolekyuli lunegalelo kwi-PTFE engenakulinganiswa neempawu zomzimba neekhemikhali.

Yintoni iTeflon Material?

Ngaba iTeflon PTFE

Ngokuqinisekileyo, iTeflon yimathiriyeli yepolymer eyenziwe yi-tetrafluoroethylene kwaye luhlobo lwemathiriyeli ene-perfluorinated. Igama layo lekhemikhali yi-polytetrafluoroethylene (PTFE).

Isakhiwo sekhemikhali yeTeflon sihluke kakhulu. Ubume bemolekyuli kukuba uF (iathom zefluorine) uthatha indawo yazo zonke ii-H (iathom zehydrogen) kwikhonkco likaC. Kwangaxeshanye, ngenxa yokuba iradiyasi yeathom fluorine mkhulu kakhulu kuneradiyasi ye-athom yekhabhoni, repulsion phakathi athom inkulu kakhulu, ngoko ke akuyi Like iiathom hydrogen, zinokulungiswa kwinqwelomoya, ngoko ke iiathom fluorine phantse spiral up ukusonga athom zekhabhoni, ukuze ihlabathi langaphandle anokuhlangana kuphela inert inert kunye nefluorine.

Ngomqobo oqinileyo we-athomu ye-fluorine, i-Teflon polymer isakhiwo sizinzileyo xa kuthelekiswa nezinye izinto.

Iipropati zeTeflon

I-PTFE yipolymer eyenziwe yi-tetrafluoroethylene monomer. I-wax ecacileyo okanye i-opaque efana ne-PE. Ubuninzi bayo buyi-2.2g / cm3 kwaye izinga lokufunxa kwamanzi lingaphantsi kwe-0.01%.

Ubume bemichiza ye-PTFE ipholima iyafana naleyo ye-PE, ngaphandle kokuba zonke iiathom ze-hydrogen kwi-polyethylene zithathelwa indawo zii-athom ze-fluorine. Ngenxa yamandla ebhondi ephezulu kunye nokusebenza okuzinzileyo kwe-CF bond, inokumelana nekhemikhali egqwesileyo kwaye inokumelana nazo zonke iiasidi ezomeleleyo (kubandakanywa ne-aqua regia) ngaphandle kweentsimbi ezinyibilikisiweyo zealkali, imidiya ye-oxidizing, kunye ne-sodium hydroxide engaphezu kwe-300 ° C. Kanye nemiphumo yee-oxidants ezinamandla, ii-agent zokunciphisa kunye neentlobo ezahlukeneyo ze-solvents eziphilayo.

I-athomu ka-F kwimolekyuli ye-PTFE i-symmetrical, kwaye izinto ezimbini kwi-CF bond zibotshwe ngokudibeneyo. Akukho zi-electron zamahhala kwi-molecule, okwenza yonke i-molecule ingathathi hlangothi. Ngoko ke, ineempawu ezibalaseleyo ze-dielectric, kwaye ukufakwa kwayo kombane akuchaphazeli Impembelelo yendalo kunye nokuphindaphinda.

Teflon Physical Properties

Umthamo wayo wokumelana nomthamo mkhulu kune-1017, ilahleko yayo ye-dielectric incinci, i-voltage yayo yokuphuka iphezulu, ukumelana kwayo kwe-arc kulungile, kwaye inokusebenza kwindawo yombane ye-250 ° C. Ngenxa yokuba akukho zibophelelo ze-hydrogen kwi-PTFE isakhiwo se-molecular, isakhiwo sinomlinganiso, ngoko ke icrystallization yayo Iqondo le-crystallization liphezulu kakhulu (ngokubanzi i-crystallinity yi-55% ~ 75%, ngamanye amaxesha iphakamileyo njenge-94%), eyenza i-PTFE ikwazi ukumelana nobushushu. Ubushushu bayo bokunyibilika bungama-324C, ubushushu bayo bokubola bungama-415°C, kwaye ubushushu bayo obuphezulu bokusetyenziswa yi-250°C. I-brittle Iqondo lokushisa yi-190 ° C, kunye neqondo lokushisa lokushisa (phantsi kweemeko ze-0.46MPa) yi-120C.

Izinto zeTeflon zineempawu ezintle zoomatshini. Amandla ayo okuqina yi-21 ~ 28MPa, amandla okugoba yi-11 ~ 14MPa, ubude yi-250% ~ 300%, kwaye i-coefficients yayo eguquguqukayo kunye ne-static friction ngokumelene nentsimbi zombini ziyi-0.04, engcono kune-nylon, i-polyformaldehyde, kunye ne-polyethylene. I-coefficient of friction yeeplastiki ezipholileyo zincinci.

I-PTFE esulungekileyo inamandla aphantsi, ukuxhathisa okulambathayo kunye nokuxhathisa okungahambi kakuhle. Ngokuqhelekileyo kuyimfuneko ukongeza iincinci ze-inorganic kwi-polymer ye-PTFE, njenge-graphite, iqela le-disulfide, i-aluminium oxide, i-glass fiber, i-carbon fiber, njl. , kwaye inokwandiswa ngokusebenzisana nezinye iipolymers ezifana ne-polyphenylase (PHB), i-polyphenylene sulfide (PFS), i-polyethylene glycol (PEEK), i-polyethylene / propylene copolymer (PFEP), njl njl.

Yenziwa njani iTeflon

Inkqubo yokuvelisa isebenzisa i-chloroform njengento eluhlaza, isebenzisa i-anhydrous hydrofluoric acid kwi-fluorinate chloroform, ubushushu bokusabela bungaphezulu kwe-65ºC, isebenzisa i-antimony pentachloride njenge-catalyst, kwaye ekugqibeleni isebenzisa ukuqhekeka kwe-thermal ukuvelisa i-tetrafluoroethylene.

I-Aokai iveliswa ngokusebenzisa i-polymerization yokumiswa okanye i-emulsion polymerization.

1. Ukulungiswa kwe-monomer tetrafluoroethylene

Kwimizi-mveliso, i-chloroform isetyenziswa njengezinto eziluhlaza, i-anhydrous hydrofluoric acid isetyenziselwa i-fluorinate chloroform, ubushushu bokusabela bungaphezulu kwe-65ºC, i-antimony pentachloride isetyenziswa njenge-catalyst, kwaye ekugqibeleni i-tetrafluoroethylene iveliswa ngokuqhekeka kwe-thermal. I-Tetrafluoroethylene inokuphinda iveliswe ngokusabela kwe-zinc kunye ne-tetrafluorodichloroethane kumaqondo obushushu aphezulu.

1. Ukulungiswa kwe-polytetrafluoroethylene

Kwi-enamel okanye insimbi engenasici ye-polymerization kettle, amanzi asetyenziswa njengento ephakathi, i-potassium persulfate isetyenziswa njenge-initiator, i-perfluorocarboxylic acid ammonium ityuwa isetyenziswa njenge-dispersant, i-fluorocarbon isetyenziswa njenge-stabilizer, kunye ne-tetrafluoroethylene i-redox i-polymerized ukufumana i-polyethylene yomgubo ocolekileyo. Tetrafluoroethylene.

Yongeza izongezo ezahlukeneyo kwi-kettle yokusabela, kwaye i-tetrafluoroethylene monomer ingena kwi-polymerization kettle kwisigaba segesi. Lungisa iqondo lokushisa kwi-kettle ukuya kwi-25 ° C, uze ungeze inani elithile le-activator (i-sodium metabisulfite) ukuqalisa i-polymerization ngokusebenzisa inkqubo ye-redox. Ngethuba lenkqubo ye-polymerization, ii-monomers zongezwa ngokuqhubekayo, kwaye uxinzelelo lwe-polymerization lugcinwe kwi-0.49 ~ 0.78MPa. Ukusasazwa okufunyenwe emva kokwenziwa kwepolymerization kuhlanjululwe kugxininiso oluthile ngamanzi, kwaye ubushushu buhlengahlengiswa ukuya kwi-15 ~ 20ºC. Emva kokudibanisa kunye nokuvuselela oomatshini, ihlanjwe ngamanzi kwaye yomiswe, oko kukuthi, Le mveliso ifunyenwe njenge-resin granular resin.

Ngaba iTeflon ikhuselekile?

I-Teflon yokugqoka ngokwayo ikhuselekile: I-Teflon impahla ngokwayo ayinayo ityhefu, ayiyi kubola, kwaye ayiyi kubangela iingozi zempilo. Oku mhlawumbi kungenxa yokuba imolekyuli yayo ayinyibiliki kwiikhemikhali zokwenyani, singasathethi ke ngokutyiswa nokufunxwa ngumzimba womntu.

Funda ngakumbi malunga nokhuseleko lweTeflon

Isetyenziselwa ntoni i-PTFE?

I-PTFE imathiriyeli ineyona ngcinezelo incinci yomphezulu phakathi kwemathiriyeli eqinileyo kwaye ayibambeleli kuyo nayiphi na into. Ikwanayo neempawu zokumelana nobushushu obuphezulu kunye nomgangatho ophantsi kunye nokungasebenzi kweekhemikhali, okwenza ukuba ilungele izicelo ezifana nokuvelisa. Iipani ezinganamatheli zisetyenziswa ngokubanzi kwizicelo ezichasene neentonga. Inkqubo echasene nokuncamathelisa ikakhulu ibandakanya iindidi ezimbini: ukufaka iphepha le-PTFE kwi-substrate kunye nokubeka I-PTFE yokwambathisa okanye ivanishi edityaniswe ngeglasi kwi-substrate ngokuncipha kobushushu.

Funda ngakumbi malunga neengubo ze-PTFE

Nangona izixhobo ze-PTFE zisenengxaki yobunzima obuphezulu kwi-welding, kunye nokuqhubela phambili kwethekhnoloji, iindlela ezintsha zokudibanisa ziza kusombulula ngokukhawuleza iintlungu ze-PTFE kwaye zisebenzise i-PTFE kuluhlu olubanzi lweenkalo.