Polytetrafluoroethylene (polytetrafluoroethylene) mwina ndi fluoropolymer yomwe imagwiritsidwa ntchito kwambiri chifukwa ili ndi zinthu zingapo zomwe zimapangitsa kuti ikhale yoyenera pakugwiritsa ntchito mosiyanasiyana.Imasinthasintha kuposa mapaipi ena ofanana ndipo imatha kukana pafupifupi mankhwala onse amakampani
Kutentha kumakhala pafupifupi -330 ° F mpaka 500 ° F, kumapereka kutentha kwakukulu kwambiri pakati pa fluoropolymers.Kuphatikiza apo, ili ndi zinthu zabwino kwambiri zamagetsi komanso kutsika kwa maginito.Ptfe chubu ndiye machubu a labotale omwe amagwiritsidwa ntchito kwambiri komanso ntchito komwe kukana mankhwala ndi kuyera ndikofunikira.PTFEili ndi coefficient yotsika kwambiri ya kukangana ndipo ndi imodzi mwazinthu "zozembera" zomwe zimadziwika
Mawonekedwe:
100% koyera PTFE utomoni
Poyerekeza ndi FEP, PFA, HP PFA, UHP PFA, ETFE, ECTFE, mapaipi osinthika kwambiri a fluoropolymer
Chemical inert, kugonjetsedwa ndi pafupifupi mankhwala onse mafakitale ndi zosungunulira
Wide kutentha osiyanasiyana
Kulowa kochepa
Kumaliza kosalala kopanda ndodo
Chotsitsa chotsika kwambiri
Kuchita bwino kwamagetsi
Zosayaka
Zopanda poizoni
Mapulogalamu:
labotale
Chemical ndondomeko
Kusanthula ndi kukonza zida
Kuwunika kwa umuna
Kutentha kochepa
kutentha kwakukulu
Magetsi
ozoni
Mapangidwe a mamolekyu a PTFE
Polytetrafluoroethylene (PTFE) imapangidwa ndi polymerization ya mamolekyu ambiri a tetrafluoroethylene.
Chithunzi chosavuta cha PTFE sichikuwonetsa mawonekedwe amitundu itatu ya molekyulu.Mu molecular poly(ethylene) yosavuta kwambiri, mpweya wam'mbuyo wa molekyulu umalumikizidwa ndi maatomu a haidrojeni, ndipo unyolowu ndi wosinthika kwambiri - si molekyulu yofanana.
Komabe, mu polytetrafluoroethylene, atomu ya fluorine mu gulu la CF2 ndi lalikulu mokwanira kuti lisokoneze atomu ya fluorine pa gulu loyandikana nalo.Muyenera kukumbukira kuti atomu iliyonse ya fluorine ili ndi mapeyala atatu a ma elekitironi omwe amatuluka
Zotsatira za izi ndikuletsa kuzungulira kwa carbon-carbon single bond.Ma atomu a fluorine amakonda kukonzedwa kuti akhale kutali kwambiri ndi maatomu oyandikana nawo a fluorine.Kuzungulira kumakonda kuphatikizira kugundana kwapawiri pakati pa maatomu a fluorine pafupi ndi maatomu a kaboni - zomwe zimapangitsa kuti kuzungulirako kusakhale kosangalatsa.
Mphamvu yonyansa imatsekereza molekyulu kukhala ndodo, ndipo maatomu a fluorine amapangidwa mozungulira kwambiri - maatomu a fluorine amapangidwa mozungulira mozungulira msana wa kaboni.Zingwe zotsogolazi zidzakanikizidwa pamodzi ngati mapensulo aatali, owonda m'bokosi
Kulumikizana kwapafupi kumeneku kumakhudza kwambiri mphamvu za intermolecular, monga muwona
Mphamvu za Intermolecular ndi malo osungunuka a PTFE
Malo osungunuka a polytetrafluoroethylene amatchulidwa ngati 327 ° C.Izi ndizokwera kwambiri pa polima iyi, kotero payenera kukhala mphamvu zambiri za van der Waals pakati pa mamolekyu
Chifukwa chiyani anthu amati magulu ankhondo a van der Waals ku PTFE ndi ofooka?
Mphamvu yobalalika ya van der Waals imayamba chifukwa cha kusinthasintha kwakanthawi kwa dipoles komwe ma elekitironi omwe ali mu molekyulu amayenda mozungulira.Chifukwa molekyulu ya PTFE ndi yayikulu, mungayembekezere mphamvu yayikulu yobalalika chifukwa pali ma elekitironi ambiri omwe amatha kuyenda.
Zomwe zimachitika ndikuti molekyu ikakula, mphamvu yobalalika imakulirakulira
Komabe, PTFE ili ndi vuto.Fluorine ndi electronegative kwambiri.Zimakonda kumangirira ma electron mu mgwirizano wa carbon-fluorine molimba kwambiri, molimba kwambiri kotero kuti ma elekitironi sangathe kuyenda momwe mukuganizira.Timalongosola mgwirizano wa carbon-fluorine ngati wopanda polarization wamphamvu
Mphamvu za Van der Waals zimaphatikizansopo kuyanjana kwa dipole-dipole.Koma mu polytetrafluoroethylene (PTFE), molekyu iliyonse imazunguliridwa ndi wosanjikiza wa maatomu a fulorini oipitsidwa pang'ono.Pankhaniyi, kuyanjana kokha komwe kungatheke pakati pa mamolekyu ndiko kukana!
Chifukwa chake mphamvu yobalalika ndi yofooka kuposa momwe mukuganizira, ndipo kulumikizana kwa dipole-dipole kumayambitsa kuthamangitsidwa.Nzosadabwitsa kuti anthu amanena kuti van der Waals mphamvu mu PTFE ndi yofooka kwambiri.Simungapeze mphamvu yonyansa, chifukwa chikoka cha mphamvu yobalalika ndi yayikulu kuposa ya mgwirizano wa dipole-dipole, koma zotsatira zake ndikuti mphamvu ya van der Waals imayamba kufooka.
Koma PTFE ili ndi malo osungunuka kwambiri, choncho mphamvu yomwe imagwirizanitsa ma molekyulu iyenera kukhala yamphamvu kwambiri.
Kodi PTFE ingakhale bwanji ndi malo osungunuka kwambiri?
PTFE ndi crystalline kwambiri, m'lingaliro ili pali malo aakulu, mamolekyu ali mu dongosolo lokhazikika.Kumbukirani, mamolekyu a PTFE amatha kuganiziridwa ngati ndodo zazitali.Mitengo iyi idzalumikizana kwambiri
Izi zikutanthauza kuti ngakhale molekyulu ya ptfe singapange dipole zazikulu zosakhalitsa, dipoles zitha kugwiritsidwa ntchito bwino kwambiri.
Ndiye kodi mphamvu za van der Waals mu PTFE ndizofooka kapena zamphamvu?
Ndikuganiza kuti nonse mungakhale olondola!Ngati maunyolo a polytetrafluoroethylene (PTFE) akonzedwa motere kuti pasakhale kukhudzana kwambiri pakati pa maunyolo, mphamvu pakati pawo idzakhala yofooka kwambiri ndipo malo osungunuka adzakhala otsika kwambiri.
Koma m’dziko lenileni, mamolekyu amalumikizana kwambiri.Mphamvu za Van der Waals sizingakhale zamphamvu monga momwe zingakhalire, koma mapangidwe a PTFE amatanthauza kuti amamva bwino kwambiri, kupanga mgwirizano wamphamvu wa intermolecular ndi malo osungunuka kwambiri.
Izi ndizosiyana ndi mphamvu zina, monga mphamvu ya dipole-dipole interaction, yomwe imachepetsedwa ndi nthawi za 23, kapena kawiri mtunda umachepetsedwa ndi nthawi za 8.
Chifukwa chake, kulongedza mwamphamvu kwa mamolekyu ooneka ngati ndodo mu PTFE kumakulitsa mphamvu ya kubalalitsidwa.
The sanali ndodo katundu
Ichi ndichifukwa chake madzi ndi mafuta sizimamatira pamwamba pa PTFE, ndi chifukwa chake mutha kukazinga mazira mu poto yophimbidwa ndi PTFE popanda kumamatira poto.
Muyenera kuganizira mphamvu zomwe zingakonze mamolekyu ena pamwamba pakePTFE.Itha kuphatikizira mtundu wina wa ma chemical bond, van der Waals force kapena hydrogen bond
Kugwirizana kwa Chemical
Chomangira cha carbon-fluorine ndi champhamvu kwambiri, ndipo sikutheka kuti mamolekyu ena aliwonse afikire muzitsulo za carbon kuti apangitse kusintha kulikonse.Sizingatheke kuti mgwirizano wa mankhwala uchitike
van der Waals forces
Tawona kuti mphamvu ya van der Waals mu PTFE siili yolimba kwambiri, ndipo idzangopangitsa PTFE kukhala ndi malo osungunuka kwambiri, chifukwa mamolekyu ali pafupi kwambiri kotero kuti amalumikizana kwambiri.
Koma ndizosiyana ndi mamolekyu ena pafupi ndi pamwamba pa PTFE.Mamolekyu ang'onoang'ono (monga mamolekyu amadzi kapena mamolekyu amafuta) amangolumikizana pang'ono ndi pamwamba, ndipo kukopa kochepa chabe kwa van der Waals kudzapangidwa.
A lalikulu molekyulu (monga mapuloteni) sadzakhala ndodo woboola pakati, kotero palibe zokwanira ogwira kukhudzana pakati pa izo ndi pamwamba kugonjetsa otsika polarization chizolowezi PTFE.
Mulimonsemo, mphamvu ya van der Waals pakati pa pamwamba pa PTFE ndi zinthu zozungulira ndizochepa komanso zosagwira ntchito.
Zomangira za haidrojeni
Mamolekyu a PTFE pamwamba amakutidwa ndi maatomu a fluorine.Ma atomu a fluorinewa ali ndi mphamvu yamagetsi kwambiri, kotero onse amakhala ndi vuto linalake.Fluorine iliyonse ilinso ndi ma 3 awiriawiri a ma elekitironi omwe amatuluka
Izi ndizomwe zimafunikira kuti apange ma hydrogen bond, monga awiri okha pa fluorine ndi atomu ya haidrojeni m'madzi.Koma izi mwachiwonekere sizichitika, mwinamwake padzakhala kukopa kwakukulu pakati pa mamolekyu a PTFE ndi mamolekyu amadzi, ndipo madzi adzamamatira ku PTFE.
Chidule
Palibe njira yothandiza kuti mamolekyu ena azitha kugwirizanitsa pamwamba pa PTFE, kotero ili ndi malo osakhala ndodo.
Kukangana kochepa
Coefficient of friction ya PTFE ndiyotsika kwambiri.Izi zikutanthauza kuti ngati muli ndi pamwamba yokutidwa ndi ptfe, zinthu zina mosavuta kutsetsereka pa izo.
Pansipa pali chidule cha zomwe zikuchitika.Izi zimachokera ku pepala la 1992 lotchedwa "Friction and Wear of Polytetrafluoroethylene".
Kumayambiriro kwa kutsetsereka, ndi PTFE pamwamba yoswa ndi misa anasamutsa kulikonse kumene kutsetsereka.Izi zikutanthauza kuti PTFE pamwamba adzavala.
Pamene kutsetsereka kunkapitirira, midadadayo inafutukuka kukhala mafilimu oonda.
Panthawi imodzimodziyo, pamwamba pa PTFE imatulutsidwa kuti ikhale yosanjikiza.
Malo onse awiri omwe amalumikizana tsopano ali ndi mamolekyu opangidwa bwino a PTFE omwe amatha kusenderana.
Pamwambapa ndi kumayambiriro polytetrafluoroethylene, polytetrafluoroethylene zikhoza kukhala zosiyanasiyana mankhwala, ndife apadera kupanga ptfe chubu,opanga payipi ptfe, mwalandiridwa kulankhula nafe
Zosaka zokhudzana ndi ptfe hose:
Nthawi yotumiza: May-05-2021