Iyini i-Fluoropolymer?

I-fluoropolymer ivamise ukuba yi-olefinic polymer equkethe ama-olefinic monomers ayingxenye noma egcwele ngokugcwele njenge-vinylidene fluoride (CH2¼CF2) kanye ne-tetrafluoroethylene (TFE) (CF2¼CF2).Lawa ma-polymers ambozwe ngemininingwane eminingi kumareferensi amaningi.Ama-polymers ane-fluorinated akhethekile ahlanganisa ama-fluoroethers, ama-fluoroacrylates, nama-fluorosilicones asetshenziswa ngevolumu encane kakhulu kune-olefinic fluoropolymers.

Ama-fluoropolymers ezohwebo ahlanganisa ama-homopolymers nama-copolymers.Ama-homopolymer aqukethe u-99% noma ngaphezulu ngesisindo se-monomer eyodwa kanye no-1% noma ngaphansi ngesisindo senye i-monomer ngokuvumelana nengqungquthela ye-American Society for Testing Materials (ASTM).Ama-copolymers aqukethe ngaphezu kuka-1% noma ngaphezulu ngesisindo sekhonomers eyodwa noma ngaphezulu.Ama-fluoropolymers amakhulu ezentengiselwano asekelwe kuma-monomers amathathu:

I-TFE, i-vinylidene fluoride (VF2), kanye ne-chlorotrifluoroethylene (CTFE) kancane.Izibonelo zama-comonomers zifaka i-perfluoromethyl vinyl ether (PMVE), i-perfluoroethyl vinyl ether (PEVE), i-perfluoropropyl vinyl ether (PPVE), i-hexafluoropropylene (HFP), i-CTFE, i-perfluorobutyl ethylene (PFBE), kanye nama-monomer angavamile njenge-2,2robistri-robistri -4,5-difluoro-1,3-dioxole.

Umthetho omuhle okufanele ukhunjulwe ukuthi ukwandisa okuqukethwe kwe-fluorine kwe-molecule ye-polymer kwandisa ukumelana kwayo kwamakhemikhali ne-solvent, ukumelana nelangabi, kanye ne-photostability;ithuthukisa izici zayo zikagesi ezifana ne-dielectric constant ephansi;yehlisa i-coefficient of friction;inyusa izinga lokuncibilika;kwandisa ukuzinza kwayo okushisayo;futhi yenze buthaka izici zayo zemishini.Ukuncibilika kwama-polymer kuzincibilikisi ngokuvamile kuncipha ngokwandisa okuqukethwe kwe-fluorine ku-molecule.

I-Fluoropolymer Classification

Ukutholwa okudabukisayo kwe-PTFE ngo-1938 ngu-Roy Plunkett we-DuPont Company kwaqala inkathi yama-fluoropolymers.PTFE ithole izinkulungwane zezicelo ngenxa yezakhiwo zayo ezihlukile.Ama-fluoroplastic ahlukahlukene athuthukisiwe kusukela kwatholakala i-PTFE.Izinkampani eziningi zikhiqiza la mapulasitiki emhlabeni jikelele.Ama-fluoropolymers ahlukaniswe abe izigaba ezimbili zama-polymers ane-perfluorinated kanye nengxenye ye-fluorinated polymers.Ama-fluoropolymers ane-perfluorinated angama-homopolymers nama-copolymers we-TFE.Amanye ama-comonomers angase aqukathe inani elincane lezinto ngaphandle kuka-C noma F.

Umlando Wokuthuthukiswa Kwepolymer

I-PTFE ayikwazi ukwakhiwa ngamasu okuncibilikisa ngenxa ye-viscosity yayo ephezulu.Ama-fluoropolymer angancibilika athuthukiswe yi-copolymerization ye-TFE.I-FEP, i-copolymer ye-TFE ne-HFP, inezinga lokushisa eliphansi eliphezulu lokusebenzisa okuqhubekayo kune-PTFE (200 C vs. 260 C) ngenxa yokuwohloka kwezakhiwo zemishini.I-PFA, i-copolymer ye-TFE ene-PPVE noma i-PEVE, inikeza ukuzinza okushisayo, ukuncibilika kokuncibilika kanye nokusetshenziswa okuphezulu okuqhubekayo okunezinga lokushisa elingu-260 C. Kokubili i-FEP ne-PFA kuthathwa njenge-perfluoropolymers.

Ama-copolymers e-ethylene ane-tetrafluoroethylene (ETFE) ne-chlorotrifluoroethylene (ECTFE) anamandla ngomshini kunama-perfluoropolymers, ahambisana nokuhweba kokunciphisa ukumelana kwawo namakhemikhali kanye nezinga lokushisa lokusebenzisa okuqhubekayo kanye nokwenyuka kwe-coefficient of friction.

Ama-amorphous copolymers we-TFE ancibilika kuzincibilikisi ezikhethekile ezine-halogenated futhi angasetshenziswa ezindaweni ezingaphezulu njengesixazululo se-polymer ukuze akhe okokunamathela okuncane.I-coating eyomile imelana cishe namakhemikhali amaningi njenge-PTFE.