Yintoni iFluoropolymer?

I-Fluoropolymer idla ngokuba yi-olefinic polymer equlathe iimonomers zeolefinic ezingaphelelanga okanye ezigutyungelwe ngokupheleleyo ezifana nevinylidene fluoride (CH2¼CF2) kunye ne-tetrafluoroethylene (TFE) (CF2¼CF2).Ezi polymers zigutyungelwe ngokweenkcukacha ezininzi kwiireferensi ezininzi.Iipolymers eziphucukileyo ezikhethekileyo zibandakanya i-fluoroethers, i-fluoroacrylates, kunye ne-fluorosilicones ezisetyenziswa kumthamo omncinci kakhulu kune-olefinic fluoropolymers.

Iifluoropolymers zorhwebo ziquka i-homopolymers kunye ne-copolymers.I-Homopolymers iqulethe i-99% okanye ngaphezulu ngobunzima be-monomer enye kunye ne-1% okanye ngaphantsi ngobunzima benye i-monomer ngokungqinelana ne-American Society for Testing Materials (ASTM).Ii-Copolymers ziqulethe ngaphezulu kwe-1% okanye ngaphezulu ngobunzima bekhonomers enye okanye ngaphezulu.Iifluoropolymers ezinkulu zorhwebo zisekwe kwiimonomers ezintathu:

I-TFE, i-vinylidene fluoride (VF2), kunye ne-chlorotrifluoroethylene encinci (CTFE).Imizekelo ye-comonomers ibandakanya i-perfluoromethyl vinyl ether (PMVE), perfluoroethyl vinyl ether (PEVE), perfluoropropyl vinyl ether (PPVE), hexafluoropropylene (HFP), CTFE, perfluorobutyl ethylene (PFBE), kunye ne monomers exotic ezifana ne-2,2romethylstri- -4,5-difluoro-1,3-dioxole.

Umgaqo omhle wokukhumbula ukuba ukwandisa umxholo we-fluorine we-polymer molekyuli kwandisa imichiza kunye nokuchasana kwe-solvent, ukumelana nomlilo, kunye ne-photostability;iphucula iimpawu zayo zombane ezifana ne-dielectric ephantsi rhoqo;ithoba i-coefficient of friction;inyusa indawo yokunyibilika;kwandisa ukuzinza kwayo kwe-thermal;kwaye buthathaka iimpawu zayo zomatshini.Ukunyibilika kweepolymers kwizinyibilikisi ngokuqhelekileyo kuncipha ngokunyusa umxholo we-fluorine we-molecule.

Ulwahlulo lweFluoropolymer

Ukufunyanwa okubuhlungu kwe-PTFE ngo-1938 nguRoy Plunkett weNkampani yeDuPont yaqala ixesha le-fluoropolymers.PTFE ifumene amawaka ezicelo ngenxa yeepropati zayo ezizodwa.Iintlobo ngeentlobo ze-fluoroplastics ziye zaphuhliswa ukususela ekufumaneni i-PTFE.Iinkampani ezininzi zivelisa ezi plastiki kwihlabathi jikelele.IiFluoropolymers zohlulwe zibe ziindidi ezimbini zeepolymers ezineperfluorinated kunye nenxalenye yefluorinated polymers.I-perfluorinated fluoropolymers zi-homopolymers kunye ne-copolymers ze-TFE.Ezinye ze-comonomers zinokuqulatha isixa esincinci sezinto ngaphandle kwe-C okanye i-F.

Imbali yoPhuhliso lwePolymer

I-PTFE ayinakwenziwa ngobuchule bokunyibilika ngenxa ye-viscosity yayo ephezulu.Iifluoropolymers ezinyibilikayo ziphuhliswe yi-copolymerization ye-TFE.I-FEP, i-copolymer ye-TFE kunye ne-HFP, inomlinganiselo ophantsi ophantsi wokusebenzisa ukushisa okuqhubekayo kune-PTFE (200 C vs. 260 C) ngenxa yokuwohloka kweempawu zomatshini.I-PFA, i-copolymer ye-TFE ene-PPVE okanye i-PEVE, inika ukuzinza kwe-thermal, ukunyibilika kwe-melt kunye nosetyenziso oluqhubekayo oluphezulu lwe-260 C. Zombini i-FEP kunye ne-PFA zibhekwa njenge-perfluoropolymers.

I-copolymers ye-ethylene ene-tetrafluoroethylene (ETFE) kunye ne-chlorotrifluoroethylene (ECTFE) inamandla ngomatshini kune-perfluoropolymers, ihamba kunye nokuthengiswa kokunciphisa ukuchasana kweekhemikhali kunye nokushisa kokusetyenziswa okuqhubekayo kunye nokunyuka kwe-coefficient of friction.

I-amorphous copolymers ye-TFE iyanyibilika kwizinyibilikisi ezikhethekileyo ze-halogenated kwaye zingasetyenziswa kumphezulu njengesisombululo sepolymer ukwenza iingubo ezibhityileyo.Utyabeka olomisiweyo luxhathisa phantse kwiikhemikhali ezininzi njenge-PTFE.