Kev tsim khoom ntawm PTFE

Tetrafluoroethylene tau npaj thawj zaug hauv xyoo 1933. Cov khoom siv ua lag luam tam sim no yog ua los ntawm fluorspar, sulfuric acid thiab chloroform.

Txheej txheem txheej txheem ntawm PTFE Polymer:

Kev tsim khoom ntawm PTFE Polymer / Resin yog ua tiav hauv ob theem.Ua ntej, TFE Monomer feem ntau yog tsim los ntawm kev sib txuas ntawm Calcium Fluoride (Fluorospar), Sulfuric Acid & Chloroform & tom qab polymerisation ntawm TFE yog nqa tawm hauv kev tswj xyuas kom zoo los tsim PTFE.Vim muaj qhov ruaj khov & muaj zog CF daim ntawv cog lus, PTFE molecule muaj cov tshuaj inertness zoo heev, siab kub tsis kam & zoo kawg nkaus hluav taws xob rwb thaiv tsev yam ntxwv;Ntxiv nrog rau kev sib txhuam zoo heev.

Purification ntawm TFE:

Pure monomer yog xav tau rau polymerization.Yog tias muaj impurities, nws yuav cuam tshuam rau cov khoom kawg.Cov roj yog thawj zaug txhuam kom tshem tawm cov hydrochloric acid thiab tom qab ntawd distilled cais lwm yam impurities.

Polymerisation ntawm TFE:

Tetrafluoroethylene ntshiab uas tsis muaj tshuaj tiv thaiv tuaj yeem ua rau polymerize nrog kev ua phem, txawm tias qhov kub thiab txias pib hauv qab ntawm chav tsev kub.Ib qho nyiaj-plated reactor, peb lub hlis twg puv nrog cov tshuaj muaj 0.2 qhov chaw ammonium persulphate, 1.5 qhov chaw borax thiab 100 qhov chaw ntawm dej, thiab nrog pH ntawm 9.2.Lub reactor raug kaw;Kev khiav tawm thiab 30 qhov chaw ntawm monomer raug tso rau hauv. Lub reactor tau agitated rau ib teev ntawm 80 ° C thiab tom qab txias muab 86% tawm los ntawm polymer.PTFE yog ua lag luam los ntawm ob tug loj txheej txheem, ib tug ua rau lub thiaj li hu ua 'granular'. polymer thiab thib ob ua rau dispersion ntawm polymer ntawm ntau finer particle loj thiab qis molecular hnyav.Ib txoj hauv kev ntawm kev tsim cov tom kawg koom nrog kev siv 0.1 °% aqueous disuccinic acid peroxide tov.Cov tshuaj tiv thaiv tau ua tiav ntawm qhov kub txog li 90 ° C.

Lwm Txoj Kev:

Decomposition ntawm TFE nyob rau hauv tus ntawm ib tug hluav taws xob arc.Polymerisation nqa tawm los ntawm emulsion txoj kev siv peroxide pib xws li H2O2 (Hydrogen peroxide) thiab ferrous sulphate.Qee zaum cov pa oxygen yog siv los ua tus pib.

Cov qauv thiab cov khoom ntawm PTFE:

Cov qauv tshuaj ntawm PTFE yog linear polymer ntawm C-F2 - C- F2 yam tsis muaj ceg thiab cov khoom zoo ntawm PTFE yog txuam nrog muaj zog & ruaj khov Carbon - Fluorine daim ntawv cog lus.

Polytetrafluoroethylene yog linear polymer dawb los ntawm ib qho tseem ceeb npaum li cas ntawm branching.Whereas lub molecule ntawm polyethylene yog nyob rau hauv daim ntawv ntawm ib tug planar zigzag nyob rau hauv lub crystalline cheeb tsam no yog sterically tsis yooj yim sua nrog PTFE vim cov fluorine atoms loj dua cov hydrogen.Raws li qhov tshwm sim, cov molecule yuav siv lub zigzag twisted nrog cov fluorine atoms ntim nruj nreem nyob rau hauv ib tug kauv nyob ib ncig ntawm lub carbon-carbon skeleton.Kev ua tiav ntawm cov kauv yuav koom nrog ntau dua 26 carbon atoms hauv qab 19 ° C thiab 30 ° C saum toj no nws muaj qhov hloov pauv uas cuam tshuam nrog 1% ntim hloov ntawm qhov kub no.Lub compact interlocking ntawm fluorine atoms ua rau ib tug molecule ntawm zoo nruj thiab nws yog qhov no feature uas ua rau lub siab crystalline melting point thiab thermal daim ntawv stability ntawm lub polymer.

Qhov sib txawv ntawm qhov sib txawv ntawm PTFE molecules yog qhov me me heev, qhov ntsuas kev sib xyaw ua ke yog 12.6 (MJ / m3) 1/2 Cov polymer hauv ntau tsis yog li muaj lub zog siab thiab tensile lub zog uas feem ntau cuam tshuam nrog cov polymers nrog lub siab softening.Cov carbon-fluorine daim ntawv cog lus ruaj khov heev.Tsis tas li ntawd, qhov twg ob lub fluorine atoms txuas rau ib qho carbon atom muaj qhov txo qis ntawm C-F daim ntawv cog lus deb ntawm 1.42 A txog 1.35 A. Raws li cov txiaj ntsig kev sib tw yuav siab li 504 kJ / mole.Txij li thaum tsuas yog lwm daim ntawv cog lus tam sim no yog qhov ruaj khov C-C daim ntawv cog lus, PTFE muaj qhov kub siab ruaj khov, txawm tias thaum kub siab tshaj nws cov crystalline melting point ntawm 327 ° C.Vim nws cov crystallinity siab thiab tsis muaj peev xwm ntawm kev sib cuam tshuam tshwj xeeb, tsis muaj cov kuab tshuaj nyob rau hauv chav tsev kub.Thaum kub nce mus txog qhov chaw melting qee cov kua fluorinated xws li per-fluorinated kerosene yuav yaj cov polymer.

Cov khoom ntawm PTFE yog nyob ntawm hom polymer thiab cov txheej txheem ntawm kev ua.Cov polymer yuav txawv ntawm qhov loj me thiab / lossis qhov hnyav molecular.Qhov loj me me yuav cuam tshuam cov ntaub ntawv ntawm kev ua thiab qhov ntau ntawm cov voids hauv cov khoom tiav thaum lub cev hnyav molecular yuav cuam tshuam rau crystallinity thiab yog li ntau lub zog ntawm lub cev.Cov txheej txheem ua haujlwm tseem yuav cuam tshuam rau ob qho tib si crystallinity thiab void cov ntsiab lus.

Qhov hnyav nruab nrab molecular hnyav ntawm kev lag luam polymers tshwm sim siab heev thiab nyob rau hauv thaj tsam 400000 txog 9000000. ICI qhia tias lawv cov ntaub ntawv muaj qhov hnyav molecular nyob rau hauv thaj tsam 500000 txog 5000000 thiab feem pua ​​crystallinity ntau dua 94 ~ raws li tsim.Fabricated qhov chaw tsis tshua muaj crystalline.Lub degree ntawm crystallinity ntawm cov khoom tiav yuav nyob ntawm tus nqi ntawm cov cua txias los ntawm kev ua haujlwm kub.Kev ua kom txias qeeb yuav ua rau siab crystallinity nrog ceev txias uas muab cov nyhuv rov qab.Cov ntaub ntawv uas tsis muaj molecular hnyav kuj yuav muaj ntau crystalline.

Nws tau pom tias cov dispersion polymer, uas yog qhov me me me me thiab qhov hnyav dua molecular, muab cov khoom lag luam nrog kev txhim kho loj heev rau flexing thiab tseem muaj zog tensile ntau dua.Cov kev txhim kho no tshwm sim los ntawm kev tsim cov fiber ntau zoo li cov qauv hauv qhov loj ntawm polymer thaum ua.