Qhov sib txawv tseem ceeb ntawm PFOA thiab PTFE yog PFOA muaj cov carboxylic acid pab pawg ua haujlwm ntxiv rau cov pa roj carbon thiab fluorine atoms, hos PTFE yog cov polymer uas muaj cov pa roj carbon thiab fluorine nkaus xwb.
PFOA yog cov organic compound uas muaj cov saw hlau thiab cov pab pawg ua haujlwm. PTFE yog cov khoom siv polymer uas muaj ntau qhov rov ua dua tshiab. Txawm li cas los xij, ob qho tshuaj no muaj cov pa roj carbon thiab fluorine atoms.
PFOA yog dab tsi?
Lub sij hawm PFOA sawv cev rau perfluorooctanoic acid. Nws yog lub hauv paus conjugate ntawm perfluorooctanoate lossis C8. Nws yog ib qho perfluorinated carboxylic acid uas muaj txiaj ntsig thoob ntiaj teb ua surfactant. Tsis tas li ntawd, nws yog ib qho tseem ceeb raws li cov khoom noj khoom haus. Nyob rau hauv nws cov qauv tshuaj, PFOA muaj cov qauv tus Tsov tus tw thiab lub taub hau pab pawg. Yog li ntawd, peb tuaj yeem hu nws ua fluorosurfactant. Lub taub hau pab pawg neeg yog hydrophilic thaum lub tail pawg yog hydrophobic thiab lipophobic. Qhov no feem ntau yog vim hais tias pawg neeg tus Tsov tus tw yog inert thiab tsis cuam tshuam nrog feem ntau ntawm cov polar thiab nonpolar compounds.
Muaj ntau daim ntawv thov ntawm PFOA xws li ntaub pua plag, upholstery, apparel, pem teb siv quav ciab, textile, hluav taws kub-tawm ua npuas ncauj thiab sealants ntau lawm. Nws yog ib qho tseem ceeb surfactant nyob rau hauv cov txheej txheem ntawm emulsion polymerization ntawm fluoropolymer. Tsis tas li ntawd, nws yog ib qho tseem ceeb hauv kev tsim cov perfluoroalkyl-hloov cov tebchaw thiab qee cov ntaub ntawv polymer ua cov khoom thaiv tsev.
PTFE yog dab tsi?
Lo lus PTFE sawv rau polytetrafluoroethylene. Teflon yog nws lub npe nrov. Cov khoom siv no yog cov khoom siv polymer, thiab nws muaj cov fluorocarbon units raws li rov ua dua. Peb tuaj yeem faib nws raws li cov khoom siv hluavtaws fluoropolymer. Cov mis loj ntawm chav rov ua dua yog (C2F4)n
PTFE cov khoom siv polymer yog cov khoom hnyav molecular uas tsuas muaj cov pa roj carbon thiab fluorine atoms. Cov khoom no muaj nyob rau hauv cov khoom theem ntawm chav tsev kub. Tsis tas li ntawd, cov khoom no tsis ntub dej vim nws hydrophobicity. Peb tuaj yeem txiav txim siab cov khoom siv no yog cov khoom tsis muaj tshuaj tiv thaiv, thiab nws muaj txiaj ntsig zoo li cov txheej tsis-stick ib yam nkaus. PTFE yog non-reactive vim lub zog ntawm C-F daim ntawv cog lus. Tsis tas li ntawd, PTFE yog qhov tseem ceeb hauv kev tsim cov ntim khoom thiab cov kav dej. Tsis tas li ntawd, peb tuaj yeem siv cov khoom siv no ua cov roj nplua nyeem ib yam - PTFE tuaj yeem txo kev sib txhuam thiab kev siv lub zog ntawm cov tshuab. Txawm li cas los xij, PTFE tsis zoo soluble hauv yuav luag tag nrho cov kuab tshuaj.
Cov txheej txheem ntau lawm ntawm Teflon feem ntau suav nrog dawb-radical polymerization. Ntawm no, peb tuaj yeem tsim PTFE los ntawm polymerizing tetrafluoroethylene. Txawm li cas los xij, txoj kev no yuav tsum muaj cov tshuab tshwj xeeb thiab cov cuab yeej siv tau zoo vim tias tetrafluoroethylene nyiam ua kom tawg mus rau hauv tetrafluoromethane, uas yog ib qho kev txaus ntshai ntawm qhov kev tsim tawm no.
Thaum xav txog nws cov khoom siv polymer, PTFE yog cov thermoplastic polymer. Nws tshwm sim raws li cov khoom dawb ntawm chav tsev kub. Qhov ceev ntawm cov khoom no yog hais txog 2200 kg / m3 Thaum qhov kub thiab txias, Teflon qhia tau hais tias muaj zog thiab tawv heev nrog nws tus kheej lubrication zog. Ntawm qhov kub thiab txias, nws muaj qhov hloov tau zoo thiab. Txij li cov khoom siv no tsis zoo heev, cov tshuaj lom neeg uas tuaj yeem ua rau muaj txiaj ntsig zoo rau nws suav nrog cov tshuaj lom neeg muaj zog xws li alkali hlau.
Qhov txawv ntawm PFOA thiab PTFE yog dab tsi?
PFOA sawv cev rau perfluorooctanoic acid thaum PTFE sawv rau polytetrafluoroethylene. Qhov sib txawv tseem ceeb ntawm PFOA thiab PTFE yog PFOA muaj cov carboxylic acid pab pawg ua haujlwm ntxiv rau cov pa roj carbon thiab fluorine atoms, hos PTFE yog cov polymer uas tsuas muaj cov pa roj carbon thiab fluorine atoms.
Hauv qab infographic ntawm qhov sib txawv ntawm PFOA thiab PTFE nthuav qhia ntau qhov sib piv ntawm ob lub polymers.
Summary – PFOA vs PTFE
PFOA thiab PTFE yog cov npe luv siv los xa mus rau cov organic sib txuas uas muaj cov npe ntev. PFOA sawv cev rau perfluorooctanoic acid thaum PTFE sawv cev rau polytetrafluoroethylene. Qhov sib txawv tseem ceeb ntawm PFOA thiab PTFE yog PFOA muaj cov carboxylic acid pab pawg ua haujlwm ntxiv rau cov pa roj carbon thiab fluorine atoms, thaum PTFE yog cov polymer uas tsuas muaj cov pa roj carbon thiab fluorine atoms.
Image Courtesy:
1. "Perfluorooctanoic acid" Los ntawm Edgar181 - Tus kheej ua haujlwm (Public Domain) ntawm Commons Wikimedia
2. "PTFE qauv" Los ntawm Calvero. - Ua tus kheej nrog ChemDraw (Public Domain) ntawm Commons Wikimedia
