Kev tsim cov tshuaj hydroxyethyl cellulose (HEC) muaj feem xyuam ntawm cellulose los hloov cellulose, lub ntuj polymer muab tau los ntawm cov nroj tsuag. HEC tau dav hauv ntau yam lag luam, suav nrog cov tshuaj, suav nrog cov tshuaj pleev li cas, tshuaj pleev ib ce, thiab kev tsim kho, vim tias nws cov thickening, ruaj khov, thiab dej-khaws cov khoom.
Taw qhia rau hydroxyethyl cellulose (HEC)
Hydroxyethyl cellulose (HEC) yog tsis-ionic, dej-soluble polymer muab tau los ntawm cellulose los ntawm kev hloov kho tshuaj lom neeg. Nws yog dav siv ua lub thickening, gelling, thiab stabilizing tus neeg sawv cev hauv ntau yam kev lag luam.
Cov Khoom Siv Raw
Cellulose: thawj cov khoom siv raw rau HEC ntau lawm. Cellulose tuaj yeem muaj los ntawm ntau cov khoom ntoo ntoo xws li ntoo pulp, paj rwb, lossis cov liaj teb.
Ethylene oxide (EO): Tus yuam sij cheem siv los qhia hydroxyethyl pawg mus rau lub cellulose cellebone.
Cov: feem ntau yog sodium hydroxide (Naoh) lossis cov poov tshuaj hydrocesium (koh) yog siv los ua cov tshuaj tua kab mob.
Cov txheej txheem tsim khoom
Zus tau los ntau lawm HEC suav nrog Ethetication ntawm cellulose nrog ethylene oxide nyob rau hauv alkaline tej yam kev mob.
Cov kauj ruam hauv qab no qhia cov txheej txheem:
1. Kev kho mob ua ntej ntawm cellulose
Cellulose yog thawj lub purified kom tshem tawm impurities li hnub ci, hoicellulose, thiab lwm yam extractives thiab lwm yam extractives. Lub cellulose huv si yog ces qhuav rau ib qho tshwj xeeb cov ntsiab lus noo noo.
2. Kev tawm tsam kev tawm tsam
Kev npaj ntawm alkaline daws: ib qho kev daws teeb meem a a a a a a a a a aa Qhov concentration ntawm alkali kev daws teeb meem yog qhov tseem ceeb thiab yuav tsum tau ua kom zoo raws li cov khoom lag luam xav tau (DS) ntawm cov khoom kawg.
Cov teeb meem teeb tsa: ua kom huv cellulose yog dispersed nyob rau hauv cov alkali daws. Cov dej sib tov yog rhaub kom muaj qhov kub tshwj xeeb, feem ntau nyob ib puag ncig 50-70 ° C, kom ntseeg tau tias lub cellulose tau nkag mus rau cov tshuaj tiv thaiv.
Tsis tas li ntawm ethylene oxide (EO): Ethylene oxide (EO) tau ntxiv qeeb mus rau lub nkoj tiv thaiv thaum tswj qhov kub thiab nplawm. Cov kev tawm tsam yog exothermic, yog li kev tswj kub yog qhov tseem ceeb heev kom tiv thaiv kev kub ntxhov.
Tshuaj Ntsuam Xyuas: Qhov kev nce qib ntawm cov kev tawm tsam yog soj ntsuam los ntawm kev txheeb xyuas cov qauv ntawm cov sijhawm sib nrug. Cov tswv yim zoo li Fourier-Transform Infrared Spectroscopy (FTIR) tuaj yeem siv los txiav txim siab txog qib (DS) ntawm cov kab cellulose cellulose.
Neutralization thiab ntxuav: Thaum cov kev xav tau ua tiav, cov tshuaj tiv thaiv yog quenched los ntawm kev daws teeb meem alkaline nrog cov acid, feem ntau acetic acid. Lub txiaj ntsig HEC tau ntxuav kom huv si nrog dej kom tshem tawm cov reagents thiab impurities.
3. Kev ua kom huv thiab ziab
Lub HEC tau ntxuav dua yog kev lim dej los ntawm kev pom lossis centrifugation tshem tawm ib qho seem uas tseem ceeb. Lub HEC tau lim dej kom qhuav rau ib cov ntsiab lus noo noo kom tau txais cov khoom kawg.
Kev Tswj Xyuas Zoo
Kev tswj hwm zoo yog qhov tseem ceeb thoob plaws hauv HEC ntau txheej txheem ua kom muaj kev sib luag thiab muaj kev huv ntawm cov khoom kawg. Cov kev tsis tseem ceeb los saib xyuas xws li:
Degree ntawm hloov (DS)
Viscosity
Yauv cov ntsiab lus
pH
Purity (tsis tuaj ntawm impurities)
Kev ntsuas kev ntsuas piv txwv xws li FTIR, Kev Ntsuas Ntsuas, thiab Kev Tshawb Xyuas Kev Tshawb Fawb Kev Tshawb Fawb Kev Pom Ntau Yam Rau Kev Tswj Xyuas Kev Tswj Xyuas Zoo.
Cov ntawv thov ntawm hydroxyethyl cellulose (HEC)
HEC pom pom cov ntawv thov hauv ntau qhov kev lag luam vim nws cov khoom muaj ntau yam:
Kws Tshuaj: siv los ua tus neeg saib xyuas tuab rau hauv qhov ncauj, cov ntsiab lus, thiab tswj cov tshuaj tawm tshuaj.
Cov tshuaj pleev ib ce: cov tshuaj pleev kom muaj tshuaj pleev, tshuaj, thiab tshuaj zawv plaub hau ua cov tuab thiab tawv thiab tawv.
Khoom noj khoom haus: ntxiv rau cov khoom noj khoom noj ua cov tshuaj noj ua tuab thiab yog tus neeg sawv cev, emulsifier, thiab stabilizer, thiab stabilizer.
Kev tsim kho: Siv nyob rau hauv cement-raws li cov neeg nplua nuj thiab grouts los txhim kho kev ua haujlwm thiab dej khaws cia.
Ib puag ncig thiab kev txiav txim siab nyab xeeb
Kev cuam tshuam ib puag ncig: Kev tsim cov HEC suav nrog kev siv tshuaj lom xws li ethylene oxide thiab alkalis, uas tuaj yeem cuam tshuam ib puag ncig. Kev coj pov tseg zoo thiab kev ua raws li cov cai tswjfwm yog qhov tseem ceeb kom txo qis kev cuam tshuam ib puag ncig.
Kev Nyab Xeeb: Ethylene Oxide yog cov roj ua kom muaj kuab heev thiab roj ntsha, cov npe kev nyab xeeb rau kev nyab xeeb thaum tuav thiab cia. Muaj peev xwm cua txaus, cov khoom tiv thaiv tus kheej (PPE), thiab cov qauv kev nyab xeeb yog tsim nyog los xyuas kom muaj kev nyab xeeb.
Hydroxyethyl cellulose (HEC) yog cov muaj txiaj ntsig zoo polymer nrog ntau cov ntawv thov hauv kev lag luam tawm ntawm cov kws tshuaj los tsim kho. Nws ntau lawm koom nrog lub etherification ntawm cellulose nrog ethylene oxide nyob rau hauv alkaline tej yam kev mob. Kev tswj kev ua kom zoo yog qhov tseem ceeb los xyuas kom muaj kev sib xws thiab muaj kev huv ntawm cov khoom kawg. Ib puag ncig thiab kev txiav txim nyab xeeb yuav tsum tau hais txog thoob plaws hauv cov txheej txheem ntau lawm. Los ntawm ua raws cov txheej txheem tsim nyog thiab cov kev cai, HEC tuaj yeem tsim tau zoo thaum muaj kev cuam tshuam ib puag ncig thiab ua kom muaj kev nyab xeeb rau ib puag ncig.
Qhov kev qhia dav dav no npog cov txheej txheem ntawm hydroxyethyl cellulose (HEC) hauv kev nkag siab zoo ntawm cov txheej txheem tseem ceeb ntawm polymer ua haujlwm.
Lub Sijhawm Post: Apr-10-2024