1. Taw qhia rau Hydroxyethyl Cellulose (HEC):
Hydroxyethylcellulose yog dej-soluble derivative ntawm cellulose, ib tug natural polymer pom nyob rau hauv cov nroj tsuag cell phab ntsa. Kev hloov pauv ntawm cellulose nrog hydroxyethyl pawg txhim kho nws cov solubility hauv dej thiab muab cov khoom tshwj xeeb rau HEC, ua rau HEC yog cov khoom tseem ceeb hauv ntau yam kev siv.
2. Qauv ntawm HEC:
Cov qauv ntawm HEC yog muab los ntawm cellulose, ib tug linear polysaccharide tsim los ntawm rov qab qab zib units txuas los ntawm β-1,4-glycosidic bonds. Hydroxyethyl pawg tau nkag mus rau hauv cov pob txha cellulose los ntawm cov tshuaj tiv thaiv etherification. Degree ntawm kev hloov pauv (DS) yog hais txog qhov nruab nrab ntawm cov pawg hydroxyethyl hauv ib chav tsev piam thaj thiab cuam tshuam rau cov solubility thiab viscosity ntawm HEC.
3. Cov yam ntxwv ntawm HEC:
A. Dej solubility: Ib qho ntawm cov khoom tseem ceeb ntawm HEC yog nws cov dej solubility siab, uas yog los ntawm kev hloov hydroxyethyl. Cov cuab yeej no ua rau nws yooj yim los tsim cov kev daws teeb meem thiab dispersions haum rau ntau yam kev siv.
b. Thickening peev xwm: HEC tau lees paub dav dav rau nws cov khoom thickening hauv cov tshuaj aqueous. Thaum dispersed nyob rau hauv dej, nws tsim ib tug ntshiab thiab viscous gel, ua rau nws haum rau daim ntaub ntawv uas yuav tsum tau viscosity tswj.
C. pH Stability: HEC nthuav tawm kev ruaj ntseg tshaj pH ntau yam, ua rau nws sib haum nrog cov formulations nyob rau hauv ob qho tib si acidic thiab alkaline ib puag ncig.
d. Temperature stability: HEC cov kev daws teeb meem nyob ruaj khov tshaj qhov kub ntau yam. Lawv tuaj yeem dhau mus rau ntau qhov cua sov thiab cua txias yam tsis muaj kev hloov pauv tseem ceeb hauv viscosity lossis lwm yam khoom.
e. Kev tsim cov yeeb yaj kiab: HEC tuaj yeem tsim cov yeeb yaj kiab hloov pauv thiab pob tshab tsim nyog rau kev siv xws li txheej txheej, nplaum thiab cov yeeb yaj kiab.
F. Kev Ua Ntog: HEC muaj cov khoom zoo li surfactant, uas muaj txiaj ntsig zoo hauv cov ntawv thov uas xav tau kev hloov kho saum npoo av lossis ruaj khov.
4. Synthesis of HEC:
Lub synthesis ntawm HEC suav nrog cov tshuaj tiv thaiv etherification ntawm cellulose nrog ethylene oxide nyob rau hauv lub xub ntiag ntawm alkaline catalyst. Cov tshuaj tiv thaiv tuaj yeem tswj tau kom ua tiav qhov kev xav tau ntawm kev hloov pauv, yog li cuam tshuam rau cov khoom kawg ntawm HEC cov khoom. Synthesis feem ntau yog ua raws li kev tswj xyuas kom ntseeg tau cov khoom sib xws thiab zoo.
5. Kev siv HEC:
A. Paints thiab Coatings: HEC yog dav siv los ua cov thickener hauv cov xim dej thiab cov coatings. Nws txhim kho rheology, txhim kho kev txhuam hniav, thiab pab txhawb kev tsim kev ruaj ntseg.
b. Cov khoom siv tu tus kheej: HEC yog cov khoom muaj nyob rau hauv cov khoom tu tus kheej xws li tshuaj zawv plaub hau, tshuaj pleev ib ce thiab tshuaj pleev ib ce. Nws ua raws li cov thickener, stabilizer thiab zaj duab xis-tsim tus neeg sawv cev, txhim kho tag nrho cov kev ua tau zoo ntawm cov formulations.
C. Pharmaceutical: Hauv kev lag luam kws tshuaj, HEC yog siv rau hauv qhov ncauj thiab tshuaj pleev. Nws tuaj yeem ua tus khi, tsis sib xws, lossis matrix yav dhau los hauv cov ntsiav tshuaj formulations, thiab ua cov viscosity hloov pauv hauv cov tshuaj pleev ib ce thiab cov tshuaj pleev.
d. Cov ntaub ntawv tsim kho: HEC yog siv rau hauv kev tsim kho kev lag luam ua tus neeg saib xyuas dej hauv cov cement-based formulations. Nws txhim kho kev tsim kho kev ua tau zoo, ncua sij hawm qhib, thiab txhim kho qhov adhesion ntawm pobzeb adhesives thiab mortars.
e. Roj thiab Roj Kev Lag Luam: HEC yog siv rau hauv kev lag luam roj thiab roj ua tus neeg sawv cev thickening rau drilling kua. Nws pab tswj cov viscosity thiab muab cov khoom ncua kev tiv thaiv kom tsis txhob muaj teeb meem.
F. Kev lag luam khoom noj khoom haus: HEC yog siv hauv kev lag luam khoom noj khoom haus ua cov thickener, stabilizer thiab gelling tus neeg sawv cev hauv ntau yam khoom, nrog rau cov kua ntses, hnav khaub ncaws thiab khoom qab zib.
6. Kev txiav txim siab:
HEC feem ntau lees paub tias muaj kev nyab xeeb (GRAS) los ntawm cov koom haum tswj hwm thiab nws siv ntau yam kev siv yog tswj xyuas kom cov neeg siv khoom muaj kev nyab xeeb thiab cov khoom siv tau zoo. Cov neeg tsim khoom yuav tsum ua raws li cov cai hauv cheeb tsam thiab tau txais kev pom zoo tsim nyog rau cov ntawv thov tshwj xeeb.
7. Yav tom ntej tiam sis thiab innovation:
Kev tshawb fawb tsis tu ncua tsom mus rau kev txhim kho HEC derivatives hloov kho nrog cov cuab yeej txhim kho rau cov ntawv thov tshwj xeeb. Kuj tseem muaj kev tsom mus rau kev tsim kho tshiab hauv kev tsim khoom lag luam thiab cov txheej txheem tsim khoom los daws cov teeb meem ib puag ncig thiab txhawb kev hloov pauv ib puag ncig.
Hydroxyethylcellulose (HEC) yog ntau yam, ntau yam polymer nrog cov khoom tshwj xeeb xws li dej solubility, thickening peev xwm, thiab kub stability. Los ntawm cov xim thiab coatings mus rau kev lag luam tshuaj thiab zaub mov, HEC plays lub luag haujlwm tseem ceeb hauv kev txhim kho kev ua haujlwm ntawm ntau yam khoom. Raws li kev tshawb fawb thiab kev txhim kho txuas ntxiv mus, HEC zoo li yuav nyob twj ywm tseem ceeb hauv ntau qhov kev lag luam, pab txhawb rau kev nce qib ntawm cov ntaub ntawv thiab cov qauv.
Post lub sij hawm: Dec-29-2023