Taw qhia rau HEC (Hydroxyethyl cellulose) thiab HPMC (HydroxyPropyyl methylculose)
Hydroxyethyl cellulose (HEC) thiab HydroxyPropyylulose (HOLMC) yog ob qho tseem ceeb ntawm cov tshuaj, suav nrog kev ua tshuaj, kev saib xyuas, thiab khoom noj. HEC thiab HPMC yog muab tau los ntawm cellulose, ntau tshaj li tej kev muaj txiaj ntsig zoo ntawm cov phab ntsa ntawm tes, uas tau paub rau nws cov qauv kev siv zog thiab versatility.
Hydroxyethyl cellulose (HEC)
Cov qauv tshuaj thiab cov khoom
Hydroxyethyl cellulose yog tsis-ionic, dej-soluble polymer muab tau los ntawm cellulose los ntawm etherification txheej txheem. Nws cov qauv tshuaj lom neeg suav nrog cov pab pawg ethylene oxide (-ch2ch2oh) txuas nrog lub cellulose caj qaum, uas ua kom tau nws cov dej solubility thiab thickening cov khoom. HEC tshwm sim zoo li cov hmoov dawb paug rau ntawm cov hmoov dawb thiab muaj npe rau nws cov viscosity siab thiab ua yeeb yaj kiab zoo heev.
Synthesis txheej txheem
Qhov synthesis ntawm hec cuam tshuam cov tshuaj tiv thaiv ntawm cov kab ke nrog ethylene oxide nyob rau hauv alkaline tej yam kev mob. Tus txheej txheem feem ntau suav nrog:
Alkalization: cellulose tau kho nrog lub zog alkali, xws li sodium hydroxide, los ua alkali cellulose.
Ethetification: Ethylene oxide yog tom qab ntawd ntxiv rau cov alkali cellulose, ua rau kev tsim ntawm hydroxyethyl cellulose.
Neutralization thiab Purification: Cov tshuaj tiv thaiv sib xyaw yog neutralized thiab lim kom tshem tawm cov khoom lag luam, yielding qhov kawg hec cov khoom.
Cov Ntawv Thov
HEC tau siv thoob plaws ntau yam lag luam vim nws cov khoom tshwj xeeb:
Kws muag tshuaj: siv los ua tus neeg sawv cev tuab, zaj duab xis-yav tas los, thiab stabilizer nyob rau hauv cov tsos gels, cream, thiab tshuaj pleev.
Kev saib xyuas tus kheej: pom nyob rau hauv cov tshuaj zawv plaub hau, cov khoom siv kho mob, pleev tshuaj, thiab cov xab npum ua cov tuab thiab emulsifier.
Xim thiab pleev xim: Txhim kho cov viscosity, cov dej ua kom muaj dej, thiab ua yeeb yaj kiab ua yeeb yaj kiab hauv cov xim pleev xim rau hauv cov dej.
Kev tsim kho: Ua haujlwm ua cov phau ntawv, cov tuab dua, thiab dej rov ua tus neeg saib xyuas hauv cov khoom noj thiab cov khoom lag luam gypsum.
Qhov Zoo
HEC muaj ob peb qhov zoo:
Cov xwm tsis-ionic: ua rau nws tau ua kom muaj ntau yam ntawm ionic thiab tsis muaj ionic.
Dej solubility: yooj yim yaj nyob rau hauv dej txias thiab dej kub, ua cov kev daws teeb meem.
Thickening efficiency: muab cov tshuaj tua zoo nkauj hauv ntau hom.
Biocompatibility: muaj kev nyab xeeb rau siv hauv cov khoom lag luam thiab cov khoom siv saib xyuas tus kheej.
HydroxyPropyyl Methylcellulose (HPMC)
Cov qauv tshuaj thiab cov khoom
HydroxyPropylencoylulose yog lwm tus neeg tsis muaj ithat, uas yog cov me me ntawm cov methoxy (-och3) thiab hydroxypropyl (-ch2chohch3) pawg. Qhov kev hloov kho no cuam tshuam tshwj xeeb cov khoom siv thermal gelation thiab ua rau HPMC soluble hauv ob qho tib si txias thiab dej kub. HPMC kuj tseem muaj xws li dawb rau cov hmoov dawb.
Synthesis txheej txheem
Kev tsim HPMC koom nrog ib txoj kev zoo ib yam li cas los xij:
Alkalization: cellulose yog kho nrog lub zog alkali los ua alkali cellulose.
Ethetification: ua ke methyl chloride thiab propylene oxide tau ntxiv rau cov alkali cellulose, ua rau kev tsim ntawm hydroxypropyl methylulose.
Neutralization thiab purification: qhov sib tov yog neutralized, thiab lim cov kauj ruam yog ua kom tau txais qhov kawg HPMC cov khoom lag luam.
Cov Ntawv Thov
HPMC cov versatility tso cai rau nws siv hauv ntau thaj teb:
Kws muag tshuaj: Ua raws li tus tswj hwm-tso tawm, binder, thiab zaj duab xis txheej khoom nyob rau hauv ntsiav tshuaj tsim.
Kev Lag Luam Khoom Noj: Ua haujlwm ua cov tuab, stabilizer, thiab emulsifier hauv cov zaub mov tiav.
Kev tsim kho: siv raws li cov tuab, dej tuav tus neeg saib xyuas, thiab cov nplaum hauv cov cement-raws li cov txiv ntseej thiab plaster.
Kev saib xyuas tus kheej: pom nyob rau hauv cov tshuaj txhuam hniav, tshuaj txhuam hniav, thiab muaj ntau yam rau nws cov khoom siv tuab thiab ruaj khov.
Qhov Zoo
HPMC yog tus tsim nyog rau ntau yam:
Thermal gelation: Cov khoom ua pov thawj pom thaum muaj cua sov, muaj txiaj ntsig nyob rau hauv qee yam cuab yeej siv khoom thiab khoom noj.
Solubility: soluble hauv ob qho tib si txias thiab dej kub, tso cai rau ntau yam siv hauv cov qauv sib txawv.
Zaj duab xis-tsim muaj peev xwm: Tsim cov yeeb yaj kiab muaj zog, hloov tau yooj yim, zoo tagnrho rau cov txheej txheem thiab kev tso tawm-tso tawm.
Tsis-toxicity: muaj kev nyab xeeb rau siv hauv cov zaub mov thiab cov ntaub ntawv thov tshuaj, nrog biocompatibility zoo.
Kev sib piv ntawm HEC thiab HPMC
Yam zoo sib xws
Keeb kwm: Ob qho tib si yog muab los ntawm cellulose thiab sib qhia cov txheej txheem zoo sib xws uas cuam tshuam nrog etherification.
Cov Khoom: Ob lub Hec thiab HPMC tsis yog-ionic, dej-soluble polymers nrog zoo thickening, zaj duab xis-ua, thiab stabilizing tej yam.
Cov ntawv thov: Lawv tau siv nyob rau hauv ntau hom kev lag luam, suav nrog cov tshuaj, kev tu tus kheej, thiab kev tsim kho.
Qho sib txawv
Kev hloov cov tshuaj hloov chaw: HEC muaj cov pab pawg hydroxyethyl, thaum HPMC muaj methoxy thiab hydroxyproplopyl pawg.
Thermal Cov Khoom Siv: HPMC cov khoom ua pov thawj thermal, tsis haum rau cov kev siv tshwj xeeb uas muaj kev ua kom sov.
Solubility: Thaum ob qho tib si yog dej-soluble, muaj cov pab pawg hydroxypropyl hauv HPMC txhim kho nws cov solubility hauv cov organic cov kuab tshuaj piv rau HEC.
Hydroxyethyl cellulose (HEC) thiab HydroxyPropyylulose (HPMC) yog cov ntawv thov corulcell HEC tshwj xeeb yog muaj nuj nqis rau nws cov viscosity siab thiab sib xyaw nrog ntau yam kev sib ntxiv, thaum HPMC yog txawv los ntawm nws cov khoom siv thermal gelation muaj zog thiab dav salubility. To taub cov khoom siv, hluavtaws, thiab cov ntawv thov ntawm cov polymers tau pab hauv kev xaiv cov kev lag luam uas tsim nyog, yog li txhim kho cov kev ua tau zoo thiab qhov zoo ntawm cov khoom kawg.
Lub Sijhawm Post: Feb-18-2025