HEC (Hydroxyethyl cellulose) thiab HPMC (HydroxyPropyylulose) yog ob feem ntau siv cellulose derivatives, uas tau siv dav hauv ntau yam kev lag luam. Cov ntaub ntawv no tau ua cov ntaub ntawv ua haujlwm tseem ceeb vim lawv lub cev thiab tshuaj lom neeg.
1. HEC (hydroxyethyl cellulose)
1.1 Cov Qauv Txheej Txheem thiab Cov Khoom
HEC yog cov dej tsis-ionic-soluble polymer tau los ntawm kev hloov tshuaj lom neeg ntawm ntuj cellulose. Nws cov qauv theem pib yog kev qhia txog hydroxyethyl chaw nyob ntawm β-d-d-flucose pob txha taub hau ntawm cellulose. Vim yog cov pab pawg hydrophilicity ntawm hydroxyethyl pab pawg nyob rau hauv nws cov qauv, HEC muaj kev lom zem solubility thiab thickening cov khoom hauv dej.
HC cov khoom ua pov thawj zoo adhesion, zaj duab xis-ua thiab lubricity, thiab kuj yog cov acid- thiab alkali-resistant thiab muaj zoo biocompatibility. Cov khoom no ua rau nws muaj qhov ua tau zoo heev tshaj, stabilizer thiab zaj duab xis-sib sau tus neeg sawv cev hauv aqueous systems. Tsis tas li ntawd, HEC muaj kev daws teeb meem muaj qhov zoo thixotropy, uas tuaj yeem qhia qhov siab viscosity nyob rau hauv qis shear quab yuam, thiab viscosity drops sai sai nyob rau hauv lub siab shear zog. Cov xeeb ceem no ua rau nws muaj cov ntawv thov tseem ceeb hauv kev kho kom muaj roj.
1.2 cov txheej txheem npaj
HEC feem ntau yog npaj los ntawm Ehereification cov tshuaj tiv thaiv ntawm ntuj cellulose. Cov khoom siv nquag siv suav nrog cov khoom siv cellule xws li paj rwb thiab ntoo, uas tau siv nrog ethylene oxide tom qab kev sib dhos kom muaj hydroxyethyl cellulose. Thaum lub sijhawm cov txheej txheem tshuaj tiv thaiv, xws li cov tshuaj tiv thaiv kub (xws li qhov ntsuas kub, pH tus nqi tseem ceeb ntawm kev hloov pauv, solubility thiab viscosity ntawm cov khoom kawg.
1.3 daim teb thov
HEC tau dav siv hauv cov khoom siv hauv tsev, cov tsho tiv no, tshuaj txhua hnub, tshuaj thiab khoom noj. Hauv cov ntaub ntawv hauv tsev, HEC tau dav siv hauv cov xis qab zib thiab gypsum raws li cov thickener zoo thiab stabilizer txhawm rau txhim kho nws cov haujlwm ua haujlwm thiab kev tawm tsam sagging. Nyob rau hauv cov txheej txheej kev lag luam, HEC tuaj yeem siv los ua cov tuab thiab rheology kho kom zoo rau cov dej nplaum kom txhim kho cov nplaum thiab txoj hnyuv ntawm cov txheej txheem. Hauv cov kuab lom txhua hnub xws li zawv plaub hau thiab tshuaj ntxuav tes, HEC yog siv los ua cov tuab thiab moisturizer muab cov khoom lag luam zoo thiab ruaj khov. Tsis tas li ntawd, hauv cov tshuaj thiab khoom noj khoom noj, HEC yog siv los ua cov ntsiav tshuaj, thiab cov duab dhos thiab cov tawv nqaij thiab tawv nqaij thiab tawv ncauj rau cov khoom noj vim nws qhov kev lom zem biocompatibility thiab qis toxicity.
2. HPMC (HydroxyPropyyl methylcellulose)
2.1 Cov Qauv Yooj Yim thiab Khoom
HPMC yog qhov tsis-ionic cellulose ether tau los ntawm kev qhia hydroxypropyl thiab methoxy pawg mus rau hauv lub cellulose pob txha pob txha taub hau. Zoo ib yam li HEC, HPMC muaj cov dej ua kom zoo, thickening, zaj duab xis tsim cov yam ntxwv thiab biocompatibility. Vim yog cov methoxy thiab hydroxyprropyl pawg nyob rau hauv nws cov qauv, HPMC tsis tsuas yog muaj solubility zoo hauv dej, tab sis kuj ua yeeb yam muaj zog ntawm cov khoom thiab tshem tawm cov khoom.
Lub viscos ntawm HPMC kev daws teeb meem yog cuam tshuam ntau ntawm qhov kub. Tsis pub dhau ib qho kub ntau, cov viscos tuaj yeem txo qis nrog kev nce qib kub. Tsis tas li ntawd, HPMC kuj muaj cov khoom lag luam zoo gel. Thaum kev daws qhov kub tshaj qhov muaj nuj nqis, cov gel yuav tsim. Cov cuab yeej no muaj cov ntawv thov tshwj xeeb muaj nqis hauv cov teb ntawm cov zaub mov thiab tshuaj.
2.2 Kev Npaj Npaj
Kev npaj ntawm HPMC zoo ib yam li HEC, thiab tseem yog nqa tawm los ntawm lub etherification tshuaj tiv thaiv ntawm cellulose. Feem ntau, cellulose reacts nrog cov epylene oxide thiab methyl chloride nyob rau hauv alkaline cov xwm txheej thiab methoxy pawg, feem. Cov khoom ntawm HPMC (xws li viscosity, solubility thiab gel kub) tuaj yeem kho tau meej los ntawm kev kho kom haum thiab cov tshuaj tiv thaiv.
2.3 daim teb thov
HPMC muaj ntau cov kev siv nyob rau tom teb ntawm kev tsim kho, tshuaj, khoom noj thiab tshuaj txhua hnub. Hauv cov ntaub ntawv hauv tsev, HPMC tau siv dav hauv cov khoom sib xyaw xis thiab gypsum ua cov ntaub pua tsev, dej tuav thiab khaws cia los txhim kho kev ua haujlwm thiab cov txiaj ntsig ntawm cov khoom siv. Hauv thaj chaw ntawm cov tshuaj, HPMC yog siv los ua cov khoom siv tso tawm, cov tshuaj nplaum thiab tshuaj pleev cov tshuaj rau cov ntsiav tshuaj thiab txhim kho cov tshuaj ruaj khov. Hauv kev lag luam khoom noj khoom haus, HPMC tau siv dav ua cov tuab thiab emulsifier hauv cov khoom ci, cov khoom noj mis thiab cov khoom siv mis thiab saj ntawm cov khoom. Tsis tas li ntawd, HPMC tseem dav siv cov kuab lom txhua hnub xws li zawv plaub hau, ntxuav tes, muab cov khoom siv cov nyhuv zoo heev thiab cov hluav taws xob.
Raws li ob qho tseem ceeb cellulose derivatives, HEC thiab HPMC ua lub luag haujlwm tseem ceeb hauv ntau qhov kev lag luam. HEC tau dav siv hauv kev tsim kho, tshuaj pleev xim rau txhua hnub thiab cov tshuaj txhua hnub vim nws cov tuab ua kom zoo nkauj, zaj duab xis-ua thiab biocompatibility. HPMC, ntawm qhov tod tes, ua lub luag haujlwm tseem ceeb hauv kev tsim kho, tshuaj thiab cov zaub mov thiab khoom noj khoom haus vim nws daim ntawv thov dav. Nrog kev nce qib ntawm thev naus laus zis, txheej txheem npaj thiab cov ntawv thov uas tau txuas ntxiv, nqa ntau qhov kev lag luam muaj kev lag luam ntsig txog kev lag luam.
Lub Sijhawm Post: Feb-17-2025