HPMC Suav lub npe hydroxypropyl cellulose, tsis yog-ionic hom, hauv qhuav siv dej tswj tus neeg saib xyuas, yog feem ntau siv dej khaws cia khoom hauv kev txig.
HPMC cov txheej txheem ntau lawm yog tsuas yog muaj fiber ntau (hauv tsev) tom qab kev sib dhos, lub txim siab thiab tiam neeg ntawm polysacchar ether. Nws tsis tau them nqi thiab tsis muaj kev cuam tshuam nrog them nqi hauv cov khoom noj paj ntawv, thiab nws cov kev ua tau zoo yog ruaj khov. Tus nqi kuj tseem qis dua lwm hom cellulose ether, yog li nws yog dav siv hauv qhuav mixed colled.
HydroxyPropy cellulose muaj nuj nqi: tuaj yeem ua rau lub tshuaj khib tshiab thickened kom muaj ib tug neeg ntub dej viscosity, tiv thaiv cais. (Thickening) dej khaws cia kuj yog qhov tseem ceeb tshaj plaws, uas yuav tsum tau siv cov dej ntshiab, yog li ntawd lub tshuaj pov tseg muaj sijhawm ntau rau hydrate. (Dej khaws cia) nws tus kheej cov roj, tuaj yeem qhia cov npuas me me, txhim kho txoj kab tshuaj tshuaj kho.
Cov viscosity ntau dua ntawm hydroxypropyl methyl cellulose ether, qhov zoo dua cov dej khaws cia. Viscosity yog qhov tseem ceeb parameter ntawm HPMC kev ua tau zoo. Tam sim no, sib txawv HPMC cov tuam ntxhab Siv cov qauv sib txawv thiab cov cuab yeej los ntsuas qhov viscosity ntawm HPMC. Cov hau kev tseem ceeb suav nrog Haakerotovisko, Hoppller, Ubbelohde thiab Brookfield.
Rau cov khoom qub, cov txiaj ntsig ntawm viscosity ntsuas los ntawm cov qauv sib txawv heev, thiab qee qhov ntau ntau ntau. Yog li ntawd, thaum piv cov viscosity, nws yuav tsum tau ua ntawm tib txoj kev ntsuas, suav nrog qhov kub thiab lwm yam.
Rau qhov loj me me, lub flexer rau particle, qhov zoo dua cov dej khaws cia. Tom qab cov khoom loj ntawm cellulose enether chwv nrog dej, qhov chaw tam sim ntawd dispolves thiab cov gel kom tiv thaiv cov lwg dej los ntawm txuas ntxiv mus rau infiltrate. Qee zaum, txawm tias lub sijhawm ntev stirring tsis tuaj yeem ua rau tusyees dispersed thiab yaj, tsim cov huab flocculent daws los yog clumping. Cov dej tuav tseg ntawm cellulose ether yog kev cuam tshuam loj heev, thiab cov solubility yog ib qho ntawm kev xaiv cellulose ether. Fineness tseem yog ib qho kev ua tau tseem ceeb ntsuas ntawm methyl cellulose ether. Mc rau c tov duab qhuav yuav tsum hmoov, cov ntsiab lus dej qis, thiab cov txiaj ntsig tseem yuav tsum tau 20% ~ 60% particle loj dua li 63um. Cov txiaj ntsig zoo rau cov solubility ntawm hydroxypropyl methyl cellulose ether. Coarser MC feem ntau yog granular thiab yooj yim solubilized nyob rau hauv dej yam tsis muaj clumping, tab sis kev sib cais yog qeeb thiab tsis haum rau kev siv hmoov av qhuav. Hauv cov tshuaj khib qhuav, mc tau tawg ntawm kev sib sau ua ke, ua kom zoo nkauj, xis mas cov ntaub ntawv, thiab tsuas yog cov khoom siv merying thiab lwm yam txiv ntoo kom zoo nkauj ether agglomerate thaum ntxiv cov dej ntxiv. Thaum MC yog yaj hauv dej, nws yog qhov nyuaj kom yaj tawm hauv kev tawg. MC nrog coarser fineness tsis yog pov tseg tsuas yog pov tseg, tab sis kuj tseem txo lub zog ntawm lub zog cug. Thaum xws li cug cug qhuav yog tsim nyob rau hauv ib thaj chaw loj, nws yog qhia tau tias kev kho chleej cug colle tsis zoo, thiab tawg yog tshwm sim los ntawm kev kho lub sijhawm sib txawv. Txog kev sib cav sib tsoo nrog kev tsim kho tshuab, vim tias lub sijhawm sib xyaw ua ke yog luv dua, cov kev xav tau zoo heev.
Feem ntau hais lus, ntau dua cov viscosity, qhov zoo dua cov dej khaws cov nyhuv khaws cia. Txawm li cas los xij, qhov siab tshaj plaws hauv viscosity yog, ntau dua cov molecular hnyav ntawm MC yog, thiab cov khoom tsis zoo ntawm lub zog thiab kev tsim kho kev tshuaj khib. Qhov siab tshaj lub viscosity, ntau pom ntau dua cov thickening cov txiaj ntsig ntawm cug, tab sis nws tsis yog ib feem ntawm kev sib raug zoo. Qhov siab tshaj lub viscosity, ntau lo nplaum dua cov cug cug ua ke yuav yog, ob qho tib si thaum kev tsim kho, kev ua tau zoo ntawm cov scraper nplaum thiab siab adhesion mus rau substrate. Tab sis nws tsis muaj txiaj ntsig zoo kom nce cov txheej txheem zog ntawm cov tshuaj nplaum ntub nws tus kheej. Ntawd yog, thaum kev tsim kho, kev tawm tsam Droop tsis pom tseeb. Ntawm qhov tsis sib xws, qee qhov hloov kho methyl cellulose muaj cov neeg muaj kev pab cuam hauv nruab nrab thiab qis viscosity muaj kev ua tau zoo hauv kev txhim kho lub zog ntawm lub zog ntawm cov tshuaj khib nyiab.
Cov dej khaws cia ntawm HPMC kuj tseem cuam tshuam nrog qhov kub siv, thiab cov dej tuav tseg ntawm methyl cellulose muaj kev nce nrog qhov kub nce siab. Tab sis nyob rau hauv daim ntawv thov zoo, muaj ntau cov chaw qhuav cug yuav tsum feem ntau (siab dua 40 degrees Qhov txo qis ntawm dej tswj tuav mus rau qhov pom tseeb uas ob leeg ua kom muaj kev cuam tshuam tau cuam tshuam. Nyob rau hauv cov kev mob no, nws tiav niam txiv tshwj xeeb los txo cov cawv ntawm cov ntsiab lus kub. Hauv qhov no, methyl hydrothethyl cellulose etherter ntxiv yog tam sim no tau txiav txim siab ua ntej ntawm kev txhim kho thev naus laus zis. Txawm hais tias nce methyl hydrotyl cellulose cellulose tshuaj noj (cov mis) (lub caij ntuj sov), kev tsim kho thiab tawg tsis tuaj yeem ua tau raws li kev xav tau ntawm kev siv. MC los ntawm qee qhov kev kho mob tshwj xeeb, xws li kev txhim kho qib kev kho mob, tuaj yeem ua rau nws cov nyhuv kom zoo dua, yog li nws tuaj yeem muab kev ua tau zoo hauv qab.
General HPMC muaj qhov kub thiab txias, tuaj yeem faib ua 60 hom, 65 hom, 75 hom. Rau cov kev npaj zoo nkauj-sib xyaw nrog dej sand qhauj tau zoo xaiv 75 HPMC nrog cov kub siab gel kub. HPMC ntau npaum li cas yuav tsum tsis txhob siab dhau, siab dhau yuav ua rau cov tshuaj cug dej thov kom nce, tab sis kuj nplaum, lub sijhawm sijhawm ntev dhau, cuam tshuam rau kev tsim kho. Cov khoom lag luam sib txawv xaiv cov viscosity HPMC, tsis txhob siv HITHENT HIGH VISCORS HPMC. Yog li ntawd, txawm hais tias hydroxypropal tshuaj yog qhov zoo, tab sis kev siv kev qhuas zoo, xaiv HPMC yog lub luag haujlwm ntawm cov neeg ua haujlwm hauv chaw ua haujlwm. Tam sim no, muaj ntau ntawm cov neeg lag luam tsis raug cai nyob rau hauv lub compound HPMC, qhov zoo yog qhov muaj qee yam kev sim, ua kom cov khoom lag luam zoo, ua rau poob tsis tsim nyog.
Lub Sijhawm Post: Feb-20-2025