Cov viscosity ntau dua ntawm hydroxypropyl methyl cellulose, 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 muaj 20%-%% me ntsis qhov loj me dua 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. Thaum kev tsim kho, kev ua haujlwm ntawm Anti - 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.
Qhov ntau dua tus nqi ntawm cellulose ether ntxiv rau hauv lub cap, kom zoo dua cov dej khaws cia, ntau dua cov viscosity, qhov zoo dua cov dej khaws cia.
HPMC fineness tseem muaj qee yam cuam tshuam rau nws cov dej ua ke, feem ntau hais lus, rau tib lub ntsej muag sib txawv ntawm cov dej ua kom ruaj khov yog qhov zoo dua.
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. Txawm hais tias methylhydroxyethyl cellulose cellulose cellulose cais, nws txoj kev vam khom rau qhov tsis muaj zog ntawm cug cug.
Ua kom nce ntau npaum li cas ntawm methyl hydroxyethyl cellulose, kev tsim kho thiab tawg tsis kam tseem 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.
Lub Sijhawm Post: Feb-20-2025