MC yog methyl cellulose, uas tau los ntawm kev kho cov paj rwb uas muaj alkali, siv cov neeg sawv cev methyl, thiab ua kom cov neeg sawv cev ether kom dhau los ntawm kev tshaj lij. Feem ntau, cov qib degree hloov tau yog 1.6 ~ 2.0, thiab solubility kuj txawv degrees ntawm kev hloov pauv sib txawv. Belongs rau cov tsis muaj ionic cellulose ether.
(1) Cov dej khaws cia ntawmMethyl CelluloseNyob ntawm nws cov nyiaj ntxiv, viscosity, particle zoo heev thiab kawg tus nqi. Feem ntau, yog tias tus nqi ntxiv yog qhov loj, lub fineness yog me me, thiab viscosity yog qhov loj, dej tswj hwm tau loj. Ntawm lawv, tus nqi ntawm kev ntxiv yog qhov cuam tshuam loj tshaj plaws ntawm cov dej khaws cia, thiab theem ntawm viscosity tsis yog ib feem ntawm cov qib ntawm cov dej khaws cia. Tus lej sib cais feem ntau yog nyob ntawm cov kev hloov kho ntawm qhov chaw ntawm cov cellulose ntawm lub cellulose sau thiab lub txiaj ntsig ntawm cov hais. Ntawm cov kev ua haujlwm ntawm cellulose saum toj no, methyl cellulose thiab hydroxypropyl cellulose muaj cov dej rov qab ua haujlwm dua.
(2) Methylcellulose yog soluble hauv dej txias, tab sis nyuaj kom yaj hauv dej kub, thiab nws cov kua aqueous yog qhov ruaj khov heev hauv cov ph = 3 ~ 12. Nws muaj qhov sib xyaw zoo nrog cov hmoov txhuv nplej siab, cov pos hniav guar, thiab lwm yam thiab ntau surfactants. Thaum qhov ntsuas kub nce mus txog qhov gelation kub, qhov tshwm sim ntawm gelation tshwm sim.
(3) Cov kev hloov pauv ntawm qhov kub yuav cuam tshuam rau cov dej tswj hwm ntawm methyl cellulose. Feem ntau, qhov ntsuas kub siab dua, qhov tsis zoo ntawm cov dej khaws cia. Yog tias cug cug Kub tshaj 40 ° C, cov dej tuav ntawm methyl cellulose yuav cuam tshuam rau kev ua haujlwm ntawm lub cug.
(4) Methyl Cellulose muaj qhov cuam tshuam tseem ceeb ntawm kev ua haujlwm thiab cov nplaum ntawm cug. "Adhesion" ntawm no yog hais txog cov adhesion tau hnov ntawm tus neeg ua haujlwm cov cuab tam thiab phab ntsa substrate, uas yog, cov shear tiv thaiv ntawm lub cug. Cov nplaum loj yog qhov loj, cov shear tiv thaiv ntawm lub tshuaj khib nyiab yog cov neeg ua haujlwm loj, thiab kev tsim kho ntawm lub tshuaj khib yog neeg pluag. Methylcellulose adhesion yog nyob rau theem theem hauv cellulose ether.
HPMC yog hydroxypropyl cellulose, uas yog cov kev kho mob ntawm ionic, siv cov tshuaj lom wb, thiab cov neeg sawv cev ntawm cov tshuaj tiv thaiv kab mob. Qib degree hloov chaw yog feem ntau 1.2 txog 2.0. Nws cov khoom sib txawv raws li kev faib ua feem ntawm methoxyl cov ntsiab lus thiab hydroxypropropyl cov ntsiab lus.
(1) HydroxyPropropy yog methylcellulose yog yooj yim soluble hauv dej txias, tab sis nws yuav ntsib teeb meem hauv cov dej kub. Tab sis nws gelation kub hauv dej kub yog qhov siab dua li ntawm methyl cellulose. Kev sib cais hauv dej txias kuj tseem txhim kho piv nrog methyl cellulose.
(2) Lub viscosity ntawm hydroxypropyl methylculose yog cuam tshuam nrog qhov loj me ntawm nws cov molecular hnyav, thiab qhov loj dua cov kab mob molecular, ntau dua viscosity. Qhov kub kuj cuam tshuam rau nws cov viscosity, raws li kub nce ntxiv, viscosity txo. Tab sis nws viscosity muaj tsawg dua los ntawm kev kub kub dua li methyl cellulose. Nws cov kev daws teeb meem yog ruaj khov ntawm kev cia ntawm chav tsev kub.
(3) HydroxyPropyyl methylculose yog ruaj khov rau kua qaub thiab alkali, thiab nws cov kua aqueous yog qhov ruaj khov heev hauv cov ph = 2 ~ 12. Caustic dej qab zib thiab kua qaub muaj cov nyhuv me me rau nws cov kev ua tau zoo, tab sis alkali tuaj yeem ua rau nws qhov kev sib cais thiab nce viscosity. HydroxyPropyyl methylulose yog ruaj khov rau cov ntsev uas zoo, tab sis thaum cov ntsev daws yog qhov siab, lub viscosposyl methylulose kev daws teeb meem.
(4) Cov dej ua haujlwm khaws ciaHydroxyPropyyl MethylcelluloseNyob ntawm nws cov nyiaj ntxiv, viscosity, thiab lwm yam
(5) HydroxyPropropy Metylcellulose tuaj yeem sib xyaw nrog dej-soluble polymer sib xyaw ua ke los ua kev daws teeb meem nrog kev sib xyaw thiab muaj zog viscosity. Xws li cov dej cawv polyvinyl, cov hmoov txhuv nplej siab ether, zaub cov pos hniav, thiab lwm yam.
(6) cov nplaum ntawm hydroxypropyl methylcellulose rau tshuaj tshuaj kho yog siab tshaj li methylcellulose.
(7) HydroxyPropyyl methylcellulose tau zoo tsis kam mus rau cov enzymes ntau dua methylculose kev ua tau qis dua ntawm methylcellulose.
Lub Sijhawm Post: Apr-28-2024