MC yog methyl cellulose, uas yog ua los ntawm cellulose ether los ntawm kev kho cov paj rwb nrog alkali, siv cov methotherfacide uas yog etherification tus neeg sawv cev, thiab mus dhau ntawm cov kev tawm tsam. Feem ntau, cov qib degree hloov tau yog 1.6 ~ 2.0, thiab solubility kuj txawv degrees ntawm kev hloov pauv sib txawv. Nws zwm rau cov tsis muaj ionic cellulose ether.
(1) Cov dej ua kom rov qab los ntawm methyl cellulose yog nyob ntawm nws cov nyiaj, viscosity, particle zoo heev thiab ntseeg tus nqi. Feem ntau, yog tias qhov nyiaj ntxiv yog qhov loj, lub fineness yog me me, thiab viscosity yog qhov loj, dej khaws cia siab dua yog siab. Ntawm lawv, tus nqi ntawm kev ntxiv yog qhov cuam tshuam loj tshaj plaws rau cov dej khaws nyiaj khaws cia, thiab theem viscosity tsis ncaj qha rau cov qib dej khaws nyiaj khaws cia. Qhov kev sib cais feem ntau yog nyob ntawm cov qib ntawm kev hloov kho saum npoo ntawm cov cellulose thiab particle txaus. 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, thiab nws yuav nyuaj rau yaj hauv dej kub. Nws cov kev daws teeb meem aqueous yog ruaj khov nyob rau hauv cov xov tooj ntawm 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, gelation tshwm sim.
(3) Kev hloov pauv qhov kub yuav cuam tshuam rau cov dej tuav ntawm tus nqi methyl ntawm methyl polulose. 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 tseg ntawm methyl cellulose yuav raug txo qis, muaj feem xyuam rau kev tsim kho ntawm lub tshuaj khib.
(4) Methyl cellulose muaj qhov cuam tshuam tseem ceeb ntawm kev tsim kho thiab nplaum ntawm cug. Qhov "adhesion" ntawm no yog hais txog lub zog nplaum 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 yog qhov siab, cov shear tiv thaiv ntawm cov neeg ua haujlwm yog loj, thiab lub zog ntawm cov neeg ua haujlwm ntawm cov txheej txheem yog loj, thiab kev tsim kho ntawm lub tshuaj khib yog neeg pluag. Methyl cellulose adhesion yog nyob rau theem qib hauv cellulose ether.
HPMC yog hydroxypropyl methylulose, uas yog ib qho tsis-ionic cellulose sib xyaw ua ke tom qab etyl chloride, thiab dhau los ntawm kev tawm tsam ethermification. Qib degree hloov chaw yog feem ntau 1.2 ~ 2.0. Nws cov khoom sib txawv vim qhov sib piv sib txawv ntawm methoxyl cov ntsiab lus thiab hydroxypropropsyl cov ntsiab lus.
(1) HydroxyPropropy yog methylcellulose yog yooj yim soluble hauv dej txias, thiab 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. Lub solubility hauv dej txias kuj tseem txhim kho piv nrog methyl cellulose.
(2) Lub viscosity ntawm hydroxypropyf methylcellulose muaj feem xyuam rau nws cov molecular hnyav, thiab qhov loj dua cov molecular hnyav, ntau dua viscosity. Qhov kub kuj cuam tshuam rau nws cov viscosity, raws li kub nce ntxiv, viscosity txo. Txawm li cas los xij, nws cov viscosity siab muaj qhov kub tsawg dua li methyl cellulose. Nws cov kev daws teeb meem yog ruaj khov thaum khaws 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 cov kev sib cais thiab nce siab txog nws viscosity. HydroxyPropyyl methylulose yog ruaj khov rau cov ntsev ua kom zoo, tab sis thaum lub hom phiaj ntawm hydroxypropen methylropylulose kev daws teeb meem.
(4) Cov dej ua kom muaj zog ntawm hydroxypropylulose nyob ntawm nws tus nqi ntxiv, thiab nws cov dej khaws cia nyob rau hauv tib tus nqi yog siab dua li ntawm methyl cellulose.
(5) HydroxyPropropy Metylcellulose tuaj yeem sib xyaw nrog cov dej-soluble polymer sib txuas ua ke los ua cov khaub ncaws hnav thiab siab dua homphosity. 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 methylcellose tau zoo dua enzyme tiv thaiv ntau dua li methylcellose, thiab nws cov kev daws teeb meem tsis tshua muaj kev cuam tshuam los ntawm cov enzymes dua methylculose.
Lub Sijhawm Post: Apr-16-202