Methylcellulose (MC)
Cov miscular molecular ntawm methylcellulose (MC) yog:
[C6h7o2 (Oh) 3-H (OCH3) n \] x
Cov txheej txheem ntau lawm yog los ua cellulose cellulose cellulose cellulose cellulose cellulose ether los ntawm cov kev tawm tsam tom qab siv cov tshuaj ntsuab, thiab cov methyl chloride yog siv los ua tus sawv cev ntawm etherid. 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.
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.
Cov dej rov qab ntawm methylcellulose nyob ntawm nws cov nyiaj ntxiv, viscosity, particle txaus thiab ua kom kawg.
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.
Carboxymetylcellulose (cmc)
Carboxymethyl cellulose, tseem hu ua sodium carboxymethyl cellulose, yog ib qho kev paub txog cellulose, thiab yog txuas txuas ntxiv thiab inexhaustible. Tshuaj cov ntaub ntawv tso cai.
Nws yog tsuas yog siv nyob rau hauv kev lag luam xab npum, kev lag luam khoom noj thiab roj kev kaw kom drilling kua, thiab tus nqi siv hauv cov tshuaj pleev ib ce tsuas yog suav rau li 1%.
Ionic cellulose ether yog tsim los ntawm ntuj fibers (rwb, thiab lwm yam) Tom qab kev kho mob Alkali, thiab tab tom muaj kev tiv thaiv kab mob.
Cov degree ntawm kev hloov pauv yog feem ntau 0.4 ~ 1.4, thiab nws cov kev ua tau zoo tau cuam tshuam los ntawm kev kawm qib siab.
CMC muaj cov kev muaj peev xwm zoo heev, thiab nws cov kua aqueous tau ncua kev ncua muaj peev xwm, tab sis tsis muaj tus nqi yas deformation tiag tiag.
Thaum lub Cmc dissolves, depolymerization yeej tshwm sim. Lub viscosity pib nce thaum xaus, hla dhau qhov siab tshaj plaws, thiab tom qab ntawd dauv mus rau ib qho toj siab. Lub viscosity viscosity muaj feem xyuam rau depolymerization.
Cov degree ntawm depolymerization yog ze rau cov nyiaj ntawm cov kuab tsis zoo (dej) hauv kev tsim qauv. Hauv cov kuab tshuaj txom nyem, xws li cov tshuaj txhuam hniav uas muaj glycerin thiab dej, cmc yuav tsis ua tiav depolymerize thiab yuav ncav cuag ib qho kev sib npaug.
Nyob rau hauv cov ntaub ntawv ntawm ib qho kev muab dej los ntawm cov dej siab, qhov ntau hydrophilic mas tau hloov dua CMC yog yooj yim dua rau depolymerize dua li tus nqi hloov tshiab.
Hydroxyethylcellulose (HEC)
Hec yog tsim los ntawm kev kho cov paj rwb ua kom zoo nrog alkali, thiab tom qab ntawd reacting nrog ethylene oxide raws li etherification tus neeg sawv cev nyob rau hauv lub xub ntiag ntawm acetone. Qib kawm ntawv hloov chaw yog feem ntau 1.5 ~ 2.0. Nws muaj muaj zog hydrophilicity thiab yog yooj yim los nqus dej noo.
Hydroxyethyl cellulose yog soluble hauv dej txias, tab sis nws yog qhov nyuaj kom yaj hauv dej kub. Nws cov kev daws teeb meem yog ruaj khov ntawm qhov kub siab tsis muaj kev sib cav.
Nws yog qhov ruaj khov rau cov acids thiab hauv paus. Alkalis tuaj yeem nrawm nws cov kev sib cais thiab ua kom nce me ntsis nws viscosity. Nws qhov kev tsis txaus ntseeg hauv dej yog ib qho tsis zoo me ntsis dua li methyl cellulose thiab hydroxypropyl methyl cellulose.
HydroxyPropylropy Cellulose (HPMC)
Cov miscular molecular ntawm HPMC yog:
\ [C6h7o2 (Oh) 3-MN (OCH3) M, OCH2CH (OH) CH3 \] x
HydroxyPropyyl methylulose yog lub cellulose ntau nws cov zis thiab kev noj tawm zuj zus.
Nws yog ib qho tsis-ionic cellulose sib xyaw ither ua los ntawm cov paj rwb tom qab kev sib dhos thiab methylene oxide thiab methyl chloride, los ntawm kev sib tw ntawm kev sib tw. 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.
HydroxyPropyyl 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. Lub solubility hauv dej txias kuj tseem txhim kho piv nrog methyl cellulose.
Lub viscosity ntawm hydroxypropyf methylcellulose muaj feem xyuam rau nws cov molecular hnyav, thiab cov 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.
Cov dej tuav tseg ntawm hydroxypropylenchlechleculose nyob ntawm nws tus nqi ntxiv nyob rau tib tus nqi ntxiv rau methyl cellulose.
HydroxyPropyyl nrho methylcellulose 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.
HydroxyPropyyl methylcellulose tuaj yeem sib xyaw nrog 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.
Hydroxypropylencellulose tau zoo dua enzyme tiv thaiv dua methylcellose, thiab nws cov kev daws teeb meem tsis tshua muaj kev mob siab tshaj li methylcellulose
Lub Sijhawm Post: Feb-14-2023