Methylcellulose (MC) yog ib hom cellulose ether. Cellulose ether tebchaw yog derivatives tau los ntawm kev hloov tshuaj ntawm natural cellulose, thiab methylcellulose yog ib qho tseem ceeb cellulose derivative tsim los ntawm methylating (methyl hloov) hydroxyl ib feem ntawm cellulose. Yog li ntawd, methylcellulose tsis yog tsuas yog cellulose derivative, tab sis kuj yog ib tug raug cellulose ether.
1. Kev npaj ntawm methylcellulose
Methylcellulose yog npaj los ntawm reacting cellulose nrog ib tug methylating tus neeg sawv cev (xws li methyl chloride los yog dimethyl sulfate) nyob rau hauv alkaline tej yam kev mob rau methylate hydroxyl ib feem ntawm cellulose. Cov tshuaj tiv thaiv no feem ntau tshwm sim ntawm pawg hydroxyl ntawm C2, C3 thiab C6 txoj haujlwm ntawm cellulose los tsim methylcellulose nrog ntau qib ntawm kev hloov pauv. Cov txheej txheem tshuaj tiv thaiv yog raws li nram no:
Cellulose (polysaccharide tsim los ntawm cov piam thaj hauv qab) yog thawj zaug ua haujlwm hauv cov kab mob alkaline;
Tom qab ntawd tus neeg sawv cev methylating tau qhia kom nkag mus rau cov tshuaj tiv thaiv etherification kom tau methylcellulose.
Txoj kev no tuaj yeem tsim cov khoom lag luam methylcellulose nrog cov viscosities sib txawv thiab cov khoom solubility los ntawm kev tswj cov tshuaj tiv thaiv thiab qib ntawm methylation.
2. Cov khoom ntawm methylcellulose
Methylcellulose muaj cov khoom tseem ceeb hauv qab no:
Solubility: Tsis zoo li ntuj cellulose, methylcellulose tuaj yeem yaj hauv dej txias tab sis tsis nyob hauv dej kub. Qhov no yog vim qhov kev taw qhia ntawm methyl substituents rhuav tshem cov hydrogen bonds ntawm cellulose molecules, yog li txo nws cov crystallinity. Methylcellulose tsim cov tshuaj pob tshab hauv dej thiab nthuav tawm cov yam ntxwv gelation ntawm qhov kub thiab txias, uas yog, cov tshuaj thickens thaum rhuab thiab rov ua kom muaj dej tom qab txias.
Non-toxicity: Methylcellulose yog non-toxic thiab tsis absorbed los ntawm tib neeg digestive system. Yog li ntawd, nws yog feem ntau siv nyob rau hauv cov khoom noj thiab tshuaj additives raws li ib tug thickener, emulsifier thiab stabilizer.
Kev tswj hwm viscosity: Methylcellulose muaj cov viscosity zoo tswj cov khoom, thiab nws cov kua viscosity muaj feem xyuam rau cov tshuaj concentration thiab molecular hnyav. Los ntawm kev tswj cov qib ntawm kev hloov pauv hauv cov tshuaj tiv thaiv etherification, methylcellulose cov khoom uas muaj qhov sib txawv viscosity tuaj yeem tau txais.
3. Kev siv cov tshuaj methylcellulose
Vim nws qhov tshwj xeeb ntawm lub cev thiab tshuaj lom neeg, methylcellulose tau siv dav hauv ntau lub lag luam.
3.1 Kev lag luam zaub mov
Methylcellulose yog cov khoom noj khoom haus uas siv ntau yam khoom noj, feem ntau yog cov thickener, emulsifier thiab stabilizer. Txij li thaum methylcellulose tuaj yeem gel thaum cua sov thiab rov ua kom muaj dej tom qab txias, nws feem ntau siv rau hauv cov khoom noj khov, ci thiab kua zaub. Tsis tas li ntawd, qhov tsawg-calorie xwm ntawm methylcellulose ua rau nws yog ib qho tseem ceeb muaj nyob rau hauv ib co qauv zaub mov uas tsis muaj calorie ntau ntau.
3.2 Pharmaceutical thiab kev kho mob kev lag luam
Methylcellulose yog dav siv nyob rau hauv kev lag luam kws tshuaj, tshwj xeeb tshaj yog nyob rau hauv cov ntsiav tshuaj ntau lawm, raws li ib tug excipient thiab binder. Vim nws muaj peev xwm hloov kho viscosity zoo, nws tuaj yeem txhim kho cov khoom siv dag zog thiab kev tawg ntawm cov ntsiav tshuaj. Tsis tas li ntawd, methylcellulose kuj tseem siv los ua ib qho khoom tsim kua muag hauv ophthalmology los kho qhov muag qhuav.
3.3 Kev tsim kho thiab cov ntaub ntawv kev lag luam
Ntawm cov khoom siv hauv tsev, methylcellulose yog siv dav hauv cov cement, gypsum, coatings thiab adhesives ua cov thickener, dej retainer thiab zaj duab xis qub. Vim nws cov dej tuav tau zoo, methylcellulose tuaj yeem txhim kho cov dej ntws thiab kev ua haujlwm ntawm cov ntaub ntawv tsim kho thiab zam kev tsim cov kab nrib pleb thiab voids.
3.4 Kev lag luam tshuaj pleev ib ce
Methylcellulose kuj tseem siv nyob rau hauv kev lag luam tshuaj pleev ib ce ua cov thickener thiab stabilizer los pab tsim cov emulsions ntev thiab gels. Nws tuaj yeem txhim kho qhov kev xav ntawm cov khoom thiab txhim kho cov nyhuv moisturizing. Nws yog hypoallergenic thiab me me, thiab haum rau cov tawv nqaij rhiab heev.
4. Kev sib piv ntawm methylcellulose nrog lwm cov cellulose ethers
Cellulose ethers yog ib tsev neeg loj. Ntxiv rau methylcellulose, kuj tseem muaj ethyl cellulose (EC), hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC) thiab lwm yam. Lawv qhov sib txawv tseem ceeb nyob hauv hom thiab qib ntawm kev hloov pauv ntawm cov khoom hloov pauv ntawm cov cellulose molecule, uas txiav txim siab lawv cov solubility, viscosity thiab daim ntawv thov.
Methylcellulose vs Hydroxypropyl Methylcellulose (HPMC): HPMC yog ib qho kev txhim kho ntawm methylcellulose. Ntxiv nrog rau cov tshuaj methyl hloov, hydroxypropyl kuj tau qhia, uas ua rau cov solubility ntawm HPMC ntau ntau. HPMC tuaj yeem yaj nyob rau hauv ntau qhov kub thiab txias, thiab nws cov thermal gelation kub siab dua li ntawm methylcellulose. Yog li ntawd, hauv cov khoom siv hauv tsev thiab kev lag luam tshuaj, HPMC muaj ntau yam kev siv.
Methylcellulose vs Ethyl Cellulose (EC): Ethyl cellulose yog insoluble hauv dej, tab sis soluble hauv organic solvents. Nws feem ntau yog siv rau hauv cov ntaub ntawv pov thawj-tso tawm cov ntaub ntawv rau txheej thiab tshuaj. Methyl cellulose yog soluble hauv dej txias thiab yog siv los ua cov thickener thiab dej tuav tus neeg sawv cev. Nws daim ntawv thov thaj chaw txawv ntawm cov ethyl cellulose.
5. Txoj kev loj hlob ntawm cellulose ethers
Nrog rau kev thov ntau ntxiv rau cov khoom siv ruaj khov thiab cov tshuaj ntsuab, cellulose ether tebchaw, suav nrog methyl cellulose, maj mam dhau los ua ib qho tseem ceeb ntawm cov khoom siv hauv ib puag ncig. Nws yog muab los ntawm cov nroj tsuag ntuj fibers, yog tauj dua tshiab, thiab tuaj yeem degraded nyob rau hauv ib puag ncig. Nyob rau hauv lub neej yav tom ntej, daim ntawv thov cov cheeb tsam ntawm cellulose ethers tej zaum yuav ntxiv nthuav, xws li nyob rau hauv lub zog tshiab, ntsuab vaj tse thiab biomedicine.
Raws li hom cellulose ether, methyl cellulose yog dav siv nyob rau hauv ntau lub lag luam vim nws lub cev thiab tshuaj lom neeg lub zog. Nws tsis tsuas yog muaj qhov zoo solubility, non-toxicity, thiab zoo viscosity hloov lub peev xwm, tab sis kuj plays lub luag haujlwm tseem ceeb hauv cov zaub mov, tshuaj, kev tsim kho thiab tshuaj pleev ib ce. Nyob rau hauv lub neej yav tom ntej, nrog kev xav tau ntau ntxiv rau cov ntaub ntawv zoo ib puag ncig, daim ntawv thov kev cia siab ntawm methyl cellulose yuav dav dua.
Post lub sij hawm: Oct-23-2024