Hydroxypropylmethylcellulose (HPMC) yog cov khoom siv ntau yam siv hauv ntau yam lag luam xws li tshuaj, khoom noj, kev tsim kho thiab tshuaj pleev ib ce. Kev nkag siab txog nws qhov muaj pes tsawg leeg, qauv, cov khoom siv thiab kev siv yuav tsum tau kawm tob txog nws cov tshuaj muaj pes tsawg leeg thiab cov txheej txheem synthesis.
muaj pes tsawg leeg thiab cov qauv
Cellulose Backbone: HPMC yog muab los ntawm cellulose, ib tug natural polymer pom nyob rau hauv cov nroj tsuag cell phab ntsa. Cellulose yog tsim los ntawm cov hlua ntev ntawm cov piam thaj txuas ua ke los ntawm β-1,4 glycosidic bonds.
Methylation: Methylcellulose yog ib qho ua ntej rau HPMC thiab yog tsim los ntawm kev kho cellulose nrog alkali thiab methyl chloride. Cov txheej txheem yuav hloov cov pawg hydroxyl (-OH) ntawm cov pob txha cellulose nrog methyl (-CH3) pawg.
Hydroxypropylation: Tom qab methylation, hydroxypropylation tshwm sim. Nyob rau hauv cov kauj ruam no, propylene oxide reacts nrog methylated cellulose, qhia hydroxypropyl (-OCH2CHOHCH3) pawg mus rau lub cellulose qaum.
Degree of Substitution (DS): Cov degree ntawm kev hloov pauv yog hais txog qhov nruab nrab ntawm cov hydroxypropyl thiab methyl pawg hauv ib chav tsev piam thaj hauv cov saw cellulose. Qhov kev ntsuas no cuam tshuam rau cov khoom ntawm HPMC, suav nrog nws cov solubility, viscosity, thiab thermal cwj pwm.
synthesis
Kev kho alkaline: Cellulose fibers yog thawj zaug kho nrog cov tshuaj alkaline, feem ntau yog sodium hydroxide (NaOH), txhawm rau rhuav tshem cov ntawv cog lus hydrogen thiab ua kom muaj kev nkag tau ntawm cov cellulose hydroxyl pawg.
Methylation: Cellulose kho nrog alkali yog reacted nrog methyl chloride (CH3Cl) nyob rau hauv kev tswj tej yam kev mob, uas ua rau hloov cov hydroxyl pawg nrog methyl pawg.
Hydroxypropylation: Methylated cellulose ntxiv reacts nrog propylene oxide (C3H6O) nyob rau hauv muaj cov catalyst xws li sodium hydroxide. Cov tshuaj tiv thaiv no qhia cov pab pawg hydroxypropyl mus rau hauv cov pob txha cellulose.
Neutralization thiab Purification: Neutralize cov tshuaj tiv thaiv sib tov kom tshem tawm cov hauv paus ntau dhau. Cov khoom tau txais kev ua kom huv si xws li pom, ntxuav, thiab ziab kom tau txais cov khoom HPMC zaum kawg.
yam ntxwv
Solubility: HPMC yog soluble hauv dej thiab tsim cov kua dej ntshiab. Solubility nyob ntawm yam xws li qib kev hloov pauv, qhov hnyav molecular, thiab kub.
Viscosity: HPMC cov kev daws teeb meem pom tus cwj pwm pseudoplastic, txhais tau hais tias lawv cov viscosity txo qis nrog nce shear npaum li cas. Viscosity tuaj yeem tswj tau los ntawm kev kho qhov tsis xws li DS, qhov hnyav molecular thiab concentration.
Zaj duab xis Tsim: HPMC tsim cov yeeb yaj kiab hloov tau yooj yim thiab pob tshab thaum nrum los ntawm nws cov tshuaj aqueous. Cov yeeb yaj kiab no pom cov ntawv thov hauv cov txheej txheem, ntim thiab tshuaj.
Thermal Stability: HPMC yog thermally ruaj khov ntawm qhov kub thiab txias, saum toj no qhov degradation tshwm sim. Thermal stability nyob ntawm tej yam xws li DS, noo noo cov ntsiab lus, thiab muaj cov additives.
Cov chaw thov
Pharmaceuticals: HPMC yog siv dav hauv cov tshuaj formulations li thickeners, binders, film-forming agents thiab sustained-release matrices. Nws txhim kho cov ntsiav tshuaj disintegration, dissolution thiab bioavailability.
Khoom noj khoom haus: Hauv kev lag luam zaub mov, HPMC yog siv los ua cov thickener, stabilizer, emulsifier thiab muab tub lim rau hauv cov khoom xws li kua ntses, hnav khaub ncaws, khoom ci thiab khoom noj siv mis.
Kev tsim kho: HPMC tau ntxiv rau cov cement-based mortars, stucco thiab pobzeb adhesives los txhim kho kev ua haujlwm, dej tuav thiab adhesion. Nws txhim kho kev ua haujlwm ntawm cov khoom siv hauv tsev no hauv ntau yam xwm txheej.
Tshuaj pleev ib ce: HPMC yog siv los ua cov thickener, emulsifier thiab stabilizer hauv cov tshuaj pleev ib ce xws li cream, tshuaj pleev thiab gels. Nws imparts ntshaw rheological zog thiab txhim khu cov khoom stability.
Hydroxypropyl methylcellulose (HPMC) yog cov khoom siv sib xyaw ua ke los ntawm cellulose los ntawm cov txheej txheem methylation thiab hydroxypropylation. Nws cov qauv tshuaj, khoom siv thiab kev siv ua rau nws muaj txiaj ntsig zoo hauv kev lag luam xws li tshuaj, khoom noj, kev tsim kho thiab tshuaj pleev ib ce. Kev tshawb fawb ntxiv thiab kev txhim kho ntawm HPMC thev naus laus zis txuas ntxiv nthuav dav nws cov ntawv thov muaj peev xwm thiab txhim kho nws cov kev ua tau zoo hauv ntau hom qauv.
Post lub sij hawm: Feb-20-2024