Hydroxypropyl methylcellulose (HPMC) yog ntau yam thiab dav siv polymer hauv ntau lub lag luam, paub txog nws cov khoom tshwj xeeb thiab kev siv. Cov tshuaj no yog ib qho derivative ntawm cellulose, ib tug natural polymer pom nyob rau hauv cov nroj tsuag cell phab ntsa. Yuav kom nkag siab txog qhov muaj pes tsawg leeg ntawm hydroxypropylmethylcellulose, nws yog ib qho tsim nyog yuav tsum nkag siab txog cov qauv thiab kev sib txuas ntawm cov cellulose derivative.
Cov qauv ntawm cellulose:
Cellulose yog ib qho nyuaj carbohydrate uas muaj cov kab sib txuas ntawm β-D-glucose units txuas los ntawm β-1,4-glycosidic bonds. Cov kua nplaum nplaum no tau tuav ua ke los ntawm hydrogen bonds los ua ib qho kev sib tw linear. Cellulose yog cov qauv tseem ceeb ntawm cov phab ntsa ntawm cov nroj tsuag, muab lub zog thiab rigidity rau cov nroj tsuag.
Derivatives ntawm Hydroxypropyl Methylcellulose:
Hydroxypropyl methylcellulose yog synthesized los ntawm chemically modifying cellulose thiab qhia hydroxypropyl thiab methyl pawg rau hauv cov saw tseem ceeb ntawm cellulose. Kev tsim khoom feem ntau suav nrog cov kauj ruam hauv qab no:
Etherification cov tshuaj tiv thaiv:
Methylation: Kho cellulose nrog cov tshuaj alkaline thiab methyl chloride los qhia methyl pawg (-CH3) rau hauv pawg hydroxyl (-OH) ntawm cellulose.
Hydroxypropylation: Methylated cellulose ntxiv reacts nrog propylene oxide los qhia hydroxypropyl pawg (-CH2CHOHCH3) rau hauv cov qauv cellulose. Cov txheej txheem no txhim kho cov dej solubility thiab hloov lub cev lub cev ntawm cellulose.
purification:
Hloov kho cellulose yog purified los tshem tawm cov unreacted reagents, by-products los yog impurities.
Qhuav thiab sib tsoo:
Cov purified hydroxypropyl methylcellulose yog qhuav thiab hauv av rau hauv cov hmoov zoo npaj siv rau ntau yam kev siv.
Cov khoom xyaw ntawm Hydroxypropyl Methylcellulose:
Cov muaj pes tsawg leeg ntawm hydroxypropyl methylcellulose yog tus cwj pwm los ntawm kev hloov pauv, uas yog hais txog qib uas hydroxypropyl thiab methyl pawg hloov hydroxyl pawg hauv cov saw cellulose. Cov qib sib txawv ntawm HPMC muaj qhov sib txawv ntawm kev hloov pauv, cuam tshuam rau lawv cov solubility, viscosity thiab lwm yam khoom.
Cov tshuaj formula ntawm hydroxypropyl methylcellulose tuaj yeem qhia tau tias yog (C6H7O2(OH)3-mn(OCH3)m(OCH2CH(OH)CH3)n)_x, qhov twg m thiab n sawv cev rau qib kev hloov.
m: degree ntawm methylation (methyl pawg ib chav tsev piam thaj)
n: degree ntawm hydroxypropylation (hydroxypropyl pawg ib chav tsev piam thaj)
x: tus naj npawb ntawm cov piam thaj hauv cov saw cellulose
Nta thiab Daim Ntawv Thov:
Solubility: HPMC yog dej-soluble, thiab qib ntawm kev hloov pauv cuam tshuam rau nws cov yam ntxwv solubility. Nws tsim cov kua dej ntshiab thiab khov rau hauv dej, ua rau nws tsim nyog rau ntau yam formulations.
Viscosity: Lub viscosity ntawm HPMC cov tshuaj nyob ntawm seb yam xws li qhov hnyav molecular thiab qib ntawm kev hloov pauv. Cov cuab yeej no yog qhov tseem ceeb rau cov ntawv thov xws li cov tshuaj uas yuav tsum tau tswj cov qauv tsim tawm.
Zaj duab xis tsim: HPMC tuaj yeem tsim cov yeeb yaj kiab nyias raws li cov tshuaj dries, ua rau nws muaj txiaj ntsig zoo hauv cov txheej txheem tshuaj, zaub mov thiab lwm yam lag luam.
Stabilizers thiab Thickeners: Hauv kev lag luam khoom noj khoom haus, HPMC yog siv los ua cov thickener thiab stabilizer nyob rau hauv ntau yam khoom, nrog rau cov kua ntses, khoom qab zib, thiab cov khoom ci.
Pharmaceutical Applications: HPMC yog dav siv nyob rau hauv cov tshuaj formulations, nrog rau cov ntsiav tshuaj, tsiav tshuaj, thiab ophthalmic daws, vim nws cov kev tswj kev tso tawm zog thiab biocompatibility.
Kev tsim kho thiab txheej txheej: HPMC yog siv rau hauv cov khoom siv xws li mortars, pobzeb adhesives thiab plasters. Nws kuj yog siv los ua cov thickener thiab stabilizer hauv cov xim thiab txheej txheej.
Cov Khoom Siv Kho Tus Kheej: Hauv kev lag luam tshuaj pleev ib ce thiab kev tu tus kheej, HPMC muaj nyob rau hauv cov khoom xws li cream, tshuaj pleev thiab tshuaj zawv plaub hau, qhov twg nws muab kev ntxhib los mos thiab ruaj khov.
Hydroxypropyl methylcellulose yog tau los ntawm methylation thiab hydroxypropylation ntawm cellulose. Nws yog ntau lub hom phiaj polymer nrog ntau yam kev siv. Nws cov khoom tshwj xeeb ua rau nws muaj txiaj ntsig hauv kev lag luam xws li tshuaj, khoom noj, kev tsim kho thiab kev saib xyuas tus kheej. Kev hloov kho ntawm cellulose tuaj yeem kho qhov zoo ntawm HPMC, ua rau nws yog ib feem tseem ceeb ntawm ntau yam khoom uas peb ntsib hauv peb lub neej txhua hnub.
Post lub sij hawm: Jan-10-2024