HydroxyPropyyl methylcellulose (HPMC) yog cov dej tsis-ionic-soluble polymer compound tau los ntawm kev hloov tshuaj lom neeg ntawm ntuj cellulose. Nws yog dav siv nyob rau hauv cov zaub mov, tshuaj, tshuaj pleev ib ce thiab kev tsim kho, thickener, emulsifier thiab ncua sij hawm rau kev npaj tshuaj. Hauv cov txheej txheem thov, lub viscosity cov yam ntxwv ntawm HPMC aqueous kev daws teeb meem yog qhov tseem ceeb rau nws qhov kev ua tau zoo hauv cov chaw sib txawv.
1. Cov qauv thiab cov khoom ntawm hydroxypropyl methylcellose
Cov qauv molecular ntawm HPMC muaj ob pab pawg hloov, hydroxypropyl (-ch₂Tsev noog₃) thiab methyl (-Och₃), uas ua rau nws muaj cov dej solubility zoo thiab hloov kho peev xwm. HPMC molecular chart muaj ib tug qauv sib zog, tab sis nws tseem tuaj yeem tsim cov qauv sib tw ntawm cov duab ua ntej hauv aqueous, ua rau muaj kev nce qib hauv viscospose aqueous, ua rau muaj kev nce qib ntxiv. Nws cov molecular hnyav, hom hloov chaw thiab qib degree hloov chaw (piv txwv li methyl hloov ntawm txhua txhua qhov kev cuam tshuam ntawm kev tawm tsam ntawm kev daws teeb meem.
2. Viscosity cov yam ntxwv ntawm cov kua aqueous
Cov yam ntxwv viscosity ntawm HPMC aqueous daws tau zoo sib xws rau cov yam xws li kev xav, lub cev hnyav, ntsuas kub thiab siv tus nqi ntawm PHEM. Feem ntau, cov viscosity ntawm HPMC aqueous daws teeb meem nrog kev nce ntawm nws cov kev xav. Its viscosity shows non-Newtonian rheological behavior, that is, as the shear rate increases, the viscosity of the solution gradually decreases, showing a shear thinning phenomenon.
(1) cov nyhuv ntawm kev pom zoo
Muaj ib qho kev sib raug zoo ntawm lub viscosity ntawm HPMC aqueous daws thiab nws cov kev xav. Raws li cov concmration ntawm HPMC nce, cov kev sib txuas lus molecular nyob rau hauv cov aqueous kev daws teeb meem, thiab hla kev nce hauv viscosity ntawm kev daws teeb meem. Ntawm cov qis dua, lub viscos aqueous nce linearly nce, viscosity kev loj hlob ntawm txoj kev daws teeb meem thiab mus txog rau tus nqi ruaj khov.
(2) cov nyhuv ntawm molecular hnyav
Qhov hnyav molecular ntawm HPMC cuam tshuam ncaj qha cuam tshuam rau cov viscosity ntawm nws cov kua aqueous. HPMC nrog siab dua molecular hnyav muaj sijhawm ntev dua molecular thiab tuaj yeem tsim ib qho qauv sib txawv ntau dua nyob rau hauv cov kev daws teeb meem aqueous, ua rau muaj txiaj ntsig zoo. Nyob rau hauv sib piv, HPMC nrog qis dua molecular hnyav muaj cov qauv sib tw network thiab qis viscosity vim nws luv molecular chains. Yog li, thaum ua ntawv thov, nws yog ib qho tseem ceeb heev los xaiv HPMC nrog txoj kev ua kom haum molecular hnyav kom ua tiav cov viscosity zoo tshaj plaws.
(3) cov nyhuv ntawm qhov kub
Qhov kub yog qhov tseem ceeb cuam tshuam cuam tshuam rau cov viscosity ntawm HPMC aqueous daws. Raws li qhov kub nce ntxiv, kev txav ntawm dej molecules muaj zog thiab viscososity ntawm kev daws teeb meem feem ntau poob. Qhov no yog vim tias thaum kub lub nce, kev ywj pheej ntawm HPMC molecular saw nce thiab kev sib cuam tshuam ntawm molecules tsis muaj zog, yog li txo lub viscosity ntawm kev daws. Txawm li cas los xij, cov lus teb ntawm HPMC los ntawm cov khoom sib txawv lossis cov hom phiaj rau kev kub ntxhov, yog li cov xwm txheej kub yuav tsum tau hloov kho raws li cov kev cai thov.
(4) cov nyhuv ntawm tus nqi PH
HPMC nws tus kheej yog qhov tsis-ionic compound, thiab viscosity ntawm nws cov aqueous daws yog nkag siab txog kev hloov pauv ntawm PH. Txawm hais tias HPMC cov khoom ua pov thawj kuj muaj kev nyob ruaj khov cov yam ntxwv hauv cov acidic lossis nruab nrab ntawm HPMC yuav raug cuam tshuam hauv cov acidic tsis muaj zog lossis alkaline ib puag ncig. Piv txwv li, nyob rau hauv cov muaj zog acid lossis muaj zog alkaline, HPMC molecules yuav yog ib nrab, yog li txo lub viscosity ntawm nws cov aqueeve daws.
3. Rheatorical tsom xam ntawm viscosity cov yam ntxwv ntawm HPMC aqueous kev daws
Kev coj txawv ntawm HPMC aqueous daws feem ntau qhia tau hais txog qhov tsis muaj txiaj ntsig zoo li cov tshuaj xws li kev daws teeb meem thiab cov roj molecular, tab sis kuj ua kom shear tus nqi. Feem ntau hais lus, ntawm cov nqi qis qis, HPMC aqueous daws teeb meem viscosity, thaum ua tus nqi shear nce ntxiv, qhov viscosity txo. Tus cwj pwm no hu ua "shear thinning" lossis "shear thinning" thiab tseem ceeb heev hauv ntau cov kev siv siv. Piv txwv li, hauv teb ntawm cov txheej txheem, kev npaj ua zaub, thiab lwm yam.
4. Lwm yam cuam tshuam rau cov viscosity ntawm HPMC aqueous kev daws
(1) cov txiaj ntsig ntawm ntsev
Qhov sib ntxiv ntawm kev surines solutes (xws li sodium chloride) tuaj yeem nce viscosity ntawm HPMC aqueous daws. Qhov no yog vim tias ntsev tuaj yeem txhim kho kev sib cuam tshuam ntawm cov qauv ntawm kev daws teeb meem, yog li HPMC lwg me me, yog li muaj kev tawm tsam viscosity. Txawm li cas los xij, cov txiaj ntsig ntawm ntsev hom thiab concentration ntawm viscosity kuj yuav tsum tau hloov kho raws li cov xwm txheej tshwj xeeb.
(2) cov nyhuv ntawm lwm cov kev sib ntxiv
Ntxiv lwm yam kev sib ntxiv (xws li surfactants, polymers, thiab lwm yam) rau HPMC aqueous kev daws teeb meem tseem yuav rau cov viscosity. Piv txwv li, surfactants yuav txo qhov viscosity ntawm HPMC, tshwj xeeb tshaj yog thaum lub surfactant concentration yog siab. Ib qho ntxiv, qee cov neeg polymers lossis cov lus hais tuaj yeem cuam tshuam nrog HPMC thiab hloov pauv cov khoom sib dhos ntawm nws cov tshuaj.
Cov yam ntxwv viscosity ntawmHydroxyPropyyl Methylcellulose Cov tshuaj aqueous tau cuam tshuam los ntawm ntau yam, muaj qhov hnyav, muaj cov tshuaj uas tsis yog-tshiab, thiab lwm yam. Nkag siab thiab ua tus yam ntxwv viscosity no yuav pab ua kom zoo siv HPMC hauv kev siv sib txawv. Hauv kev siv cov tswv yim, cov txheej txheem HPMC uas tsim nyog yuav tsum tau xaiv raws li cov kev xav tau zoo tshaj plaws thiab cov khoom siv hluav taws xob.
Lub sij hawm ncua: Mar-01-2025