Hydroxypropyl methylcellulose (HPMC) yog cov dej-soluble polymer compound dav siv hauv tshuaj, khoom noj, khoom siv hauv tsev thiab lwm yam. Vim nws cov thickening zoo, film-forming, emulsifying, bonding thiab lwm yam khoom, nws yog dav siv raws li ib tug thickener, stabilizer thiab suspending tus neeg sawv cev. Cov khoom rheological ntawm HPMC, tshwj xeeb tshaj yog nws qhov kev ua tau zoo ntawm qhov sib txawv ntawm qhov kub thiab txias, yog qhov tseem ceeb cuam tshuam rau nws cov txiaj ntsig ntawm daim ntawv thov.
1. Txheej txheem cej luam ntawm HPMC Rheological Properties
Rheological zog yog ib qho kev xav txog kev deformation thiab ntws cov yam ntxwv ntawm cov khoom nyob rau hauv sab nraud quab yuam. Rau cov ntaub ntawv polymer, viscosity thiab shear thinning tus cwj pwm yog ob qhov kev ntsuas rheological feem ntau. Cov khoom rheological ntawm HPMC feem ntau cuam tshuam los ntawm yam xws li qhov hnyav molecular, concentration, hnyav zog thiab kub. Raws li cov non-ionic cellulose ether, HPMC nthuav tawm pseudoplasticity nyob rau hauv aqueous tov, uas yog, nws viscosity txo nrog nce shear npaum li cas.
2. Cov nyhuv kub ntawm HPMC Viscosity
Qhov kub thiab txias yog ib qho tseem ceeb cuam tshuam rau cov khoom rheological ntawm HPMC. Raws li qhov kub thiab txias, qhov viscosity ntawm HPMC cov tshuaj feem ntau txo qis. Qhov no yog vim qhov nce hauv qhov kub thiab txias tsis muaj zog ntawm hydrogen bond kev sib cuam tshuam ntawm cov dej molecules, yog li txo cov kev sib cuam tshuam quab yuam ntawm HPMC molecular chains, ua rau cov saw hlau molecular yooj yim rau swb thiab ntws. Yog li ntawd, ntawm qhov kub siab dua, HPMC cov kev daws teeb meem pom cov viscosity qis dua.
Txawm li cas los xij, qhov hloov pauv viscosity ntawm HPMC tsis yog kev sib raug zoo. Thaum qhov kub nce mus rau ib qho twg, HPMC tuaj yeem dhau los ua cov txheej txheem dej nag. Rau HPMC, kev sib raug zoo ntawm solubility thiab kub yog qhov nyuaj: nyob rau hauv ib tug tej yam kub thiab txias, HPMC yuav precipitate los ntawm cov tshuaj, uas yog manifested raws li ib tug ntse nce nyob rau hauv cov kua viscosity los yog tsim gel. Qhov tshwm sim no feem ntau tshwm sim thaum nws los ze lossis tshaj qhov kub ntawm HPMC.
3. Qhov cuam tshuam ntawm qhov kub thiab txias ntawm tus cwj pwm rheological ntawm HPMC tov
Tus cwj pwm rheological ntawm HPMC cov tshuaj feem ntau pom muaj cov nyhuv shear-thinning, uas yog, viscosity txo qis thaum lub shear tus nqi nce. Cov kev hloov hauv qhov kub thiab txias muaj qhov cuam tshuam loj rau cov nyhuv shear-thinning. Feem ntau, thaum kub nce, qhov viscosity ntawm HPMC cov tshuaj txo qis, thiab nws cov nyhuv shear-thinning yuav pom tseeb dua. Qhov no txhais tau hais tias nyob rau ntawm qhov kub thiab txias, qhov viscosity ntawm HPMC cov tshuaj ua ntau dua nyob ntawm tus nqi shear, piv txwv li, ntawm tib tus nqi shear, cov tshuaj HPMC ntawm qhov kub thiab txias ntws yooj yim dua li qhov kub thiab txias.
Tsis tas li ntawd, qhov nce hauv qhov kub thiab txias kuj cuam tshuam rau thixotropy ntawm HPMC tov. Thixotropy yog hais txog cov cuab yeej uas cov viscosity ntawm cov tshuaj txo qis nyob rau hauv qhov kev txiav txim ntawm shear force, thiab cov viscosity maj mam rov qab los tom qab lub shear quab yuam raug tshem tawm. Feem ntau, qhov nce hauv qhov kub thiab txias ua rau muaj qhov nce hauv thixotropy ntawm HPMC cov tshuaj, piv txwv li, tom qab lub zog shear raug tshem tawm, cov viscosity rov qab tau qeeb dua li qhov kub thiab txias.
4. Qhov cuam tshuam ntawm qhov kub thiab txias ntawm tus cwj pwm gelation ntawm HPMC
HPMC muaj cov khoom tshwj xeeb thermal gelation, piv txwv li, tom qab cua sov mus rau qhov kub thiab txias (gel kub), cov tshuaj HPMC yuav hloov los ntawm lub xeev cov tshuaj mus rau lub xeev gel. Cov txheej txheem no cuam tshuam rau qhov kub thiab txias. Raws li qhov kub thiab txias, kev sib cuam tshuam ntawm hydroxypropyl thiab methyl hloov pauv hauv HPMC molecules nce, ua rau muaj kev cuam tshuam ntawm cov saw hlau molecular, yog li tsim cov gel. Qhov tshwm sim no yog qhov tseem ceeb hauv kev lag luam kws tshuaj thiab zaub mov vim nws tuaj yeem siv los kho cov kev ntxhib los mos thiab tso tawm cov khoom ntawm cov khoom.
5. Daim ntawv thov thiab qhov tseem ceeb
Cov nyhuv ntawm qhov kub thiab txias ntawm cov khoom rheological ntawm HPMC yog qhov tseem ceeb hauv kev siv tswv yim. Rau daim ntawv thov ntawm HPMC cov kev daws teeb meem, xws li tshuaj tiv thaiv-tso tawm kev npaj, zaub mov thickeners, lossis cov tswj hwm rau cov khoom siv hauv tsev, cov txiaj ntsig ntawm qhov kub thiab txias ntawm cov khoom siv rheological yuav tsum tau txiav txim siab los xyuas kom meej qhov ruaj khov thiab ua haujlwm ntawm cov khoom nyob rau hauv qhov sib txawv kub. Piv txwv li, thaum npaj cov tshuaj kub-rhiab heev, cov nyhuv ntawm qhov kub thiab txias hloov ntawm viscosity thiab gelation tus cwj pwm ntawm HPMC matrix yuav tsum tau txiav txim siab los txhim kho cov tshuaj tso tawm.
Qhov kub thiab txias muaj qhov cuam tshuam loj rau cov khoom rheological ntawm hydroxypropyl methylcellulose. Qhov kub nce feem ntau txo qhov viscosity ntawm HPMC cov kev daws teeb meem, txhim kho nws cov nyhuv shear-thinning thiab thixotropy, thiab kuj tseem tuaj yeem ua rau cov thermal gelation. Hauv kev siv cov tswv yim, kev nkag siab thiab tswj cov txiaj ntsig ntawm qhov kub thiab txias ntawm cov khoom rheological ntawm HPMC yog tus yuam sij rau kev ua kom zoo ntawm cov khoom lag luam thiab cov txheej txheem tsis zoo.
Post lub sij hawm: Sep-05-2024