HPMC, los yog Hydroxypropyl Methylcellulose, yog cov khoom siv hluav taws xob uas siv dav hauv cov chaw muag tshuaj, zaub mov, tshuaj pleev ib ce thiab kev tsim kho. Nws muaj ntau yam zoo heev xws li solubility, stability, transparency thiab film-forming zog raws li ib tug thickener, nplaum, zaj duab xis qub, ncua tus neeg sawv cev thiab kev tiv thaiv colloid.
Hais txog qhov viscosity ntawm HPMC, nws yog ib lub tswv yim nyuaj vim tias viscosity cuam tshuam los ntawm ntau yam, xws li concentration, molecular hnyav, hnyav, qhov kub thiab txias.
Kev sib raug zoo ntawm molecular hnyav thiab viscosity: Qhov hnyav molecular ntawm HPMC yog ib qho tseem ceeb uas txiav txim siab nws cov viscosity. Feem ntau hais lus, qhov siab dua qhov hnyav molecular, siab dua qhov viscosity ntawm HPMC. Yog li, cov tuam ntxhab feem ntau muab HPMC cov khoom lag luam nrog cov khoom sib txawv molecular kom tau raws li qhov xav tau ntawm kev lag luam sib txawv. Qhov hnyav Molecular feem ntau yog qhia raws li tus nqi K (xws li K100, K200, thiab lwm yam). Qhov loj dua tus nqi K, qhov viscosity siab dua.
Qhov cuam tshuam ntawm qhov concentration: Lub viscosity ntawm HPMC cov tshuaj hauv dej nce nrog qhov nce ntawm cov concentration. Piv txwv li, 1% concentration ntawm HPMC cov tshuaj yuav muaj viscosity ntau zaus ntau dua li ntawm 0.5% concentration tov. Qhov no tso cai rau cov viscosity ntawm cov tshuaj tswj tau los ntawm kev kho qhov concentration ntawm HPMC hauv daim ntawv thov.
Cov nyhuv ntawm cov kuab tshuaj: HPMC tuaj yeem yaj hauv dej lossis cov kuab tshuaj organic, tab sis cov kuab tshuaj sib txawv cuam tshuam rau nws cov viscosity. Feem ntau, HPMC muaj zoo solubility nyob rau hauv dej thiab cov kua viscosity siab, thaum lub viscosity nyob rau hauv cov organic solvents txawv nyob ntawm seb lub polarity ntawm cov kuab tshuaj thiab cov degree ntawm kev hloov ntawm HPMC.
Qhov cuam tshuam ntawm qhov kub thiab txias: Lub viscosity ntawm HPMC cov tshuaj hloov pauv nrog qhov kub thiab txias. Feem ntau, cov viscosity ntawm HPMC cov tshuaj txo qis thaum kub nce. Qhov no yog vim qhov nce ntawm qhov kub thiab txias ua rau kom ceev molecular zog thiab nce fluidity ntawm cov tshuaj, uas txo cov viscosity.
Qhov cuam tshuam ntawm shear npaum li cas: HPMC tov yog cov kua uas tsis yog-Newtonian, thiab nws cov viscosity hloov nrog tus nqi shear. Qhov no txhais tau hais tias thaum lub sij hawm nplawm los yog twj tso kua mis, lub viscosity hloov nrog lub zog ntawm kev ua haujlwm. Feem ntau, HPMC kev daws teeb meem nthuav tawm cov yam ntxwv ntawm shear thinning, uas yog, viscosity txo qis ntawm qhov siab shear.
HPMC qib thiab cov lus qhia tshwj xeeb: Cov qib sib txawv ntawm HPMC cov khoom kuj tseem muaj qhov sib txawv ntawm viscosity. Piv txwv li, HPMC qib qis viscosity cov khoom yuav muaj viscosity ntawm 20-100 mPas ntawm 2% concentration, thaum lub siab viscosity qib HPMC cov khoom yuav muaj viscosity txog li 10,000-200,000 mPas ntawm tib lub concentration. Yog li ntawd, thaum xaiv HPMC, nws yog ib qho tseem ceeb uas yuav tau xaiv cov qib viscosity uas tsim nyog raws li cov ntawv thov tshwj xeeb.
Standard test method: Lub viscosity ntawm HPMC feem ntau yog ntsuas los ntawm ib tug viscometer los yog rheometer. Cov txheej txheem kuaj pom muaj xws li rotational viscometer thiab capillary viscometer. Kev kuaj mob xws li kub, concentration, hom hnyav, thiab lwm yam tuaj yeem muaj kev cuam tshuam loj rau cov txiaj ntsig, yog li cov kev ntsuas no yuav tsum tau tswj nruj me ntsis thaum kuaj.
Lub viscosity ntawm HPMC yog ib tug complex parameter cuam tshuam los ntawm ntau yam, thiab nws adjustability ua rau nws dav siv nyob rau hauv ntau yam kev siv. Txawm hais tias nyob rau hauv cov khoom noj, tshuaj, khoom siv hauv tsev lossis kev lag luam tshuaj pleev ib ce, kev nkag siab thiab tswj cov viscosity ntawm HPMC yog ib qho tseem ceeb los xyuas kom meej cov khoom zoo thiab kev ua tau zoo.
Post lub sij hawm: Aug-28-2024