Dab tsi yog cov khoom rheological ntawm HPMC?

Dab tsi yog cov khoom rheological ntawmHPMC?

Hydroxypropyl methylcellulose (HPMC) yog ntau yam polymer uas pom kev siv dav hauv ntau yam lag luam, suav nrog tshuaj, kev tsim kho, khoom noj khoom haus, thiab tshuaj pleev ib ce, feem ntau vim nws qhov tshwj xeeb rheological zog. Rheology yog kev kawm txog kev ntws thiab deformation ntawm cov ntaub ntawv, thiab nkag siab txog cov khoom rheological ntawm HPMC yog qhov tseem ceeb rau kev ua kom zoo dua nws cov kev ua tau zoo hauv ntau daim ntawv thov.

Viscosity: HPMC nthuav tawm pseudoplastic lossis shear-thinning tus cwj pwm, txhais tau tias nws cov viscosity txo qis nrog nce shear npaum li cas. Cov cuab yeej no yog qhov tseem ceeb hauv cov ntawv thov xws li kev tsim tshuaj, qhov uas nws tso cai rau kev siv yooj yim, sib kis, thiab daim ntawv thov. Viscosity tuaj yeem hloov kho los ntawm kev hloov kho qib ntawm kev hloov pauv (DS) thiab molecular hnyav ntawm HPMC.

Thixotropy: Thixotropy yog hais txog qhov kev hloov pauv ntawm gel-sol hloov tau nthuav tawm los ntawm qee cov ntaub ntawv nyob rau hauv kev nyuaj siab shear. HPMC gels tsim thaum so tuaj yeem tawg hauv qab shear thiab rov ua lawv cov qauv gel thaum qhov kev ntxhov siab raug tshem tawm. Cov cuab yeej no muaj txiaj ntsig zoo hauv daim ntawv thov xws li xim, qhov uas nws tiv thaiv sagging thaum lub sij hawm thov, tab sis xyuas kom meej txheej txheej ib zaug.

Hydration: HPMC yog hygroscopic thiab nqus tau dej, ua rau o thiab nce viscosity. Lub degree ntawm hydration nyob ntawm seb yam xws li kub, pH, thiab ionic zog ntawm ib puag ncig nruab nrab. Hydration plays lub luag haujlwm tseem ceeb hauv kev tswj cov tshuaj tso tawm ntawm cov tshuaj formulations thiab tswj cov dej noo hauv cov khoom noj.

Temperature Sensitivity:HPMCCov kev daws teeb meem pom qhov kub-nyob ntawm viscosity, nrog viscosity txo qis thaum kub nce. Txawm li cas los xij, tus cwj pwm no tuaj yeem sib txawv nyob ntawm seb muaj pes tsawg leeg xws li polymer concentration thiab pH daws. Qhov kub thiab txias yog qhov tseem ceeb hauv cov ntawv thov xws li cov khoom siv, uas nws cuam tshuam rau kev ua haujlwm thiab teeb tsa lub sijhawm.

Salt Sensitivity: HPMC cov kev daws teeb meem tuaj yeem ua rau muaj kev nkag siab zoo rau cov ntsev, nrog qee cov ntsev ua rau kom muaj viscosity thiab lwm yam ua rau viscosity txo. Qhov tshwm sim no yog vim muaj kev cuam tshuam ntawm HPMC molecules thiab ions hauv kev daws. Ntsev rhiab heev yog qhov tseem ceeb hauv cov tshuaj formulations thiab khoom noj khoom haus uas cov ntsiab lus ntsev yuav tsum tau ua tib zoo tswj.

Shear Rate Dependence: Cov khoom rheological ntawm HPMC cov kev daws teeb meem yog nyob ntawm seb tus nqi shear npaum li cas. Thaum qis shear tus nqi, viscosity yog siab dua vim muaj zog molecular entanglement, whereas nyob rau hauv siab shear tus nqi, viscosity txo vim shear thinning. Kev nkag siab txog qhov kev cia siab ntawm shear yog qhov tseem ceeb rau kev tsim cov txheej txheem ua haujlwm hauv ntau daim ntawv thov.

Particle Suspension: HPMC tuaj yeem ua tus neeg sawv cev ncua rau cov khoom hauv cov kua dej vim nws cov thickening thiab stabilizing zog. Nws pab tiv thaiv kev sib tsoo ntawm cov khoom sib txuas, ua kom cov khoom sib xws thiab sib xws hauv cov khoom xws li cov xim, cov nplaum, thiab cov tshuaj raug tshem tawm.

Gel Tsim:HPMCtuaj yeem tsim cov gels ntawm qhov siab siab lossis nyob rau hauv lub xub ntiag ntawm crosslinking agents xws li divalent cations. Cov gels no nthuav tawm cov khoom viscoelastic thiab siv rau hauv daim ntawv thov xws li kev tswj cov tshuaj xa mus, qhov twg yuav tsum tau tso tawm cov khoom xyaw nquag.

Cov khoom rheological ntawm HPMC, suav nrog viscosity, thixotropy, hydration, kub thiab ntsev rhiab heev, shear rate dependence, particle suspension, thiab gel tsim, ua lub luag haujlwm tseem ceeb hauv kev txiav txim siab nws cov kev ua tau zoo hauv ntau daim ntawv thov kev lag luam. Kev nkag siab thiab tswj cov khoom no yog qhov tseem ceeb rau kev txhim kho kev tsim thiab kev ua haujlwm ntawm HPMC-based cov khoom.