1. Cov khoom tseem ceeb ntawm HPMC
Hydroxypropyl methylcellulose (HPMC)yog ib tug nonionic cellulose ether dav siv nyob rau hauv lub tsev cov ntaub ntawv, tshuaj, zaub mov, tshuaj pleev ib ce thiab lwm yam lag luam. Nws cov khoom tshwj xeeb physicochemical, xws li solubility, thickening, film-forming thiab thermal gelation zog, ua rau nws yog ib qho tseem ceeb muaj nyob rau hauv ntau daim ntawv thov kev lag luam. Qhov kub thiab txias yog ib qho tseem ceeb cuam tshuam rau kev ua haujlwm ntawm HPMC, tshwj xeeb tshaj yog nyob rau hauv cov nqe lus ntawm solubility, viscosity, thermal gelation thiab thermal stability.
2. Qhov cuam tshuam ntawm qhov kub thiab txias ntawm qhov solubility ntawm HPMC
HPMC yog ib qho thermoreversibly soluble polymer, thiab nws solubility hloov nrog kub:
Lub xeev kub qis (dej txias): HPMC yooj yim soluble hauv dej txias, tab sis nws yuav nqus dej thiab o thaum nws thawj zaug sib cuag dej los tsim cov gel. Yog hais tias stirring tsis txaus, lumps yuav tsim. Yog li ntawd, nws yog feem ntau pom zoo kom ntxiv HPMC maj mam thaum nplawm los txhawb kev sib cais tsis sib xws.
Qhov nruab nrab kub (20-40 ℃): Nyob rau hauv qhov kub thiab txias, HPMC muaj solubility zoo thiab viscosity siab, thiab yog haum rau ntau lub tshuab uas yuav tsum tau thickening los yog stabilization.
Kub kub (siab tshaj 60 ° C): HPMC yog nquag tsim cov gel kub ntawm qhov kub thiab txias. Thaum qhov kub nce mus txog qhov tshwj xeeb gel kub, cov tshuaj yuav ua opaque lossis txawm coagulate, cuam tshuam rau daim ntawv thov. Piv txwv li, nyob rau hauv lub tsev cov ntaub ntawv xws li mortar los yog putty hmoov, yog hais tias cov dej kub siab heev, HPMC tej zaum yuav tsis zoo yaj, yog li cuam tshuam rau kev tsim kho zoo.
3. Qhov kub thiab txias ntawm HPMC viscosity
Lub viscosity ntawm HPMC cuam tshuam zoo heev los ntawm qhov kub thiab txias:
Ua kom kub, txo viscosity: Lub viscosity ntawm HPMC cov tshuaj feem ntau txo qis nrog qhov kub thiab txias. Piv txwv li, qhov viscosity ntawm HPMC cov tshuaj yuav siab ntawm 20 ° C, thaum nyob rau ntawm 50 ° C, nws cov viscosity yuav poob qis heev.
Kub poob qis, viscosity rov qab: Yog tias HPMC cov tshuaj tau txias tom qab cua sov, nws cov viscosity yuav rov qab ib nrab, tab sis nws yuav tsis tuaj yeem rov qab mus rau lub xeev thawj zaug.
HPMC ntawm cov qib viscosity sib txawv coj txawv txawv: high-viscosity HPMC yog rhiab heev rau qhov kub thiab txias hloov, thaum tsawg-viscosity HPMC muaj tsawg viscosity fluctuations thaum kub hloov. Yog li ntawd, nws yog ib qho tseem ceeb tshwj xeeb los xaiv HPMC nrog txoj cai viscosity nyob rau hauv ntau daim ntawv thov scenarios.
4. Cov nyhuv ntawm qhov kub thiab txias ntawm lub thermal gelation ntawm HPMC
Ib qho tseem ceeb ntawm HPMC yog thermal gelation, uas yog, thaum kub nce mus rau ib theem, nws cov tshuaj yuav tig mus rau hauv gel. Qhov kub no feem ntau hu ua gelation kub. Ntau hom HPMC muaj qhov sib txawv gelation kub, feem ntau ntawm 50-80 ℃.
Hauv kev lag luam khoom noj thiab tshuaj, tus yam ntxwv ntawm HPMC yog siv los npaj cov tshuaj tso tawm lossis cov khoom noj khoom haus.
Hauv kev tsim kho, xws li cov cement mortar thiab putty hmoov, cov thermal gelation ntawm HPMC tuaj yeem muab cov dej tuav, tab sis yog tias qhov chaw tsim kho qhov kub thiab txias, gelation yuav cuam tshuam rau kev tsim kho.
5. Qhov cuam tshuam ntawm qhov kub thiab txias ntawm lub thermal stability ntawm HPMC
Cov qauv tshuaj lom neeg ntawm HPMC yog qhov ruaj khov nyob rau hauv qhov tsim nyog qhov kub thiab txias, tab sis lub sij hawm ntev raug rau qhov kub thiab txias yuav ua rau degradation.
Lub sij hawm luv luv ntawm qhov kub siab (xws li cua sov tam sim ntawd mus rau saum 100 ℃): tej zaum yuav tsis cuam tshuam rau cov tshuaj HPMC, tab sis yuav ua rau muaj kev hloov pauv ntawm lub cev, xws li txo viscosity.
Lub sij hawm ntev kub siab (xws li cov cua kub tsis tu ncua saum 90 ℃): tej zaum yuav ua rau cov saw molecular ntawm HPMC tawg, ua rau qhov tsis tuaj yeem txo qis hauv viscosity, cuam tshuam rau nws cov thickening thiab zaj duab xis-tsim zog.
Qhov kub siab heev (tshaj 200 ℃): HPMC tuaj yeem raug thermal decomposition, tso cov khoom tsis zoo xws li methanol thiab propanol, thiab ua rau cov khoom tsis muaj xim lossis carbonize.
6. Cov lus pom zoo ntawm daim ntawv thov rau HPMC nyob rau hauv qhov sib txawv ntawm qhov kub thiab txias
Txhawm rau muab kev ua si tag nrho rau kev ua haujlwm ntawm HPMC, kev ntsuas tsim nyog yuav tsum tau ua raws li qhov sib txawv ntawm qhov kub thiab txias:
Nyob rau hauv qhov kub thiab txias (0-10 ℃): HPMC dissolves maj mam, thiab nws raug nquahu kom yaj ua ntej hauv dej sov (20-40 ℃) ua ntej siv.
Nyob rau hauv ib puag ncig qhov kub thiab txias (10-40 ℃): HPMC muaj kev ua haujlwm ruaj khov thiab tsim nyog rau feem ntau cov ntawv thov, xws li cov coatings, mortars, khoom noj khoom haus thiab tshuaj excipients.
Nyob rau hauv ib puag ncig kub (siab tshaj 40 ℃): Tsis txhob ntxiv HPMC ncaj qha rau cov kua kub kub. Nws raug nquahu kom yaj nws hauv dej txias ua ntej cua sov, lossis xaiv qhov kub siab tiv thaiv HPMC kom txo tau qhov cuam tshuam ntawm thermal gelation ntawm daim ntawv thov.
Kub muaj qhov cuam tshuam tseem ceeb rau kev solubility, viscosity, thermal gelation thiab thermal stability ntawmHPMC. Thaum lub sij hawm ua ntawv thov, nws yog ib qho tsim nyog yuav tsum xaiv tus qauv thiab txoj kev siv HPMC raws li qhov kub thiab txias los xyuas kom meej tias nws qhov kev ua tau zoo. Kev nkag siab txog qhov kub thiab txias ntawm HPMC tuaj yeem tsis tsuas yog txhim kho cov khoom zoo, tab sis kuj zam qhov tsis tsim nyog los ntawm kev hloov pauv kub thiab txhim kho kev tsim khoom thiab cov txiaj ntsig kev lag luam.
Lub sij hawm xa tuaj: Mar-28-2025