1. Cov khoom yooj yim ntawm HPMC
HydroxyPropyyl methylcellulose (HPMC)yog cov neeg nonionic cellulose ether dav siv nyob rau hauv cov ntaub ntawv hauv tsev, tshuaj, khoom noj, pleev tshuaj thiab lwm yam kev lag luam. Nws tshwj xeeb lub cev, xws li solubility, thickening, zaj duab xis-ua thiab thermal gelation cov khoom, ua nws cov khoom tseem ceeb hauv ntau cov ntawv thov. Qhov kub yog ib qho ntawm cov ntsiab lus cuam tshuam rau kev ua haujlwm ntawm HPMC, tshwj xeeb tshaj yog nyob rau solubility, thoj, thermal gelation thiab thermal ruaj khov.
2. Cov nyhuv ntawm cov solubility ntawm HPMC
HPMC yog ib qho thermoreversibly soluble polymer, thiab nws solubility hloov nrog ntsuas kub:
Tsawg lub xeev (dej txias): HPMC yooj yim soluble hauv dej txias, tab sis nws yuav nqus dej thiab o thaum nws thawj zaug tiv toj dej los ua gel hais. Yog tias nplawm tsis txaus, qog yuav ua. Yog li, nws feem ntau pom zoo ntxiv HPMC maj mam thaum ua rau txhawb kev sib cais.
Nruab nrab kub (20-40 ℃): Hauv qhov ntsuas kub no, HPMC muaj kev ua haujlwm zoo thiab yog qhov tsim nyog rau ntau lub tshuab uas yuav tsum tau ua kom tuab lossis ruaj khov.
Kev kub siab (saum 60 ° C): HPMC yog nquag los ua cov gel kub ntawm qhov kub. Thaum qhov ntsuas kub tau mus txog qhov ntsuas kub tshwj xeeb, kev daws yuav dhau los ua opaque lossis txawm coagulate, cuam tshuam rau daim ntawv thov kev siv. Piv txwv li, hauv tsev cov ntaub ntawv xws li cug lossis putty hmoov, yog tias cov dej kub dhau, HPMC yuav tsis muaj kev cuam tshuam zoo, yog li cuam tshuam rau kev tsim kho zoo.
3. Cov nyhuv ntawm kub ntawm HPMC viscosity
Lub viscosity ntawm HPMC tau cuam tshuam heev los ntawm qhov kub:
Kev daws teeb meem kub dua, txo viscosity: viscosity ntawm HPMC cov tshuaj feem ntau yog txo qis nrog kev nce kub. Piv txwv li, lub viscosity ntawm qee qhov kev daws teeb meem HPMC yuav siab ntawm 20 ° C, thaum nyob ntawm 50 ° C, nws viscosity yuav poob qis.
Kub tsawg, viscosity recovers: Yog tias HPMC tov yog txias dua tom qab cua sov, nws yuav tsis tuaj yeem rov qab mus rau thawj lub xeev.
HPMC ntawm cov qauv viscosity sib txawv coj tus cwj pwm sib txawv: high-viscosity HPMC tsis tshua muaj kev hloov pauv thaum ntsuas kub hloov. Yog li ntawd, nws yog ib qho tseem ceeb rau xaiv hpmc nrog txoj cai viscosity hauv kev thov sib txawv.
4. Cov nyhuv ntawm qhov kub ntawm lub thermal gelation ntawm HPMC
Ib qho tseem ceeb ntawm HPMC yog thermal gelation, uas yog, thaum lub qhov kub nce mus rau ib theem, nws txoj kev daws teeb meem yuav hloov mus ua gel. Qhov no feem ntau yog hu ua gelation kub. Ntau hom HPMC muaj kev sib txawv ntau qhov chaw kub, feem ntau ntawm 50-80 ℃.
Nyob rau hauv cov zaub mov thiab kev lag luam tshuaj, cov xeeb ceem ntawm HPMC yog siv los npaj cov tshuaj muaj zog lossis tso tawm cov zaub mov.
Nyob rau hauv kev kho cov kev siv, xws li cug cug thiab putty hmoov, lub thermal gelation, tab sis yog tias cov kev tsim kho dej kub dhau lawm, gelation yuav cuam tshuam rau kev ua haujlwm.
5. Cov nyhuv ntawm qhov kub ntawm lub thermal stability ntawm hpmc
Tus qauv tshuaj ntawm HPMC yog qhov ruaj ntseg nyob rau hauv qhov ntsuas kub kom haum, tab sis ntev ntev kom muaj qhov kub siab yuav ua rau muaj kev cuam tshuam.
Lub sijhawm luv luv kub siab (xws li instantaneous cua sov rau saum toj no 100 ℃): Tej zaum yuav cuam tshuam rau cov tshuaj lom neeg ntawm HPMC, tab sis yuav ua rau cov khoom siv lub cev, xws li kev tawm suab.
Ntev ntev ntev (xws li txuas ntxiv cov cua sov saum toj no 90 ℃): ua rau cov molecular tso rau hauv viscosity, cuam tshuam nws cov thickening thiab zaj duab xis-ua cov khoom.
Huab cua kub heev (dhau 200 ℃): HPMC tuaj yeem yauv tawm cov tshuaj lom neeg xws li Methanol thiab propanol, thiab ua rau cov khoom rau discolor lossis txawm tias carbonize.
6. Daim ntawv thov cov lus pom zoo rau HPMC hauv qhov chaw kub sib txawv
Txhawm rau muab kev ua si tag nrho rau kev ua haujlwm ntawm HPMC, tsim nyog ntsuas yuav tsum tau coj raws li qhov chaw kub:
Hauv qhov chaw kub tsawg (0-10 ℃): HPMC yws qeeb, thiab nws raug nquahu kom ua ntej yaj nws hauv dej sov (20-40 ℃) ua ntej siv.
Nyob rau hauv ib txwm ib puag ncig (10-40 ℃): HPMC muaj kev ua tau ruaj khov thiab haum rau cov ntawv thov feem ntau, cov ntawv thov neeg nplua,, khoom noj khoom haus thiab tshuaj kom zoo nkauj.
Hauv qhov kub ib puag ncig (saum 40 ℃): Zam kev ntxiv HPMC ncaj qha rau cov kua dej kub. Nws raug nquahu kom yaj nws hauv dej txias ua ntej nws, lossis xaiv cov cua kub tiv taus HPMC los txo qhov kev cuam tshuam ntawm thermal gelation rau ntawm daim ntawv thov.
Kub muaj qhov cuam tshuam tseem ceeb rau solubility, viscosity, thermal gelation thiab thermal stability ntawmHPMCCov. Thaum lub sij hawm ua ntawv thov cov txheej txheem, nws yog qhov tsim nyog xaiv cov qauv thiab txoj kev siv HPMC raws li cov kev mob tshwj xeeb kom ntseeg tau tias nws qhov kev ua tau zoo tshaj plaws. To taub txog qhov kub siab tshaj plaws ntawm HPMC tsis tuaj yeem txhim kho cov khoom lag luam tsis tseem ceeb, tab sis kuj tseem yuav hloov kho thiab txhim kho ntau cov txiaj ntsig.
Lub sijhawm Post: Mar-28-2025