Hydroxypropyl methylcellulose (HPMC) yog ib hom polymer compound nrog ntau hom kev lag luam, tshwj xeeb tshaj yog nyob rau hauv kev lag luam tshuaj, khoom noj khoom haus, khoom siv hauv tsev thiab tshuaj pleev ib ce. Nws cov dej solubility thiab thickening zog ua rau nws zoo tagnrho thickener, stabilizer thiab zaj duab xis qub. Kab lus no yuav tham txog qhov nthuav dav txog kev sib cais thiab o ntawm HPMC hauv dej, nrog rau nws qhov tseem ceeb hauv ntau daim ntawv thov.
1. Cov qauv thiab cov khoom ntawm HPMC
HPMC yog ib qho uas tsis yog-ionic cellulose ether tsim los ntawm kev hloov kho tshuaj ntawm cellulose. Nws cov qauv tshuaj muaj cov tshuaj methyl thiab hydroxypropyl, uas hloov qee cov hydroxyl pawg hauv cellulose molecular saw, muab HPMC cov khoom sib txawv ntawm cov cellulose ntuj. Vim nws cov qauv tshwj xeeb, HPMC muaj cov yam ntxwv tseem ceeb hauv qab no:
Dej solubility: HPMC tuaj yeem yaj hauv dej txias thiab kub thiab muaj zog thickening zog.
Kev ruaj ntseg: HPMC muaj qhov dav dav rau pH qhov tseem ceeb thiab tuaj yeem nyob ruaj khov nyob rau hauv ob qho tib si acidic thiab alkaline.
Thermal gelation: HPMC muaj cov yam ntxwv ntawm thermal gelation. Thaum kub nce, HPMC aqueous tov yuav tsim ib gel thiab yaj thaum kub poob.
2. Lub expansion mechanism ntawm HPMC hauv dej
Thaum HPMC los rau hauv kev sib cuag nrog dej, pawg hydrophilic hauv nws cov saw molecular (xws li hydroxyl thiab hydroxypropyl) yuav cuam tshuam nrog dej molecules los tsim hydrogen bonds. Cov txheej txheem no ua rau HPMC cov saw hlau molecular maj mam nqus dej thiab nthuav dav. Cov txheej txheem nthuav dav ntawm HPMC tuaj yeem muab faib ua cov theem hauv qab no:
2.1 Thawj theem nqus dej
Thaum HPMC cov khoom ua ntej nkag mus rau hauv cov dej, cov dej molecules yuav nkag mus rau hauv cov khoom sai sai, ua rau lub ntsej muag ntawm cov khoom nthuav dav. Cov txheej txheem no feem ntau yog vim muaj kev sib cuam tshuam ntawm cov pab pawg hydrophilic hauv HPMC molecules thiab dej molecules. Txij li thaum HPMC nws tus kheej tsis yog-ionic, nws yuav tsis yaj sai li ionic polymers, tab sis yuav nqus dej thiab nthuav ua ntej.
2.2 Internal expansion theem
Raws li lub sijhawm dhau mus, cov dej molecules maj mam nkag mus rau sab hauv ntawm cov khoom, ua rau cov cellulose chains hauv cov khoom pib nthuav dav. Tus nqi nthuav dav ntawm HPMC cov khoom yuav ua rau qeeb ntawm theem no vim tias kev nkag mus ntawm cov dej molecules yuav tsum tau kov yeej txoj kev nruj ntawm cov saw hlau molecular hauv HPMC.
2.3 Ua tiav theem kev sib cais
Tom qab lub sijhawm ntev txaus, HPMC cov khoom yuav yaj tag nrho hauv dej los tsim cov kua dej tsis sib xws. Lub sijhawm no, cov saw hlau molecular ntawm HPMC yog randomly curled nyob rau hauv dej, thiab cov tshuaj yog thickened los ntawm kev sib cuam tshuam intermolecular. Lub viscosity ntawm cov tshuaj HPMC yog ze ze rau nws qhov hnyav molecular, kua concentration thiab dissolution kub.
3. Cov yam ntxwv cuam tshuam rau kev nthuav dav thiab kev tawg ntawm HPMC
3.1 Kub
Tus cwj pwm kev sib cais ntawm HPMC yog ze ze rau cov dej kub. Feem ntau, HPMC tuaj yeem yaj hauv dej txias thiab dej kub, tab sis cov txheej txheem kev sib cais coj txawv ntawm qhov kub sib txawv. Hauv dej txias, HPMC feem ntau nqus dej thiab o ua ntej, thiab tom qab ntawd maj mam yaj; Thaum nyob rau hauv dej kub, HPMC yuav raug thermal gelation ntawm ib tug tej yam kub thiab txias, uas txhais tau hais tias nws tsim ib tug gel es tsis yog ib tug tov ntawm kub.
3.2 Concentration
Qhov siab dua ntawm cov tshuaj HPMC, qhov qeeb qeeb ntawm qhov nthuav dav, vim tias muaj pes tsawg tus dej molecules hauv cov kua dej siab uas tuaj yeem siv los ua ke nrog HPMC molecular chains raug txwv. Tsis tas li ntawd, qhov viscosity ntawm cov tshuaj yuav nce ntxiv nrog kev nce hauv concentration.
3.3 Particle loj
Qhov loj me me ntawm HPMC kuj cuam tshuam rau nws qhov nthuav dav thiab kev sib cais. Cov khoom me me nqus dej thiab swell sai heev vim lawv qhov loj ntawm thaj chaw tshwj xeeb, thaum cov khoom loj dua nqus dej maj mam thiab siv sijhawm ntev dua kom yaj tag.
3.4 pH tus nqi
Txawm hais tias HPMC muaj qhov hloov pauv tau zoo rau kev hloov pauv hauv pH, nws tus cwj pwm o thiab kev sib cais yuav raug cuam tshuam los ntawm acidic lossis alkaline. Nyob rau hauv nruab nrab rau tsis muaj zog acidic thiab tsis muaj zog alkaline tej yam kev mob, o thiab dissolution txheej txheem ntawm HPMC yog kuj ruaj khov.
4. Lub luag haujlwm ntawm HPMC hauv kev siv sib txawv
4.1 Pharmaceutical kev lag luam
Hauv kev lag luam kws tshuaj, HPMC tau siv dav los ua ib qho kev sib khi thiab tsis sib xws hauv cov tshuaj ntsiav tshuaj. Txij li thaum HPMC swells hauv dej thiab tsim cov gel, qhov no yuav pab txo qis cov tshuaj tso tawm, yog li ua tiav cov txiaj ntsig tso tawm. Tsis tas li ntawd, HPMC kuj tseem siv tau los ua cov khoom tseem ceeb ntawm cov tshuaj yeeb yaj kiab txheej los txhim kho kev ruaj ntseg ntawm cov tshuaj.
4.2 Cov khoom siv hauv tsev
HPMC kuj tseem ua lub luag haujlwm tseem ceeb hauv cov khoom siv hauv tsev, tshwj xeeb tshaj yog ua cov thickener thiab dej retainer rau cement mortar thiab gypsum. Cov cuab yeej o ntawm HPMC hauv cov ntaub ntawv no ua rau nws khaws cov dej noo hauv qhov kub thiab txias ib puag ncig, yog li tiv thaiv kev tsim cov kab nrib pleb thiab txhim kho lub zog ntawm cov khoom siv.
4.3 Kev lag luam zaub mov
Hauv kev lag luam zaub mov, HPMC yog siv los ua cov thickener, emulsifier thiab stabilizer. Piv txwv li, hauv cov khoom ci, HPMC tuaj yeem txhim kho kev ruaj ntseg ntawm khob noom cookie thiab txhim kho kev ntxhib los mos thiab saj ntawm cov khoom. Tsis tas li ntawd, cov khoom o ntawm HPMC kuj tuaj yeem siv los tsim cov khoom noj muaj roj tsawg lossis tsis muaj rog kom ua rau lawv txaus siab thiab ruaj khov.
4.4 Tshuaj pleev ib ce
Hauv cov tshuaj pleev ib ce, HPMC tau siv dav hauv cov khoom tu tawv nqaij, tshuaj zawv plaub hau thiab cov tshuaj ua kom txias ua cov thickener thiab stabilizer. Cov gel tsim los ntawm kev nthuav dav ntawm HPMC hauv dej pab txhim kho kev ntxhib los mos ntawm cov khoom thiab tsim cov yeeb yaj kiab tiv thaiv ntawm daim tawv nqaij kom cov tawv nqaij hydrated.
5. Cov ntsiab lus
Cov cuab yeej o ntawm HPMC hauv dej yog lub hauv paus rau nws daim ntawv thov dav. HPMC nthuav dav los ntawm kev nqus dej los tsim cov tshuaj lossis gel nrog viscosity. Cov cuab yeej no ua rau nws siv dav hauv ntau qhov chaw xws li tshuaj, kev tsim kho, khoom noj thiab tshuaj pleev ib ce.
Post lub sij hawm: Oct-09-2024