Hydroxypropyl methylcellulose (HPMC) yog ib qho polymer uas yaj tau hauv dej uas siv ntau, siv dav hauv tshuaj, tshuaj pleev ib ce, khoom noj thiab kev lag luam, tshwj xeeb tshaj yog hauv kev npaj cov gels. Nws cov khoom siv lub cev thiab tus cwj pwm yaj muaj qhov cuam tshuam loj rau qhov ua tau zoo hauv ntau daim ntawv thov. Qhov kub ntawm gelation ntawm HPMC gel yog ib qho ntawm nws cov khoom siv lub cev tseem ceeb, uas cuam tshuam ncaj qha rau nws cov kev ua tau zoo hauv ntau yam kev npaj, xws li kev tswj hwm kev tso tawm, kev tsim zaj duab xis, kev ruaj khov, thiab lwm yam.
1. Cov qauv thiab cov khoom ntawm HPMC
HPMC yog cov polymer uas yaj tau hauv dej los ntawm kev ntxiv ob hom tshuaj hloov pauv, hydroxypropyl thiab methyl, rau hauv cov pob txha cellulose molecular. Nws cov qauv molecular muaj ob hom tshuaj hloov pauv: hydroxypropyl (-CH2CHOHCH3) thiab methyl (-CH3). Cov yam xws li cov ntsiab lus hydroxypropyl sib txawv, qib ntawm methylation, thiab qib ntawm polymerization yuav muaj feem cuam tshuam tseem ceeb rau kev yaj, tus cwj pwm gelling, thiab cov khoom siv kho tshuab ntawm HPMC.
Hauv cov kua dej, AnxinCel®HPMC tsim cov kua colloidal ruaj khov los ntawm kev tsim cov hydrogen bonds nrog cov dej molecules thiab cuam tshuam nrog nws cov pob txha cellulose. Thaum qhov chaw sab nraud (xws li kub, lub zog ionic, thiab lwm yam) hloov pauv, kev sib cuam tshuam ntawm HPMC molecules yuav hloov pauv, ua rau gelation.
2. Kev txhais thiab cov yam cuam tshuam ntawm qhov kub thiab txias ntawm cov gelation
Qhov kub ntawm Gelation (Gelation Temperature, T_gel) yog hais txog qhov kub uas cov kua HPMC pib hloov ntawm kua mus rau khoom thaum qhov kub ntawm cov kua nce mus txog qee qib. Ntawm qhov kub no, kev txav mus los ntawm HPMC molecular saw yuav raug txwv, tsim cov qauv network peb-seem, ua rau muaj cov tshuaj zoo li gel.
Qhov kub ntawm HPMC gelation cuam tshuam los ntawm ntau yam, ib qho tseem ceeb tshaj plaws yog cov ntsiab lus hydroxypropyl. Ntxiv nrog rau cov ntsiab lus hydroxypropyl, lwm yam uas cuam tshuam rau qhov kub ntawm gel suav nrog qhov hnyav molecular, qhov concentration ntawm cov tshuaj, pH tus nqi, hom kuab tshuaj, lub zog ionic, thiab lwm yam.
3. Cov nyhuv ntawm cov ntsiab lus hydroxypropyl rau ntawm HPMC gel kub
3.1 Qhov nce ntawm cov hydroxypropyl cov ntsiab lus ua rau qhov kub ntawm gel nce ntxiv
Qhov kub ntawm HPMC gelation muaj feem cuam tshuam nrog qib ntawm hydroxypropyl hloov pauv hauv nws lub molecule. Thaum cov ntsiab lus hydroxypropyl nce ntxiv, tus lej ntawm cov hydrophilic substituents ntawm HPMC molecular saw nce ntxiv, ua rau muaj kev sib cuam tshuam ntawm lub molecule thiab dej. Qhov kev sib cuam tshuam no ua rau cov saw molecular ncab ntxiv, yog li txo qhov muaj zog ntawm kev sib cuam tshuam ntawm cov saw molecular. Hauv qee qhov kev sib xyaw ua ke, kev nce cov ntsiab lus hydroxypropyl pab txhim kho qib ntawm hydration thiab txhawb kev sib koom ua ke ntawm cov saw molecular, yog li ntawd cov qauv network tuaj yeem tsim tau ntawm qhov kub siab dua. Yog li ntawd, qhov kub ntawm gelation feem ntau nce nrog hydroxypropyl nce nrog cov ntsiab lus nce ntxiv.
HPMC nrog cov ntsiab lus hydroxypropyl siab dua (xws li HPMC K15M) feem ntau ua rau pom qhov kub siab dua ntawm qhov concentration ntau dua li AnxinCel®HPMC nrog cov ntsiab lus hydroxypropyl qis dua (xws li HPMC K4M). Qhov no yog vim tias cov ntsiab lus hydroxypropyl siab dua ua rau nws nyuaj rau cov molecules sib cuam tshuam thiab tsim cov tes hauj lwm ntawm qhov kub qis dua, xav tau qhov kub siab dua kom kov yeej qhov hydration no thiab txhawb kev sib cuam tshuam intermolecular los tsim cov qauv tes hauj lwm peb-seem.
3.2 Kev sib raug zoo ntawm cov ntsiab lus hydroxypropyl thiab kev sib xyaw ua ke ntawm cov tshuaj
Qhov concentration ntawm cov tshuaj kuj yog ib qho tseem ceeb uas cuam tshuam rau qhov kub ntawm HPMC. Hauv cov tshuaj HPMC uas muaj concentration siab, kev sib cuam tshuam ntawm cov molecule muaj zog dua, yog li qhov kub ntawm cov gelation yuav siab dua txawm tias cov ntsiab lus hydroxypropyl qis dua. Ntawm qhov concentration qis, kev sib cuam tshuam ntawm cov molecule HPMC tsis muaj zog, thiab cov tshuaj yuav zoo li gel ntawm qhov kub qis dua.
Thaum cov ntsiab lus hydroxypropyl nce ntxiv, txawm hais tias hydrophilicity nce ntxiv, qhov kub siab dua tseem xav tau los tsim cov gel. Tshwj xeeb tshaj yog nyob rau hauv cov xwm txheej qis concentration, qhov kub gelation nce ntxiv ntau dua. Qhov no yog vim HPMC nrog cov ntsiab lus hydroxypropyl siab nyuaj dua los ua kom muaj kev sib cuam tshuam ntawm cov saw hlau molecular los ntawm kev hloov pauv kub, thiab cov txheej txheem gelation xav tau lub zog thermal ntxiv kom kov yeej cov nyhuv hydration.
3.3 Cov nyhuv ntawm cov ntsiab lus hydroxypropyl rau cov txheej txheem gelation
Hauv qee qhov ntau ntawm cov ntsiab lus hydroxypropyl, cov txheej txheem gelation yog dominated los ntawm kev sib cuam tshuam ntawm hydration thiab molecular saw. Thaum cov ntsiab lus hydroxypropyl hauv HPMC molecule qis, qhov hydration tsis muaj zog, kev sib cuam tshuam ntawm cov molecules muaj zog, thiab qhov kub qis dua tuaj yeem txhawb kev tsim cov gel. Thaum cov ntsiab lus hydroxypropyl siab dua, qhov hydration tau txhim kho ntau heev, kev sib cuam tshuam ntawm cov molecular saw ua rau tsis muaj zog, thiab qhov kub gelation nce ntxiv.
Cov ntsiab lus hydroxypropyl siab dua kuj tseem yuav ua rau muaj kev nce ntxiv ntawm cov viscosity ntawm HPMC kua, qhov kev hloov pauv uas qee zaum ua rau qhov kub ntawm gelation nce ntxiv.
Cov ntsiab lus Hydroxypropyl muaj qhov cuam tshuam loj rau qhov kub gelation ntawmHPMC. Raws li cov ntsiab lus hydroxypropyl nce ntxiv, qhov hydrophilicity ntawm HPMC nce ntxiv thiab kev sib cuam tshuam ntawm cov saw hlau molecular tsis muaj zog, yog li nws qhov kub gelation feem ntau nce ntxiv. Qhov xwm txheej no tuaj yeem piav qhia los ntawm cov txheej txheem sib cuam tshuam ntawm hydration thiab cov saw hlau molecular. Los ntawm kev kho cov ntsiab lus hydroxypropyl ntawm HPMC, kev tswj hwm qhov kub gelation tuaj yeem ua tiav, yog li ua kom zoo dua qhov kev ua tau zoo ntawm HPMC hauv kev lag luam tshuaj, khoom noj thiab lwm yam kev siv hauv kev lag luam.
Lub sijhawm tshaj tawm: Lub Ib Hlis-04-2025