Hydroxypropyl methylcellulose (HPMC) yog ntau yam polymer uas pom muaj kev siv dav hauv ntau yam lag luam xws li tshuaj, khoom noj, tshuaj pleev ib ce, thiab kev tsim kho. Ib qho ntawm nws cov khoom tshwj xeeb yog nws lub peev xwm los tsim cov gels hauv cov xwm txheej tshwj xeeb. Nkag siab txog qhov kub thiab txias ntawm HPMC yog qhov tseem ceeb rau kev txhim kho nws cov kev siv hauv ntau daim ntawv thov.
Taw qhia rau HPMC:
Hydroxypropyl methylcellulose (HPMC) yog semi-synthetic, inert, viscoelastic polymer muab tau los ntawm cellulose. Nws yog feem ntau siv los ua cov thickener, stabilizer, emulsifier, thiab zaj duab xis qub vim nws cov yeeb yaj kiab zoo heev thiab muaj peev xwm hloov kho cov rheology ntawm aqueous systems. HPMC yog soluble hauv dej txias, thiab nws cov tshuaj viscosity nyob ntawm seb yam xws li qhov hnyav ntawm molecular, qib ntawm kev hloov pauv, thiab concentration.
Gelation Mechanism:
Gelation yog hais txog cov txheej txheem los ntawm cov kev daws teeb meem hloov mus rau hauv gel, nthuav tawm cov cwj pwm zoo li tus cwj pwm nrog lub peev xwm los tswj nws cov duab. Nyob rau hauv cov ntaub ntawv ntawm HPMC, gelation feem ntau tshwm sim los ntawm ib tug thermally induced txheej txheem los yog los ntawm kev ntxiv ntawm lwm yam tshuaj xws li ntsev.
Factors cuam tshuam gelation:
Kev Cuam Tshuam ntawm HPMC: Kev siab dua ntawm HPMC feem ntau ua rau kom nrawm dua vim muaj kev sib cuam tshuam ntawm cov polymer-polymer.
Molecular Luj: Siab molecular hnyav HPMC polymers zoo li tsim gels yooj yim dua vim muaj zog entanglements thiab intermolecular kev sib tshuam.
Degree of Hloov: Qhov degree ntawm kev hloov pauv, uas qhia txog qhov twg ntawm hydroxypropyl thiab methyl hloov pauv ntawm cov pob txha cellulose, cuam tshuam rau qhov kub thiab txias. Kev hloov pauv ntau dua tuaj yeem txo qhov kub ntawm gelation.
Muaj Cov Ntsev: Qee cov ntsev, xws li alkali hlau chlorides, tuaj yeem txhawb nqa gelation los ntawm kev cuam tshuam nrog cov saw hlau polymer.
Kub: Kub ua lub luag haujlwm tseem ceeb hauv gelation. Raws li qhov kub thiab txias, cov saw hlau polymer tau txais lub zog kinetic, ua kom yooj yim molecular rearrangements tsim nyog rau kev tsim gel.
Gelation Kub ntawm HPMC:
Qhov kub ntawm gelation ntawm HPMC tuaj yeem sib txawv nyob ntawm ntau yam uas tau hais ua ntej. Feem ntau, HPMC gels ntawm qhov kub siab tshaj nws qhov kub thiab txias, uas feem ntau yog li ntawm 50 ° C txog 90 ° C. Txawm li cas los xij, qhov ntau yam no tuaj yeem sib txawv nyob ntawm qib tshwj xeeb ntawm HPMC, nws cov concentration, molecular hnyav, thiab lwm yam kev tsim.
Daim ntawv thov ntawm HPMC Gels:
Pharmaceuticals: HPMC gels yog siv dav hauv cov tshuaj formulations rau kev tswj cov tshuaj tso tawm, tshuaj pleev ib ce, thiab raws li viscosity modifiers nyob rau hauv cov ntaub ntawv ua kua.
Kev Lag Luam Khoom Noj: Hauv kev lag luam khoom noj khoom haus, HPMC gels yog siv los ua cov thickeners, stabilizers, thiab gelling agents hauv ntau yam khoom xws li kua ntses, khoom qab zib, thiab cov khoom noj siv mis.
Kev tsim kho: HPMC gels nrhiav tau daim ntawv thov hauv cov khoom siv xws li cementitious mortars, uas lawv ua raws li cov dej tuav cov neeg ua haujlwm, txhim kho kev ua haujlwm thiab adhesion.
Tshuaj pleev ib ce: HPMC gels tau muab tso rau hauv cov tshuaj pleev ib ce xws li cream, tshuaj pleev ib ce, thiab cov khoom tu plaub hau rau lawv cov thickening thiab stabilizing zog.
gelation kub ntawm HPMC nyob ntawm ntau yam xws li concentration, molecular hnyav, degree ntawm hloov, thiab muaj cov additives xws li ntsev. Thaum lub gelation kub feem ntau ntog nyob rau hauv thaj tsam ntawm 50 ° C mus rau 90 ° C, nws muaj peev xwm sib txawv heev raws li cov kev cai formulation. Kev nkag siab txog tus cwj pwm gelation ntawm HPMC yog qhov tseem ceeb rau nws txoj kev siv tau zoo thoob plaws hauv kev siv tshuaj, khoom noj, kev tsim kho, thiab kev lag luam tshuaj pleev ib ce. Kev tshawb fawb ntxiv rau hauv cov xwm txheej cuam tshuam rau HPMC gelation tuaj yeem ua rau kev txhim kho cov qauv tsim kho thiab cov ntawv thov tshiab rau ntau yam polymer no.
Post lub sij hawm: Mar-28-2024