Abstract:
Hydroxypropyl Methylcellulose (HPMC) yog cov khoom siv dav siv polymer hauv cov tshuaj, khoom noj khoom haus, tshuaj pleev ib ce, thiab ntau yam kev lag luam vim nws cov khoom tshwj xeeb xws li kev ua yeeb yaj kiab, muaj peev xwm ua kom tuab, thiab tswj kev tso tawm cov yam ntxwv.Txawm li cas los xij, kev nkag siab txog nws cov thermal stability thiab degradation tus cwj pwm nyob rau hauv ib puag ncig sib txawv yog qhov tseem ceeb rau kev ua kom cov khoom zoo thiab kev ua tau zoo.
Taw qhia:
HPMC yog ib tug semi-synthetic polymer muab los ntawm cellulose thiab hloov los ntawm kev sib ntxiv ntawm hydroxypropyl thiab methyl pawg.Nws daim ntawv thov dav dav hauv ntau qhov kev lag luam yuav tsum muaj kev nkag siab zoo ntawm nws txoj kev ruaj ntseg nyob rau hauv cov xwm txheej sib txawv.Thermal stability yog hais txog lub peev xwm ntawm ib yam khoom los tiv thaiv degradation los yog decomposition thaum raug tshav kub.Kev degradation ntawm HPMC tuaj yeem tshwm sim los ntawm ntau txoj hauv kev, suav nrog hydrolysis, oxidation, thiab thermal decomposition, nyob ntawm ib puag ncig yam.
Thermal Stability ntawm HPMC:
Lub thermal stability ntawm HPMC yog cuam tshuam los ntawm ntau yam, nrog rau qhov hnyav molecular, qib ntawm kev hloov, thiab muaj cov impurities.Feem ntau, HPMC pom zoo thermal stability, nrog decomposition kub feem ntau yog li ntawm 200 ° C mus rau 300 ° C.Txawm li cas los xij, qhov no tuaj yeem sib txawv nyob ntawm qib tshwj xeeb thiab kev tsim ntawm HPMC.
Cov teebmeem ntawm qhov kub thiab txias:
Qhov ntsuas kub siab tuaj yeem ua kom lub cev tsis zoo ntawm HPMC, ua rau txo qis hauv molecular hnyav, viscosity, thiab cov khoom ua yeeb yaj kiab.Tshaj li qhov kub thiab txias, thermal decomposition ua qhov tseem ceeb, uas ua rau tso tawm cov khoom tsis haum xws li dej, carbon dioxide, thiab cov organic tebchaw me me.
Cov teebmeem ntawm Humidity:
Cov av noo kuj tuaj yeem cuam tshuam qhov thermal stability ntawm HPMC, tshwj xeeb tshaj yog nyob rau hauv qhov chaw noo noo siab.Cov dej molecules tuaj yeem pab txhawb hydrolytic degradation ntawm HPMC chains, ua rau cov saw saws thiab txo cov kev ntseeg siab ntawm polymer.Tsis tas li ntawd, kev nqus dej noo tuaj yeem cuam tshuam rau lub cev ntawm HPMC cov khoom lag luam, xws li kev coj tus cwj pwm o thiab kev sib cais kinetics.
Cov teebmeem ntawm pH:
Cov pH ntawm ib puag ncig tuaj yeem cuam tshuam rau kev degradation kinetics ntawm HPMC, tshwj xeeb tshaj yog nyob rau hauv aqueous daws.Cov xwm txheej pH heev (acidic lossis alkaline) tuaj yeem ua kom cov tshuaj tiv thaiv hydrolysis, ua rau kom muaj kev puas tsuaj sai ntawm cov saw hlau polymer.Yog li ntawd, pH stability ntawm HPMC formulations yuav tsum tau ua tib zoo soj ntsuam xyuas cov khoom ua tau zoo thiab txee lub neej.
Kev sib cuam tshuam nrog lwm yam khoom:
HPMC tuaj yeem cuam tshuam nrog lwm yam khoom muaj nyob hauv nws ib puag ncig, xws li tshuaj, tshuaj ntxiv, thiab cov khoom ntim.Cov kev sib cuam tshuam no tuaj yeem cuam tshuam qhov thermal stability ntawm HPMC los ntawm ntau lub tswv yim, suav nrog catalysis ntawm cov tshuaj tiv thaiv degradation, tsim cov complexes, los yog lub cev adsorption rau ntawm qhov chaw.
Kev nkag siab txog kev ruaj ntseg thermal thiab degradation tus cwj pwm ntawm HPMC yog qhov tseem ceeb rau kev ua kom nws qhov kev ua tau zoo hauv ntau yam kev siv.Cov yam ntxwv xws li kub, av noo, pH, thiab kev sib cuam tshuam nrog lwm yam tshuaj tuaj yeem cuam tshuam rau kev ruaj ntseg ntawm HPMC-raws li cov khoom.Los ntawm kev ua tib zoo tswj cov kev txwv no thiab xaiv cov qauv tsim nyog, cov tuam txhab tsim khoom tuaj yeem ua kom zoo thiab ua tau zoo ntawm HPMC-muaj cov qauv hauv ntau qhov chaw.Kev tshawb fawb ntxiv yog xav tau los piav qhia txog cov txheej txheem degradation tshwj xeeb thiab tsim cov tswv yim los txhim kho cov thermal stability ntawm HPMC.
Post lub sij hawm: May-08-2024