1. Taw qhia
Hydroxypropyl methylcellulose (HPMC) yog ib qho tseem ceeb hluavtaws cellulose derivative dav siv nyob rau hauv tsev cov ntaub ntawv, tshuaj npaj, zaub mov additives thiab tshuaj pleev ib ce. Nws cov dej tuav tau zoo yog ib qho ntawm cov yam ntxwv tseem ceeb ntawm HPMC daim ntawv thov dav.
2. Cov qauv thiab cov khoom ntawm HPMC
2.1 Cov qauv tshuaj
HPMC yog semi-synthetic cellulose ether. Cov hydroxypropyl thiab methyl substituents nyob rau hauv cov qauv tshuaj muab nws tshwj xeeb solubility thiab colloidal zog. Cov qauv hauv paus ntawm HPMC muaj β-D-glucose chains ntawm cellulose, uas qee pawg hydroxyl hloov los ntawm methyl thiab hydroxypropyl pawg. Txoj hauj lwm thiab qib ntawm kev hloov pauv ntawm cov khoom hloov pauv ncaj qha cuam tshuam rau kev solubility, viscosity thiab dej tuav ntawm HPMC.
2.2 Lub cev muaj zog
Dej solubility: HPMC yog yooj yim soluble nyob rau hauv dej txias thiab tsim ib tug colloidal tov nyob rau hauv dej kub.
Thickening khoom: Nws tuaj yeem tsim cov kua dej khov hauv dej thiab muaj cov nyhuv thickening zoo.
Cov cuab yeej ua yeeb yaj kiab: Nws tuaj yeem tsim cov duab pob tshab thiab elastic.
Suspension: Nws muaj qhov ua tau zoo ntawm kev ncua hauv kev daws teeb meem thiab tuaj yeem txhim kho qhov teeb meem raug ncua.
3. Kev tuav dej ntawm HPMC
3.1 Dej tuav mechanism
Kev tuav dej ntawm HPMC feem ntau yog los ntawm kev sib cuam tshuam ntawm hydroxyl thiab cov pab pawg hloov pauv hauv nws cov qauv molecular thiab dej molecules. Tshwj xeeb, HPMC khaws cov dej los ntawm cov txheej txheem hauv qab no:
Hydrogen bonding: Cov pab pawg hydroxyl hauv HPMC molecules tsim hydrogen bonds nrog dej molecules. Lub zog no ua rau cov dej molecules kom ruaj khov nyob ib puag ncig HPMC, txo cov dej evaporation.
Cov nyhuv viscosity siab: Cov tshuaj viscosity siab tsim los ntawm HPMC hauv dej tuaj yeem cuam tshuam cov dej txav, yog li txo cov dej poob.
Network qauv: Cov qauv network tsim los ntawm HPMC hauv dej tuaj yeem ntes thiab khaws cov dej molecules, kom cov dej sib npaug sib npaug hauv cov qauv network.
Cov nyhuv Colloid: Lub colloid tsim los ntawm HPMC tuaj yeem kaw dej hauv lub colloid thiab ua kom lub sijhawm khaws dej.
3.2 Yam cuam tshuam rau kev tuav dej
Kev hloov pauv qib: Kev tuav dej ntawm HPMC raug cuam tshuam los ntawm qib kev hloov pauv (DS). Qhov siab dua qhov kev hloov pauv, qhov muaj zog hydrophilicity ntawm HPMC thiab nws cov dej tuav tau zoo dua.
Molecular Luj: Siab dua molecular hnyav pab tsim kom muaj zog molecular saw network, yog li txhim kho dej tuav.
Concentration: Qhov concentration ntawm HPMC cov tshuaj muaj qhov cuam tshuam loj rau kev tuav dej. Cov kev daws teeb meem siab muaj peev xwm tsim cov kev daws teeb meem ntau dua thiab ruaj khov dua cov qauv sib txuas, yog li khaws cov dej ntau dua.
Kub: Cov dej tuav ntawm HPMC sib txawv nrog qhov kub thiab txias. Thaum qhov kub nce siab, qhov viscosity ntawm HPMC cov tshuaj txo qis, ua rau txo qis hauv dej tuav.
4. Kev thov ntawm HPMC hauv ntau qhov chaw
4.1 Cov khoom siv hauv tsev
Hauv cov khoom siv hauv tsev, HPMC yog siv los ua cov dej ntim rau cov cement thiab gypsum-based khoom. Nws lub luag haujlwm tseem ceeb suav nrog:
Txhim kho kev tsim kho kev ua haujlwm: Los ntawm kev tswj hwm qhov tsim nyog ntawm cov dej noo, lub sijhawm qhib ntawm cov cement thiab gypsum txuas ntxiv, ua rau cov txheej txheem tsim kho smoother.
Txo cov kab nrib pleb: Cov dej tuav tau zoo pab txo cov kab nrib pleb uas tsim los thaum lub sij hawm ziab thiab txhim kho lub zog thiab kav ntev ntawm cov khoom kawg.
Txhim kho daim ntawv cog lus muaj zog: Hauv cov pobzeb nplaum, HPMC tuaj yeem ua kom muaj zog ntawm daim ntawv cog lus thiab txhim kho kev sib raug zoo.
4.2 Kev npaj tshuaj
Hauv kev npaj tshuaj, kev tuav dej ntawm HPMC ua lub luag haujlwm tseem ceeb hauv kev tso tawm thiab kev ruaj ntseg ntawm cov tshuaj:
Sustained-release npaj: HPMC tuaj yeem siv los ua cov tshuaj tiv thaiv-tso tawm rau cov tshuaj kom ua tiav cov tshuaj tso tawm los ntawm kev tswj cov dej nkag mus thiab cov tshuaj yaj yeeb.
Thickeners thiab binders: Hauv cov tshuaj ua kua thiab cov ntsiav tshuaj, HPMC ua cov thickener thiab binder kom muaj kev ruaj ntseg thiab sib xws ntawm cov tshuaj.
4.3 Khoom noj khoom haus additives
Hauv kev lag luam khoom noj khoom haus, HPMC ua cov thickener thiab stabilizer, thiab nws cov dej tuav yog siv rau:
Txhim kho saj: Los ntawm kev tuav dej, HPMC tuaj yeem txhim kho kev ntxhib los mos thiab saj ntawm cov zaub mov, ua rau nws muaj kuab heev thiab qab.
Txhim kho lub neej txee: Los ntawm kev tuav dej, HPMC tuaj yeem tiv thaiv dej poob thaum khaws cia, yog li txuas lub txee lub neej.
4.4 Tshuaj pleev ib ce
Hauv cov tshuaj pleev ib ce, cov dej tuav ntawm HPMC yog siv rau:
Cov nyhuv moisturizing: Raws li moisturizer, HPMC tuaj yeem pab txhawm rau ya raws ntawm daim tawv nqaij thiab muab cov nyhuv moisturizing ntev.
Stabilizing suspensions: Hauv emulsions thiab suspensions, HPMC stabilizes cov khoom thiab tiv thaiv stratification thiab sedimentation.
Kev tuav dej ntawm HPMC ua rau nws yog cov khoom siv tseem ceeb hauv ntau qhov chaw. Nws khaws cov dej thiab txo cov dej evaporation los ntawm hydrogen bonding, siab viscosity cuam tshuam, network qauv thiab cov teebmeem colloid. Kev tuav dej yog cuam tshuam los ntawm kev hloov pauv, qhov hnyav molecular, concentration thiab kub, uas txiav txim siab qhov ua tau zoo ntawm HPMC hauv ib daim ntawv thov tshwj xeeb. Txawm hais tias nyob rau hauv cov khoom siv hauv tsev, kev npaj tshuaj, khoom noj khoom haus lossis tshuaj pleev ib ce, kev tuav dej ntawm HPMC ua lub luag haujlwm tseem ceeb hauv kev txhim kho cov khoom zoo thiab kev ua tau zoo.
Post lub sij hawm: Jun-26-2024