Hydroxypropylmethylcellulose (HPMC) yog cov khoom siv polymer nrov siv hauv kev lag luam xws li tshuaj, kev tsim kho, zaub mov thiab kev saib xyuas tus kheej. Nws yog ib daim ntawv hloov kho ntawm cellulose tau los ntawm reacting methylcellulose nrog propylene oxide. HPMC yog cov hmoov dawb los yog dawb, tsis muaj ntxhiab, tsis qab, yooj yim soluble hauv dej, ethanol thiab lwm yam kuab tshuaj organic. Daim ntawv no tham txog cov kev qhia tseem ceeb ntawm HPMC.
viscosity
Viscosity yog qhov tseem ceeb tshaj plaws kev ntsuas ntawm HPMC, uas txiav txim siab nws tus cwj pwm ntws thiab kev siv hauv ntau yam lag luam. HPMC muaj viscosity siab, uas txhais tau hais tias nws muaj tuab, zoo li zib ntab zoo nkauj. Lub viscosity ntawm HPMC tuaj yeem hloov kho los ntawm kev hloov cov qib ntawm kev hloov ntawm hydroxyl pawg. Qhov siab dua qhov kev hloov pauv, qhov viscosity siab dua.
Degree ntawm kev hloov
Qib ntawm kev hloov pauv (DS) yog lwm qhov kev qhia tseem ceeb ntawm HPMC, uas yog hais txog cov pawg hydroxyl hloov los ntawm pawg hydroxypropyl thiab methyl pawg. DS ntawm HPMC feem ntau yog nyob ntawm 0.1 txog 1.7, nrog rau DS siab dua qhia tias muaj kev hloov kho ntau dua. DS ntawm HPMC cuam tshuam rau nws cov solubility, viscosity thiab gel zog.
molecular hnyav
Qhov hnyav molecular ntawm HPMC kuj yog ib qho tseem ceeb ntawm kev ntsuas uas cuam tshuam rau nws lub cev thiab tshuaj lom neeg xws li solubility, viscosity, thiab gelation. HPMC feem ntau muaj qhov hnyav molecular ntawm 10,000 txog 1,000,000 Daltons, nrog cov khoom hnyav dua molecular qhia txog cov saw hlau ntev dua. Qhov hnyav molecular ntawm HPMC cuam tshuam rau nws cov thickening efficiency, zaj duab xis tsim muaj peev xwm thiab dej tuav.
Tus nqi PH
Tus nqi pH ntawm HPMC yog ib qho tseem ceeb kev ntsuas ntsuas cuam tshuam rau nws cov solubility thiab viscosity. HPMC yog soluble hauv acidic thiab alkaline daws, tab sis nws cov viscosity siab dua nyob rau hauv acidic tej yam kev mob. Cov pH ntawm HPMC tuaj yeem hloov kho los ntawm kev ntxiv cov kua qaub lossis lub hauv paus. HPMC feem ntau muaj pH ntawm 4 thiab 9.
noo noo cov ntsiab lus
Cov dej noo ntawm HPMC yog qhov tseem ceeb tshaj plaws kev ntsuas uas cuam tshuam rau nws qhov ruaj khov thiab kev ua haujlwm. HPMC yog hygroscopic, uas txhais tau hais tias nws absorbs noo noo los ntawm huab cua. Cov dej noo ntawm HPMC yuav tsum khaws cia qis dua 7% kom ntseeg tau tias nws ruaj khov thiab zoo. Cov dej noo ntau tuaj yeem ua rau polymer caking, clumping thiab degradation.
Cov ntsiab lus tshauv
Cov ntsiab lus tshauv ntawm HPMC yog ib qho tseem ceeb kev ntsuas ntsuas cuam tshuam rau nws cov purity thiab zoo. Tshauv hais txog cov inorganic seem tshuav tom qab HPMC raug hlawv. Cov hmoov tshauv ntawm HPMC yuav tsum tsawg dua 7% kom ntseeg tau tias nws purity thiab zoo. Cov ntsiab lus tshauv siab yuav qhia tau tias muaj impurities lossis paug hauv cov polymer.
Gelation kub
Lub gel kub ntawm HPMC yog ib qho tseem ceeb kev ntsuas ntsuas uas cuam tshuam rau nws cov gel kev ua tau zoo. HPMC tuaj yeem gel hauv qee qhov kub thiab txias. Lub gelation kub ntawm HPMC tuaj yeem hloov kho los ntawm kev hloov pauv qib thiab qhov hnyav molecular. Lub gelling kub ntawm HPMC feem ntau yog 50 txog 90 ° C.
nyob rau hauv xaus
Hydroxypropylmethylcellulose (HPMC) yog ib qho khoom siv polymer nrog ntau yam kev qhia tshwj xeeb. Cov kev qhia tseem ceeb ntawm HPMC suav nrog viscosity, degree ntawm kev hloov pauv, qhov hnyav molecular, pH tus nqi, cov ntsiab lus noo noo, cov ntsiab lus tshauv, gelation kub, thiab lwm yam. Los ntawm kev paub txog cov kev qhia tshwj xeeb no, peb tuaj yeem xaiv hom HPMC txoj cai rau peb daim ntawv thov tshwj xeeb thiab ua kom nws zoo thiab ruaj khov.
Post lub sij hawm: Sep-04-2023