Hydroxypropyl Methylcellulose (HPMC)yog ib qho non-ionic cellulose ether uas siv ntau, siv dav hauv cov ntaub ntawv tsim kho, tshuaj, khoom noj, tshuaj pleev xim, thiab lwm yam teb. Nws qhov kev ua tau zoo ruaj khov thiab zoo cuam tshuam ncaj qha rau qhov khoom kawg; yog li ntawd, kev sim tshuaj HPMC thaum lub sijhawm tsim khoom thiab daim ntawv thov yog qhov tseem ceeb heev.
1. Kev Ntsuas Qhov Zoo Li Cas thiab Cov Khoom Siv Yooj Yim
Ua ntej yuav kuaj, yuav tsum xub pom cov qauv ua ntej. HPMC zoo yuav tsum yog hmoov dawb lossis dawb tawm uas muaj dej ntws zoo, tsis muaj pob, tsw, lossis tsis huv. Nws cov kua dej yuav tsum pob tshab lossis me ntsis turbid, tsis muaj cov khoom dai kom pom tseeb. Tom qab ntawd, nws cov dej noo yuav raug txiav txim siab, feem ntau siv lub tshuab ntsuas dej noo infrared lossis txoj kev ziab (105 ℃ txoj kev hnyav tas li). Cov khoom tsim nyog feem ntau muaj cov dej noo hauv qab 5%.
Kev txiav txim siab txog cov tshauv qhia txog nws cov ntsiab lus inorganic impurity. Cov qauv raug hlawv hauv lub cub tawg muffle ntawm 550 ℃ kom qhov hnyav tas li. Cov tshauv feem ntau yuav tsum tsis pub tshaj 1.5%. Cov tshauv ntau dhau yuav cuam tshuam rau qhov pob tshab thiab kev ruaj khov ntawm viscosity.
2. Kev Ntsuas Qhov Ntsws
Viscosity yog ib qho ntawm cov cim qhia kev ua tau zoo tshaj plaws ntawm HPMC, txiav txim siab ncaj qha nws cov thickening, dej khaws cia, thiab zaj duab xis-tsim cov teebmeem. Kev sim feem ntau yog ua tiav siv lub rotational viscometer (xws li Brookfield viscometer) lossis Ubbelohde capillary viscometer.
Thaum lub sijhawm kuaj, qee qhov concentration (feem ntau yog 2%) ntawm HPMC aqueous kua raug kuaj ntawm qhov kub thiab txias (feem ntau 20 ± 0.1 ℃). Ntau hom HPMC muaj ntau yam viscosity sib txawv, xws li 400, 15000, thiab 100000 mPa · s. Qhov viscosity ntsuas yuav tsum ua raws li cov khoom txheem; txwv tsis pub, nws qhia tias nws qib ntawm polymerization lossis hloov pauv tsis ruaj khov.
3. Qib Kev Ntsuas Hloov Chaw (Cov Ntsiab Lus Methoxy thiab Hydroxypropoxy)
Kev ua tau zoo ntawm HPMC feem ntau yog txiav txim siab los ntawm cov ntsiab lus ntawm cov neeg hloov pauv.
Cov ntsiab lus methoxy (–OCH₃) cuam tshuam rau kev yaj, qhov kub ntawm gel, thiab kev ua haujlwm ntawm qhov chaw;
Cov hydroxypropoxy (–OCH₂CHOHCH₃) cov ntsiab lus cuam tshuam rau kev yooj ywm thiab kev khaws dej.
Cov txheej txheem txiav txim siab feem ntau siv cov tshuaj titration lossis roj chromatography. Piv txwv li, tom qab acid hydrolysis, cov qauv tsim cov cawv sib xws, uas tom qab ntawd raug tshuaj xyuas ntau los ntawm titration lossis chromatography. Cov khoom lag luam HPMC tsim nyog feem ntau muaj 19% -24% methoxyl cov ntsiab lus thiab 4% -12% hydroxypropoxyl cov ntsiab lus.
4. Kev Ntsuas Kub Gel
Cov yam ntxwv thermogelation ntawm HPMC yog qhov tseem ceeb parameter sib txawv nws los ntawm lwm cov cellulose ethers. Thaum lub sijhawm sim, HPMC aqueous kua yog maj mam rhuab thiab do, thiab qhov kub uas cov kua hloov pauv los ntawm meej mus rau turbid yog kaw ua nws qhov kub gel.
Feem ntau, HPMC nrog cov ntsiab lus methoxyl siab dua muaj qhov kub qis dua gel, thaum cov ntsiab lus hydroxypropoxyl siab dua ua rau qhov kub siab dua gel. Qhov ntsuas no cuam tshuam txog qhov ruaj khov ntawm cov khoom hauv kev siv xws li kev tsim kho mortar thiab txheej ntsiav tshuaj.
5. Tus nqi pH thiab kev sim dej kom yaj
Tom qab npaj 2% HPMC kua, nws cov pH raug ntsuas siv lub pH meter. Qhov ntau thiab tsawg ib txwm yog 5.0–8.0. Hauv qhov ntau thiab tsawg no, HPMC ruaj khov thiab yuav tsis cuam tshuam tsis zoo nrog feem ntau cov ntaub ntawv inorganic lossis cov khoom ntxiv.
Qhov kev sim solubility ntsuas nws qhov kev sib kis thiab qhov nrawm ntawm kev yaj hauv dej txias. HPMC zoo yuav tsum tawg sai sai hauv qab kev sib xyaw, tsim cov tshuaj sib xyaw thiab pob tshab hauv 30 feeb.
6. Kev Tshawb Pom Qhov Huv Si thiab Kev Tsis Huv
Kev kuaj pom kev huv feem ntau suav nrog kev kuaj cov hlau hnyav, chlorides, sulfates, thiab cov kev txwv ntawm cov kab mob me me.
Cov hlau hnyav (ua Pb) feem ntau yuav tsum tsis pub tshaj 20 ppm; chloride ≤ 0.2%, sulfate ≤ 0.5%;
Rau kev siv tshuaj lossis khoom noj, yuav tsum kuaj xyuas tag nrho cov kab mob, cov kab mob coliform, thiab cov pwm/yeast kom paub tseeb tias muaj kev nyab xeeb.
7. Kev Tshuaj Xyuas Thermogravimetric thiab Fourier Transform Infrared Spectroscopy
Txhawm rau soj ntsuam ntxiv txog cov qauv thiab thermal stability ntawm HPMC, thermogravimetric analysis (TGA) thiab Fourier transform infrared spectroscopy (FTIR) tuaj yeem siv tau.
TGA tuaj yeem ntes tau qhov hloov pauv ntawm HPMC ntawm qhov kub sib txawv, yog li txiav txim siab nws qhov kub thiab txias ntawm kev lwj thiab qhov ruaj khov;
FTIR tshuaj xyuas cov qauv pab pawg ua haujlwm los ntawm cov ncov nqus, txheeb xyuas qhov muaj cov yam ntxwv -OH, -OCH₃, thiab -OCH₂CHOHCH₃ nqus cov kab kom paub meej tias qhov tseeb ntawm cov qauv molecular.
Qhov kev sim tshuaj uas tau hais los saum toj no tso cai rau kev ntsuam xyuas tag nrho ntawm cov khoom siv physicochemical thiab kev siv tau ntawm HPMC. Viscosity, qib ntawm kev hloov pauv, thiab cov dej noo yog cov cim qhia kev tswj hwm zoo; thaum pH, cov ntsiab lus tshauv, thiab qhov kub gelation qhia txog nws cov txheej txheem ua thiab kev huv. Kev ua raws li cov txheej txheem sim no tsis yog tsuas yog ua kom cov khoom ruaj khov thiab kev ua tau zoo sib xws tab sis kuj muab kev txhawb nqa cov ntaub ntawv txhim khu kev qha rau kev nyab xeeb thiabKev siv HPMC zoohauv kev lag luam xws li kev tsim kho, tshuaj, thiab khoom noj.
Lub sijhawm tshaj tawm: Lub Kaum Hli-31-2025