HPMC (Hydroxypropyl Methylcellulose) yog ib hom polysaccharide polymer uas siv dav hauv tshuaj, khoom noj, tshuaj lom neeg thiab lwm yam teb. Nws cov yam ntxwv yaj yog ib qho ntawm cov chaw kub hauv kev tshawb fawb thiab kev siv.
1. Cov qauv molecular thiab cov yam ntxwv solubility ntawm HPMC
HPMC yog cov tshuaj polymer uas yaj tau hauv dej los ntawm kev hloov kho etherification ntawm cellulose. Nws cov qauv chav tsev yog β-D-glucose, uas txuas nrog los ntawm 1,4-glycosidic bonds. Cov qauv saw hlau tseem ceeb ntawm HPMC yog los ntawm cov cellulose ntuj, tab sis ib feem ntawm nws cov hydroxyl pawg raug hloov los ntawm methoxy pawg (-OCH₃) thiab hydroxypropyl pawg (-CH₂CH(OH)CH₃), yog li nws qhia txog tus cwj pwm yaj sib txawv ntawm cov cellulose ntuj.
Cov qauv molecular ntawm HPMC muaj qhov cuam tshuam loj heev rau nws qhov solubility. Qib ntawm kev hloov pauv (DS, Qib ntawm Kev Hloov Pauv) thiab molar hloov pauv (MS, Molar Hloov Pauv) ntawm HPMC yog cov yam ntxwv tseem ceeb uas txiav txim siab nws cov yam ntxwv solubility. Qhov siab dua ntawm kev hloov pauv, ntau pawg hydroxyl hauv lub molecule raug hloov los ntawm hydrophobic methoxy lossis hydroxypropyl pawg, uas ua rau kom muaj kev solubility ntawm HPMC hauv cov organic solvents thiab txo qhov solubility hauv dej. Ntawm qhov tsis sib xws, thaum qib ntawm kev hloov pauv qis, HPMC muaj hydrophilic ntau dua hauv dej thiab nws cov nqi yaj sai dua.
2. Txoj kev yaj ntawm HPMC
Qhov solubility ntawm HPMC hauv dej yog ib qho txheej txheem nyuaj thiab tshuaj lom neeg, thiab nws cov txheej txheem yaj feem ntau suav nrog cov kauj ruam hauv qab no:
Theem ntub dej: Thaum HPMC kov dej, cov dej molecules yuav ua ntej tsim cov zaj duab xis hydration ntawm qhov chaw ntawm HPMC los qhwv cov khoom HPMC. Hauv cov txheej txheem no, cov dej molecules cuam tshuam nrog cov hydroxyl thiab methoxy pawg hauv cov molecules HPMC los ntawm cov hydrogen bonds, ua rau cov HPMC molecules maj mam ntub.
Theem o: Nrog rau kev nkag mus ntawm cov dej molecules, HPMC cov khoom me me pib nqus dej thiab o, qhov ntim nce ntxiv, thiab cov saw hlau molecular maj mam xoob. Lub peev xwm o ntawm HPMC raug cuam tshuam los ntawm nws qhov hnyav molecular thiab cov khoom hloov pauv. Qhov loj dua qhov hnyav molecular, lub sijhawm o ntev dua; qhov muaj zog dua qhov hydrophilicity ntawm cov khoom hloov pauv, qhov ntau dua qib ntawm o.
Theem Kev Yaj: Thaum cov HPMC molecules nqus dej txaus, cov saw hlau molecular pib sib cais ntawm cov khoom me me thiab maj mam tawg mus rau hauv cov tshuaj. Qhov ceev ntawm cov txheej txheem no raug cuam tshuam los ntawm cov yam xws li kub, qhov nrawm ntawm kev sib tov thiab cov khoom siv yaj.
HPMC feem ntau qhia tau tias nws yaj tau zoo hauv dej, tshwj xeeb tshaj yog thaum sov li chav. Txawm li cas los xij, nws tsim nyog sau tseg tias thaum qhov kub nce mus txog qee qib, HPMC yuav ua rau pom qhov "thermal gel", uas yog, qhov yaj yuav txo qis thaum qhov kub nce. Qhov no yog vim muaj kev txav mus los ntawm cov dej molecules ntawm qhov kub siab thiab kev sib cuam tshuam hydrophobic ntawm HPMC molecules, ua rau muaj kev sib raug zoo ntawm cov molecules thiab kev tsim cov qauv gel.
3. Cov yam ntxwv cuam tshuam rau qhov solubility ntawm HPMC
Qhov solubility ntawm HPMC raug cuam tshuam los ntawm ntau yam, suav nrog nws cov khoom siv lub cev thiab tshuaj lom neeg thiab cov xwm txheej sab nraud. Cov yam tseem ceeb suav nrog:
Qib ntawm kev hloov pauv: Raws li tau hais los saum toj no, hom thiab tus lej ntawm cov neeg hloov pauv ntawm HPMC ncaj qha cuam tshuam rau nws qhov solubility. Cov neeg hloov pauv ntau dua, cov pab pawg hydrophilic tsawg dua hauv lub molecule thiab qhov phem dua qhov solubility. Ntawm qhov tsis sib xws, thaum muaj tsawg dua cov neeg hloov pauv, qhov hydrophilicity ntawm HPMC tau txhim kho thiab qhov solubility zoo dua.
Qhov hnyav molecular: Qhov hnyav molecular ntawm HPMC yog ncaj qha proportional rau nws lub sijhawm yaj. Qhov hnyav molecular loj dua, qhov qeeb qeeb ntawm cov txheej txheem yaj. Qhov no yog vim tias HPMC molecular saw nrog qhov hnyav molecular loj dua thiab cov molecules nruj dua, ua rau nws nyuaj rau cov dej molecules nkag mus, ua rau qeeb qeeb o thiab yaj.
Kub ntawm cov tshuaj: Kub yog ib qho tseem ceeb uas cuam tshuam rau qhov solubility ntawm HPMC. HPMC yaj sai dua ntawm qhov kub qis dua, thaum ntawm qhov kub siab dua nws yuav tsim cov gel thiab txo nws cov solubility. Yog li ntawd, HPMC feem ntau yog npaj rau hauv dej kub qis kom tsis txhob gelation ntawm qhov kub siab.
Hom tshuaj yaj: HPMC tsis yog tsuas yog yaj hauv dej xwb, tab sis kuj yaj tau hauv qee cov kuab tshuaj organic, xws li ethanol, isopropyl cawv, thiab lwm yam. Kev yaj hauv cov kuab tshuaj organic nyob ntawm hom thiab kev faib tawm ntawm cov tshuaj hloov pauv. Hauv qab qhov xwm txheej ib txwm muaj, HPMC muaj kev yaj tsis zoo hauv cov kuab tshuaj organic, thiab yuav tsum ntxiv dej kom txaus los pab yaj.
Tus nqi pH: HPMC muaj qee qhov kev kam rau tus nqi pH ntawm cov tshuaj, tab sis nyob rau hauv cov kua qaub thiab alkali hnyav, qhov solubility ntawm HPMC yuav raug cuam tshuam. Feem ntau hais lus, HPMC muaj solubility zoo dua hauv pH ntau ntawm 3 txog 11.
4. Daim ntawv thov ntawm HPMC hauv ntau qhov chaw sib txawv
Qhov solubility ntawm HPMC ua rau nws muaj txiaj ntsig zoo hauv ntau qhov chaw:
Kev lag luam tshuaj: HPMC feem ntau siv ua cov ntaub ntawv txheej, cov nplaum thiab cov neeg sawv cev tso tawm ntev rau cov ntsiav tshuaj tshuaj. Hauv cov txheej tshuaj, HPMC tuaj yeem tsim ib zaj duab xis sib xws los txhim kho kev ruaj khov ntawm cov tshuaj; hauv cov qauv tso tawm ntev, HPMC tswj hwm qhov nrawm ntawm cov tshuaj los ntawm kev tswj nws qhov nrawm, yog li ua tiav kev xa tshuaj ntev.
Kev lag luam zaub mov: Hauv zaub mov, HPMC siv ua cov khoom ua kom tuab, emulsifier thiab stabilizer. Vim tias HPMC muaj cov dej solubility zoo thiab kub stability, nws tuaj yeem muab cov qauv thiab saj tsim nyog rau ntau yam zaub mov. Tib lub sijhawm, qhov xwm txheej tsis-ionic ntawm HPMC tiv thaiv nws los ntawm kev cuam tshuam nrog lwm cov khoom xyaw zaub mov thiab tswj kev ruaj khov ntawm lub cev thiab tshuaj lom neeg ntawm zaub mov.
Kev lag luam tshuaj lom neeg txhua hnub: HPMC feem ntau siv ua cov khoom ua kom tuab thiab emulsifier hauv cov khoom xws li tshuaj zawv plaub hau, tshuaj pleev ib ce thiab tshuaj pleev ntsej muag. Nws cov dej yaj zoo thiab cov nyhuv ua kom tuab ua rau nws muaj kev paub zoo heev. Tsis tas li ntawd, HPMC tuaj yeem sib koom ua ke nrog lwm cov khoom xyaw nquag los txhim kho kev ua haujlwm ntawm cov khoom.
Cov ntaub ntawv siv hauv kev tsim kho: Hauv kev lag luam kev tsim kho, HPMC siv ua cov khoom ua kom tuab thiab khaws dej hauv cov cement mortars, cov nplaum pobzeb thiab cov txheej txheem. HPMC tuaj yeem txhim kho kev ua haujlwm ntawm cov ntaub ntawv no, txuas ntxiv lawv lub sijhawm siv, thiab txhim kho lawv txoj kev tiv thaiv tawg.
Ua ib yam khoom siv polymer uas muaj solubility zoo, HPMC tus cwj pwm yaj yog cuam tshuam los ntawm ntau yam, xws li cov qauv molecular, kub, pH tus nqi, thiab lwm yam. Hauv cov teb sib txawv, qhov solubility ntawm HPMC tuaj yeem ua kom zoo dua los ntawm kev kho cov yam no kom tau raws li qhov xav tau sib txawv. Qhov solubility ntawm HPMC tsis yog tsuas yog txiav txim siab nws cov kev ua tau zoo hauv cov kua dej, tab sis kuj cuam tshuam ncaj qha rau nws cov haujlwm hauv kev lag luam tshuaj, khoom noj, tshuaj txhua hnub thiab kev tsim kho.
Lub sijhawm tshaj tawm: Lub Kaum Hli-14-2024