Cellulose ether derivatives yog chav kawm ntawm cov tshuaj hloov kho cov pa ntawm cov polymers. Vim yog lawv cov dej solubility zoo, viscosity kev hloov kho ua tau zoo xws li kub thiab pH, cov tshuaj, cov tshuaj, khoom noj thiab tshuaj pleev ib ce. Lub viscosity tswj muaj nuj nqi ntawm cellulose muaj ether yog ib qho ntawm cov yam ntxwv tseem ceeb ntawm nws cov ntawv thov dav hauv ntau daim ntawv thov txhua hnub.
1. Cov qauv thiab kev faib tawm ntawm cov kws ua haujlwm ntawm cellulose
Cellulose ether derivatives tau npaj los ntawm ntuj cellulose los ntawm etherification cov tshuaj tiv thaiv. Cellulose yog cov kab ke polymer tsim los ntawm cov piam thaj sib txuas nrog β-1,4-glycosidic bonds. Cov txheej txheem npaj ntawm cellulose feem ntau yuav cuam tshuam nrog cov cellulose los ua kom muaj qhov sib txawv cellulatives (xws li methoxy, hydroxyethyl, hydroxyprropyl, thiab lwm yam).
Nyob ntawm cov hloov chaw, ib txwm muaj ether derivose muaj cov kws kho cellulose (mc), hydloylartyl cellulose (HECC), Hydbox cellulose (HECC) Cellulose (HECC) Tus naj npawb thiab txoj haujlwm ntawm cov neeg tuaj hloov tsis yog cuam tshuam rau cov dej solubility ntawm cellulose kev ua kom muaj peev xwm hauv cov kev daws teeb meem aqueous.
2. Viscosity Tsim Kho Mechanism
Lub viscosity kev ua nyhuv ntawm cov cellulose cov neeg hais ua ke tsuas yog los ntawm lawv cov kev sib nrauj hauv dej thiab qhov kev coj cwj pwm txuas ntxiv ntawm cov saw molecular. Thaum cov neeg hais txog cellulose tau yaj nyob hauv dej, polar pawg ua ke nrog cov roj av molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, ua rau lub cellulose molecules, nce kev sib txhuam ntawm cov dej sib txhuam, thiab yog li nce cov viscosity ntawm kev daws teeb meem.
Qhov ntau ntawm viscosity yog ze ze rau cov molecular hnyav, hloov hom hloov chaw, Qib ntawm polymerization (DP) ntawm cov kws ua haujlwm cellulose. Feem ntau, qhov hnyav dua cov molecular hnyav ntawm cov neeg ua haujlwm ntawm cellulose thiab ntev dua cov molecular, ntau dua cov viscosity ntawm kev daws. Nyob rau tib lub sijhawm, hloov chaw sib txawv cuam tshuam rau cov hydrophilicity ntawm cellibhilicity ntawm cellulose ither molecules, thiab yog li cuam tshuam rau lawv solubility thiab viscosity nyob rau hauv dej. Piv txwv li, HPMC muaj cov dej solubility zoo thiab viscosity stability vim nws hydroxypropyl thiab methyl hloov. CMC, txawm li cas los xij, muaj cov viscosity ntau dua vim nws qhia tsis tau cov pab pawg carboxyl, uas tuaj yeem sib cuam tshuam ntau dua nrog cov lwg dej hauv cov aqueous.
3. Cov nyhuv ntawm cov ntsiab lus sab nraud ntawm viscosity
Lub viscosity ntawm cellulose ntawm cellulose nyob ntawm tsis tsuas yog nyob ntawm nws tus kheej cov qauv, tab sis kuj yog ib puag ncig sab nraud, suav nrog qhov kub thiab txias, thiab lwm yam.
3.1 kub
Qhov kub yog qhov tseem ceeb cuam tshuam rau cov viscosity ntawm cellulose ether. Feem ntau, cov viscosity ntawm cellulose ether tawm nrog kev nce kub. Qhov no yog vim hais tias nce kub excelective molecular suab nrov molecules, txo cov kev cuam tshuam ntawm cov nyhuv molecules ntawm cov dej lwg me me, yog li txo viscosity. Txawm li cas los xij, qee qhov kev pab cuam cellulose (xws li HPMC) kev nthuav dav thermal cov yam ntxwv tsis pub dhau qhov kub thiab thaum nws thiaj li ua tau zoo ntxiv thiab thaum kawg ua rau cov gel.
3.2 PIC NQE
Tus nqi pH tseem muaj qhov cuam tshuam tseem ceeb ntawm viscosity ntawm cellulose ether. Rau cov cellulose muaj kev pab cuam nrog ionic hloov chaw (xws li CMC), yog li cuam tshuam rau kev sib cuam tshuam ntawm cov molecules thiab viscosity ntawm kev daws. Ntawm ntau qhov tseem ceeb dua, cov pab pawg carboxyl yog ntau dua ionized, ua rau muaj zog dua electrostatic rapulsion, ua cov molecular saw yooj yim rau nthuav tawm thiab nce visccosity; Thaum nyob ntawm qhov tseem ceeb tshaj qhov, cov pab pawg carboxyl tsis yooj yim ionized, lub electrostatic repulsion raug txo, cov molecular saw curls, thiab viscosity txo.
3.3 ion concentration
Cov nyhuv ntawm ion concentration ntawm viscosity ntawm cellulose ether yog pom tseeb kiag li. Cellulose ether nrog ionic hloov yuav raug cuam tshuam los ntawm cov thaiv cov nyhuv ntawm sab nraud ions hauv kev daws. Raws li ion concentration hauv kev daws teeb meem nce, sab nraud ntawm cellules rov ua kom nruj dua, yog li txo lub viscosity ntawm txoj kev daws teeb meem. Tshwj xeeb tshaj yog nyob rau hauv lub siab-ntsev ib puag ncig, viscosity ntawm cmc yuav txo qis qhov tseem ceeb rau kev tsim qauv.
4. Viscosity tswj hauv cov ntawv thov
Cellulose ether tau siv dav hauv ntau thaj teb vim nws zoo nkauj viscosity kev hloov kho.
4.1 Cov Ntaub Ntawv Hauv Tsev
Hauv cov ntaub ntawv hauv tsev, cellulose ether (xws li HPMC) feem ntau siv nyob rau hauv cov khoom sib xyaw kom huv thiab lwm yam khoom los sib xyaw thiab txhim kho cov khoom siv flui thiab los tiv thaiv cov khoom thaum tsim kho. Nyob rau tib lub sijhawm, nws kuj tseem tuaj yeem ncua cov dej evapororation, txhim kho cov dej khaws cia, thiab yog li txhim kho lub zog thiab cov khoom kawg ntawm cov khoom kawg.
4.2 Txheej thiab inks
Cellulose Cov neeg ua kom muaj kev hais ua kom nruj raws li cov tuab thiab stabilizers hauv cov dej ua cov txheej txheem thiab inks. Los ntawm kev kho lub viscosity, lawv xyuas kom muaj kev vam meej thiab nplaum ntawm cov txheej thaum lub sijhawm kev tsim kho. Ib qho ntxiv, nws kuj tseem tuaj yeem txhim kho cov anti-splashing ntawm txheej, txo cov sagging, thiab ua kom cov kev tsim kho ntau dua.
4.3 tshuaj thiab khoom noj
Hauv cov liaj teb ntawm cov tshuaj thiab cov khoom noj, xws li HPMC, CMC) feem ntau siv raws li cov tuab tuab, emulsifiers lossis embilizers lossis stabilizers. Piv txwv li, HPMC, ua cov khoom siv txheej xim rau cov ntsiav tshuaj, tuaj yeem ua tiav cov khoom siv tawm ntawm cov tshuaj los ntawm kev tswj hwm tus lej xaus. Nyob rau hauv cov zaub mov, cmc yog siv los ua kom viscosity, txhim kho saj, thiab txuas lub txee lub neej ntawm cov zaub mov.
4.4 Tshuaj pleev ib ce
Daim ntawv thov cov kws kho mob cellulose hauv cov tshuaj pleev ib ce yog feem ntau muaj cov khoom lag luam xws li emulsions, gels thiab ntsej muag lub ntsej muag. Los kho cov viscosity, cov khoom siv cellulose tuaj yeem muab cov khoom tsim nyog fluidity thiab ua ib zaj duab xis noo nyob rau daim tawv nqaij kom nce thaum siv thaum siv sijhawm.
Cellulose ether derivatives tuaj yeem tswj lub viscosity ntawm kev daws teeb meem los ntawm lawv cov qauv molecular thiab cov kev qhia zoo rau cov chaw sab nraud. Qhov no tau coj mus rau lawv cov ntawv thov dav hauv ntau daim teb zoo li kev tsim kho, tshuaj, khoom noj, thiab tshuaj pleev ib ce. Nrog kev txhim kho kev kawm txuas ntxiv ntawm kev tshawb fawb thiab thev naus laus zis, cov haujlwm ntawm cellulose muaj kev cuam tshuam ntxiv kom muab cov kev daws teeb meem ntau dua rau ntau daim teb.
Lub Sijhawm Post: Feb-17-2025