Viscosity ntawm Cellulose Ethers

Lub viscosity ntawmcellulose ethersyog ib qho khoom tseem ceeb uas txiav txim siab nws cov txiaj ntsig hauv ntau yam kev siv. Cellulose ethers, xws li Hydroxypropyl Methylcellulose (HPMC), Hydroxyethyl Cellulose (HEC), thiab lwm yam, muaj cov yam ntxwv viscosity sib txawv nyob ntawm cov yam ntxwv xws li kev hloov pauv, qhov hnyav molecular, thiab cov concentration hauv cov tshuaj. Ntawm no yog ib lub ntsiab lus luv luv:

1. Degree of Hloov (DS):
   • Qib ntawm kev hloov pauv yog hais txog qhov nruab nrab ntawm cov hydroxyethyl, hydroxypropyl, lossis lwm pab pawg qhia txog ib chav tsev anhydroglucose hauv cov saw cellulose.
   • Siab dua DS feem ntau ua rau muaj viscosity ntau dua.
2. Molecular Luj:
   • Qhov hnyav molecular ntawm cellulose ethers tuaj yeem cuam tshuam lawv cov viscosity. Siab molecular hnyav polymers feem ntau ua rau cov viscosity ntau dua.
3. Concentration:
   • Viscosity yog nyob ntawm concentration. Raws li qhov concentration ntawm cellulose ether nyob rau hauv ib qho kev daws nce, yog li ntawd viscosity.
   • Kev sib raug zoo ntawm concentration thiab viscosity yuav tsis yog linear.
4. Kub:
   • Kub tuaj yeem cuam tshuam rau solubility thiab viscosity ntawm cellulose ethers. Qee qhov xwm txheej, viscosity tuaj yeem txo qis nrog qhov kub thiab txias vim kev txhim kho solubility.
5. Hom Cellulose Ether:
   • Ntau hom cellulose ethers yuav muaj qhov sib txawv viscosity profiles. Piv txwv li, Hydroxypropyl Methylcellulose (HPMC) tuaj yeem pom cov yam ntxwv sib txawv viscosity piv rau Hydroxyethyl Cellulose (HEC).
6. Solvent lossis Solution Conditions:
   • Kev xaiv ntawm cov kuab tshuaj los yog cov kev daws teeb meem (pH, ionic zog) tuaj yeem cuam tshuam cov viscosity ntawm cellulose ethers.

Daim ntawv thov raws li viscosity:

1. Tsawg viscosity:
   • Siv nyob rau hauv daim ntaub ntawv uas ib tug tsawg thickness los yog sib xws yog xav tau.
   • Piv txwv suav nrog qee cov txheej txheem, tshuaj tsuag daim ntawv thov, thiab cov qauv tsim kom yooj yim rau kev nchuav.
2. Nruab nrab viscosity:
   • Feem ntau siv nyob rau hauv ntau yam lag luam rau kev siv xws li nplaum, tshuaj pleev ib ce, thiab tej yam khoom noj.
   • Strikes qhov sib npaug ntawm fluidity thiab thickness.
3. High viscosity:
   • Zoo dua rau cov ntawv thov uas muaj cov nyhuv thickening lossis gelling yog qhov tseem ceeb.
   • Siv nyob rau hauv cov tshuaj formulations, cov ntaub ntawv siv, thiab high-viscosity khoom noj khoom haus.

Kev ntsuas viscosity:

Viscosity feem ntau ntsuas siv viscometers lossis rheometers. Txoj kev tshwj xeeb yuav txawv raws li hom cellulose ether thiab daim ntawv thov npaj. Viscosity feem ntau tshaj tawm hauv chav xws li centipoise (cP) lossis mPa·s.

Nws yog ib qho tseem ceeb uas yuav tau xav txog qhov xav tau viscosity ntau rau ib daim ntawv thov thiab xaiv cov qib cellulose ether raws li. Cov neeg tsim khoom muab cov ntaub ntawv qhia txog cov yam ntxwv viscosity ntawm lawv cov cellulose ethers nyob rau hauv cov xwm txheej sib txawv.