Cellulose ethers yog ib chav kawm sib txawv ntawm cov tebchaw uas tau los ntawm cellulose, ib yam khoom ntuj tsim muaj nyob hauv cov phab ntsa ntawm cov nroj tsuag.Lawv tau siv dav hauv ntau qhov kev lag luam vim lawv cov khoom tshwj xeeb, suav nrog kev solubility hauv ntau cov kuab tshuaj.Kev nkag siab txog tus cwj pwm solubility ntawm cellulose ethers yog qhov tseem ceeb rau lawv cov kev siv tshuaj, khoom noj, kev tsim kho, thiab lwm yam haujlwm.
Cellulose ethers feem ntau yog tsim los ntawm kev hloov kho cellulose los ntawm cov tshuaj tiv thaiv etherification.Cov hom cellulose ethers muaj xws li methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), thiab carboxymethyl cellulose (CMC).Txhua yam qhia txog cov yam ntxwv sib txawv raws li nws cov qauv tshuaj thiab qib kev hloov pauv.
Lub solubility ntawm cellulose ethers yog cuam tshuam los ntawm tej yam xws li degree ntawm polymerization, degree ntawm kev hloov, molecular hnyav, thiab qhov xwm ntawm pab pawg neeg.Feem ntau, cellulose ethers nrog qib qis ntawm kev hloov pauv thiab siab dua qhov hnyav molecular yog tsawg dua soluble piv rau cov uas muaj qib siab dua ntawm kev hloov pauv thiab qhov hnyav dua molecular.
Ib qho ntawm cov khoom tseem ceeb tshaj plaws ntawm cellulose ethers yog lawv lub peev xwm ua kom yaj hauv ntau cov kuab tshuaj, suav nrog dej, cov kuab tshuaj organic, thiab qee yam polar thiab cov kua tsis muaj polar.Dej solubility yog qhov tseem ceeb ntawm ntau cov cellulose ethers thiab tseem ceeb tshwj xeeb rau kev siv tshuaj, khoom noj khoom haus, thiab cov khoom tu tus kheej.
Cov dej-soluble cellulose ethers xws li HEC, HPC, thiab CMC ua kom pom tseeb, viscous daws thaum dispersed hauv dej.Cov kev daws teeb meem no nthuav tawm tus cwj pwm pseudoplastic, txhais tau tias lawv cov viscosity txo qis hauv kev ntxhov siab, ua rau lawv tsim nyog siv los ua cov thickeners, stabilizers, thiab cov neeg ua yeeb yaj kiab tsim hauv cov khoom noj thiab tshuaj formulations.
Solubility ntawm cellulose ethers hauv cov kuab tshuaj organic nyob ntawm lawv cov qauv tshuaj thiab cov polarity ntawm cov kuab tshuaj.Piv txwv li, MC thiab EC yog soluble nyob rau hauv ntau yam ntawm cov organic solvents, xws li acetone, ethanol, thiab chloroform, vim lawv cov qib qis ntawm kev hloov pauv thiab tus cwj pwm hydrophobic.Cov khoom no ua rau lawv muaj txiaj ntsig hauv kev siv xws li txheej txheej, nplaum, thiab tswj-tso tshuaj xa cov tshuab.
HEC thiab HPC, uas muaj cov pab pawg hydroxyethyl thiab hydroxypropyl, raws li txoj cai, nthuav tawm kev ua kom zoo dua solubility hauv cov kuab tshuaj organic xws li cawv thiab glycols.Cov cellulose ethers no feem ntau yog siv los ua cov thickeners thiab rheology modifiers hauv cov khoom siv kho kom zoo nkauj thiab kev tu tus kheej, nrog rau cov xim pleev xim dej thiab cov coatings.
CMC yog soluble nyob rau hauv dej thiab tej yam polar solvents vim nws cov carboxymethyl substituents, uas impart dej-solubility rau polymer saw.Nws yog dav siv los ua tus neeg sawv cev thickening, stabilizer, thiab emulsifier hauv cov khoom noj khoom haus, tshuaj, thiab cov ntawv thov kev lag luam.
Kev solubility ntawm cellulose ethers kuj tuaj yeem cuam tshuam los ntawm lwm yam xws li kub, pH, thiab muaj ntsev lossis lwm yam khoom ntxiv.Piv txwv li, qhov sib ntxiv ntawm electrolytes xws li sodium chloride los yog calcium chloride tuaj yeem txo qhov solubility ntawm cov dej-soluble cellulose ethers los ntawm kev txhawb cov polymer aggregation los yog nag lossis daus.
cellulose ethers muaj ntau yam solubility zog uas ua rau lawv muaj txiaj ntsig additives nyob rau hauv ntau yam kev lag luam.Lawv muaj peev xwm yaj nyob rau hauv dej, organic solvents, thiab polar kua ua rau muaj ntau yam kev siv xws li tshuaj formulations mus rau cov ntaub ntawv siv.Kev nkag siab txog tus cwj pwm solubility ntawm cellulose ethers yog qhov tseem ceeb rau kev txhim kho lawv cov kev ua tau zoo thiab kev ua haujlwm ntawm ntau yam khoom thiab cov txheej txheem.
Lub sij hawm xa tuaj: Plaub Hlis-24-2024