Sodium Carboxymethyl Cellulose Viscosity

Qhov viscosity ntawm sodium carboxymethyl cellulose kuj tseem muab faib ua ntau qib raws li kev siv sib txawv. Lub viscosity ntawm hom ntxuav yog 10 ~ 70 (qis dua 100), qhov siab tshaj plaws ntawm viscosity yog los ntawm 200 ~ 1200 rau kev kho kom zoo nkauj hauv tsev thiab lwm yam lag luam, thiab qhov viscosity ntawm qib zaub mov yog siab dua. Lawv txhua tus siab dua 1000, thiab qhov viscosity ntawm ntau yam lag luam tsis zoo ib yam.

Vim nws siv tau ntau yam.
Qhov viscosity ntawm sodium carboxymethyl cellulose yog cuam tshuam los ntawm nws cov molecular mass, concentration, kub thiab pH nqi, thiab nws yog sib xyaw nrog ethyl lossis carboxypropyl cellulose, gelatin, xanthan gum, carrageenan, locust bean gum, guar gum, agar, sodium alginate, pectin, gum arabic thiab starch thiab nws cov derivatives muaj kev sib raug zoo (piv txwv li synergistic effect).

Thaum tus nqi pH yog 7, qhov viscosity ntawm sodium carboxymethyl cellulose kua yog qhov siab tshaj plaws, thiab thaum tus nqi pH yog 4 ~ 11, nws ruaj khov heev. Carboxymethylcellulose nyob rau hauv daim ntawv ntawm alkali hlau thiab ammonium ntsev yog soluble hauv dej. Divalent hlau ions Ca2 +, Mg2 +, Fe2 + tuaj yeem cuam tshuam nws viscosity. Hnyav hlau xws li nyiaj, barium, chromium lossis Fe3 + tuaj yeem ua rau nws precipitate tawm ntawm cov kua. Yog tias qhov concentration ntawm ions raug tswj, xws li ntxiv ntawm tus neeg sawv cev chelating citric acid, ib qho kua viscous ntau dua tuaj yeem tsim, ua rau cov pos hniav mos lossis tawv.

Sodium carboxymethyl cellulose yog ib hom cellulose ntuj, uas feem ntau yog ua los ntawm paj rwb linter lossis ntoo pulp ua cov khoom siv raw thiab raug rau etherification reaction nrog monochloroacetic acid nyob rau hauv alkaline mob.

Raws li cov lus qhia ntawm cov khoom siv raw thiab kev hloov pauv ntawm hydroxyl hydrogen hauv cellulose D-glucose unit los ntawm carboxymethyl pawg, cov dej-soluble polymer sib xyaw nrog ntau qib ntawm kev hloov pauv thiab sib txawv molecular qhov hnyav faib tau txais.

Vim tias sodium carboxymethyl cellulose muaj ntau yam tshwj xeeb thiab zoo heev, nws yog dav siv hauv kev lag luam tshuaj txhua hnub, khoom noj thiab tshuaj thiab lwm yam kev lag luam.

Ib qho ntawm cov cim qhia tseem ceeb tshaj plaws ntawm sodium carboxymethyl cellulose yog qhov viscosity ntawm sodium carboxymethyl cellulose. Tus nqi ntawm viscosity muaj feem cuam tshuam nrog ntau yam xws li concentration, kub thiab shear rate. Txawm li cas los xij, cov yam xws li concentration, kub thiab shear rate yog cov yam sab nraud uas cuam tshuam rau viscosity ntawm sodium carboxymethyl cellulose.

Nws qhov hnyav molecular thiab kev faib tawm molecular yog cov yam ntxwv sab hauv uas cuam tshuam rau viscosity ntawm sodium carboxymethyl cellulose kua. Rau kev tswj hwm kev tsim khoom thiab kev txhim kho kev ua haujlwm ntawm cov khoom ntawm sodium carboxymethyl cellulose, kev tshawb fawb txog nws qhov hnyav molecular thiab kev faib tawm molecular muaj qhov tseem ceeb heev, thaum viscosity Kev ntsuas tsuas yog ua lub luag haujlwm siv.

Newton txoj cai hauv rheology, thov nyeem cov ntsiab lus tseem ceeb ntawm "rheology" hauv kev siv tshuaj lom neeg lub cev, nws nyuaj rau piav qhia hauv ib lossis ob kab lus. Yog tias koj yuav tsum hais nws: rau cov tshuaj dilute ntawm cmc ze rau Newtonian kua, qhov kev ntxhov siab shear yog proportional rau qhov nrawm ntawm ntug txiav, thiab cov coefficient proportional ntawm lawv hu ua viscosity coefficient lossis kinematic viscosity.

Qhov viscosity yog los ntawm cov zog ntawm cov saw hlau molecular cellulose, suav nrog cov zog dispersion thiab hydrogen bonds. Tshwj xeeb, qhov polymerization ntawm cellulose derivatives tsis yog ib qho qauv linear tab sis ib qho qauv ntau ceg. Hauv cov tshuaj, ntau cov cellulose ntau ceg tau intertwined los ua ib qho qauv spatial network. Qhov nruj dua qhov qauv, qhov loj dua qhov zog ntawm cov saw hlau molecular hauv cov tshuaj tshwm sim.

Yuav kom tsim tau cov dej ntws hauv cov tshuaj cellulose derivatives uas tsis sib xyaw, yuav tsum kov yeej lub zog ntawm cov saw hlau molecular, yog li cov tshuaj uas muaj polymerization siab yuav tsum muaj lub zog ntau dua los tsim cov dej ntws. Rau kev ntsuas viscosity, lub zog ntawm CMC cov tshuaj yog lub ntiajteb txawj nqus. Nyob rau hauv qhov xwm txheej ntawm lub ntiajteb txawj nqus tas li, cov qauv saw hlau ntawm CMC cov tshuaj nrog cov polymerization loj muaj lub zog loj, thiab cov dej ntws qeeb. Cov dej ntws qeeb qhia txog viscosity.

Qhov viscosity ntawm sodium carboxymethyl cellulose feem ntau yog cuam tshuam nrog qhov hnyav molecular, thiab muaj tsawg yam ua rau qib kev hloov pauv. Qhov ntau dua qib kev hloov pauv, qhov ntau dua qhov hnyav molecular, vim tias qhov hnyav molecular ntawm pawg carboxymethyl hloov pauv loj dua li pawg hydroxyl yav dhau los.

Cov ntsev sodium ntawm cellulose carboxymethyl ether, ib qho anionic cellulose ether, yog cov hmoov dawb lossis mis nyuj dawb fibrous lossis granule, nrog qhov ceev ntawm 0.5-0.7 g / cm3, yuav luag tsis muaj ntxhiab, tsis muaj saj, thiab hygroscopic. Nws yooj yim rau disperse hauv dej los ua cov kua colloidal pob tshab, thiab tsis yaj hauv cov organic solvents xws li ethanol. Lub pH ntawm 1% aqueous kua yog 6.5 txog 8.5. Thaum pH> 10 lossis <5, qhov viscosity ntawm sodium carboxymethylcellulose raug txo qis, thiab kev ua tau zoo tshaj plaws thaum pH = 7.

Nws ruaj khov thaum kub. Qhov viscosity nce sai hauv qab 20 ℃, thiab hloov maj mam ntawm 45 ℃. Kev ua kom sov ntev tshaj 80 ℃ tuaj yeem ua rau cov colloid puas tsuaj thiab txo qhov viscosity thiab kev ua haujlwm. Nws yooj yim yaj hauv dej, thiab cov tshuaj yog pob tshab; nws ruaj khov heev hauv cov tshuaj alkaline, thiab nws yooj yim rau hydrolyze hauv qhov muaj kua qaub. Thaum tus nqi pH yog 2-3, nws yuav precipitate.