Sodium Carboxymethyl Cellulose Viscosity

Lub viscosity ntawm sodium carboxymethyl cellulose kuj tau muab faib ua ntau qib raws li kev siv sib txawv. Lub viscosity ntawm ntxhua khaub ncaws yog 10 ~ 70 (qis dua 100), qhov siab tshaj ntawm viscosity yog los ntawm 200 ~ 1200 rau kev kho kom zoo nkauj hauv tsev thiab lwm yam lag luam, thiab viscosity ntawm cov zaub mov qib siab dua. Lawv tag nrho saum 1000, thiab viscosity ntawm ntau yam lag luam tsis zoo ib yam.

Vim nws txoj kev siv ntau yam.
Lub viscosity ntawm sodium carboxymethyl cellulose yog cuam tshuam los ntawm nws cov txheeb ze molecular mass, concentration, kub thiab pH nqi, thiab nws yog tov nrog ethyl los yog carboxypropyl cellulose, gelatin, xanthan gum, carrageenan, locust taum 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 tov yog qhov siab tshaj plaws, thiab thaum tus nqi pH yog 4 ~ 11, nws kuj ruaj khov. Carboxymethylcellulose nyob rau hauv daim ntawv ntawm alkali hlau thiab ammonium ntsev yog soluble nyob rau hauv dej. Divalent hlau ions Ca2+, Mg2+, Fe2+ tuaj yeem cuam tshuam nws cov viscosity. Cov hlau hnyav xws li nyiaj, barium, chromium lossis Fe3+ tuaj yeem ua rau nws tawm ntawm cov tshuaj. Yog hais tias cov concentration ntawm ions raug tswj, xws li ntxiv cov chelating tus neeg sawv cev citric acid, ib qho kua nplaum ntau tuaj yeem tsim, ua rau cov pos hniav mos los yog tawv.

Sodium carboxymethyl cellulose yog ib yam ntawm ntuj cellulose, uas feem ntau yog ua los ntawm paj rwb linter los yog ntoo pulp raws li raw cov ntaub ntawv thiab raug rau etherification cov tshuaj tiv thaiv nrog monochloroacetic acid nyob rau hauv alkaline tej yam kev mob.

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

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

Ib qho tseem ceeb tshaj plaws ntsuas ntawm sodium carboxymethyl cellulose yog viscosity ntawm sodium carboxymethyl cellulose. Tus nqi ntawm viscosity muaj feem xyuam rau ntau yam xws li concentration, kub thiab shear tus nqi. Txawm li cas los xij, yam xws li concentration, kub thiab shear tus nqi yog lwm yam tseem ceeb uas cuam tshuam rau viscosity ntawm sodium carboxymethyl cellulose.

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

Newton txoj cai lij choj hauv rheology, thov nyeem cov ntsiab lus ntawm "rheology" hauv lub cev chemistry, nws nyuaj rau piav qhia hauv ib lossis ob kab lus. Yog hais tias koj yuav tsum hais nws: rau ib tug dilute daws ntawm cmc ze rau ib tug Newtonian kua, lub shear stress yog proportional rau lub txiav ntug tus nqi, thiab proportional coefficient ntawm lawv yog hu ua viscosity coefficient los yog kinematic viscosity.

Viscosity yog muab los ntawm lub zog ntawm cellulose molecular chains, nrog rau cov dispersion rog thiab hydrogen bonds. Hauv particular, lub polymerization ntawm cellulose derivatives tsis yog ib tug linear qauv tab sis ib tug multi-branched qauv. Hauv kev daws teeb meem, ntau cov cellulose feem ntau cuam tshuam los ua ib qho kev sib txuas hauv network. Tus qauv nruj dua, lub zog ntau dua ntawm cov saw hlau molecular hauv qhov kev daws teeb meem.

Txhawm rau tsim kom muaj cov dej ntws hauv cov kua dej ntawm cov cellulose derivatives, lub zog ntawm cov saw hlau molecular yuav tsum tau kov yeej, yog li kev daws teeb meem nrog qib siab ntawm polymerization yuav tsum muaj zog ntau dua los ua kom muaj dej ntws. Rau kev ntsuas viscosity, lub zog ntawm cov tshuaj CMC yog lub ntiajteb txawj nqus. Nyob rau hauv qhov xwm txheej ntawm lub ntiajteb txawj nqus tas mus li, cov saw hlau ntawm cov tshuaj CMC nrog rau qib loj ntawm polymerization muaj lub zog loj, thiab cov dej ntws qeeb. Cov dej ntws qeeb qhia txog viscosity.

Lub viscosity ntawm sodium carboxymethyl cellulose feem ntau muaj feem xyuam rau qhov hnyav molecular, thiab muaj me ntsis ua nrog rau qib ntawm kev hloov. Qhov ntau dua qhov kev hloov pauv, qhov hnyav dua molecular, vim tias qhov hnyav molecular ntawm pawg carboxymethyl hloov pauv loj dua li yav dhau los pawg hydroxyl.

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

Nws yog thermally ruaj khov. Lub viscosity nce sai hauv qab 20 ℃, thiab hloov maj mam ntawm 45 ℃. Lub sijhawm ntev cua sov siab tshaj 80 ℃ tuaj yeem ua rau cov colloid thiab txo cov viscosity thiab kev ua tau zoo. Nws yog yooj yim soluble nyob rau hauv dej, thiab cov kua yog pob tshab; Nws yog ruaj khov heev nyob rau hauv alkaline tov, thiab nws yog ib qho yooj yim rau hydrolyze nyob rau hauv lub xub ntiag ntawm acid. Thaum tus nqi pH yog 2-3, nws yuav los nag.