Tus qauv thiab yam ntxwv ntawm CMC
CMC yog ib hom khoom nyoos tseem ceeb yog ua los ntawm cov tshuaj polymerization cellulose ether nrog cellulose, caustic soda thiab chloroacetic acid, compound nrog lub molecular lem xws li phav phav rau lab tus. CMC yog dawb los yog yellowish hmoov, los yog cov khoom fibrous, tsis muaj ntxhiab, tsis qab, tsis muaj kuab lom. CMC yog ib hom tshuaj muaj roj molecular siab tuaj yeem ua rau dej o tuaj, ua dej hauv lub cev los ua daim nplaum nplaum nplaum nplaum, dej ntsuas ntawm tus nqi p ntsuas ntawm 6.5 ~ 8.5.
Cov khoom tsis yaj hauv cawv, ether, acetone thiab chloroform thiab lwm cov organic solvents. Khoom CMC rau ntawm lub teeb thiab lub chav sov txias zog nyob hauv lub nplhaib qhuav zis, yuav khaws tau ntev. Lub ntsiab tseem ceeb los ntsuas qhov zoo ntawm CMC yog qhov kev hloov ntawm qhov kev hloov (DS) thiab cov ntawv pov thawj ntawm polymerization (DP). Kev hloov qhov sib xyaw ntawm carboxymethyl sodium puag hais txog kev txuas hauv txhua lub tsev ntawm cellulose Qhov nruab nrab ntawm pawg. Glucose anhydride cellulose molecules ntawm 3 cawv pawg: 1 thawj thiab 2 cawv haus cawv. 3 cawv radicals tuaj yeem nrog cov tshuaj chloride sodium acetate. Cov haujlwm ua dej num ua dej num nrog cov cawv loj, yog li cov neeg hloov ua ntej yuav hloov cov pawg ua qhov reactant molecules ntawm qhov ntev. Hloov qhov siab tshaj plaws yog 3, tab sis siv nyob rau hauv kev lag luam yog qhov loj tshaj plaws kev hloov chaw yog 0.5 ~ 1.2 CMC. Feem ntau hais lus, DS txawv, qhov ntawm CMC kuj txawv: DS loj zog, zoo dua qub thiab ruaj ntseg ntawm kev daws; thaum D S> 0.3 yog soluble nyob rau hauv ib qho dej aqueous alkaline; DS = 0.7, yog soluble hauv kub glycerine; thaum D S> 0.8, ces cov kua qaub thiab cov ntsev kuj tsis zoo, thiab tsis precipitate.
Cov degree ntawm polymerization hais txog cov cellulose saw ntev, txiav txim siab qhov loj ntawm nws cov viscosity. Lub cellulose saw ntev viscosity yog loj, yog li CMC kua. CMC molecule exhibits ib tus qauv tawm qauv.
Qhov loj ntawm CMC viscosity thiab pH, qhov ntev ntawm cua sov, lub xub ntiag los yog tsis muaj ntsev thiab lwm yam. Cov tshuaj no yog pseudoplastic kua, nrog rau kev tshee zaus, qhov pom meej viscosity tsawg tsawg, tsis muaj ib yam ua nrog shear lub sij hawm, thaum lub shear yog nres tam sim ntawd rov qab mus rau ntawm thawj viscosity; dry CMC tau tuaj yeem tiv thaiv 140 ~ 150 kub li ob peb feeb; thiab feem ntau ntawm tib qhov kev daws,
Thaum uas txo kev kub hnyiab tau nce cov dej CMC, ua kom txias dua tom qab rov qab los, tab sis ntev ntev ntawm kev kub siab yuav ua rau lub degradation ntawm CMC thiab ua rau kom tsis txhob muaj qhov tsis txaus; nrog rau kev txo cov tshuaj phaus, lub zog ntog, qhov no yog vim muaj cov kab mob acidic pH, carboxyl suppressed ionization resulting viscosity decreases; qee qhov muaj ntsev hlau thiab CMC cov tshuaj tiv thaiv, cellulose glycollic acid hlau ntsev los nag cov ntxhuav. Txhuas ntsev, ntsev ntsev thiab lead ntsev, Gao Tieyan, silver, tooj liab ntsev thiab zirconium Yandu yuav hnov mob rau cov ntsev los nag thiab CMC, tov viscosity CMC yuav tsis ploj; calcium ntsev thiab cov tshuaj magnesium ntsev cov nag, kom nws siv tau rau dej; qaug concentration ntawm alkali hlau ntsev muaj feem ntau txo qhov viscosity ntawm kev daws ntawm alkali hlau ntsev, tab sis lub hav zoov muaj zog concentration yuav ua rau cov viscosity ntawm cov kua, nyob hauv ib txhia txawm ua rau gelation mob; CMC tsis yog soluble hauv cov organic solvents, tab sis kuj yuav tsim tau qee cov tshuaj o, tab sis CMC tsis tau yaj; CMC yog hygroscopic khoom, tso rau hauv huab cua, qhuav CMC tuaj yeem nqus tau 12% ~ 25% ntawm cov dej, qhuav CMC tsis tshua muaj teeb meem microbial, thiab nws txoj kev tov los ntawm cov kab mob ua rau tuaj yeem ua rau muaj kev puas tsuaj me ntsis, viscosity tsawg. CMC raws li ntxais cov khoom ntawm colloid, nrog tag nrho cov khib nyiab. Tsis tas li ntawd, CMC solution kuj siv tau rau hauv cov khoom ua ke, gelling agent, stabilizing tus neeg saib xyuas thiab dispersing tus neeg sawv cev thiab zaj duab xis tsim tus neeg sawv cev.