Cellulose ether yog ib qho hluavtaws polymer ua los ntawm cov khoom siv hauv ntuj los ntawm cov khoom siv raw los ntawm kev hloov kho tshuaj lom neeg. Cellulose ether yog ib tug derivative ntawm ntuj cellulose, cellulose ntau lawm, nws cov khoom siv hluav taws xob sib txawv yog cellulose, ntuj polymer sib txuas. Vim yog qhov tshwj xeeb ntawm cov qauv ntuj cellulose, cellulose nws tus kheej tsis muaj peev xwm hnov cov neeg sawv cev ntawm tus neeg sawv cev. Tab sis tom qab kev kho mob ntawm ofering of tus neeg sawv cev ntawm cov pab pawg ntawm cov tshuaj txhuam thiab cov tshuaj lom neeg ether tau muaj peev xwm dhau los ntawm cov tshuaj tiv thaiv ntawm lub cev sawv cev - lossis pab pawg.
Cov yam ntxwv ntawm Cellulose cov neeg muaj kev pab yog nyob ntawm hom, tus lej thiab xa tawm ntawm cov neeg hloov chaw. Kev faib tawm ntawm cellulose ether yog tseem yog los ntawm cov hloov chaw, qib kaum kev, solubility thiab cov ntaub ntawv ntsig txog tuaj yeem raug cais. Raws li hom kev hloov chaw ntawm cov molecular, nws tuaj yeem faib ua ib qho ether thiab sib xyaw ether. MC feem ntau yog siv los ua ib qho ete, thaum HPMC yog sib xyaw ether. Methyl cellulose ether mc yog ib chav ntawm cov qauv roj hmab me me hloov los ntawm cov qauv khoom siv methhot ether Hizc yog chav nyob ntawm hydroxyl yog ib feem ntawm cov methoxide hloov, lwm feem ntawm hydroxypropyl hloov cov khoom lag luam, cov qauv) yog [OCH7CHO2) MN-Hydroxyethy ither ajc, uas yog siv dav thiab muag ntawm kev ua lag luam.
Los ntawm solubility tuaj yeem faib ua Ionic hom thiab hom tsis yog-ionic. Dej-soluble tsis-ionic cellulose ionet yog mas tsim ntawm Alkyl ether thiab Hydroxyl ether ether ob hom ntawm ntau yam. Ionic CMC feem ntau yog siv nyob rau hauv cov hluavtaws xab npum, textile, luam ntawv, khoom noj thiab roj av siv. Tsis yog-ionic mc, HPMC, Hemp thiab lwm yam tsuas yog siv rau hauv cov ntaub ntawv tsim, cov kua txiv hmab txiv ntoo, tshuaj, txhua hnub chemistry thiab lwm yam chemical thiab lwm yam kev chemical. Raws li thickening tus neeg sawv cev, dej tswj hwm tus neeg saib xyuas, stabilizer, dispersant, zaj duab xis tsim tus neeg sawv cev.
Cellulose ether dej kom txuag
Hauv kev tsim cov ntaub ntawv hauv tsev, tshwj xeeb tshaj yog cov cellulose tov, cellulose ua lub luag haujlwm (collectified cug), yog qhov tseem ceeb.
Lub luag haujlwm tseem ceeb ntawm cov dej-soluble cellulose ether hauv collab feem ntau muaj peev xwm muaj peev xwm, thiab peb yog kev sib cuam tshuam nrog cov cement.
Cellulose ether dej los khaws, nyob ntawm lub hauv paus collhing, tshuaj khib dej ua, lub sijhawm tsim hws kom zoo nkauj. Cov dej tuav tseg ntawm cellulose ether los ntawm solubility thiab lub cev qhuav dej ntawm cellulose ether nws tus kheej. Nws yog qhov paub zoo tias cellulose molecular chains, txawm hais tias lawv muaj ntau cov pab pawg hydrated heev uas muaj dej muaj txiaj ntsig vim yog lawv cov qauv crystalline. Cov hydration muaj peev xwm ntawm pawg hydroxyl ib leeg tsis txaus them rau cov kev sib koom ua kom muaj zog thiab cov van der wAsals rog. Thaum cov neeg hloov pauv tau qhia rau hauv cov molecular chart, tsis tsuas yog hloov chaw ua kom lub pob zeb ua kom puas yog tawg vim kev sib tw ntawm cov kev sib tw ntawm cov saw hlau. Qhov loj dua cov neeg hloov chaw yog, ntau dua qhov kev ncua deb ntawm cov lwg me me. Qhov ntau dua cov kev puas tsuaj ntau dua ntawm hydrogen kev ua haujlwm, cellulose kev nthuav dav, kev daws teeb meem rau hauv cellulose kev daws teeb meem. Raws li qhov kub nce, cov hydration ntawm cov polymer txo thiab cov dej ntawm txoj saw hlau tau tsav tawm. Thaum lub cev ua haujlwm qhuav yog qhov txaus, cov lwg me me pib sib sau ua ke thiab cov gel folds tawm hauv ib qho kev sib tw peb sab. Qhov cuam tshuam rau cov dej khaws cia ntawm cov tshuaj khib suav nrog cellulose itthat viscosity, ntau yam thiab kev pabcuam kub.
Qhov ntau dua viscosity ntawm cellulose ether, qhov zoo dua cov dej khaws cia, lub viscosity ntawm polymer tov. Lub cev hnyav molecular (qib ntawm polymerization) ntawm polymer kuj tau txiav txim siab los ntawm cov qauv molecular ntawm cov qauv molecular ntawm cov neeg hloov pauv ncaj qha cuam tshuam rau cov viscosity ntau. [ETA] = Km Alpha
Intrinsic viscosity ntawm polymer daws teeb meem
M polymer molecular hnyav
lus polymer yam ntxwv tsis tu ncua
K viscosity Tib Coefficient
Lub viscer ntawm polymer tov nyob ntawm qhov hnyav molecular ntawm cov polymer. Lub viscosity thiab concentration ntawm cellulose cellulose cov kev daws teeb meem muaj feem xyuam rau ntau yam kev siv. Yog li no, txhua cellulose ether muaj ntau yam txawv viscosions kuj tseem yog feem ntau los ntawm kev ua kom pom tseeb, uas yog qhov ua kom nruj me ntsis molecular mus ua tiav.
Rau qhov loj me me, lub flexer rau particle, qhov zoo dua cov dej khaws cia. Cov khoom loj ntawm cellulose ether chwv nrog dej, qee zaum ntev rhuav tshem cov khoom noj kom tiv thaiv kom tsis txhob muaj kev nkag mus, kev tsim cov av nkos flocculent daws los yog Agglomerate. Lub solubility ntawm cellulose ether yog ib qho ntawm qhov los xaiv cellulose ether.
Thickening thiab thixotropy ntawm cellulose ether
Qhov thib ob cov nyhuv ntawm cellulose ether - Thickening nyob ntawm: cellulose nyob ntawm: kev daws teeb meem, kev sib tov, kub thiab lwm yam. Cov khoom lag luam gelation ntawm cov kev daws teeb meem tshwj xeeb rau alkyl cellulose thiab nws tau hloov cov derivatives. Cov kev nkag rau cov gelation muaj feem xyuam rau cov degree ntawm kev hloov chaw, kev daws teeb meem thiab ntxiv. Rau hydroxyl hloov ua txiv neej, gel khoom tseem muaj feem xyuam rau qib ntawm Hydroxyl kev hloov kho. Rau kev daws cov viscosity tsawg MC thiab HPMC tuaj yeem npaj tau 10%-nruab nrab kev daws teeb meem MC thiab HPMC tuaj yeem npaj tau 2% -3% Kev daws teeb meem, thiab feem ntau yog viscosity ntawm cellulose ntawm cellulose tau muab qhab nia los ntawm 1% -2% kev daws teeb meem. High molecular phaus cellulose tuab ether fickener kev ua tau zoo, [η] = 2.92 × 10-2 (dpn) 0.905, dpn yog qhov nruab nrab polymerization qib ntawm siab. Tsawg molecular hnyav cellulose cellulose tsawg los ntxiv ntxiv kom ua tiav lub hom phiaj viscosity. Nws cov viscosity yog tsawg dua ntawm shear tus nqi, siab viscosity kom ua tiav lub hom phiaj viscosity, tus nqi uas xav tau ntxiv tsawg dua, viscosity nyob ntawm lub thicking efficiency. Yog li ntawd, kom ua tiav qhov xwm txheej, ib qho nqi ntawm cellulose ether (concentration ntawm kev daws teeb meem) thiab daws viscosity yuav tsum tau lav. Lub gelation kub ntawm kev daws teeb meem tau txo tus kheej nrog kev nce ntawm kev daws teeb meem, thiab gelation tau tshwm sim ntawm chav tsev kub tom qab ncav ib co siab. HPMC muaj lub siab loj ntawm kev xav txog chav tsev kub.
Kev sib thooj kuj tseem tuaj yeem hloov kho los ntawm xaiv cov perr me me thiab cov cellulose muaj kev pab cuam tshuam nrog cov qib sib txawv ntawm kev hloov kho. Lub npe hu ua kev hloov kho yog kev qhia txog cov pab pawg hydroxyl hauv ib qho kev hloov pauv ntawm cov qauv pob txha pob ntseg ntawm MC. Los ntawm kev hloov pauv tus txheeb ze hloov cov teeb meem ntawm ob qho chaw hloov, yog qhov tseeb ntawm pawg me me thiab hydroxyl pawg. Ntau yam thaj tsam ntawm cellulose ether yog tsim los ntawm kev hloov tus txheeb ze hloov cov kev hloov pauv ntawm ob hom kev hloov chaw.
kev sib txheeb ntawm kev sib raug zoo thiab kev hloov kho. Hauv daim duab 5, ntxiv rau ntawm cellulose ether cuam tshuam rau kev siv dej ntawm cov tshuaj khib thiab hloov pauv cov dej xis thiab xis mas, uas yog cov nyhuv tuab. Qhov siab dua qhov ntau dua, kev siv dej ntau.
Cov ntaub ntawv uas muaj neeg ua haujlwm uas muaj neeg raug pab siv nyob rau hauv cov ntaub ntawv muaj hmoov yuav tsum yaj tawm hauv dej txias thiab muab cov system nrog kev sib xws. Yog tias ib tug muab shear tus nqi tseem yog flocculent thiab colloidal nws yog ib qho khoom seem lossis cov khoom lag luam txom nyem.
Kuj tseem muaj txoj kev sib raug zoo ntawm kev sib deev ntawm Cellule sib xyaw ua ke ntawm cellule, ntau dua qhov tshuaj tua kab cig, ntau dua qhov tshuaj, ntau yam pom tseeb.
Cellulose ether cov tshuaj muaj cov viscosity siab muaj siab thixotrospy, uas yog ib qho ntawm cov yam ntxwv ntawm cellulose ether. Cov kev daws teeb meem aqueous ntawm MC hom hom polymers feem ntau muaj pseudopastic, tsis yog-thixotropic fluidity hauv qab no lawv qhov kub thiab txias, tab sis Newtonian ntws tawm ntawm cov nqi qis. Pseudoplastic nce nrog kev nce ntawm molecular hnyav lossis concentration ntawm cellulose ether thiab yog muaj kev ywj pheej ntawm hom thiab degree. Yog li no, cellulose muaj kev hais ua tus neeg viscosity qib, txawm tias Hemmc lossis Hemmc lossis Hemm, ib txwm qhia tib yam li kev xav thiab kub nyob tas li. Thaum qhov kub nce ntxiv, cov txheej txheem gel yog tsim thiab siab thixotropic txaus tshwm sim. Cellulose muaj cov neeg muaj kev pab cuam hauv siab thiab cov viscosity tsis tshua muaj tshwm sim hauv qab no Thixotropy txawm nyob hauv qab cov pa taws kub. Cov cuab yeej no yog cov txiaj ntsig zoo rau kev tsim kho lub tshuab tsim kho kom haum nws cov dej ntws thiab ntws dai. Nws yuav tsum tau piav qhia ntawm no tias ntau dua cov viscosity ntawm cellulose, tab sis ntau dua cov txheeb ze molecular hnyav ntawm cov solubility, uas muaj qhov tsis zoo rau cug tshuaj micrical conctration thiab kev tsim kho. Qhov siab tshaj lub viscosity, ntau pom ntau dua cov thickening cov txiaj ntsig ntawm cug, tab sis nws tsis yog ua kom tiav kev sib raug zoo. Qee qhov tsis muaj viscosity, tab sis hloov kho cellulose ether hauv kev txhim kho cov tshuaj khib nyiab muaj kev ua kom zoo dua, nrog cov dej hauv ether ethere dej sib tuav tau zoo dua.
Lub sijhawm Post: Mar-30-2022