Cellulose ether hauv cov khoom siv cement

Cellulose ether yog ib hom khoom siv ntau yam uas tuaj yeem siv rau hauv cov khoom siv cement. Daim ntawv no qhia txog cov khoom siv tshuaj lom neeg ntawm methyl cellulose (MC) thiab hydroxypropyl methyl cellulose (HPMC /) feem ntau siv hauv cov khoom siv cement, cov txheej txheem thiab cov hauv paus ntsiab lus ntawm cov tshuaj net thiab cov yam ntxwv tseem ceeb ntawm cov tshuaj. Qhov txo qis ntawm thermal gel kub thiab viscosity nyob rau hauv cov khoom cement tau tham los ntawm kev paub ntau lawm.

Cov lus tseem ceeb:cellulose ether; Methyl cellulose;Hydroxypropyl methyl cellulose; Kub gel kub; viscosity

1. Txheej txheem cej luam

Cellulose ether (CE luv luv) yog ua los ntawm cellulose los ntawm etherification cov tshuaj tiv thaiv ntawm ib los yog ob peb etherifying agents thiab qhuav sib tsoo. CE tuaj yeem muab faib ua ionic thiab non-ionic hom, ntawm cov uas tsis yog-ionic hom CE vim nws cov yam ntxwv thermal gel thiab solubility, ntsev tsis kam, tiv thaiv tshav kub, thiab muaj qhov tsim nyog ua haujlwm. Nws tuaj yeem siv ua tus neeg saib xyuas dej, tus neeg sawv cev ncua kev kawm, emulsifier, zaj duab xis tsim tus neeg sawv cev, roj nplua nyeem, nplaum thiab rheological txhim kho. Cov chaw noj txawv teb chaws tseem ceeb yog latex coatings, cov ntaub ntawv hauv tsev, roj drilling thiab lwm yam. Piv nrog rau cov teb chaws txawv teb chaws, kev tsim khoom thiab kev siv cov dej-soluble CE tseem nyob rau hauv nws cov me nyuam mos. Nrog rau kev txhim kho ntawm tib neeg kev noj qab haus huv thiab kev paub txog ib puag ncig. Dej-soluble CE, uas tsis muaj teeb meem rau lub cev thiab tsis ua rau ib puag ncig, yuav muaj kev loj hlob zoo.

Hauv cov khoom siv hauv tsev feem ntau xaiv CE yog methyl cellulose (MC) thiab hydroxypropyl methyl cellulose (HPMC), tuaj yeem siv ua xim, plaster, mortar thiab cement khoom plasticizer, viscosifier, dej tuav tus neeg saib xyuas, tus neeg saib xyuas huab cua thiab tus neeg saib xyuas. Cov khoom siv hauv tsev feem ntau yog siv los ntawm qhov kub thiab txias, siv cov xwm txheej yog cov hmoov sib tov qhuav thiab dej, tsis tshua muaj kev cuam tshuam cov yam ntxwv thiab cov yam ntxwv kub ntawm CE, tab sis hauv kev tsim cov khoom siv cement thiab lwm yam tshwj xeeb kub, cov yam ntxwv ntawm CE yuav ua lub luag haujlwm tag nrho.

2. Cov khoom siv tshuaj lom neeg ntawm CE

CE tau txais los ntawm kev kho cov cellulose los ntawm ntau txoj hauv kev tshuaj thiab lub cev. Raws li cov qauv kev hloov tshuaj sib txawv, feem ntau tuaj yeem muab faib ua: MC, HPMC, hydroxyethyl cellulose (HEC), thiab lwm yam. : Txhua CE muaj cov qauv ntawm cellulose - dehydrated qabzib. Nyob rau hauv tus txheej txheem ntawm kev tsim CE, cellulose fibers yog thawj rhuab nyob rau hauv ib tug alkaline tov thiab ces kho nrog etherifying agents. Cov khoom siv tshuaj tiv thaiv fibrous yog purified thiab pulverized los tsim cov hmoov sib xws ntawm ib qho kev nplua nuj.

Cov txheej txheem tsim khoom ntawm MC tsuas yog siv methane chloride ua tus neeg sawv cev etherifying. Ntxiv nrog rau kev siv cov tshuaj methane chloride, kev tsim tawm ntawm HPMC kuj tseem siv propylene oxide kom tau txais cov pab pawg hydroxypropyl. Ntau yam CE muaj qhov sib txawv methyl thiab hydroxypropyl hloov pauv, uas cuam tshuam rau cov organic sib raug zoo thiab thermal gel kub ntawm CE kua.

Tus naj npawb ntawm Kev Hloov Pauv ntawm cov dej qabzib cov qauv ntawm cov cellulose tuaj yeem qhia tau los ntawm feem pua ​​​​ntawm pawg lossis qhov nruab nrab ntawm cov pab pawg hloov pauv (piv txwv li, DS - Degree of Hloov). Tus naj npawb ntawm cov pab pawg hloov pauv txiav txim siab cov khoom ntawm CE cov khoom. Cov nyhuv ntawm qhov nruab nrab ntawm kev hloov pauv ntawm solubility ntawm etherification cov khoom yog raws li nram no:

(1) tsis tshua muaj kev hloov pauv qib soluble hauv lye;

(2) me ntsis siab ntawm kev hloov pauv soluble hauv dej;

(3) qib siab ntawm kev hloov pauv yaj hauv polar organic solvents;

(4) Cov qib siab ntawm kev hloov pauv yaj hauv cov kuab tshuaj tsis muaj polar organic.

3. Txoj kev sib cais ntawm CE

CE muaj cov khoom tshwj xeeb solubility, thaum qhov kub nce mus rau qhov kub thiab txias, nws yog insoluble hauv dej, tab sis hauv qab no kub, nws solubility yuav nce nrog qhov kub thiab txias. CE yog soluble hauv dej txias (thiab qee zaum hauv cov kuab tshuaj organic tshwj xeeb) los ntawm cov txheej txheem o thiab dej. CE cov kev daws teeb meem tsis muaj kev txwv tsis pub solubility uas tshwm sim hauv kev sib cais ntawm cov ntsev ionic. Cov concentration ntawm CE feem ntau txwv rau viscosity uas tuaj yeem tswj tau los ntawm cov khoom siv ntau lawm, thiab kuj txawv raws li cov viscosity thiab tshuaj ntau yam uas tus neeg siv xav tau. Kev daws teeb meem ntawm cov viscosity tsawg CE feem ntau yog 10% ~ 15%, thiab siab viscosity CE feem ntau txwv rau 2% ~ 3%. Ntau hom CE (xws li hmoov los yog cov hmoov av kho hmoov lossis granular) tuaj yeem cuam tshuam txog kev npaj cov tshuaj li cas.

3.1 CE yam tsis muaj kev kho deg

Txawm hais tias CE yog soluble nyob rau hauv dej txias, nws yuav tsum tau dispersed nyob rau hauv dej kom tsis txhob clumping. Qee zaum, lub tshuab hluav taws xob kub ceev lossis funnel yuav siv tau rau hauv dej txias kom tawg CE hmoov. Txawm li cas los xij, yog tias cov hmoov tsis kho tau ntxiv ncaj qha rau hauv dej txias yam tsis muaj qhov sib tov txaus, cov pob txha loj yuav tsim. Lub ntsiab yog vim li cas rau caking yog tias CE hmoov hais tsis yog tag nrho ntub. Thaum tsuas yog ib feem ntawm cov hmoov yog yaj, ib zaj duab xis gel yuav raug tsim, uas tiv thaiv cov hmoov seem ntawm kev txuas ntxiv mus. Yog li ntawd, ua ntej dissolution, CE hais yuav tsum tau tag nrho dispersed kom deb li deb tau. Ob txoj kev dispersion hauv qab no feem ntau siv.

3.1.1 Dry mix dispersion method

Txoj kev no feem ntau yog siv hauv cov khoom siv cement. Ua ntej ntxiv dej, sib tov lwm cov hmoov nrog CE hmoov sib npaug, kom CE hmoov cov khoom tawg mus. Yam tsawg kawg nkaus sib xyaw: Lwm cov hmoov: CE hmoov = (3 ~ 7): 1.

Nyob rau hauv txoj kev no, CE dispersion yog ua tiav nyob rau hauv qhuav lub xeev, siv lwm cov hmoov raws li qhov nruab nrab rau disperse CE hais nrog ib leeg, yog li kom tsis txhob muaj kev sib nrig sib sib raug zoo ntawm CE hais thaum ntxiv dej thiab cuam tshuam ntxiv dispersion. Yog li ntawd, dej kub tsis xav tau rau dispersion, tab sis tus nqi dissolution nyob ntawm cov hmoov hais thiab stirring tej yam kev mob.

3.1.2 Cov txheej txheem dej kub dispersion

(1) Thawj 1/5 ~ 1/3 ntawm cov dej uas xav tau cua sov rau 90C saum toj no, ntxiv CE, thiab tom qab ntawd do kom txog thaum tag nrho cov khoom sib cais ntub dej, thiab tom qab ntawd cov dej seem hauv dej txias los yog dej khov ntxiv kom txo qhov kub ntawm cov khoom. daws, ib zaug mus txog CE dissolution kub, cov hmoov pib hydrate, viscosity nce.

(2) Koj tuaj yeem ua kom sov tag nrho cov dej, thiab tom qab ntawd ntxiv CE kom do thaum txias kom txog thaum cov dej tiav. Kev ua kom txias txaus yog qhov tseem ceeb heev rau kev ua kom tiav cov dej ntawm CE thiab tsim cov viscosity. Rau qhov zoo tshaj plaws viscosity, MC cov tshuaj yuav tsum tau txias rau 0 ~ 5 ℃, thaum HPMC tsuas yog yuav tsum tau txias rau 20 ~ 25 ℃ lossis qis dua. Txij li thaum tag nrho cov dej yuav tsum tau ua kom txias txaus, HPMC cov kev daws teeb meem feem ntau yog siv qhov dej txias tsis tuaj yeem siv: raws li cov ntaub ntawv, HPMC muaj qhov kub thiab txias tsawg dua MC ntawm qhov kub qis kom ua tiav tib lub viscosity. Nws yog ib nqi sau cia hais tias cov dej kub dispersion txoj kev tsuas yog ua rau CE hais disperse tusyees ntawm qhov kub thiab txias, tab sis tsis muaj kev daws teeb meem nyob rau lub sij hawm no. Yuav kom tau txais kev daws nrog ib qho viscosity, nws yuav tsum tau txias dua.

3.2 Nto kho dispersible CE hmoov

Feem ntau, CE yuav tsum muaj ob qho tib si dispersible thiab sai hydration (ua viscosity) cov yam ntxwv hauv dej txias. Nto kho CE yog ib ntus insoluble hauv dej txias tom qab kev kho tshuaj tshwj xeeb, uas ua kom ntseeg tau tias thaum CE ntxiv rau hauv dej, nws yuav tsis tuaj yeem tsim cov viscosity tam sim ntawd thiab tuaj yeem tawg mus rau hauv cov txheej txheem me me. Lub sijhawm "ntev" ntawm hydration lossis viscosity tsim yog qhov tshwm sim ntawm kev sib xyaw ua ke ntawm qib kev kho saum npoo, qhov kub thiab txias, pH ntawm lub cev, thiab CE kua concentration. Kev ncua ntawm hydration feem ntau txo qis ntawm qhov siab dua, qhov kub thiab txias, thiab qib pH. Feem ntau, txawm li cas los xij, qhov concentration ntawm CE tsis suav nrog kom txog thaum nws nce mus txog 5% (qhov loj ntawm cov dej).

Txhawm rau kom tau txais txiaj ntsig zoo tshaj plaws thiab ua kom dej tiav, qhov chaw kho CE yuav tsum tau nplawm rau ob peb feeb hauv qhov nruab nrab, nrog rau pH ntau ntawm 8.5 txog 9.0, kom txog rau thaum qhov siab tshaj plaws viscosity mus txog (feem ntau 10-30 feeb). Thaum pH hloov mus rau qhov yooj yim (pH 8.5 txog 9.0), qhov chaw kho CE dissolves tag nrho thiab sai, thiab cov tshuaj tuaj yeem ruaj khov ntawm pH 3 txog 11. Txawm li cas los xij, nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias kev kho cov pH ntawm lub siab concentration slurry. yuav ua rau lub viscosity siab dhau rau kev siv thiab nchuav. Cov pH yuav tsum tau kho tom qab cov slurry tau diluted mus rau qhov xav tau concentration.

Txhawm rau ua kom tiav, cov txheej txheem tawg ntawm CE suav nrog ob txheej txheem: lub cev dispersion thiab tshuaj lom neeg tawg. Qhov tseem ceeb yog disperse CE particles nrog rau ib leeg ua ntej dissolution, yog li kom tsis txhob agglomeration vim siab viscosity thaum uas tsis muaj kub dissolution, uas yuav cuam tshuam ntxiv dissolution.

4. Cov khoom ntawm CE kua

Ntau hom CE aqueous daws yuav gellate ntawm lawv qhov kub thiab txias. Cov gel yog thim rov qab thiab tsim cov tshuaj thaum txias dua. Lub reversible thermal gelation ntawm CE yog tshwj xeeb. Hauv ntau cov khoom siv cement, qhov tseem ceeb ntawm kev siv cov viscosity ntawm CE thiab cov dej tuav thiab lubrication, thiab cov viscosity thiab gel kub muaj kev sib raug zoo, nyob rau hauv cov gel kub, qhov kub thiab txias, qhov viscosity ntawm CE ntau dua, qhov zoo dua cov dej tuav tau zoo.

Cov lus piav qhia tam sim no rau qhov tshwm sim gel yog qhov no: hauv cov txheej txheem ntawm kev sib cais, qhov no zoo ib yam

Lub polymer molecules ntawm cov xov txuas nrog cov dej molecular txheej, ua rau o. Cov dej molecules ua zoo li cov roj lubricating, uas tuaj yeem rub sib nrug ntev ntawm cov khoom siv polymer molecules, kom cov tshuaj muaj cov khoom ntawm cov kua nplaum uas yooj yim rau pov tseg. Thaum qhov kub ntawm cov tshuaj nce, cov cellulose polymer maj mam poob dej thiab viscosity ntawm cov tshuaj txo. Thaum lub gel taw tes yog mus txog, lub polymer ua kom lub cev qhuav dej, ua rau muaj kev sib txuas ntawm cov polymers thiab tsim cov gel: lub zog ntawm cov gel tseem nce ntxiv raws li qhov kub thiab txias tseem nyob saum lub gel point.

Thaum cov tshuaj txias, cov gel pib thim rov qab thiab cov viscosity txo. Thaum kawg, cov viscosity ntawm cov kua txias rov qab mus rau qhov pib kub nce nkhaus thiab nce nrog qhov txo qis ntawm qhov kub. Cov tshuaj yuav tau txias rau nws thawj viscosity nqi. Yog li ntawd, cov txheej txheem thermal gel ntawm CE yog thim rov qab.

Lub luag haujlwm tseem ceeb ntawm CE hauv cov khoom siv cement yog ua cov viscosifier, plasticizer thiab dej tuav tus neeg sawv cev, yog li yuav ua li cas tswj cov viscosity thiab gel kub tau dhau los ua ib qho tseem ceeb hauv cov khoom cement feem ntau siv nws thawj qhov kub thiab txias taw tes hauv qab ib feem ntawm qhov nkhaus, Yog li qhov qis dua qhov kub, qhov siab dua qhov viscosity, qhov pom tseeb dua cov nyhuv ntawm viscosifier dej tuav. Cov txiaj ntsig ntawm extrusion cement board ntau lawm kab kuj qhia tau tias qhov qis ntawm cov khoom siv kub yog nyob rau hauv tib cov ntsiab lus ntawm CE, qhov zoo dua qhov viscosification thiab dej tuav cov nyhuv. Raws li cov cement system yog ib qho cuab yeej cuab tam lub cev thiab tshuaj lom neeg, muaj ntau yam cuam tshuam rau kev hloov ntawm CE gel kub thiab viscosity. Thiab qhov cuam tshuam ntawm ntau yam Taianin sib txawv thiab qib tsis zoo ib yam, yog li daim ntawv thov siv tau kuj pom tias tom qab sib xyaw cov cement, qhov tseeb gel kub taw tes ntawm CE (uas yog, cov kua nplaum thiab dej tuav cov nyhuv poob yog pom tseeb heev ntawm qhov kub thiab txias. ) yog qis dua qhov ntsuas kub ntawm gel qhia los ntawm cov khoom, yog li ntawd, nyob rau hauv kev xaiv ntawm CE cov khoom yuav coj mus rau hauv tus account cov yam uas ua rau gel kub poob. Cov hauv qab no yog cov ntsiab lus tseem ceeb uas peb ntseeg tias cuam tshuam rau viscosity thiab gel kub ntawm CE cov tshuaj hauv cov khoom cement.

4.1 Kev cuam tshuam ntawm pH tus nqi ntawm viscosity

MC thiab HPMC tsis yog-ionic, yog li cov viscosity ntawm cov tshuaj ntau dua li cov viscosity ntawm ntuj ionic kua nplaum muaj qhov dav ntawm DH ruaj khov, tab sis yog tias tus nqi pH siab tshaj qhov ntau ntawm 3 ~ 11, lawv yuav maj mam txo cov viscosity ntawm ib. siab dua los yog nyob rau hauv cia rau lub sij hawm ntev, tshwj xeeb tshaj yog cov viscosity siab. Lub viscosity ntawm CE cov khoom lag luam txo qis hauv cov kua qaub lossis cov kua qaub muaj zog, uas yog vim lub cev qhuav dej ntawm CE los ntawm cov hauv paus thiab cov kua qaub. Yog li ntawd, qhov viscosity ntawm CE feem ntau txo qis rau qee yam hauv alkaline ib puag ncig ntawm cov khoom cement.

4.2 Kev cuam tshuam ntawm cov cua sov thiab nplawm ntawm cov txheej txheem gel

Qhov kub ntawm gel point yuav raug cuam tshuam los ntawm kev sib xyaw ua ke ntawm cov cua sov thiab nplawm shear tus nqi. Kev kub ceev nplawm thiab cua kub ceev feem ntau yuav ua rau cov gel kub ntau, uas yog qhov zoo rau cov khoom siv cement tsim los ntawm kev sib xyaw ua ke.

4.3 Kev cuam tshuam ntawm cov concentration ntawm kub gel

Ua kom cov concentration ntawm cov tshuaj feem ntau txo cov gel kub, thiab cov ntsiab lus ntawm cov viscosity tsawg CE yog siab dua cov viscosity siab CE. Xws li DOW's METHOCEL A

Lub gel kub yuav raug txo los ntawm 10 ℃ rau txhua txhua 2% nce nyob rau hauv cov concentration ntawm cov khoom. 2% nce nyob rau hauv cov concentration ntawm F-hom khoom yuav txo tau cov gel kub los ntawm 4 ℃.

4.4 Kev cuam tshuam ntawm cov khoom siv ntxiv ntawm thermal gelation

Hauv kev tsim cov khoom siv hauv tsev, ntau cov ntaub ntawv yog cov ntsev inorganic, uas yuav muaj kev cuam tshuam loj rau cov gel kub ntawm cov tshuaj CE. Nyob ntawm seb cov additive puas ua raws li coagulant los yog solubilizing tus neeg sawv cev, qee cov additives tuaj yeem ua rau lub thermal gel kub ntawm CE, thaum lwm tus tuaj yeem txo cov thermal gel kub ntawm CE: piv txwv li, hnyav-txhim kho ethanol, PEG-400 (polyethylene glycol) , anediol, thiab lwm yam., tuaj yeem ua kom cov gel point. Cov ntsev, glycerin, sorbitol thiab lwm yam tshuaj yuav txo cov gel point, uas tsis yog-ionic CE feem ntau yuav tsis raug precipitated vim polyvalent hlau ions, tab sis thaum lub electrolyte concentration los yog lwm yam tshuaj yaj nyob rau hauv ib tug tej yam kev txwv, CE cov khoom yuav salted tawm nyob rau hauv kev daws teeb meem, qhov no yog vim muaj kev sib tw ntawm electrolytes rau dej, ua rau txo cov dej ntawm CE, cov ntsev cov ntsiab lus ntawm cov khoom CE feem ntau yog me ntsis siab dua li cov khoom Mc, thiab cov ntsev cov ntsiab lus sib txawv me ntsis. nyob rau hauv txawv HPMC.

Ntau cov khoom xyaw hauv cov khoom cement yuav ua rau cov gel taw tes ntawm CE poob, yog li kev xaiv cov khoom siv ntxiv yuav tsum coj mus rau hauv tus account tias qhov no yuav ua rau cov gel point thiab viscosity ntawm CE hloov.

5. Cov lus xaus

(1) cellulose ether yog ntuj cellulose los ntawm etherification cov tshuaj tiv thaiv, muaj cov qauv txheej txheem ntawm lub cev qhuav dej qabzib, raws li hom thiab tus naj npawb ntawm cov pab pawg hloov ntawm nws txoj haujlwm hloov thiab muaj cov khoom sib txawv. Cov non-ionic ether xws li MC thiab HPMC tuaj yeem siv los ua viscosifier, tus neeg saib xyuas dej, tus neeg saib xyuas huab cua thiab lwm yam siv dav hauv cov khoom siv hauv tsev.

(2) CE muaj qhov tshwj xeeb solubility, tsim kev daws teeb meem ntawm qhov kub thiab txias (xws li gel kub), thiab tsim cov khoom gel lossis cov khoom sib xyaw ua ke ntawm gel kub. Txoj kev sib cais tseem ceeb yog txoj kev sib xyaw qhuav dispersion, dej kub dispersion txoj kev, thiab lwm yam, hauv cov khoom siv cement feem ntau siv yog qhuav mixing dispersion txoj kev. Tus yuam sij yog disperse CE tusyees ua ntej nws dissolves, tsim ib tug tov ntawm tsawg kub.

(3) Kev daws teeb meem, qhov kub thiab txias, pH tus nqi, tshuaj lom neeg cov khoom ntxiv thiab nplawm tus nqi yuav cuam tshuam rau gel kub thiab viscosity ntawm CE kua, tshwj xeeb tshaj yog cov khoom cement yog inorganic ntsev daws nyob rau hauv ib puag ncig alkaline, feem ntau txo cov gel kub thiab viscosity ntawm CE kua. , nqa cov teebmeem. Yog li ntawd, raws li cov yam ntxwv ntawm CE, thawj zaug, nws yuav tsum tau siv nyob rau hauv qhov kub thiab txias (hauv qab lub gel kub), thiab qhov thib ob, lub zog ntawm additives yuav tsum tau coj mus rau hauv tus account.