Cellulose ether siv nyob rau hauv qhuav mix mortar

Cov teebmeem ntawm ntau hom cellulose ib leeg ethers thiab sib xyaw ethers hauv cov khoom sib xyaw qhuav ntawm cov dej tuav thiab thickening, fluidity, workability, air-entraining effect, thiab lub zog ntawm qhuav-siv mortar raug tshuaj xyuas.Nws zoo dua li ib qho ether;txoj kev loj hlob kev taw qhia ntawm daim ntawv thov ntawm cellulose ether nyob rau hauv qhuav-mixed mortar yog prospected.

Lo lus tseem ceeb:cellulose ether;qhuav-mixed mortar;ib leeg ether;sib xyaw ether

Cov tshuaj khib nyiab ib txwm muaj teeb meem xws li tawg yooj yim, los ntshav, kev ua haujlwm tsis zoo, ib puag ncig muaj kuab paug, thiab lwm yam, thiab yuav maj mam hloov los ntawm cov tshuaj khib nyiab qhuav.Qhuav-sib xyaw mortar, tseem hu ua pre-mixed (qhuav) mortar, qhuav hmoov khoom, qhuav mix, qhuav hmoov mortar, qhuav-siv mortar, yog ib tug semi-tiav tshuaj mortar tsis tov dej.Cellulose ether muaj cov khoom zoo xws li thickening, emulsification, ncua kev kawm ntawv, tsim zaj duab xis, tiv thaiv colloid, noo noo tuav, thiab adhesion, thiab yog ib qho tseem ceeb admixture nyob rau hauv qhuav-siv mortar.

Daim ntawv no qhia txog qhov zoo, qhov tsis zoo thiab kev loj hlob ntawm cellulose ether nyob rau hauv daim ntawv thov ntawm qhuav-siv mortar.

1. Cov yam ntxwv ntawm cov tshuaj khib nyiab qhuav

Raws li kev tsim kho, cov tshuaj khib nyiab qhuav tuaj yeem siv tau tom qab ntsuas kom raug thiab sib xyaw ua ke hauv kev tsim khoom, thiab tom qab ntawd sib xyaw nrog dej ntawm qhov chaw tsim kho raws li qhov ntsuas dej-cement piv.Piv nrog rau cov tshuaj khib nyiab, cov tshuaj khib nyiab qhuav muaj qhov zoo hauv qab no:①Cov khoom zoo heev, cov khoom sib xyaw qhuav yog tsim raws li cov qauv kev tshawb fawb, kev ua haujlwm loj loj, ua ke nrog cov khoom siv tsim nyog los xyuas kom meej tias cov khoom tuaj yeem ua tau raws li qhov tshwj xeeb zoo;②Ntau Yam Muaj Ntau, ntau yam kev ua haujlwm mortars tuaj yeem tsim raws li qhov xav tau sib txawv;③Kev tsim kho tau zoo, yooj yim rau kev thov thiab khawb, tshem tawm qhov xav tau ntawm substrate pre-wetting thiab tom qab watering txij nkawm;④Yooj yim siv, tsuas yog ntxiv dej thiab do, yooj yim rau kev thauj thiab khaws cia, yooj yim rau kev tswj xyuas kev tsim kho;⑤ntsuab thiab kev tiv thaiv ib puag ncig, tsis muaj plua plav ntawm qhov chaw tsim kho, tsis muaj ntau pawg ntawm cov khoom siv raw, txo qhov cuam tshuam rau ib puag ncig;⑥kev lag luam, qhuav-siv mortar zam kev siv tsis tsim nyog ntawm cov khoom siv raw vim yog cov khoom xyaw tsim nyog, thiab tsim nyog rau kev siv tshuab ua kom luv luv ntawm kev tsim kho thiab txo cov nqi tsim kho.

Cellulose ether yog ib qho tseem ceeb admixture ntawm qhuav-mixed mortar.Cellulose ether tuaj yeem tsim cov calcium-silicate-hydroxide (CSH) ruaj khov nrog cov xuab zeb thiab cov cement kom ua tau raws li cov kev xav tau ntawm cov khoom siv mortar tshiab.

2. Cellulose ether li admixture

Cellulose ether yog ib qho kev hloov kho ntuj tsim polymer uas cov hydrogen atoms ntawm pawg hydroxyl hauv cellulose structural unit tau hloov los ntawm lwm pab pawg.Hom, kom muaj nuj nqis thiab kev faib tawm ntawm pawg hloov pauv ntawm cov saw hlau loj hauv cellulose txiav txim seb hom thiab qhov xwm txheej.

Cov pab pawg hydroxyl ntawm cov cellulose ether molecular saw tsim cov pa oxygen intertermolecular, uas tuaj yeem txhim kho qhov sib xws thiab ua tiav ntawm cov cement hydration;nce qhov sib xws ntawm mortar, hloov rheology thiab compressibility ntawm mortar;txhim kho qhov tawg tsis kam ntawm mortar;Entraining cua, txhim kho kev ua haujlwm ntawm mortar.

2.1 Daim ntawv thov ntawm carboxymethyl cellulose

Carboxymethylcellulose (CMC) yog ionic dej-soluble ib leeg cellulose ether, thiab nws cov ntsev ntsev feem ntau yog siv.Pure CMC yog dawb los yog milky dawb fibrous hmoov los yog granules, tsw thiab tasteless.Cov cim tseem ceeb los ntsuas qhov zoo ntawm CMC yog qib kev hloov pauv (DS) thiab viscosity, pob tshab thiab ruaj khov ntawm kev daws.

Tom qab ntxiv CMC rau hauv mortar, nws muaj qhov pom tseeb thickening thiab dej tuav cov teebmeem, thiab cov nyhuv thickening feem ntau nyob ntawm nws qhov hnyav molecular thiab qib ntawm kev hloov.Tom qab ntxiv CMC rau 48 teev, nws tau ntsuas tias qhov nqus dej ntawm cov qauv mortar txo qis.Qhov qis dua qhov nqus dej, qhov siab dua cov dej khaws cia;cov dej tuav cov nyhuv nce nrog qhov nce ntawm CMC ntxiv.Vim tias cov dej tuav tau zoo, nws tuaj yeem ua kom ntseeg tau tias cov tshuaj khib nyiab qhuav qhuav tsis los ntshav lossis cais tawm.Tam sim no, CMC feem ntau yog siv los ua tus neeg saib xyuas kev tiv thaiv hauv dams, docks, txuas hniav thiab lwm lub tsev, uas tuaj yeem txo qhov cuam tshuam ntawm cov dej ntawm cov cement thiab nplua aggregates thiab txo cov pa phem ib puag ncig.

CMC yog ib qho ionic compound thiab muaj cov kev xav tau siab ntawm cov cement, txwv tsis pub nws tuaj yeem hnov ​​​​mob nrog Ca (OH) 2 yaj hauv cov cement tom qab sib xyaw rau hauv cov cement slurry los tsim cov dej-insoluble calcium carboxymethylcellulose thiab poob nws cov viscosity, zoo heev txo cov dej tuav kev ua tau zoo. ntawm CMC yog impaired;Lub enzyme tsis kam ntawm CMC yog qhov tsis zoo.

2.2 Kev siv ntawmhydroxyethyl cellulosethiab hydroxypropyl cellulose

Hydroxyethyl cellulose (HEC) thiab hydroxypropyl cellulose (HPC) yog cov dej tsis-ionic-soluble ib leeg cellulose ethers nrog ntsev ntau.HEC ruaj khov rau cua sov;yooj yim soluble nyob rau hauv dej txias thiab kub;Thaum pH tus nqi yog 2-12, viscosity hloov me ntsis.HPC yog soluble hauv dej hauv qab 40°C thiab ntau tus polar solvents.Nws muaj thermoplasticity thiab deg kev ua haujlwm.Qhov siab dua qhov kev hloov pauv, qhov dej kub qis dua uas HPC tuaj yeem yaj.

Raws li tus nqi ntawm HEC ntxiv rau hauv mortar nce, lub zog compressive, tensile lub zog thiab corrosion kuj ntawm mortar txo nyob rau hauv ib lub sij hawm luv luv, thiab kev ua tau zoo hloov me ntsis raws sij hawm.HEC kuj cuam tshuam rau kev faib cov pores nyob rau hauv mortar.Tom qab ntxiv HPC rau hauv mortar, qhov porosity ntawm mortar tsawg heev, thiab cov dej yuav tsum tau txo, yog li txo qhov kev ua haujlwm ntawm cov mortar.Hauv kev siv tiag tiag, HPC yuav tsum tau siv ua ke nrog cov yas yas los txhim kho kev ua haujlwm ntawm mortar.

2.3 Kev siv methyl cellulose

Methylcellulose (MC) yog non-ionic ib leeg cellulose ether, uas tuaj yeem tawg sai sai thiab o hauv dej kub ntawm 80-90.°C, thiab yaj sai sai tom qab txias.Cov tshuaj aqueous ntawm MC tuaj yeem tsim cov gel.Thaum rhuab, MC tsis yaj hauv dej los ua ib lub gel, thiab thaum txias, cov gel melts.Qhov no tshwm sim yog reversible kiag li.Tom qab ntxiv MC rau hauv mortar, cov dej tuav tau zoo dua.Kev tuav dej ntawm MC nyob ntawm nws qhov viscosity, qib ntawm kev hloov pauv, kev ua kom zoo, thiab tus nqi ntxiv.Ntxiv MC tuaj yeem txhim kho cov khoom tiv thaiv sagging ntawm mortar;txhim kho lubricity thiab uniformity ntawm dispersed hais, ua rau lub mortar smoother thiab ntau uniformity, cov nyhuv ntawm troweling thiab smoothing yog zoo tagnrho, thiab kev ua hauj lwm kev ua tau zoo.

Tus nqi ntawm MC ntxiv muaj kev cuam tshuam zoo rau lub mortar.Thaum MC cov ntsiab lus ntau dua 2%, lub zog ntawm cov mortar raug txo mus rau ib nrab ntawm qhov qub.Cov dej tuav cov nyhuv nce ntxiv nrog qhov nce ntawm cov viscosity ntawm MC, tab sis thaum lub viscosity ntawm MC nce mus txog ib qho nqi, cov solubility ntawm MC txo, cov dej tuav tsis tau hloov ntau, thiab kev tsim kho kev ua haujlwm poob qis.

2.4 Daim ntawv thov ntawm hydroxyethylmethylcellulose thiab hydroxypropylmethylcellulose

Ib qho ether muaj qhov tsis zoo ntawm qhov tsis zoo dispersibility, agglomeration thiab ceev ceev hardening thaum tus nqi ntxiv me me, thiab ntau cov voids nyob rau hauv mortar thaum cov nyiaj ntxiv yog loj, thiab hardness ntawm cov pob zeb deteriorates;Yog li ntawd, kev ua haujlwm, compressive zog, thiab flexural zog Cov kev ua tau zoo tsis zoo tagnrho.Mixed ethers tuaj yeem kov yeej qhov tsis txaus ntawm ib leeg ethers rau qee yam;tus nqi ntxiv yog tsawg dua li ntawm ib leeg ethers.

Hydroxyethylmethylcellulose (HEMC) thiab hydroxypropylmethylcellulose (HPMC) yog nonionic sib xyaw cellulose ethers nrog cov khoom ntawm txhua qhov hloov pauv cellulose ether.

Cov tsos ntawm HEMC yog dawb, dawb dawb hmoov los yog granule, odorless thiab tasteless, hygroscopic, insoluble nyob rau hauv dej kub.Kev sib cais tsis cuam tshuam los ntawm tus nqi pH (zoo ib yam li MC), tab sis vim yog qhov sib ntxiv ntawm hydroxyethyl pawg ntawm cov saw hlau molecular, HEMC muaj ntsev ntau dua li MC, yooj yim rau yaj hauv dej, thiab muaj qhov kub thiab txias dua.HEMC muaj zog tuav dej ntau dua MC;viscosity stability, mildew kuj, thiab dispersibility muaj zog dua HEC.

HPMC yog cov hmoov dawb los yog dawb dawb, tsis muaj tshuaj lom, tsis qab thiab tsw ntxhiab.Kev ua tau zoo ntawm HPMC nrog cov kev qhia tshwj xeeb sib txawv heev.HPMC dissolves nyob rau hauv dej txias rau hauv ib tug ntshiab los yog me ntsis turbid colloidal tov, soluble nyob rau hauv ib co organic solvents, thiab kuj soluble nyob rau hauv dej.Cov kuab tshuaj sib xyaw ntawm cov kuab tshuaj organic, xws li ethanol hauv qhov tsim nyog, hauv dej.Cov tshuaj aqueous muaj cov yam ntxwv ntawm kev ua haujlwm saum npoo av, siab pob tshab thiab kev ua haujlwm ruaj khov.Kev sib cais ntawm HPMC hauv dej kuj tsis cuam tshuam los ntawm pH.Solubility sib txawv nrog viscosity, qis dua viscosity, ntau dua solubility.Nrog rau qhov txo qis ntawm methoxyl cov ntsiab lus hauv HPMC cov molecules, gel point ntawm HPMC nce, cov dej solubility txo, thiab cov dej ua haujlwm kuj txo.Ntxiv nrog rau cov yam ntxwv ntawm qee cov cellulose ethers, HPMC kuj muaj cov ntsev zoo, qhov ruaj khov, enzyme tsis kam, thiab siab dispersibility.

Lub luag haujlwm tseem ceeb ntawm HEMC thiab HPMC hauv cov tshuaj khib nyiab qhuav yog raws li hauv qab no.①Kev tuav dej zoo.HEMC thiab HPMC tuaj yeem ua kom ntseeg tau tias cov mortar yuav tsis ua teeb meem xws li xuab zeb, hmoov thiab lub zog txo ntawm cov khoom vim tsis muaj dej thiab cov cement hydration tsis tiav.Txhim kho uniformity, workability thiab khoom hardening.Thaum tus nqi ntawm HPMC ntxiv yog ntau dua 0.08%, cov txiaj ntsig kev ntxhov siab thiab cov yas viscosity ntawm cov tshuaj khib kuj nce ntxiv nrog qhov nce ntawm HPMC.②Raws li ib tug air-entraining neeg sawv cev.Thaum cov ntsiab lus ntawm HEMC thiab HPMC yog 0.5%, cov ntsiab lus roj yog qhov loj tshaj plaws, txog 55%.Lub zog flexural thiab compressive zog ntawm mortar.③Txhim kho kev ua haujlwm.Qhov sib ntxiv ntawm HEMC thiab HPMC txhawb nqa daim npav nyias-txheej mortar thiab paving ntawm plastering mortar.

HEMC thiab HPMC tuaj yeem ncua sijhawm hydration ntawm mortar hais, DS yog qhov tseem ceeb tshaj plaws uas cuam tshuam rau hydration, thiab cov nyhuv ntawm methoxyl cov ntsiab lus ntawm ncua hydration yog ntau dua li cov ntsiab lus hydroxyethyl thiab hydroxypropyl.

Nws yuav tsum raug sau tseg tias cellulose ether muaj qhov cuam tshuam ob npaug ntawm kev ua haujlwm ntawm mortar, thiab nws tuaj yeem ua lub luag haujlwm zoo yog tias siv kom raug, tab sis nws yuav muaj qhov tsis zoo yog tias siv tsis raug.Qhov kev ua tau zoo ntawm cov tshuaj khib nyiab qhuav yog thawj zaug cuam tshuam txog kev hloov pauv ntawm cellulose ether, thiab cov khoom siv cellulose ether kuj muaj feem xyuam rau cov khoom xws li tus nqi thiab kev txiav txim ntxiv.Hauv kev siv tswv yim, ib hom cellulose ether tuaj yeem xaiv, lossis ntau hom cellulose ether tuaj yeem siv ua ke.

3. Outlook

Txoj kev loj hlob sai ntawm cov tshuaj khib nyiab qhuav muab cov cib fim thiab cov nyom rau kev txhim kho thiab siv cov cellulose ether.Cov kws tshawb fawb thiab cov neeg tsim khoom yuav tsum tuav lub sijhawm los txhim kho lawv cov qib kev txawj ntse, thiab ua haujlwm hnyav kom muaj ntau yam thiab txhim kho cov khoom ruaj khov.Thaum ua tau raws li qhov yuav tsum tau siv rau kev siv cov tshuaj khib nyiab qhuav, nws tau ua tiav kev dhia hauv kev lag luam cellulose ether.