Kev siv cellulose ether hauv cov ntaub ntawv cement

1 Kev Taw Qhia
Tuam Tshoj tau txhawb nqa cov tshuaj mortar sib xyaw ua ke tau ntau tshaj 20 xyoo. Tshwj xeeb tshaj yog nyob rau xyoo tas los no, cov chaw haujlwm ntawm tsoomfwv hauv tebchaws tau muab qhov tseem ceeb rau kev tsim cov tshuaj mortar sib xyaw ua ke thiab tau tshaj tawm cov cai txhawb nqa. Tam sim no, muaj ntau tshaj 10 lub xeev thiab cov nroog hauv lub tebchaws uas tau siv cov tshuaj mortar sib xyaw ua ke. Ntau tshaj 60%, muaj ntau tshaj 800 lub tuam txhab ua tshuaj mortar sib xyaw ua ke siab dua qhov ntsuas ib txwm muaj, nrog lub peev xwm tsim txhua xyoo ntawm 274 lab tons. Xyoo 2021, kev tsim cov tshuaj mortar sib xyaw ua ke txhua xyoo yog 62.02 lab tons.

Thaum lub sijhawm tsim kho, cov mortar feem ntau poob dej ntau dhau thiab tsis muaj sijhawm thiab dej txaus los hydrate, ua rau tsis muaj zog thiab tawg ntawm cov cement paste tom qab hardening. Cellulose ether yog cov polymer admixture feem ntau hauv cov mortar qhuav-mixed. Nws muaj cov haujlwm ntawm kev khaws dej, thickening, retardation thiab cua entrainment, thiab tuaj yeem txhim kho qhov kev ua tau zoo ntawm cov mortar.

Yuav kom cov mortar ua tau raws li qhov yuav tsum tau thauj mus los thiab daws cov teeb meem ntawm kev tawg thiab lub zog qis, nws yog qhov tseem ceeb heev uas yuav tsum ntxiv cellulose ether rau hauv cov mortar. Tsab xov xwm no luv luv qhia txog cov yam ntxwv ntawm cellulose ether thiab nws cov kev cuam tshuam rau kev ua tau zoo ntawm cov ntaub ntawv cement, vam tias yuav pab daws cov teeb meem kev siv tshuab ntawm cov mortar sib xyaw ua tiav.

2 Kev Taw Qhia rau cellulose ether
Cellulose Ether (Cellulose Ether) yog tsim los ntawm cellulose los ntawm kev sib xyaw ua ke ntawm ib lossis ntau tus neeg sawv cev etherification thiab kev sib tsoo qhuav.

2.1 Kev faib tawm ntawm cellulose ethers
Raws li cov qauv tshuaj lom neeg ntawm ether substituents, cellulose ethers tuaj yeem muab faib ua anionic, cationic thiab nonionic ethers. Ionic cellulose ethers feem ntau suav nrog carboxymethyl cellulose ether (CMC); non-ionic cellulose ethers feem ntau suav nrog methyl cellulose ether (MC), hydroxypropyl methyl cellulose ether (HPMC) thiab hydroxyethyl fiber Ether (HC) thiab lwm yam. Non-ionic ethers raug muab faib ua cov dej-soluble ethers thiab roj-soluble ethers. Non-ionic dej-soluble ethers feem ntau yog siv rau hauv cov khoom mortar. Nyob rau hauv lub xub ntiag ntawm calcium ions, ionic cellulose ethers tsis ruaj khov, yog li lawv tsis tshua siv rau hauv cov khoom qhuav-mix mortar uas siv cement, slaked lime, thiab lwm yam ua cov ntaub ntawv cementing. Non-ionic dej-soluble cellulose ethers yog siv dav hauv kev lag luam cov ntaub ntawv tsim kho vim lawv qhov kev ncua kev ruaj khov thiab cov dej khaws cia cov nyhuv.
Raws li cov neeg sawv cev etherification sib txawv xaiv hauv cov txheej txheem etherification, cellulose ether cov khoom suav nrog methyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, cyanoethyl cellulose, carboxymethyl cellulose, Ethyl cellulose, benzyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxypropyl methyl cellulose, benzyl cyanoethyl cellulose thiab phenyl cellulose.

Cov cellulose ethers siv rau hauv cov mortar feem ntau suav nrog methyl cellulose ether (MC), hydroxypropyl methyl cellulose (HPMC), hydroxyethyl methyl cellulose ether (HEMC) thiab hydroxyethyl cellulose ether (HEMC). Ntawm lawv, HPMC thiab HEMC yog cov siv dav tshaj plaws.

2.2 Cov khoom siv tshuaj lom neeg ntawm cellulose ether
Txhua lub cellulose ether muaj cov qauv yooj yim ntawm cellulose-anhydroglucose qauv. Hauv cov txheej txheem ntawm kev tsim cov cellulose ether, cov cellulose fiber thawj zaug raug cua sov hauv cov kua alkaline thiab tom qab ntawd kho nrog tus neeg sawv cev etherifying. Cov khoom siv fibrous reaction yog purified thiab av kom ua cov hmoov sib xws nrog qee qhov fineness.

Hauv kev tsim MC, tsuas yog methyl chloride siv ua tus neeg sawv cev etherifying; ntxiv rau methyl chloride, propylene oxide kuj tseem siv los tau txais hydroxypropyl substituents hauv kev tsim HPMC. Ntau yam cellulose ethers muaj cov nqi hloov pauv methyl thiab hydroxypropyl sib txawv, uas cuam tshuam rau qhov sib xws ntawm cov organic thiab qhov kub ntawm cov cellulose ether.

2.3 Cov yam ntxwv ntawm kev yaj ntawm cellulose ether

Cov yam ntxwv ntawm kev yaj ntawm cellulose ether muaj feem cuam tshuam loj heev rau kev ua haujlwm ntawm cov cement mortar. Cellulose ether tuaj yeem siv los txhim kho kev sib koom ua ke thiab kev khaws dej ntawm cov cement mortar, tab sis qhov no nyob ntawm seb cellulose ether yaj tag nrho hauv dej. Cov yam tseem ceeb uas cuam tshuam rau kev yaj ntawm cellulose ether yog lub sijhawm yaj, kev sib xyaw ceev thiab qhov zoo ntawm hmoov.

2.4 Lub luag haujlwm ntawm kev poob rau hauv cov cement mortar

Ua ib qho tseem ceeb ntxiv rau cov cement slurry, Destroy muaj nws cov nyhuv hauv cov hauv qab no.
(1) Txhim kho qhov ua haujlwm tau ntawm cov mortar thiab ua rau kom cov viscosity ntawm cov mortar nce ntxiv.
Kev siv cov nplaim taws tuaj yeem tiv thaiv cov mortar los ntawm kev sib cais thiab tau txais lub cev yas sib xws thiab sib xws. Piv txwv li, cov rooj muag khoom uas muaj HEMC, HPMC, thiab lwm yam, yooj yim rau cov mortar nyias-txheej thiab plastering. , Shear rate, kub, collapse concentration thiab yaj ntsev concentration.
(2) Nws muaj cov nyhuv ntawm huab cua.
Vim yog cov khoom tsis huv, kev qhia cov pab pawg rau hauv cov khoom me me txo qhov zog ntawm cov khoom me me, thiab nws yooj yim los qhia cov khoom ruaj khov, sib xws thiab zoo rau hauv cov mortar sib xyaw nrog qhov chaw sib xyaw hauv cov txheej txheem. "Kev ua haujlwm ntawm pob" txhim kho kev ua haujlwm ntawm cov mortar, txo cov dej noo ntawm cov mortar thiab txo cov thermal conductivity ntawm cov mortar. Kev sim tau qhia tias thaum qhov sib xyaw ntawm HEMC thiab HPMC yog 0.5%, cov roj ntawm cov mortar yog qhov loj tshaj plaws, kwv yees li 55%; thaum qhov sib xyaw ntau dua 0.5%, cov ntsiab lus ntawm cov mortar maj mam hloov mus rau hauv cov roj cov ntsiab lus raws li qhov ntau ntxiv.
(3) Khaws nws tsis hloov pauv.

Cov quav ciab tuaj yeem yaj, roj thiab do rau hauv cov mortar, thiab pab kom cov txheej nyias ntawm mortar thiab plastering hmoov du. Nws tsis tas yuav ntub ua ntej. Tom qab kev tsim kho, cov khoom siv cementitious kuj tuaj yeem muaj lub sijhawm ntev ntawm kev sib txuas lus ntawm ntug dej hiav txwv kom txhim kho kev sib txuas ntawm mortar thiab substrate.

Cov teebmeem hloov pauv ntawm cellulose ether rau cov khoom siv cement tshiab feem ntau suav nrog kev ua kom tuab, khaws dej, cua nkag thiab qeeb. Nrog rau kev siv dav dav ntawm cellulose ethers hauv cov khoom siv cement, kev sib cuam tshuam ntawm cellulose ethers thiab cement slurry maj mam dhau los ua qhov chaw tshawb fawb.