1 Kev Taw Qhia
Tuam Tshoj tau txhawb nqa cov khoom sib xyaw ua ke rau ntau tshaj 20 xyoo. Tshwj xeeb tshaj yog nyob rau hauv xyoo tas los no, cov koom haum tseem ceeb hauv lub tebchaws tau txuas nrog qhov tseem ceeb rau kev txhim kho cov mortar npaj txhij thiab tshaj tawm cov cai txhawb nqa. Tam sim no, muaj ntau tshaj 10 lub xeev thiab lub nroog hauv lub tebchaws uas tau siv cov tshuaj sib xyaw ua ke. Ntau tshaj 60%, muaj ntau tshaj 800 npaj-sib tov mortar tuam txhab uas muag saum toj no tus qauv zoo tib yam, muaj peev xwm tsim txhua xyoo ntawm 274 lab tons. Xyoo 2021, kev tsim khoom txhua xyoo ntawm cov khoom sib xyaw ua ke yog 62.02 lab tons.
Thaum lub sij hawm kev tsim kho, cov mortar feem ntau poob dej ntau dhau thiab tsis muaj sijhawm txaus thiab dej kom hydrate, ua rau lub zog tsis txaus thiab tawg ntawm cov cement paste tom qab hardening. Cellulose ether yog ib hom polymer admixture nyob rau hauv qhuav-mixed mortar. Nws muaj lub luag haujlwm ntawm dej tuav, thickening, retardation thiab huab cua nkag, thiab tuaj yeem txhim kho kev ua haujlwm ntawm cov mortar.
Txhawm rau ua kom cov mortar ua tau raws li kev thauj mus los thiab daws cov teeb meem ntawm kev tawg thiab kev sib txuas tsis muaj zog, nws tseem ceeb heev kom ntxiv cellulose ether rau hauv mortar. Kab lus no luv luv qhia txog cov yam ntxwv ntawm cellulose ether thiab nws cov kev cuam tshuam ntawm kev ua haujlwm ntawm cov ntaub ntawv cement-based, vam tias yuav pab daws cov teeb meem cuam tshuam txog kev npaj sib xyaw mortar.
2 Taw qhia txog cellulose ether
Cellulose Ether (Cellulose Ether) yog tsim los ntawm cellulose los ntawm cov tshuaj tiv thaiv etherification ntawm ib lossis ntau tus neeg ua haujlwm etherification thiab kev sib tsoo qhuav.
2.1 Kev faib tawm ntawm cellulose ethers
Raws li cov qauv tshuaj 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 muab faib ua dej-soluble ethers thiab roj-soluble ethers. Cov dej-soluble ethers uas tsis yog-ionic feem ntau yog siv hauv cov khoom khib nyiab. Nyob rau hauv lub xub ntiag ntawm calcium ions, ionic cellulose ethers tsis ruaj tsis khov, yog li lawv tsis tshua muaj siv nyob rau hauv qhuav-mix mortar khoom uas siv cov cement, slaked txiv qaub, thiab lwm yam raws li cov ntaub ntawv cementing. Non-ionic dej-soluble cellulose ethers yog dav siv nyob rau hauv lub tsev cov ntaub ntawv kev lag luam vim hais tias ntawm lawv suspension stability thiab dej tuav nyhuv.
Raws li qhov sib txawv etherification agents xaiv nyob rau hauv cov txheej txheem etherification, cellulose ether cov khoom muaj xws li methyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, cyanoethyl cellulose, carboxymethyl cellulose, Ethyl cellulose, benzyl cellulose, carboxymethyl hydrobenzyl cellulose, cyanoethyl cellulose thiab phenyl cellulose.
Cellulose ethers siv nyob rau hauv mortar feem ntau muaj xws li 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 ntawm cellulose ether
Txhua cellulose ether muaj cov qauv hauv paus ntawm cellulose-anhydroglucose qauv. Nyob rau hauv tus txheej txheem ntawm kev tsim cellulose ether, cellulose fiber yog thawj rhuab nyob rau hauv ib tug alkaline tov thiab ces kho nrog ib tug etherifying tus neeg saib xyuas. Cov khoom siv tshuaj tiv thaiv fibrous yog purified thiab hauv av los tsim cov hmoov sib xws nrog ib qho kev nplua nuj.
Hauv kev tsim cov MC, tsuas yog methyl chloride yog siv los ua tus neeg sawv cev etherifying; Ntxiv nrog rau methyl chloride, propylene oxide kuj tseem siv tau kom tau txais cov khoom siv hydroxypropyl hauv kev tsim HPMC. Ntau yam cellulose ethers muaj ntau yam methyl thiab hydroxypropyl hloov pauv, uas cuam tshuam rau cov organic compatibility thiab thermal gel kub ntawm cov tshuaj cellulose ether.
2.3 Cov yam ntxwv ntawm kev tawg ntawm cellulose ether
Cov yam ntxwv tawg ntawm cellulose ether muaj kev cuam tshuam zoo rau kev ua haujlwm ntawm cov cement mortar. Cellulose ether tuaj yeem siv los txhim kho lub cohesiveness thiab dej tuav ntawm cement mortar, tab sis qhov no nyob ntawm cellulose ether ua tiav thiab tag nrho yaj hauv dej. Lub ntsiab yam tseem ceeb cuam tshuam rau kev tawg ntawm cellulose ether yog lub sij hawm dissolution, stirring ceev thiab hmoov fineness.
2.4 Lub luag haujlwm ntawm kev tso dej hauv cov cement mortar
Raws li ib qho tseem ceeb ntxiv ntawm cov cement slurry, Destroy muaj nws cov nyhuv hauv cov hauv qab no.
(1) Txhim kho kev ua haujlwm ntawm cov tshuaj khib thiab ua kom cov viscosity ntawm cov tshuaj khib.
Kev sib xyaw cov nplaim hluav taws tuaj yeem tiv thaiv cov mortar los ntawm kev sib cais thiab tau txais ib lub cev zoo li qub thiab tsis sib xws. Piv txwv li, lub rooj muag khoom uas suav nrog HEMC, HPMC, thiab lwm yam, yog yooj yim rau cov txheej txheej mortar thiab plastering. , Shear tus nqi, qhov kub thiab txias, vau concentration thiab yaj ntsev concentration.
(2) Nws muaj cov nyhuv cua-entraining.
Vim yog impurities, kev taw qhia ntawm cov pab pawg mus rau hauv cov khoom txo lub zog saum npoo ntawm cov khoom, thiab nws yog ib qho yooj yim los ua kom paub cov khoom ruaj khov, zoo ib yam thiab zoo nyob rau hauv mortar tov nrog nplawm nto hauv cov txheej txheem. "Ball efficiency" txhim kho kev tsim kho ntawm cov mortar, txo cov dej noo ntawm cov tshuaj khib thiab txo cov thermal conductivity ntawm mortar. Kev ntsuam xyuas tau pom tias thaum qhov sib xyaw ntawm HEMC thiab HPMC yog 0.5%, cov ntsiab lus roj ntawm cov mortar yog qhov loj tshaj plaws, txog 55%; Thaum cov nyiaj sib tov ntau dua 0.5%, cov ntsiab lus ntawm cov tshuaj khib nyiab maj mam hloov mus rau hauv cov ntsiab lus roj raws li qhov nyiaj nce.
(3) Cia nws tsis hloov.
Cov wax tuaj yeem yaj, lubricate thiab do hauv mortar, thiab pab txhawb kev smoothing ntawm nyias txheej ntawm mortar thiab plastering hmoov. Nws tsis tas yuav tsum tau ntub dej ua ntej. Tom qab kev tsim kho, cov khoom siv cementitious kuj tuaj yeem muaj lub sijhawm ntev ntawm cov dej tsis tu ncua raws ntug dej hiav txwv los txhim kho qhov adhesion ntawm cov tshuaj khib thiab cov substrate.
Kev hloov kho cov teebmeem ntawm cellulose ether ntawm cov khoom siv cement-based tshiab feem ntau suav nrog cov thickening, dej tuav, cua nkag thiab retardation. Nrog rau kev siv cellulose ethers thoob plaws hauv cov khoom siv cement, kev sib cuam tshuam ntawm cellulose ethers thiab cement slurry yog maj mam dhau los ua qhov kev tshawb fawb hotspot.
Post lub sij hawm: Dec-16-2021