Hauv cov mortar sib xyaw ua tiav, qhov ntxiv ntawm hydroxypropyl methyl cellulose HPMC yog qhov tsawg heev, tab sis nws tuaj yeem txhim kho qhov kev ua tau zoo ntawm cov mortar ntub, uas yog ib qho tseem ceeb uas cuam tshuam rau kev ua tau zoo ntawm cov mortar. Cellulose ethers nrog viscosity sib txawv thiab ntxiv ntau npaum li cas muaj qhov cuam tshuam zoo rau kev txhim kho qhov kev ua tau zoo ntawm cov mortar qhuav. Tam sim no, ntau cov masonry thiab plastering mortars muaj cov khoom khaws dej tsis zoo, thiab kev sib cais dej slurry tshwm sim tom qab ob peb feeb ntawm sawv ntsug. Kev khaws dej yog ib qho kev ua tau zoo tseem ceeb ntawm methyl cellulose ether, thiab nws kuj yog ib qho kev ua tau zoo uas ntau lub tuam txhab tsim cov mortar qhuav hauv tsev, tshwj xeeb tshaj yog cov neeg nyob hauv thaj chaw uas muaj qhov kub siab dua hauv sab qab teb, them sai sai rau. Cov yam ntxwv cuam tshuam rau qhov kev khaws dej ntawm cov mortar qhuav suav nrog qhov ntau ntawm HPMC ntxiv, viscosity ntawm HPMC, qhov zoo ntawm cov khoom me me thiab qhov kub ntawm qhov chaw uas nws siv.
1. Lub Tswv Yim: Cellulose ether yog ib qho polymer molecular siab ua los ntawm cov cellulose ntuj los ntawm kev hloov kho tshuaj. Cellulose ether yog ib qho derivative ntawm cellulose ntuj. Kev tsim cov cellulose ether txawv ntawm cov polymers hluavtaws. Nws cov khoom siv yooj yim tshaj plaws yog cellulose, ib qho polymer compound ntuj. Vim yog cov qauv tshwj xeeb ntawm cellulose ntuj, cellulose nws tus kheej tsis muaj peev xwm los cuam tshuam nrog cov neeg sawv cev etherifying. Tab sis tom qab tus neeg sawv cev o tuaj kho, cov hydrogen bonds muaj zog ntawm cov saw hlau molecular thiab hauv cov saw hlau raug rhuav tshem, thiab kev tso tawm ntawm pawg hydroxyl hloov mus ua cov alkali cellulose reactive. Tom qab tus neeg sawv cev etherification reacts, pawg -OH hloov mus rau pawg -OR. Tau txais cellulose ether. Qhov xwm txheej ntawm cellulose ether nyob ntawm hom, ntau npaum li cas thiab kev faib tawm ntawm cov substituents. Kev faib tawm ntawm cellulose ethers kuj yog raws li hom substituents, qib ntawm etherification, solubility thiab cov ntawv thov cuam tshuam. Raws li hom substituents ntawm cov saw hlau molecular, nws tuaj yeem faib ua monoether thiab sib xyaw ether. Lub HPMC peb feem ntau siv yog sib xyaw ether. Hydroxypropyl methyl cellulose ether HPMC yog ib yam khoom uas ib feem ntawm pawg hydroxyl ntawm lub tshuab hloov los ntawm pawg methoxy thiab lwm qhov hloov los ntawm pawg hydroxypropyl. HPMC feem ntau yog siv rau hauv cov ntaub ntawv tsim kho, cov tshuaj pleev xim latex, tshuaj, tshuaj lom neeg txhua hnub, thiab lwm yam. Siv ua cov khoom siv tuab, cov neeg sawv cev khaws dej, cov khoom ruaj khov, cov khoom tawg, thiab cov neeg sawv cev tsim zaj duab xis.
2. Kev khaws dej ntawm cellulose ether: hauv kev tsim cov ntaub ntawv tsim kho, tshwj xeeb tshaj yog cov mortar qhuav, cellulose ether ua lub luag haujlwm tseem ceeb, tshwj xeeb tshaj yog hauv kev tsim cov mortar tshwj xeeb (hloov kho mortar), nws yog qhov tseem ceeb. lub luag haujlwm tseem ceeb ntawm cov dej-soluble cellulose ether hauv mortar yog feem ntau hauv peb yam. Ib qho yog lub peev xwm khaws dej zoo heev, qhov thib ob yog qhov cuam tshuam rau qhov sib xws thiab thixotropy ntawm mortar, thiab qhov thib peb yog kev cuam tshuam nrog cement. Cov nyhuv khaws dej ntawm cellulose ether nyob ntawm qhov nqus dej ntawm cov txheej hauv paus, cov khoom sib xyaw ntawm cov mortar, cov txheej tuab ntawm cov mortar, qhov xav tau dej ntawm cov mortar, thiab lub sijhawm teeb tsa ntawm cov khoom coagulating. Kev khaws dej ntawm cellulose ether nws tus kheej los ntawm kev yaj thiab qhuav ntawm cellulose ether nws tus kheej.
qhov tuab thiab thixotropy ntawm cellulose ether: Lub luag haujlwm thib ob ntawm cellulose ether-thickenening nyob ntawm: qib ntawm polymerization ntawm cellulose ether, kev daws teeb meem, kub thiab lwm yam mob. Cov khoom gelation ntawm cov tshuaj yog cov khoom tshwj xeeb ntawm alkyl cellulose thiab nws cov derivatives hloov kho. Cov yam ntxwv gelation muaj feem cuam tshuam nrog qib ntawm kev hloov pauv, kev daws teeb meem thiab cov khoom ntxiv.
Lub peev xwm khaws dej zoo ua rau cov cement hydration tiav dua, tuaj yeem txhim kho qhov ntub dej ntawm cov mortar ntub, ua rau lub zog sib txuas ntawm cov mortar, thiab lub sijhawm tuaj yeem hloov kho. Kev ntxiv cov cellulose ether rau hauv cov tshuaj tsuag txau tuaj yeem txhim kho kev txau lossis kev ua haujlwm ntawm cov mortar, nrog rau lub zog ntawm cov qauv. Yog li ntawd, cellulose ether tau siv dav ua cov khoom ntxiv tseem ceeb hauv cov mortar sib xyaw ua tiav.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-16-2021