Cellulose ethermuaj kev khaws dej zoo heev, uas tuaj yeem tiv thaiv cov dej noo hauv cov mortar ntub kom tsis txhob evaporate ua ntej lossis raug nqus los ntawm cov txheej hauv paus, thiab xyuas kom meej tias cov cement tau hydrated tag nrho, yog li thaum kawg xyuas kom meej cov khoom siv kho tshuab ntawm cov mortar, uas yog qhov tshwj xeeb tshaj yog rau cov mortar nyias-txheej thiab cov txheej hauv paus nqus dej lossis mortar tsim nyob rau hauv qhov kub siab thiab qhuav. Cov nyhuv khaws dej ntawm cellulose ether tuaj yeem hloov pauv cov txheej txheem kev tsim kho ib txwm muaj thiab txhim kho kev nce qib ntawm kev tsim kho. Piv txwv li, kev tsim kho plastering tuaj yeem ua tiav ntawm cov substrates nqus dej yam tsis tau ntub ua ntej.
Qhov viscosity, dosage, ambient kub thiab molecular qauv ntawm cellulose ether muaj feem cuam tshuam loj rau nws cov dej tuav kev ua tau zoo. Nyob rau hauv tib yam mob, qhov ntau dua viscosity ntawm cellulose ether, qhov zoo dua qhov khaws cia dej; qhov ntau dua qhov ntau npaum li cas, qhov zoo dua qhov khaws cia dej. Feem ntau, me me ntawm cellulose ether tuaj yeem txhim kho qhov khaws cia dej ntawm mortar. Thaum cov tshuaj mus txog ib qho. Thaum qib ntawm kev khaws cia dej nce, qhov sib txawv ntawm qhov ceev khaws cia dej qeeb qeeb; thaum qhov kub thiab txias nce, qhov khaws cia dej ntawm cellulose ether feem ntau txo qis, tab sis qee cov cellulose ethers hloov kho kuj muaj kev khaws cia dej zoo dua nyob rau hauv qhov kub siab; cov fibers nrog qib qis dua ntawm kev hloov pauv Vegan ether muaj kev ua tau zoo dua qhov khaws cia dej.
Pawg hydroxyl ntawm cov cellulose ether molecule thiab cov pa oxygen ntawm cov ether bond yuav koom nrog cov dej molecule los tsim cov hydrogen bond, tig cov dej dawb mus rau hauv cov dej khi, yog li ua lub luag haujlwm zoo hauv kev khaws dej; cov dej molecule thiab cov cellulose ether molecular saw Interdiffusion tso cai rau cov dej molecules nkag mus rau sab hauv ntawm cov cellulose ether macromolecular saw thiab raug rau cov zog khi muaj zog, yog li tsim cov dej khi thiab cov dej entangled, uas txhim kho cov dej khaws cia ntawm cov cement slurry; cellulose ether txhim kho cov cement slurry tshiab. Cov khoom rheological, cov qauv porous network thiab osmotic siab lossis cov khoom tsim zaj duab xis ntawm cellulose ether cuam tshuam kev sib kis ntawm dej.
Cellulose ether muab cov mortar ntub dej nrog viscosity zoo heev, uas tuaj yeem ua rau muaj peev xwm sib txuas ntawm cov mortar ntub dej thiab txheej hauv paus, thiab txhim kho kev ua haujlwm tiv thaiv kev sagging ntawm cov mortar. Nws yog dav siv rau hauv plastering mortar, cib bonding mortar thiab sab nraud phab ntsa rwb thaiv tsev system. Cov nyhuv thickening ntawm cellulose ether kuj tseem tuaj yeem ua rau muaj peev xwm tiv thaiv kev tawg thiab kev sib xws ntawm cov ntaub ntawv sib xyaw tshiab, tiv thaiv cov khoom delamination, sib cais thiab los ntshav, thiab tuaj yeem siv rau hauv fiber concrete, underwater concrete thiab self-compacting concrete.
Qhov ua kom tuab ntawm cellulose ether rau cov ntaub ntawv cement los ntawm qhov viscosity ntawm cellulose ether kua. Nyob rau hauv tib lub xeev, qhov viscosity siab dua ntawm cellulose ether, qhov viscosity zoo dua ntawm cov ntaub ntawv cement hloov kho, tab sis yog tias viscosity siab dhau, nws yuav cuam tshuam rau qhov fluidity thiab kev ua haujlwm ntawm cov khoom (xws li lo rau riam plastering). Cov mortar self-leveling thiab cov pob zeb self-compacting, uas xav tau fluidity siab, xav tau viscosity qis ntawm cellulose ether. Tsis tas li ntawd, qhov thickening effect ntawm cellulose ether yuav ua rau kom muaj dej ntau ntxiv rau cov ntaub ntawv cement thiab ua rau cov mortar ntau ntxiv.
Qhov viscosity ntawm cellulose ether kua nyob ntawm cov hauv qab no: qhov hnyav molecular ntawm cellulose ether, concentration, kub, shear rate thiab txoj kev sim. Nyob rau hauv tib lub xeev, qhov loj dua qhov hnyav molecular ntawm cellulose ether, qhov siab dua qhov viscosity ntawm cov kua; qhov siab dua qhov concentration, qhov siab dua qhov viscosity ntawm cov kua. Thaum siv nws, yuav tsum tau ceev faj kom tsis txhob muaj ntau dhau thiab cuam tshuam rau kev ua haujlwm ntawm mortar thiab concrete; cellulose ether Lub viscosity ntawm ether kua yuav txo qis nrog qhov nce ntawm qhov kub, thiab qhov siab dua qhov concentration, qhov loj dua qhov cuam tshuam ntawm qhov kub; cellulose ether kua feem ntau yog cov kua pseudoplastic nrog cov cuab yeej ntawm shear thinning, qhov ntau dua qhov shear rate thaum lub sijhawm sim, qhov me dua qhov viscosity, yog li ntawd, qhov cohesion ntawm mortar yuav txo qis nyob rau hauv qhov kev ua ntawm lub zog sab nraud, uas yog qhov zoo rau kev tsim kho scraping ntawm mortar, yog li ntawd mortar tuaj yeem muaj kev ua haujlwm zoo thiab cohesion tib lub sijhawm; Vim tias cov kua cellulose ether tsis yog non-Newtonian Rau cov kua dej, thaum cov txheej txheem sim, cov cuab yeej thiab cov khoom siv lossis cov chaw sim siv los sim cov viscosity sib txawv, cov txiaj ntsig ntawm kev sim ntawm tib cov kua cellulose ether yuav txawv heev.
Cov cellulose ether molecules tuaj yeem kho qee cov dej molecules ntawm cov khoom tshiab ntawm ntug ntawm cov saw molecular, yog li ua rau cov viscosity ntawm cov tshuaj nce ntxiv. Cov saw molecular ntawm cellulose ether yog intertwined los ua ib lub network peb-dimensional, uas tseem yuav ua rau nws cov kua dej muaj viscosity zoo.
Cov kua dej cellulose ether uas muaj viscosity siab muaj thixotropy siab, uas kuj yog ib qho tseem ceeb ntawm cellulose ether. Cov kua dej ntawmmethyl cellulosefeem ntau muaj pseudoplastic thiab tsis yog thixotropic fluidity qis dua nws qhov kub gel, tab sis qhia Newtonian ntws cov khoom ntawm qhov qis shear rates. Pseudoplasticity nce nrog rau qhov hnyav molecular lossis concentration ntawm cellulose ether, tsis hais hom substituent thiab qib ntawm kev hloov pauv. Yog li ntawd, cellulose ethers ntawm tib qib viscosity, tsis hais mc, HPmc, HEmc, yuav ib txwm qhia tib yam rheological khoom ntev li ntev tau qhov concentration thiab kub tau khaws cia tas li. Cov qauv gels yog tsim thaum qhov kub nce, thiab cov dej ntws thixotropic siab tshwm sim. Qhov concentration siab thiab viscosity qis cellulose ethers qhia thixotropy txawm tias qis dua qhov kub gel. Cov khoom no yog qhov zoo rau kev hloov kho ntawm leveling thiab sagging hauv kev tsim kho ntawm lub tsev mortar. Nws yuav tsum tau piav qhia ntawm no tias qhov siab dua qhov viscosity ntawm cellulose ether, qhov zoo dua qhov khaws cia dej, tab sis qhov siab dua qhov viscosity, qhov siab dua qhov hnyav molecular ntawm cellulose ether, thiab qhov sib xws txo qis hauv nws cov solubility, uas muaj qhov cuam tshuam tsis zoo rau qhov concentration mortar thiab kev ua haujlwm tsim kho. Qhov viscosity siab dua, qhov pom tseeb dua qhov thickening effect ntawm cov mortar, tab sis nws tsis yog proportional tag nrho. Qee qhov nruab nrab thiab qis viscosity, tab sis cov cellulose ether hloov kho muaj kev ua tau zoo dua hauv kev txhim kho lub zog ntawm cov mortar ntub. Nrog rau kev nce ntawm viscosity, cov dej khaws cia ntawm cellulose ether txhim kho.
Lub sijhawm tshaj tawm: Plaub Hlis-28-2024