Hauv cov mortar sib xyaw ua ke, ntev li me ntsiscellulose ethertuaj yeem txhim kho qhov kev ua tau zoo ntawm cov mortar ntub, nws tuaj yeem pom tias cellulose ether yog cov khoom siv tseem ceeb uas cuam tshuam rau kev ua haujlwm ntawm mortar.
Kev xaiv ntawm ntau hom sib txawv, sib txawv viscosities, sib txawv qhov loj me, sib txawv degrees ntawm viscosity thiab ntxiv cov cellulose ethers kuj muaj cov teebmeem sib txawv rau kev txhim kho kev ua tau zoo ntawm cov hmoov qhuav mortar. Tam sim no, ntau lub masonry thiab plastering mortars muaj kev ua tau zoo tsis zoo, thiab cov dej slurry yuav sib cais tom qab ob peb feeb ntawm sawv. Yog li nws yog ib qho tseem ceeb heev uas yuav tsum ntxiv cellulose ether rau hauv cement mortar.
kev khaws dej
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 tshuaj mortar qhuav hauv tsev, tshwj xeeb tshaj yog cov neeg nyob rau sab qab teb uas muaj qhov kub siab, tau them sai sai rau.
Hauv kev tsim cov ntaub ntawv siv hauv tsev, tshwj xeeb tshaj yog cov hmoov qhuav mortar, cellulose ether ua lub luag haujlwm tseem ceeb, tshwj xeeb tshaj yog hauv kev tsim cov mortar tshwj xeeb (hloov kho mortar), nws yog ib qho tseem ceeb thiab tseem ceeb.
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 dawb, dej sib xyaw, thiab txhim kho kev khaws dej 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.
thickening thiab thixotropy
Cellulose etherNws ua rau cov mortar ntub muaj viscosity zoo heev, uas tuaj yeem ua rau muaj peev xwm sib txuas ntawm cov mortar ntub 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 phab ntsa sab nraud rwb thaiv tsev. 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.
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 ntawm methyl cellulose feem ntau muaj pseudoplastic thiab non-thixotropic fluidity qis dua nws qhov kub gel, tab sis qhia Newtonian flow cov yam ntxwv 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 cov yam ntxwv ntev li ntev tau qhov concentration thiab kub tau khaws cia tas li. Cov gels qauv tau tsim thaum qhov kub nce siab, thiab cov dej ntws thixotropic heev tshwm sim.
Cov cellulose ethers uas muaj concentration siab thiab viscosity qis qhia txog thixotropy txawm tias qis dua qhov kub ntawm gel. Cov khoom no muaj txiaj ntsig zoo rau kev kho qhov sib npaug thiab sagging hauv kev tsim kho ntawm cov mortar tsev. Nws yuav tsum tau piav qhia ntawm no tias qhov viscosity siab dua ntawm cellulose ether, qhov zoo dua qhov khaws cia dej, tab sis qhov viscosity siab dua, qhov hnyav molecular ntawm cellulose ether siab dua, thiab qhov txo qis hauv nws cov solubility, uas muaj qhov cuam tshuam tsis zoo rau qhov concentration ntawm mortar thiab kev ua haujlwm ntawm kev tsim kho.
Kev cob qhia cua
Cellulose ether muaj qhov cuam tshuam rau huab cua rau cov khoom siv cement tshiab. Cellulose ether muaj ob qho tib si hydrophilic pawg (hydroxyl pawg, ether pawg) thiab hydrophobic pawg (methyl pawg, glucose rings), thiab yog ib qho surfactant nrog kev ua haujlwm ntawm qhov chaw, yog li muaj qhov cuam tshuam rau huab cua. Qhov cuam tshuam ntawm huab cua ntawm cellulose ether yuav tsim cov nyhuv "pob", uas tuaj yeem txhim kho kev ua haujlwm ntawm cov khoom sib xyaw tshiab, xws li kev ua kom cov yas thiab du ntawm cov mortar thaum lub sijhawm ua haujlwm, uas yog qhov zoo rau kev nthuav dav ntawm cov mortar; nws tseem yuav ua rau cov zis ntawm cov mortar nce ntxiv, txo cov nqi tsim khoom ntawm cov mortar; tab sis nws yuav ua rau cov porosity ntawm cov khoom tawv thiab txo nws cov khoom siv kho tshuab xws li lub zog thiab elastic modulus.
Ua ib qho surfactant, cellulose ether kuj muaj cov nyhuv ntub lossis lubricating rau cov cement me me, uas ua rau cov khoom siv cement-based fluidity ua ke nrog nws cov nyhuv cua-entraining, tab sis nws cov nyhuv thickening yuav txo fluidity. Cov nyhuv ntawm fluidity yog kev sib xyaw ua ke ntawm cov plasticizing thiab thickening effects. Feem ntau hais lus, thaum cov ntsiab lus ntawm cellulose ether qis heev, qhov kev ua tau zoo tseem ceeb yog plasticization lossis dej txo; thaum cov ntsiab lus siab, cov nyhuv thickening ntawm cellulose ether nce sai, thiab nws cov nyhuv cua-entraining feem ntau yuav saturated. Yog li nws qhia tau tias yog cov nyhuv thickening lossis kev nce ntxiv ntawm kev thov dej.
kev qeeb qeeb
Cellulose etheryuav ua rau lub sijhawm teeb tsa ntawm cov cement paste lossis mortar ntev dua, thiab ncua qhov hydration kinetics ntawm cement, uas yog qhov zoo rau kev txhim kho lub sijhawm ua haujlwm ntawm cov ntaub ntawv sib xyaw tshiab, txhim kho qhov sib xws ntawm mortar thiab poob ntawm cov pob zeb poob qis dhau sijhawm, tab sis kuj tseem yuav ua rau kev tsim kho qeeb.
Lub sijhawm tshaj tawm: Plaub Hlis-25-2024