Nyob rau hauv npaj-mixed mortar, ntxiv tus nqi ntawmcellulose ethertsawg heev, tab sis nws tuaj yeem txhim kho kev ua haujlwm ntawm cov khib nyiab ntub dej, thiab nws yog ib qho tseem ceeb ntxiv uas cuam tshuam rau kev tsim kho ntawm mortar. Tsim nyog xaiv ntawm cellulose ethers ntawm ntau yam, txawv viscosities, txawv particle loj, txawv degrees ntawm viscosity thiab ntxiv cov nyiaj yuav muaj txiaj ntsig zoo rau kev txhim kho kev ua haujlwm ntawm cov hmoov qhuav mortar.
Tam sim no, ntau cov masonry thiab plastering mortars muaj kev tuav dej tsis zoo, thiab cov dej slurry yuav sib cais tom qab ob peb feeb ntawm kev sawv. Kev tuav dej yog ib qho tseem ceeb ntawm methyl cellulose ether, thiab nws kuj yog ib qho kev ua tau zoo uas ntau lub tsev tsim khoom qhuav-sib xyaw, tshwj xeeb tshaj yog cov nyob rau yav qab teb cov cheeb tsam uas muaj qhov kub thiab txias, ua tib zoo saib xyuas. Cov yam ntxwv cuam tshuam rau cov dej tuav cov nyhuv ntawm cov tshuaj khib nyiab qhuav suav nrog cov nyiaj MC ntxiv, qhov viscosity ntawm MC, qhov zoo ntawm cov khoom thiab qhov kub ntawm qhov chaw siv.
1. Lub tswv yim
Cellulose ether yog ib qho hluavtaws polymer ua los ntawm ntuj cellulose los ntawm kev hloov tshuaj lom neeg. Cellulose ether yog derivative ntawm natural cellulose. Kev tsim cov cellulose ether yog txawv los ntawm hluavtaws polymers. Nws cov khoom siv yooj yim tshaj plaws yog cellulose, lub ntuj polymer compound. Vim qhov tshwj xeeb ntawm cov qauv cellulose, cellulose nws tus kheej tsis muaj peev xwm ua rau cov tshuaj etherification. Txawm li cas los xij, tom qab kev kho mob ntawm tus neeg mob o, lub zog hydrogen bonds ntawm cov saw hlau molecular thiab cov chains raug rhuav tshem, thiab cov active tso tawm ntawm pawg hydroxyl los ua reactive alkali cellulose. Tau txais cellulose ether.
Cov khoom ntawm cellulose ethers nyob ntawm seb hom, tus lej thiab kev faib tawm ntawm cov khoom hloov pauv. Kev faib tawm ntawm cellulose ethers kuj yog nyob ntawm hom kev hloov pauv, qib ntawm etherification, solubility thiab lwm yam khoom siv. Raws li hom kev hloov pauv ntawm cov saw hlau molecular, nws tuaj yeem muab faib ua monoether thiab sib xyaw ether. Peb feem ntau siv MC li monoether, thiab PMC ua ether sib xyaw. Methyl cellulose ether MC yog cov khoom lag luam tom qab cov pab pawg hydroxyl ntawm cov piam thaj hauv cov cellulose ntuj raug hloov los ntawm pawg methoxy. Nws yog ib qho khoom tau los ntawm kev hloov ib feem ntawm pawg hydroxyl ntawm chav tsev nrog methoxy pawg thiab lwm qhov nrog ib pawg hydroxypropyl. Cov qauv qauv yog [C6H7O2(OH) 3-mn(OCH3)m[OCH2CH(OH)CH3]n] x Hydroxyethyl methyl cellulose ether HEMC, cov no yog cov hom tseem ceeb uas tau siv thiab muag hauv khw.
Nyob rau hauv cov nqe lus ntawm solubility, nws yuav muab faib ua ionic thiab non-ionic. Dej-soluble non-ionic cellulose ethers yog tsim los ntawm ob series ntawm alkyl ethers thiab hydroxyalkyl ethers. Ionic CMC feem ntau yog siv rau hauv cov khoom siv hluavtaws, textile printing thiab dyeing, zaub mov thiab roj tshawb nrhiav. Non-ionic MC, PMC, HEMC, thiab lwm yam yog siv hauv cov khoom siv hauv tsev, latex coatings, tshuaj, tshuaj txhua hnub, thiab lwm yam. Siv ua thickener, dej tuav tus neeg saib xyuas, stabilizer, dispersant thiab zaj duab xis tsim tus neeg sawv cev.
2. Dej tuav ntawm cellulose ether
Kev tuav dej ntawm cellulose ether: Hauv kev tsim cov khoom siv hauv tsev, tshwj xeeb tshaj yog cov hmoov qhuav mortar, cellulose ether plays lub luag haujlwm tsis tuaj yeem hloov tau, tshwj xeeb tshaj yog nyob rau hauv cov khoom tshwj xeeb mortar (hloov mortar), nws yog ib qho tseem ceeb thiab tseem ceeb tivthaiv.
Lub luag haujlwm tseem ceeb ntawm cov dej-soluble cellulose ether hauv mortar feem ntau muaj peb yam, ib qho yog cov dej tuav tau zoo, lwm qhov yog kev cuam tshuam ntawm kev sib xws thiab thixotropy ntawm mortar, thiab qhov thib peb yog kev sib cuam tshuam nrog cov cement. Cov dej tuav cov nyhuv ntawm cellulose ether nyob ntawm qhov nqus dej ntawm lub hauv paus txheej, muaj pes tsawg leeg ntawm mortar, lub thickness ntawm lub mortar txheej, cov dej xav tau ntawm cov mortar, thiab lub sij hawm teem ntawm cov khoom siv. Cov dej tuav ntawm cellulose ether nws tus kheej los ntawm solubility thiab lub cev qhuav dej ntawm cellulose ether nws tus kheej. Raws li peb txhua tus paub, txawm hais tias cov cellulose molecular saw muaj ntau ntawm cov hydratable OH pawg, nws tsis yog soluble hauv dej, vim hais tias cov qauv cellulose muaj ib tug high degree ntawm crystallinity.
Lub peev xwm hydration ntawm hydroxyl pawg ib leeg tsis txaus los npog cov hydrogen bonds thiab van der Waals rog ntawm cov molecules. Yog li ntawd, nws tsuas swells tab sis tsis yaj nyob rau hauv dej. Thaum ib qho kev hloov pauv tau nkag mus rau hauv cov saw hlau molecular, tsis yog tsuas yog cov khoom hloov pauv puas tsuaj rau cov saw hlau hydrogen, tab sis kuj tseem cuam tshuam cov interchain hydrogen daim ntawv cog lus raug rhuav tshem vim qhov sib txuas ntawm cov khoom sib hloov ntawm cov saw hlau uas nyob ib sab. Qhov loj dua qhov hloov pauv, qhov kev ncua deb ntawm cov molecules ntau dua. Qhov deb dua. Qhov ntau dua qhov cuam tshuam ntawm kev rhuav tshem hydrogen bonds, cellulose ether ua dej-soluble tom qab cellulose lattice nthuav dav thiab cov tshuaj nkag mus, tsim cov tshuaj viscosity siab. Thaum qhov kub nce siab, cov dej ntawm cov polymer tsis muaj zog, thiab cov dej ntawm cov chains raug tsav tawm. Thaum lub cev qhuav dej txaus, cov molecules pib sib sau ua ke, tsim cov qauv peb-dimensional network gel thiab folded tawm. Cov yam ntxwv cuam tshuam rau cov dej tuav ntawm mortar muaj xws li viscosity ntawm cellulose ether, tus nqi ntxiv, qhov zoo ntawm cov khoom thiab qhov kub thiab txias.
Qhov ntau dua qhov viscosity ntawm cellulose ether, qhov dej tuav tau zoo dua. Viscosity yog qhov tseem ceeb ntawm kev ua haujlwm MC. Tam sim no, cov tuam txhab MC sib txawv siv cov kev sib txawv thiab cov cuab yeej los ntsuas qhov viscosity ntawm MC. Cov txheej txheem tseem ceeb yog Haake Rotovisko, Hoppler, Ubbelohde thiab Brookfield. Rau tib yam khoom, cov txiaj ntsig viscosity ntsuas los ntawm txoj kev sib txawv yog qhov sib txawv heev, thiab qee qhov muaj qhov sib txawv ob npaug. Yog li ntawd, thaum sib piv viscosity, nws yuav tsum tau nqa tawm ntawm tib txoj kev sim, xws li kub, rotor, thiab lwm yam.
Feem ntau hais lus, qhov siab dua qhov viscosity, qhov zoo dua cov dej tuav. Txawm li cas los xij, qhov siab dua qhov viscosity thiab siab dua qhov hnyav molecular ntawm MC, qhov sib piv ntawm nws cov solubility yuav muaj kev cuam tshuam tsis zoo rau lub zog thiab kev tsim kho ntawm mortar. Qhov siab dua qhov viscosity, qhov pom tseeb dua cov nyhuv thickening ntawm mortar, tab sis nws tsis ncaj qha proportional. Qhov siab dua qhov viscosity, qhov viscous ntau dua cov mortar ntub yuav, uas yog, thaum lub sij hawm tsim kho, nws yog manifested li sticking rau scraper thiab siab adhesion rau lub substrate. Tab sis nws tsis muaj txiaj ntsig los ua kom lub zog muaj zog ntawm cov mortar ntub nws tus kheej. Thaum lub sij hawm tsim kho, qhov kev ua tau zoo anti-sag tsis pom tseeb. Ntawm qhov tsis sib xws, qee qhov nruab nrab thiab qis viscosity tab sis hloov kho methyl cellulose ethers muaj kev ua tau zoo hauv kev txhim kho lub zog ntawm cov khoom ntub dej.
Qhov ntau dua ntawm cov cellulose ether ntxiv rau hauv mortar, qhov dej tuav tau zoo dua, thiab qhov viscosity siab dua, qhov dej tuav tau zoo dua.
Hais txog particle loj, qhov finer particle, qhov zoo dua cov dej tuav. Tom qab cov khoom loj ntawm cellulose ether tuaj rau hauv kev sib cuag nrog dej, qhov chaw tam sim ntawd dissolves thiab tsim cov gel los qhwv cov khoom los tiv thaiv cov dej molecules los ntawm kev nkag mus ntxiv. Qee lub sij hawm nws tsis tuaj yeem sib cais thiab yaj txawm tias tom qab lub sij hawm ntev nplawm, tsim cov huab flocculent tov los yog agglomeration. Nws cuam tshuam rau cov dej tuav ntawm cellulose ether, thiab solubility yog ib qho tseem ceeb ntawm kev xaiv cellulose ether.
Fineness kuj yog ib qho tseem ceeb Performance index ntawm methyl cellulose ether. MC siv rau qhuav hmoov mortar yog yuav tsum tau hmoov, nrog dej tsawg, thiab cov fineness kuj yuav tsum tau 20% ~ 60% ntawm particle loj yuav tsum tsawg tshaj li 63um. Lub fineness cuam tshuam rau solubility ntawm methyl cellulose ether. Coarse MC feem ntau yog granular, thiab nws yog ib qho yooj yim rau yaj nyob rau hauv dej tsis muaj agglomeration, tab sis lub dissolution tus nqi qeeb heev, yog li nws tsis haum rau siv nyob rau hauv qhuav hmoov mortar. Nyob rau hauv qhuav hmoov mortar, MC yog dispersed ntawm cementing cov ntaub ntawv xws li aggregate, nplua muab tub lim thiab cement, thiab tsuas yog hmoov zoo txaus yuav zam methyl cellulose ether agglomeration thaum tov nrog dej. Thaum MC ntxiv nrog dej kom yaj cov agglomerates, nws nyuaj heev rau disperse thiab yaj.
Coarse fineness ntawm MC tsis yog tsuas yog khib nyiab, tab sis kuj txo lub zog hauv zos ntawm mortar. Thaum xws li cov hmoov qhuav mortar yog siv rau hauv ib cheeb tsam loj, kev kho ceev ntawm cov hmoov qhuav hauv zos yuav txo qis, thiab cov kab nrib pleb yuav tshwm sim vim lub sijhawm sib txawv. Rau cov tshuaj txau nrog cov khoom siv kho tshuab, qhov yuav tsum tau ua kom zoo yog siab dua vim lub sijhawm sib xyaw luv. Qhov zoo ntawm MC kuj muaj qee yam cuam tshuam rau nws cov dej tuav. Feem ntau hais lus, rau methyl cellulose ethers nrog tib viscosity tab sis txawv fineness, nyob rau hauv tib qhov sib ntxiv, qhov finer lub finer qhov zoo dua cov dej tuav nyhuv.
Cov dej tuav ntawm MC kuj muaj feem xyuam rau qhov kub thiab txias siv, thiab cov dej tuav ntawm methyl cellulose ether txo qis nrog qhov kub thiab txias. Txawm li cas los xij, hauv kev siv cov khoom siv tiag tiag, cov hmoov av qhuav feem ntau yog siv rau cov kub kub ntawm qhov kub siab (siab dua 40 degrees) hauv ntau qhov chaw, xws li sab nrauv phab ntsa putty plastering nyob rau hauv lub hnub nyob rau hauv lub caij ntuj sov, uas feem ntau accelerates curing ntawm cement thiab hardening ntawm qhuav hmoov mortar. Qhov poob ntawm cov dej tuav tus nqi ua rau pom pom tseeb tias ob qho tib si kev ua haujlwm thiab kev ua haujlwm tawg tau cuam tshuam, thiab nws yog qhov tseem ceeb tshwj xeeb los txo qhov cuam tshuam ntawm qhov kub thiab txias hauv qhov xwm txheej no.
Txawm tiasmethyl hydroxyethyl cellulose etheradditives yog tam sim no suav hais tias yog nyob rau hauv lub forefront ntawm technologies txoj kev loj hlob, lawv dependence rau kub tseem yuav ua rau tsis muaj zog ntawm kev ua tau zoo ntawm qhuav hmoov mortar. Txawm hais tias tus nqi ntawm methyl hydroxyethyl cellulose yog nce (lub caij ntuj sov mis), kev ua hauj lwm thiab tawg kuj tseem tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv. Los ntawm qee qhov kev kho tshwj xeeb ntawm MC, xws li nce qib ntawm etherification, thiab lwm yam, cov dej tuav tau tuaj yeem tswj tau ntawm qhov kub siab dua, kom nws tuaj yeem muab kev ua tau zoo dua hauv cov xwm txheej hnyav.
Lub sij hawm xa tuaj: Plaub Hlis-28-2024