Cov ntsiab lus:
Raws li cov khoom tseem ceeb tshaj plaws hauv cov nplais nplaum, cellulose ether muaj kev cuam tshuam rau kev kos duab lub zog thiab qhib lub sij hawm ntawm cov nplais nplaum, thiab ob yam khoom no kuj yog qhov tseem ceeb ntawm cov pobzeb ua haujlwm siab. Cov teebmeem ntawm ethers ntawm cov khoom ntawm cov pobzeb nplaum tau sau tseg thiab tshuaj xyuas.
Cellulose ether; Pulled knot zog; Lub sijhawm qhib
1 Kev Taw Qhia
Cement-raws li pobzeb nplaum yog tam sim no qhov loj tshaj plaws ntawm daim ntawv thov tshwj xeeb qhuav-sib xyaw mortar, uas yog tsim los ntawm cov cement raws li cov khoom siv cementitious thiab ntxiv los ntawm cov khoom sib xyaw ua ke, cov dej tuav cov neeg ua haujlwm, cov neeg ua haujlwm thaum ntxov, cov hmoov latex thiab lwm yam organic lossis inorganic additives. sib tov. Feem ntau, nws tsuas yog yuav tsum tau tov nrog dej thaum siv. Piv nrog rau cov cement mortar zoo tib yam, nws tuaj yeem txhim kho lub zog sib txuas ntawm cov khoom siv thiab cov substrate, thiab muaj kev ua haujlwm zoo thiab cov dej zoo thiab dej tsis kam. Nws yog tsuas yog siv los paste cov ntaub ntawv zoo nkauj xws li lub tsev sab hauv thiab sab nrauv phab ntsa vuas, pem teb vuas, thiab lwm yam. Nws yog dav siv nyob rau hauv sab hauv thiab sab nrauv phab ntsa, pem teb, chav dej, chav ua noj thiab lwm qhov chaw kho kom zoo nkauj lub tsev. Nws yog tam sim no feem ntau siv pobzeb sib txuas cov ntaub ntawv.
Feem ntau thaum peb txiav txim siab qhov kev ua tau zoo ntawm cov pobzeb nplaum, peb tsis tsuas yog them sai sai rau nws txoj haujlwm ua haujlwm thiab muaj peev xwm tiv thaiv zawv zawg, tab sis kuj xyuam xim rau nws lub zog txhua yam thiab lub sijhawm qhib. Cellulose ether nyob rau hauv pobzeb nplaum tsis tsuas yog cuam tshuam rau lub rheological zog ntawm cov plooj (porcelain adhesive), xws li kev ua haujlwm du, nplaum riam, thiab lwm yam, tab sis kuj muaj kev cuam tshuam zoo rau cov khoom siv ntawm cov nplais nplaum.
2. Kev cuam tshuam rau lub sijhawm qhib ntawm pobzeb nplaum
Thaum cov hmoov roj hmab thiab cellulose ether sib koom ua ke hauv cov khib nyiab ntub dej, qee cov ntaub ntawv qauv qhia tau hais tias cov hmoov roj hmab muaj zog kinetic zog los txuas rau cov khoom siv cement hydration, thiab cellulose ether muaj ntau nyob rau hauv cov kua dej interstitial, uas cuam tshuam ntau dua Mortar viscosity thiab teem sij hawm. Qhov nro ntawm cellulose ether yog siab dua li ntawm cov hmoov roj hmab, thiab ntau dua cellulose ether enrichment ntawm mortar interface yuav muaj txiaj ntsig zoo rau kev tsim cov hydrogen bonds ntawm lub hauv paus nto thiab cellulose ether.
Nyob rau hauv lub mortar ntub dej, cov dej nyob rau hauv lub mortar evaporates, thiab cellulose ether yog enriched rau ntawm qhov chaw, thiab ib tug zaj duab xis yuav tsim nyob rau ntawm qhov chaw ntawm lub mortar nyob rau hauv 5 feeb, uas yuav txo tau cov tom ntej no evaporation tus nqi, raws li cov dej ntau dua. tshem tawm ntawm cov mortar thicker Ib feem ntawm nws migrates mus rau lub thinner mortar txheej, thiab cov zaj duab xis tsim nyob rau hauv thaum pib yog ib nrab yaj, thiab cov migration ntawm dej yuav coj ntau cellulose ether enrichment nyob rau hauv mortar nto. Raws li pom hauv daim duab 1
Yog li ntawd, zaj duab xis tsim ntawm cellulose ether nyob rau saum npoo ntawm mortar muaj kev cuam tshuam zoo rau kev ua haujlwm ntawm mortar. 1) Cov zaj duab xis tsim yog nyias dhau thiab yuav yaj ob zaug, uas tsis tuaj yeem txwv cov evaporation ntawm dej thiab txo lub zog. 2) Cov zaj duab xis tsim yog tuab heev, qhov concentration ntawm cellulose ether nyob rau hauv mortar interstitial kua yog siab, lub viscosity siab, thiab nws tsis yooj yim rau tawg zaj duab xis nto thaum cov vuas yog pasted. Nws tuaj yeem pom tias cov yeeb yaj kiab tsim cov khoom ntawm cellulose ether muaj kev cuam tshuam ntau dua rau lub sijhawm qhib.
Hom cellulose ether (HPMC, HEMC, MC, thiab lwm yam) thiab cov degree ntawm etherification (substitution degree) ncaj qha cuam tshuam rau cov yeeb yaj kiab-forming zog ntawm cellulose ether, nrog rau cov hardness thiab toughness ntawm zaj duab xis.
Migration xeev ntawm cellulose ether nyob rau hauv ntub mortar (sab sauv yog ntom ceramic pobzeb, sab qis yog ntxeem tau pob zeb hauv paus)
3 Kev cuam tshuam ntawm lub zog rub tawm
Ntxiv nrog rau kev muab cov khoom siv tau hais los saum toj no rau cov tshuaj khib nyiab, cellulose ether kuj tseem ncua cov dej kinetics ntawm cov cement. Cov nyhuv retarding no feem ntau yog vim qhov adsorption ntawm cellulose ether molecules ntawm ntau theem ntxhia hauv cov cement system tau hydrated, tab sis feem ntau hais lus, qhov kev pom zoo yog tias cellulose ether molecules feem ntau adsorbed ntawm dej xws li CSH thiab calcium hydroxide. Ntawm cov khoom siv tshuaj, nws tsis tshua muaj adsorbed ntawm thawj theem ntxhia ntawm clinker. Tsis tas li ntawd, cellulose ether txo qhov kev txav mus los ntawm ions (Ca2+, SO42-, ...) hauv cov pore tov vim qhov nce viscosity ntawm cov pore tov, yog li ncua ntxiv cov txheej txheem hydration.
Viscosity yog lwm qhov tseem ceeb, uas sawv cev rau cov yam ntxwv ntawm cov cellulose ether. Raws li tau hais los saum toj no, cov viscosity feem ntau cuam tshuam rau cov dej khaws cia thiab tseem muaj txiaj ntsig zoo rau kev ua haujlwm ntawm cov mortar tshiab. Txawm li cas los xij, cov kev tshawb fawb sim tau pom tias cov viscosity ntawm cellulose ether yuav luag tsis cuam tshuam rau cov cement hydration kinetics. Qhov hnyav Molecular muaj me ntsis cuam tshuam rau hydration, thiab qhov siab tshaj plaws ntawm qhov sib txawv ntawm qhov hnyav molecular tsuas yog 10min. Yog li ntawd, molecular hnyav tsis yog ib qho tseem ceeb parameter los tswj cov cement hydration.
Cov qauv dav dav yog tias rau MHEC, qhov siab dua ntawm methylation, qhov cuam tshuam tsawg dua ntawm cellulose ether. Tsis tas li ntawd, cov nyhuv retarding ntawm hydrophilic hloov pauv (xws li hloov mus rau HEC) muaj zog dua li kev hloov pauv hydrophobic (xws li hloov mus rau MH, MHEC, MHPC). Cov nyhuv retarding ntawm cellulose ether feem ntau cuam tshuam los ntawm ob yam tsis muaj, hom thiab ntau ntawm cov pab pawg hloov.
Peb qhov kev sim ua haujlwm tseem pom tau tias cov ntsiab lus ntawm cov khoom hloov pauv ua lub luag haujlwm tseem ceeb hauv lub zog ntawm cov nplais nplaum. Peb tau soj ntsuam qhov kev ua tau zoo ntawm HPMC nrog cov qib sib txawv ntawm kev hloov pauv hauv cov nplais nplaum, thiab kuaj cov txiaj ntsig ntawm cellulose ethers uas muaj cov pab pawg sib txawv nyob rau hauv cov kev kho mob sib txawv ntawm kev cuam tshuam ntawm cov khoom siv ntawm cov nplais nplaum, daim duab 2 thiab daim duab 3 yog cov kev hloov pauv. hauv methoxyl (DS) cov ntsiab lus thiab hydroxypropoxyl (MS) cov ntsiab lus ntawm cov khoom rub tawm ntawm cov nplais nplaum ntawm chav tsev kub.
Hauv kev sim, peb xav txog HPMC, uas yog ib qho ether sib xyaw, yog li peb yuav tsum muab ob daim duab ua ke. Rau HPMC, nws xav tau qee qhov kev nqus dej kom ntseeg tau tias nws cov dej solubility thiab lub teeb xa mus. Peb paub cov ntsiab lus ntawm kev hloov pauv Nws kuj txiav txim siab qhov kub thiab txias ntawm HPMC, uas kuj txiav txim siab txog kev siv ib puag ncig ntawm HPMC. Nyob rau hauv txoj kev no, pawg ntsiab lus ntawm HPMC uas feem ntau siv tau kuj yog nyob rau hauv ntau yam. Nyob rau hauv no ntau yam, yuav ua li cas los ua ke methoxy thiab hydroxypropoxy Nyob rau hauv thiaj li yuav ua tiav cov nyhuv zoo tshaj plaws yog cov ntsiab lus ntawm peb kev tshawb fawb. Nyob rau hauv ib tug tej yam ntau yam, ib tug nce nyob rau hauv cov ntsiab lus ntawm methoxyl pawg yuav ua rau ib tug downward trend nyob rau hauv lub zog rub tawm, thaum ib tug nce nyob rau hauv cov ntsiab lus ntawm hydroxypropoxyl pawg yuav ua rau ib tug nce nyob rau hauv lub zog rub tawm. Muaj qhov zoo sib xws rau cov sijhawm qhib. Cov nyhuv ntawm HPMC nrog cov ntsiab lus sib txawv ntawm cov khoom siv kho tshuab raws li lub sijhawm qhib ntawm 20 feeb.
Cov kev hloov pauv ntawm lub zog ntawm cov neeg kho tshuab nyob rau hauv lub sijhawm qhib yog ua raws li qhov kub thiab txias, uas yog raws li qhov toughness ntawm cellulose ether zaj duab xis peb tau tham txog hauv Tshooj 2. Cov ntsiab lus ntawm methoxyl (DS) yog siab thiab cov ntsiab lus. ntawm hydroxypropoxyl HPMC nrog cov ntsiab lus qis (MS) muaj qhov zoo ntawm cov yeeb yaj kiab, tab sis nws yuav cuam tshuam rau cov dej ntub dej ntawm cov mortar ntub rau cov khoom siv saum npoo av.
4 Cov ntsiab lus
Cellulose ethers, tshwj xeeb tshaj yog methyl cellulose ethers xws li HEMC thiab HPMC, yog ib qho tseem ceeb additives nyob rau hauv ntau qhuav-siv mortar daim ntaub ntawv. Cov cuab yeej tseem ceeb tshaj plaws ntawm cellulose ethers yog lawv cov dej tuav hauv cov khoom siv hauv tsev. Yog tias tsis ntxiv cellulose ether, cov txheej nyias ntawm cov mortar tshiab yuav qhuav sai heev, yog li cov cement tsis tuaj yeem hydrated nyob rau hauv ib txwm muaj, yog li cov mortar tsis tuaj yeem tawv thiab tsis tuaj yeem tau txais cov khoom zoo rau lub hauv paus txheej. Muaj ntau yam uas cuam tshuam rau cov dej tuav ntawm cellulose ether, xws li ntau npaum li cas thiab viscosity, thiab nws cov khoom siv sab hauv: qhov kev hloov pauv muaj feem cuam tshuam ntau dua rau qhov kev ua tau zoo kawg ntawm mortar. Tau ntev, peb tau ntseeg tias viscosity ntawm cellulose ether yog qhov tseem ceeb rau cov khoom siv cement. Lub sijhawm teeb tsa ntawm cov cement muaj qhov cuam tshuam zoo. Cov kev tshawb fawb tsis ntev los no tau pom tias qhov kev hloov pauv ntawm viscosity muaj qhov cuam tshuam me ntsis rau lub sijhawm teeb tsa ntawm cov cement. Ntawm qhov tsis sib xws, hom thiab kev sib xyaw ntawm cov pab pawg hloov pauv yog qhov tseem ceeb tshaj plaws cuam tshuam rau kev ua haujlwm ntawm cellulose ether. Thaum peb cia siab tias yuav ua tau zoo ntawm cov pobzeb nplaum cov khoom, peb tsis tsuas yog yuav tsum xav txog cov cuab yeej rheological hloov pauv los ntawm cellulose ether, uas ua rau cov tshuaj khib nyiab yooj yim dua, tab sis kuj xav txog cov teebmeem ntawm cov khoom siv cellulose ether nrog rau qib tsim nyog ntawm hloov. pab.
Post lub sij hawm: Feb-09-2023