Cellulose ethers nyob rau hauv npaj-mixed mortar additives

1. Lub luag haujlwm tseem ceeb ntawm cellulose ether

Hauv kev npaj sib xyaw mortar, cellulose ether yog cov khoom siv tseem ceeb uas tau ntxiv rau hauv tus nqi qis heev tab sis tuaj yeem txhim kho kev ua haujlwm ntawm cov mortar ntub thiab cuam tshuam rau kev tsim kho ntawm mortar.

2. Hom cellulose ethers

Kev tsim cov cellulose ether yog tsim los ntawm ntuj fibers los ntawm alkali dissolution, grafting cov tshuaj tiv thaiv (etherification), ntxuav, ziab, sib tsoo thiab lwm yam txheej txheem.

Raws li cov ntaub ntawv tseem ceeb, cov fibers ntuj tuaj yeem muab faib ua: paj rwb fiber, cedar fiber, beech fiber, thiab lwm yam. Lawv cov qib ntawm polymerization txawv, uas cuam tshuam rau qhov kawg viscosity ntawm lawv cov khoom. Tam sim no, loj cellulose manufacturers siv paj rwb fiber (by-product ntawm nitrocellulose) ua raw khoom.

Cellulose ethers tuaj yeem muab faib ua ionic thiab nonionic. Hom ionic feem ntau suav nrog carboxymethyl cellulose ntsev, thiab hom non-ionic feem ntau suav nrog methyl cellulose, methyl hydroxyethyl (propyl) cellulose, hydroxyethyl cellulose, thiab lwm yam.

Tam sim no, cov cellulose ethers siv nyob rau hauv npaj sib tov mortar yog methyl cellulose ether (MC), methyl hydroxyethyl cellulose ether (MHEC), methyl hydroxypropyl cellulose ether (MHPG), hydroxypropyl Methyl cellulose ether (HPMC). Hauv cov khoom sib xyaw ua ke, vim tias ionic cellulose (carboxymethyl cellulose ntsev) tsis ruaj khov nyob rau hauv lub xub ntiag ntawm calcium ions, nws tsis tshua muaj siv nyob rau hauv cov khoom npaj sib xyaw uas siv cov cement, slaked txiv qaub, thiab lwm yam raws li cov khoom siv cementing. Hauv qee qhov chaw hauv Suav teb, carboxymethyl cellulose ntsev yog siv los ua cov thickener rau qee cov khoom siv sab hauv tsev ua tiav nrog cov hmoov txhuv nplej siab hloov raws li cov khoom siv cementing tseem ceeb thiab Shuangfei hmoov ua cov muab tub lim. Cov khoom no yog nquag mus rau mildew thiab tsis resistant rau dej, thiab tam sim no tau phased tawm. Hydroxyethyl cellulose kuj tseem siv rau hauv qee cov khoom sib xyaw ua ke, tab sis muaj kev lag luam me me heev.

3. Kev ua haujlwm tseem ceeb ntawm cellulose ether

(1) Solubility

Cellulose yog polyhydroxy polymer compound uas tsis yaj los yog yaj. Tom qab etherification, cellulose yog soluble hauv dej, dilute alkali tov thiab organic hnyav, thiab muaj thermoplasticity. Solubility feem ntau nyob ntawm plaub yam: thawj, solubility sib txawv nrog viscosity, qis dua viscosity, ntau dua solubility. Thib ob, cov yam ntxwv ntawm cov pab pawg tau qhia hauv cov txheej txheem etherification, qhov loj dua cov pab pawg tau qhia, qhov qis dua solubility; qhov ntau polar pawg qhia, qhov yooj yim ntawm cellulose ether yog yaj hauv dej. Thib peb, qib ntawm kev hloov pauv thiab kev faib tawm ntawm pawg etherified hauv macromolecules. Feem ntau cov cellulose ethers tuaj yeem tsuas yog yaj hauv dej raws li qee qhov kev hloov pauv. Plaub, qib ntawm polymerization ntawm cellulose ether, siab dua cov degree ntawm polymerization, qhov tsawg soluble; Qhov qis dua ntawm cov degree ntawm polymerization, qhov dav ntawm cov degree ntawm kev hloov pauv uas tuaj yeem yaj hauv dej.

(2) Kev ruaj ntseg dej

Kev tuav dej yog ib qho tseem ceeb ntawm kev ua haujlwm ntawm cellulose ether, thiab nws kuj yog ib qho kev ua tau zoo uas ntau lub tuam txhab qhuav hmoov, tshwj xeeb tshaj yog cov nyob rau yav qab teb cov cheeb tsam uas muaj qhov kub thiab txias, xyuam xim rau. Cov yam ntxwv cuam tshuam rau cov dej tuav cov nyhuv ntawm mortar suav nrog tus nqi ntawm cellulose ether ntxiv, viscosity, particle fineness thiab kub ntawm qhov chaw siv. Qhov siab dua ntawm cov cellulose ether ntxiv, qhov zoo dua cov dej tuav; qhov ntau dua qhov viscosity, qhov zoo dua cov dej tuav; qhov finer particles, qhov zoo dua cov dej tuav nyhuv.

(3) viscosity

Viscosity yog ib qho tseem ceeb parameter ntawm cellulose ether khoom. Tam sim no, cov tuam txhab sib txawv ntawm cov cellulose ether siv ntau txoj kev thiab cov cuab yeej los ntsuas qhov viscosity. 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, siab dua qhov hnyav molecular ntawm cellulose ether, thiab kev txo qis hauv nws cov solubility yuav muaj kev cuam tshuam tsis zoo rau lub zog thiab kev tsim kho ntawm cov 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. Thaum lub sij hawm tsim kho, nws yog manifested raws li sticking rau lub 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.

(4) Qhov zoo ntawm cov khoom:

Cov cellulose ether siv rau cov khoom sib xyaw ua ke yuav tsum yog hmoov, nrog cov dej tsis muaj dej, thiab qhov zoo kuj xav tau 20% mus rau 60% ntawm qhov loj me me kom tsawg dua 63 μm. Lub fineness cuam tshuam rau solubility ntawm cellulose ether. Coarse cellulose ethers feem ntau yog nyob rau hauv daim ntawv ntawm granules, uas yog ib qho yooj yim rau disperse thiab yaj nyob rau hauv dej tsis muaj agglomeration, tab sis lub dissolution tus nqi yog qeeb heev, yog li ntawd lawv tsis haum rau siv nyob rau hauv npaj sib tov mortar (qee yam khoom siv hauv tsev yog flocculent, tsis yooj yim rau disperse thiab yaj nyob rau hauv dej, thiab nquag mus rau caking). Hauv cov khoom sib xyaw ua ke, cellulose ether yog dispersed ntawm aggregates, nplua fillers thiab cement thiab lwm yam ntaub ntawv cementing. Tsuas yog cov hmoov zoo txaus tuaj yeem zam cov cellulose ether agglomeration thaum sib tov nrog dej. Thaum cellulose ether ntxiv nrog dej kom yaj cov agglomeration, nws nyuaj heev rau disperse thiab yaj.

(5) Kev hloov kho ntawm cellulose ether

Kev hloov kho ntawm cellulose ether yog qhov txuas ntxiv ntawm nws qhov kev ua tau zoo, thiab nws yog qhov tseem ceeb tshaj plaws. Cov khoom ntawm cellulose ether tuaj yeem txhim kho kom zoo dua nws cov dej noo, dispersibility, adhesion, thickening, emulsification, dej tuav thiab zaj duab xis-tsim zog, nrog rau nws impermeability rau roj.

4. Qhov cuam tshuam ntawm qhov kub thiab txias ntawm cov dej tuav ntawm mortar

Cov dej tuav ntawm cellulose ether txo qis nrog qhov nce ntawm qhov kub thiab txias. Hauv kev siv cov khoom siv, mortar feem ntau yog siv rau kub substrates ntawm qhov kub thiab txias (siab tshaj 40 ° C) hauv ntau qhov chaw. Kev poob hauv dej tuav tau ua rau muaj kev cuam tshuam rau kev ua haujlwm thiab kev ua haujlwm tawg. Nws qhov kev cia siab ntawm qhov kub thiab txias tseem yuav ua rau lub zog tsis muaj zog ntawm mortar, thiab nws yog qhov tseem ceeb tshwj xeeb los txo qhov cuam tshuam ntawm qhov kub thiab txias hauv qhov xwm txheej no. Cov zaub mov txawv txawv tau hloov kho kom haum, thiab ntau qhov kev hloov pauv tseem ceeb tau ua hauv cov zaub mov txawv raws caij nyoog. Txawm hais tias nce qhov ntau npaum li cas (lub caij ntuj sov mis), kev ua haujlwm thiab kev ua haujlwm tawg tseem tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv, uas yuav tsum tau muaj qee qhov tshwj xeeb kev kho mob ntawm cellulose ether, xws li nce qib ntawm etherification, thiab lwm yam, kom cov dej tuav tau zoo. ua tiav ntawm qhov kub thiab txias. Nws tuav cov txiaj ntsig zoo dua thaum nws siab, kom nws muab kev ua tau zoo dua hauv cov xwm txheej hnyav.

5. Daim ntawv thov nyob rau hauv npaj-mixed mortar

Hauv cov khoom sib xyaw ua ke, cellulose ether plays lub luag haujlwm ntawm dej tuav, thickening thiab txhim kho kev tsim kho. Kev tuav dej zoo ua kom ntseeg tau tias cov mortar yuav tsis ua rau cov xuab zeb, hmoov av thiab lub zog txo vim dej tsis txaus thiab dej tsis tiav. Cov nyhuv thickening zoo heev txhim kho lub zog ntawm cov mortar ntub dej. Qhov sib ntxiv ntawm cellulose ether tuaj yeem txhim kho cov viscosity ntub dej ntawm cov khib nyiab ntub dej, thiab muaj cov viscosity zoo rau ntau lub substrates, yog li txhim kho phab ntsa kev ua haujlwm ntawm cov khib nyiab ntub dej thiab txo cov khib nyiab. Tsis tas li ntawd, lub luag haujlwm ntawm cellulose ether hauv cov khoom sib txawv kuj txawv. Piv txwv li, hauv cov nplais nplaum, cellulose ether tuaj yeem ua rau lub sijhawm qhib thiab kho lub sijhawm; nyob rau hauv mechanical spraying mortar, nws tuaj yeem txhim kho lub zog ntawm cov mortar ntub dej; nyob rau hauv tus kheej-leveling, nws muaj peev xwm tiv thaiv kev sib hais haum, Segregation thiab stratification. Yog li ntawd, raws li ib qho tseem ceeb additive, cellulose ether yog dav siv nyob rau hauv qhuav hmoov mortar.