Cellulose ethers nyob rau hauv cov khoom siv sib xyaw ua ke

1. Lub luag haujlwm tseem ceeb ntawm cellulose ether

Hauv cov mortar sib xyaw ua ke, cellulose ether yog cov khoom siv tseem ceeb uas tau ntxiv rau hauv qhov tsawg heev tab sis tuaj yeem txhim kho kev ua tau zoo ntawm cov mortar ntub thiab cuam tshuam rau kev ua tau zoo ntawm cov mortar.

2. Hom cellulose ethers

Kev tsim cov cellulose ether feem ntau yog ua los ntawm cov fiber ntuj los ntawm kev yaj alkali, kev sib xyaw ua ke (etherification), ntxuav, ziab, sib tsoo thiab lwm yam txheej txheem.

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

Cellulose ethers muaj peev xwm 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 rau hauv cov mortar sib xyaw ua ke feem ntau yog methyl cellulose ether (MC), methyl hydroxyethyl cellulose ether (MHEC), methyl hydroxypropyl cellulose ether (MHPG), hydroxypropyl Methyl cellulose ether (HPMC). Hauv cov mortar sib xyaw ua ke, vim tias ionic cellulose (carboxymethyl cellulose ntsev) tsis ruaj khov nyob rau hauv qhov muaj calcium ions, nws tsis tshua muaj siv rau hauv cov khoom sib xyaw ua ke uas siv cement, slaked lime, thiab lwm yam ua cov ntaub ntawv cementing. Hauv qee qhov chaw hauv Suav teb, carboxymethyl cellulose ntsev siv ua cov khoom tuab rau qee cov khoom siv hauv tsev uas ua tiav nrog cov hmoov txhuv nplej hloov kho ua cov ntaub ntawv cementing tseem ceeb thiab Shuangfei hmoov ua cov khoom sau. Cov khoom no yooj yim rau pwm thiab tsis tiv taus dej, thiab tam sim no raug tshem tawm. Hydroxyethyl cellulose kuj tseem siv rau hauv qee cov khoom sib xyaw ua ke, tab sis muaj feem me me ntawm kev lag luam.

3. Cov ntsuas kev ua tau zoo tseem ceeb ntawm cellulose ether

(1) Kev yaj tau

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

(2) Kev khaws dej

Kev khaws dej yog ib qho tseem ceeb ntawm cellulose ether, thiab nws kuj yog ib qho kev ua tau zoo uas ntau lub tuam txhab tsim hmoov qhuav hauv tsev, tshwj xeeb tshaj yog cov neeg nyob rau sab qab teb uas muaj qhov kub siab, tau them sai sai rau. Cov yam ntxwv cuam tshuam rau kev khaws dej ntawm cov mortar suav nrog qhov ntau ntawm cellulose ether ntxiv, viscosity, particle fineness thiab qhov kub ntawm qhov chaw siv. Qhov ntau ntawm cellulose ether ntxiv, qhov zoo dua qhov kev khaws dej; qhov ntau dua qhov viscosity, qhov zoo dua qhov kev khaws dej; qhov me dua cov khoom me me, qhov zoo dua qhov kev khaws dej.

(3) Qhov nplaum

Viscosity yog ib qho tseem ceeb ntawm cov khoom cellulose ether. Tam sim no, cov chaw tsim khoom cellulose ether sib txawv siv ntau txoj kev thiab cov cuab yeej los ntsuas qhov viscosity. Rau cov khoom tib yam, cov txiaj ntsig viscosity ntsuas los ntawm ntau txoj kev sib txawv yog txawv heev, thiab qee qhov txawm tias muaj ob npaug sib txawv. Yog li ntawd, thaum piv viscosity, nws yuav tsum tau ua tiav ntawm tib txoj kev sim, suav nrog qhov kub, rotor, thiab lwm yam.

Feem ntau hais lus, qhov siab dua qhov viscosity, qhov zoo dua qhov dej khaws cia nyhuv. Txawm li cas los xij, qhov siab dua qhov viscosity, qhov siab dua qhov hnyav molecular ntawm cellulose ether, thiab qhov txo qis hauv nws cov solubility yuav muaj qhov cuam tshuam tsis zoo rau lub zog thiab kev tsim kho ntawm cov mortar. Qhov siab dua qhov viscosity, qhov ntau dua qhov thickening nyhuv ntawm cov mortar, tab sis nws tsis yog proportional ncaj qha. Qhov siab dua qhov viscosity, qhov ntau dua viscosity ntawm cov ntub mortar yuav yog. Thaum lub sijhawm tsim kho, nws yog manifested li lo rau ntawm scraper thiab siab adhesion rau lub substrate. Tab sis nws tsis pab kom nce lub zog ntawm cov ntub mortar nws tus kheej. Thaum lub sijhawm tsim kho, qhov kev ua tau zoo tiv thaiv-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 heev hauv kev txhim kho lub zog ntawm cov ntub mortar.

(4) Qhov zoo ntawm cov khoom me me:

Cov cellulose ether siv rau cov mortar sib xyaw ua ke yuav tsum yog hmoov, nrog cov dej tsawg, thiab qhov zoo kuj xav tau 20% txog 60% ntawm qhov loj me me kom tsawg dua 63 μm. Qhov zoo cuam tshuam rau qhov solubility ntawm cellulose ether. Cov cellulose ethers loj feem ntau yog cov granules, uas yooj yim rau disperse thiab yaj hauv dej yam tsis muaj agglomeration, tab sis qhov kev yaj qeeb heev, yog li lawv tsis haum rau kev siv hauv cov mortar sib xyaw ua ke (qee cov khoom hauv tsev yog flocculent, tsis yooj yim rau disperse thiab yaj hauv dej, thiab yooj yim rau caking). Hauv cov mortar sib xyaw ua ke, cellulose ether yog disperse ntawm cov aggregates, cov fillers zoo thiab cement thiab lwm yam khoom siv cementing. Tsuas yog cov hmoov zoo txaus tuaj yeem zam kev 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 qhov kev ntub dej, kev sib kis, kev nplaum, kev tuab, kev sib xyaw, kev khaws dej thiab kev tsim zaj duab xis, nrog rau nws qhov tsis nkag mus rau roj.

4. Qhov cuam tshuam ntawm qhov kub thiab txias rau kev khaws dej ntawm cov mortar

Qhov kev khaws dej ntawm cellulose ether txo qis nrog rau qhov kub nce ntxiv. Hauv kev siv cov khoom siv, mortar feem ntau siv rau cov substrates kub ntawm qhov kub siab (siab dua 40 ° C) hauv ntau qhov chaw. Qhov kev poob qis ntawm kev khaws dej ua rau muaj kev cuam tshuam rau kev ua haujlwm thiab kev tiv thaiv tawg. Nws qhov kev vam khom rau qhov kub tseem yuav ua rau cov khoom mortar qaug zog, thiab nws yog qhov tseem ceeb heev kom txo qhov cuam tshuam ntawm cov yam ntxwv kub hauv qab no. Cov zaub mov txawv mortar tau hloov kho kom zoo, thiab ntau qhov kev hloov pauv tseem ceeb tau ua rau cov zaub mov txawv rau lub caij. Txawm hais tias nce qhov koob tshuaj (lub caij ntuj sov mis), qhov kev ua haujlwm thiab kev tiv thaiv tawg tseem tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv, uas xav tau qee qhov kev kho mob tshwj xeeb ntawm cellulose ether, xws li nce qib ntawm etherification, thiab lwm yam, kom cov dej khaws cia tuaj yeem ua tiav ntawm qhov kub siab. Nws tswj tau qhov cuam tshuam zoo dua thaum nws siab, yog li nws muab kev ua tau zoo dua hauv cov xwm txheej hnyav.

5. Daim ntawv thov rau hauv cov mortar sib xyaw ua tiav

Hauv cov mortar sib xyaw ua ke, cellulose ether ua lub luag haujlwm ntawm kev khaws dej, ua kom tuab thiab txhim kho kev ua haujlwm ntawm kev tsim kho. Kev ua haujlwm zoo ntawm kev khaws dej ua kom ntseeg tau tias cov mortar yuav tsis ua rau xuab zeb, hmoov thiab txo lub zog vim tsis muaj dej txaus thiab tsis muaj dej txaus. Qhov cuam tshuam ntawm kev tuab ua rau lub zog ntawm cov mortar ntub zoo dua. Kev ntxiv cellulose ether tuaj yeem txhim kho qhov viscosity ntub ntawm cov mortar ntub, thiab muaj viscosity zoo rau ntau yam substrates, yog li txhim kho kev ua haujlwm ntawm phab ntsa ntawm cov mortar ntub 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 nplaum pobzeb, cellulose ether tuaj yeem ua rau lub sijhawm qhib thiab kho lub sijhawm; hauv cov mortar txau tshuab, nws tuaj yeem txhim kho lub zog ntawm cov mortar ntub; hauv kev sib npaug tus kheej, nws tuaj yeem tiv thaiv kev sib sau ua ke, kev sib cais thiab kev faib ua pawg. Yog li ntawd, ua ib qho khoom ntxiv tseem ceeb, cellulose ether yog siv dav hauv cov hmoov qhuav mortar.