Qhov siab dua qhov viscosity ntawm hydroxypropyl methylcellulose, qhov zoo dua cov dej tuav kev ua haujlwm. Viscosity yog qhov tseem ceeb rau kev ua haujlwm ntawm HPMC. Tam sim no, cov tuam txhab HPMC sib txawv siv cov kev sib txawv thiab cov cuab yeej los ntsuas qhov viscosity ntawm HPMC. Cov txheej txheem tseem ceeb yog Haake Rotovisko, Hoppler, Ubbelohde thiab Brookfield.
Rau tib yam khoom, cov viscosity tau ntsuas los ntawm ntau txoj kev sib txawv heev, thiab qee qhov txawm tias ob zaug sib txawv. Yog li ntawd, thaum sib piv viscosities, nco ntsoov ua nws ntawm tib txoj kev sim, xws li kub, ntxaiv, thiab lwm yam.
Hais txog qhov loj me me, qhov zoo dua cov khoom, qhov zoo dua cov dej tuav. Thaum cov khoom loj ntawm cellulose ether tuaj rau hauv kev sib cuag nrog dej, qhov chaw tam sim ntawd dissolves los ua ib lub gel, uas qhwv cov khoom thiab tiv thaiv kev nkag mus tsis tu ncua ntawm cov dej molecules. . Nws feem ntau cuam tshuam cov dej tuav cov nyhuv ntawm nws cov cellulose ether, thiab solubility yog ib qho tseem ceeb ntawm kev xaiv cellulose ether. Fineness kuj yog ib qho tseem ceeb qhia txog kev ua tau zoo ntawm methylcellulose ether. MC siv rau hauv mortar qhuav yuav tsum yog hmoov, uas tsis muaj noo noo cov ntsiab lus, thiab cov fineness kuj yuav tsum tau 20% mus rau 60% ntawm particle loj yuav tsum tsawg tshaj li 63um. Fineness cuam tshuam rau solubility ntawm hydroxypropyl methylcellulose ether. Coarse MC feem ntau yog granular thiab yooj yim soluble nyob rau hauv dej tsis muaj caking, tab sis tus nqi dissolution qeeb heev, yog li nws tsis haum rau siv nyob rau hauv qhuav mortar. Hauv mortar qhuav, MC yog dispersed nyob rau hauv cov ntaub ntawv cementitious xws li aggregate, nplua muab tub lim thiab cement. Tsuas yog cov hmoov uas zoo txaus yuav tiv thaiv methylcellulose ether los ntawm clumping thaum tov nrog dej. Thaum MC ntxiv dej kom yaj cov aggregates, nws nyuaj rau disperse thiab yaj. MC nrog coarser fineness tsis tsuas yog ua rau pov tseg, tab sis kuj txo lub zog hauv zos ntawm mortar. Thaum hom mortar qhuav no yog tsim nyob rau hauv ib cheeb tsam loj, kev kho ceev ntawm cov tshuaj khib nyiab hauv zos tau txo qis, thiab tawg tau tshwm sim vim lub sijhawm sib txawv. Rau cov tshuaj tsuag mortar siv txhua yam kev tsim kho, yuav tsum tau fineness ntau dua vim lub sij hawm sib tov luv.
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 molecular hnyav ntawm MC, qhov sib thooj ntawm cov solubility txo qis, uas 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 ntawm cov tshuaj khib nyiab, tab sis nws tsis yog proportional. Qhov siab dua qhov viscosity, cov nplaum nplaum ntub dej. Nws yuav lo rau lub scraper thaum lub sij hawm tsim kho thiab muaj siab adhesion rau lub substrate. Tab sis nws ua me ntsis kom nce lub zog ntawm cov mortar ntub nws tus kheej. Thaum lub sij hawm tsim kho, qhov kev ua tau zoo los tiv thaiv sag tsis pom tseeb. Hauv qhov sib piv, qee qhov qis-viscosity tab sis hloov kho methylcellulose ethers muaj cov khoom 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.
Qhov zoo ntawm HPMC kuj muaj qee yam cuam tshuam rau nws cov dej tuav. Feem ntau hais lus, rau methyl cellulose ethers nrog tib viscosity tab sis sib txawv fineness, thaum qhov sib ntxiv yog tib yam, lub finer lub fineness, qhov zoo dua cov dej tuav nyhuv.
Kev tuav dej ntawm HPMC kuj tseem cuam tshuam nrog kev siv kub. Cov dej tuav ntawm methylcellulose ether txo qis thaum kub nce. Txawm li cas los xij, hauv kev siv cov khoom siv tiag tiag, cov tshuaj khib nyiab qhuav feem ntau yog tsim los ntawm cov khoom kub kub nrog qhov kub siab (siab tshaj 40 degrees) hauv ntau qhov chaw, xws li plastering plastering rau sab nrauv phab ntsa nyob rau hauv lub caij ntuj sov lub hnub, uas feem ntau accelerates solidification ntawm cement thiab discoloration. cement. tawv. Qhuav mortar. Qhov txo qis hauv dej tuav ua kom pom tseeb tias kev ua haujlwm thiab kev ua haujlwm tawg yuav raug cuam tshuam, thiab nws yog qhov tseem ceeb tshwj xeeb los txo qhov cuam tshuam ntawm qhov kub thiab txias hauv cov xwm txheej zoo li no. Txawm hais tias methylhydroxyethylcellulose ether additives yog tam sim no suav hais tias yog nyob rau hauv pem hauv ntej ntawm kev tsim kho technology, lawv dependence nyob rau hauv qhov kub thiab txias tseem tuaj yeem ua rau tsis muaj zog ntawm cov tshuaj khib nyiab qhuav. Txawm hais tias qhov ntau npaum li cas ntawm methylhydroxyethylcellulose (Xia formula) tau nce, cov txheej txheem ua haujlwm thiab tawg kuj tseem tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv. Los ntawm qee qhov kev kho mob tshwj xeeb, xws li nce qib ntawm etherification, thiab lwm yam, MC tuaj yeem tswj xyuas cov dej kom zoo ntawm qhov kub thiab txias, yog li muab kev ua haujlwm zoo dua hauv cov xwm txheej hnyav.
Post lub sij hawm: Feb-06-2024