Hydroxypropyl methylcellulose yog sivHPMCendows ntub mortar nrog cov viscosity zoo heev, uas tuaj yeem ua rau muaj qhov adhesion ntawm cov khib nyiab ntub dej thiab cov txheej hauv paus, thiab txhim kho kev ua haujlwm ntawm cov tshuaj khib nyiab. hauv mortar. Cov nyhuv thickening ntawm cellulose ether tuaj yeem ua rau kom muaj kev sib haum xeeb thiab kev tiv thaiv kev sib cais ntawm cov khoom siv cement tshiab, tiv thaiv delamination, cais thiab los ntshav ntawm mortar thiab pob zeb, thiab tuaj yeem siv rau hauv cov khoom siv fiber ntau, cov pob zeb hauv qab dej thiab nws tus kheej. pob zeb.
Hydroxypropyl methylcellulose nce viscosity ntawm cement-based cov ntaub ntawv los ntawm viscosity ntawm cellulose ether kua. Lub viscosity ntawm cellulose ether kua feem ntau yog ntsuas los ntawm qhov ntsuas "viscosity". Lub viscosity ntawm cellulose ether feem ntau yog hais txog ib qho concentration (xws li 2%) ntawm cellulose ether tov ntawm qhov ntsuas kub (xws li 20 ° C) thiab shearing Tus nqi viscosity ntsuas los ntawm cov ntsuas ntsuas ntsuas (xws li kev sib hloov viscometer) nyob rau hauv cov xwm txheej ceev (los yog kev sib hloov tus nqi, xws li 20 rpm).
Viscosity yog ib qho tseem ceeb rau kev ntsuas kev ua haujlwm ntawm cellulose ether. Qhov siab dua qhov viscosity ntawm hydroxypropyl methylcellulose tov, qhov zoo dua qhov viscosity ntawm cov cement-based khoom, qhov zoo dua qhov adhesion rau substrate, qhov zoo dua los tiv thaiv sagging thiab anti-dispersing muaj peev xwm. Muaj zog, tab sis yog tias nws cov viscosity loj dhau lawm, nws yuav cuam tshuam rau cov dej ntws thiab kev ua haujlwm ntawm cov khoom siv cement (xws li nplaum plastering riam thaum siv plastering mortar). Yog li ntawd, viscosity ntawm cellulose ether siv nyob rau hauv qhuav sib tov mortar feem ntau yog 15,000 ~ 60,000 mPa. S-1, self-leveling mortar thiab nws tus kheej-compacting pob zeb uas yuav tsum tau ntau dua fluidity yuav tsum tau qis viscosity ntawm cellulose ether.
Tsis tas li ntawd, cov nyhuv thickening ntawm hydroxypropyl methylcellulose ua rau cov dej xav tau ntawm cov khoom siv cement, yog li ua kom cov qoob loo ntawm cov mortar.
Lub viscosity ntawm hydroxypropyl methylcellulose kua yog nyob ntawm cov hauv qab no:
Cellulose ether molecular hnyav (los yog degree ntawm polymerization) thiab concentration, tov kub, shear npaum li cas, thiab xeem txoj kev.
1. Qhov siab dua ntawm polymerization ntawm cellulose ether, qhov loj dua qhov hnyav molecular, thiab siab dua qhov viscosity ntawm nws cov kua aqueous;
2. Qhov ntau npaum li cas (lossis concentration) ntawm cellulose ether, qhov siab dua qhov viscosity ntawm nws cov kua aqueous, tab sis yuav tsum tau them nyiaj rau kev xaiv cov tshuaj uas tsim nyog thaum siv nws, kom tsis txhob muaj ntau npaum li cas thiab cuam tshuam rau kev ua haujlwm ntawm mortar. thiab pob zeb;
3. Zoo li feem ntau cov kua dej, cov viscosity ntawm cellulose ether tov yuav txo nrog qhov kub thiab txias, thiab siab dua qhov concentration ntawm cellulose ether, qhov kub thiab txias yuav ua tau ntau dua;
4. Cov tshuaj Cellulose ether feem ntau yog pseudoplastics nrog shear thinning zog. Qhov siab dua tus nqi shear thaum lub sij hawm kuaj, qhov viscosity qis dua.
Yog li ntawd, lub cohesion ntawm lub mortar yuav raug txo vim qhov kev txiav txim ntawm sab nraud quab yuam, uas yog zoo rau cov scraping siv ntawm mortar, thiaj li hais tias lub mortar muaj peev xwm ua tau zoo workability thiab cohesion nyob rau tib lub sij hawm. Txawm li cas los xij, thaum lub concentration ntawm cellulose ether tov yog tsawg heev thiab viscosity tsawg heev, nws yuav qhia cov yam ntxwv ntawm Newtonian kua. Thaum cov concentration nce ntxiv, cov tshuaj yuav maj mam qhia cov yam ntxwv ntawm cov kua dej pseudoplastic, thiab qhov siab dua qhov concentration, qhov pom tseeb dua pseudoplasticity.
Post lub sij hawm: Oct-10-2022