Hydroxypropyl methylcellulose endows ntub mortar nrog viscosity zoo heev, uas tuaj yeem ua rau muaj peev xwm ua kom muaj peev xwm sib txuas ntawm cov khib nyiab ntub dej thiab cov txheej txheej, thiab txhim kho cov kev ua haujlwm ntawm cov tshuaj khib nyiab. Nws yog dav siv nyob rau hauv plastering mortar, sab nrauv phab ntsa rwb thaiv tsev system thiab cib tsev nyob rau 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-based tshiab, tiv thaiv delamination, cais thiab los ntshav ntawm mortar thiab pob zeb, thiab tuaj yeem siv rau hauv fiber ntau pob zeb, underwater pob zeb thiab nws tus kheej-compacting pob zeb. .
Hydroxypropyl methylcellulose yog sivHPMCnce viscosity ntawm cement-based cov ntaub ntawv los ntawm viscosity ntawm cellulose ether kua. Qhov ntsuas ntawm "viscosity" feem ntau yog siv los ntsuas qhov viscosity ntawm cellulose ether kua. Lub viscosity ntawm cellulose ether feem ntau yog hais txog cov tshuaj cellulose ether nrog ib qho concentration (xws li 2%). Ceev (los yog kev sib hloov tus nqi, xws li 20 rpm), tus nqi viscosity ntsuas nrog ib qho kev ntsuas ntsuas (xws li viscometer rotational).
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 cement-based cov ntaub ntawv, qhov zoo dua qhov adhesion rau substrate, thiab qhov zoo dua qhov kev tiv thaiv sagging thiab anti-dispersion 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 muab cov riam plastering 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 self-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 yuav ua rau kom cov dej xav tau ntawm cov khoom siv cement, yog li ua kom cov qoob loo ntawm mortar.
Lub viscosity ntawm hydroxypropyl methylcellulose daws nyob ntawm cov hauv qab no:
Molecular hnyav (los yog degree ntawm polymerization) thiab concentration ntawm cellulose ether, tov kub, shear npaum li cas thiab xeem txoj kev.
1. Qhov siab dua ntawm polymerization ntawm cellulose ether thiab qhov loj dua qhov hnyav molecular, qhov 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 kev saib xyuas yuav tsum tau coj los xaiv qhov tsim nyog npaum li cas thaum siv nws, thiaj li tsis cuam tshuam rau kev ua haujlwm ntawm mortar thiab pob zeb yog tias lub noj ntau dhau lawm;
3. Zoo li feem ntau cov kua dej, cov viscosity ntawm cellulose ether daws yuav txo qis nrog qhov kub thiab txias, thiab qhov siab dua ntawm cov cellulose ether, qhov kub ntawm qhov kub yuav ntau dua;
4. Cellulose ether kua feem ntau yog pseudoplastic, uas muaj cov cuab yeej ntawm shear thinning. Qhov ntau dua tus nqi shear thaum lub sij hawm kuaj, qhov viscosity qis dua.
Yog li ntawd, lub cohesion ntawm mortar yuav raug txo vim yog sab nraud quab yuam, uas muaj txiaj ntsig zoo rau kev siv cov tshuaj khib nyiab, kom cov mortar tuaj yeem muaj kev ua haujlwm zoo thiab sib koom ua ke tib lub sijhawm. Txawm li cas los xij, cov tshuaj cellulose ether yuav pom cov yam ntxwv ntawm Newtonian kua thaum lub concentration tsawg heev thiab cov viscosity tsawg. Thaum cov concentration nce, cov tshuaj yuav maj mam nthuav tawm cov yam ntxwv ntawm cov kua dej pseudoplastic, thiab qhov siab dua qhov concentration, qhov pom tseeb dua pseudoplasticity.
Post lub sij hawm: Dec-20-2022