Dej Retention Mechanism ntawm HPMC hauv Cement Mortar

Hydroxypropyl Methylcellulose (HPMC) yog ib qho khoom siv feem ntau siv hauv cov khoom siv cement, nrog rau cov tshuaj khib. Nws ua haujlwm rau ntau lub hom phiaj, suav nrog kev tuav dej, txhim kho kev ua haujlwm, thiab txhim kho cov khoom adhesion. Cov dej tuav mechanism ntawm HPMC hauv cov cement mortar muaj ntau yam:

1. Hydrophilic Nature: HPMC yog hydrophilic polymer, txhais tau tias nws muaj kev sib raug zoo rau dej. Thaum ntxiv rau mortar, nws tuaj yeem nqus thiab khaws cov dej hauv nws cov qauv molecular.
2. Lub cev Barrier: HPMC tsim ib lub cev barrier nyob ib ncig ntawm cov cement hais thiab lwm yam aggregates nyob rau hauv lub mortar sib tov. Qhov kev thaiv no yuav pab tiv thaiv cov evaporation ntawm cov dej los ntawm qhov sib tov, yog li tswj qhov xav tau dej-cement piv rau hydration.
3. Kev hloov kho viscosity: HPMC tuaj yeem ua kom cov viscosity ntawm cov mortar sib xyaw, uas yuav pab txo cov dej sib cais (los ntshav) thiab kev sib cais ntawm cov khoom. Qhov kev hloov kho viscosity no ua rau muaj kev tuav dej zoo dua hauv cov tshuaj khib nyiab.
4. Zaj duab xis tsim: HPMC tuaj yeem tsim ib zaj duab xis nyias saum npoo ntawm cov cement thiab aggregates. Cov yeeb yaj kiab no ua raws li cov txheej txheem tiv thaiv, txo cov dej los ntawm evaporation thiab txhim kho cov txheej txheem dej ntawm cov cement hais.
5. Kev tso dej qeeb: HPMC tuaj yeem tso dej maj mam dhau sijhawm raws li cov tshuaj khib nyiab kho. Qhov kev tso dej ncua sij hawm no pab txhawb nqa cov txheej txheem hydration ntawm cov cement, txhawb kev txhim kho lub zog thiab kav ntev hauv cov tshuaj khib nyiab.
6. Kev sib cuam tshuam nrog Cement: HPMC cuam tshuam nrog cov cement hais los ntawm hydrogen bonding thiab lwm yam mechanisms. Qhov kev sib cuam tshuam no pab kom ruaj khov ntawm cov dej-cement sib tov, tiv thaiv theem kev sib cais thiab tswj kom homogeneity.
7. Particle Suspension: HPMC tuaj yeem ua tus neeg sawv cev ncua, khaws cov khoom cement thiab lwm cov khoom sib xyaw ua ke sib cais thoob plaws hauv cov khoom sib tov. Qhov kev ncua no tiv thaiv kev hais tawm ntawm cov khoom thiab ua kom cov dej sib npaug.

Zuag qhia tag nrho, cov dej khaws cia ntawm HPMC hauv cov cement mortar muaj kev sib xyaw ntawm lub cev, tshuaj, thiab cov teebmeem rheological uas ua haujlwm ua ke los tswj cov dej noo uas yuav tsum tau ua kom pom dej kom zoo thiab ua haujlwm ntawm cov tshuaj khib nyiab.