Hydroxypropyl Methyl Cellulose (HPMC)yog ib qho dej-soluble cellulose ether, uas yog siv dav hauv cov khoom siv hauv tsev, txheej, tshuaj thiab zaub mov. Hauv cov khoom siv cement-based, HPMC, raws li kev hloov kho, feem ntau ntxiv rau cov cement mortar los txhim kho nws cov kev ua tau zoo, tshwj xeeb tshaj yog nyob rau hauv cov txheej txheem ntawm kev tsim kho thiab siv. Nws muaj qhov cuam tshuam loj heev rau cov dej ntws, dej tuav, kev ua haujlwm thiab kev sib tsoo ntawm cov tshuaj khib nyiab.

 

1. Qhov cuam tshuam ntawm HPMC rau qhov fluidity ntawm cov cement mortar
Lub fluidity ntawm cov cement mortar yog qhov taw qhia tseem ceeb los ntsuas nws qhov kev tsim kho, uas cuam tshuam ncaj qha rau kev tsim kho thiab kev ua haujlwm zoo. Raws li cov khoom siv polymer, HPMC muaj cov dej solubility zoo thiab ua haujlwm saum npoo av. Tom qab ntxiv rau cov cement mortar, nws tuaj yeem tsim ib zaj duab xis nyias los ntawm kev sib cuam tshuam ntawm cov tshuaj khib nyiab, ua kom cov viscosity ntawm cov tshuaj khib, thiab yog li txhim kho cov dej ntws thiab kev ua haujlwm ntawm cov tshuaj khib. Tshwj xeeb, HPMC tuaj yeem kho qhov sib xws ntawm cov mortar, ua kom yooj yim rau kev thov thiab sib npaug sib npaug thaum lub sijhawm tsim kho, zam kev tsim kho teeb meem tshwm sim los ntawm kev ziab ntawm cov mortar.

HPMC tseem tuaj yeem txuas ntxiv lub sijhawm qhib ntawm mortar, uas yog, nce lub sijhawm siv ntawm mortar thaum tsim kho, thiab zam kev tsim kho cuam tshuam los ntawm cov dej ntws nrawm dhau, tshwj xeeb tshaj yog nyob rau hauv qhov kub thiab txias ib puag ncig.

 

2. Cov nyhuv ntawm HPMC rau cov dej tuav ntawm cov cement mortar
Kev tuav dej ntawm cov cement mortar yog qhov tseem ceeb rau nws cov tawv tawv thiab kev txhim kho lub zog. Txij li cov txheej txheem cement hydration yuav tsum muaj dej txaus, yog tias cov dej poob ntawm mortar sai dhau thiab cov cement hydration tsis tiav, nws yuav cuam tshuam ncaj qha rau qhov kawg lub zog thiab durability ntawm mortar. HPMC tuaj yeem txhim kho cov dej khaws cia ntawm mortar. Cov hydroxypropyl thiab methyl pawg muaj nyob rau hauv nws cov qauv molecular muaj zog hydrophilicity, uas muaj peev xwm tsim ib tug niaj hnub dej tuav txheej nyob rau hauv mortar thiab txo cov dej evaporation tus nqi.

Tshwj xeeb tshaj yog nyob rau hauv qhov kub thiab tsis muaj av noo ib puag ncig, qhov sib ntxiv ntawm HPMC tuaj yeem ncua sijhawm kom qhuav ntawm cov cement mortar, ua kom cov hydration ntawm cov cement, thiab yog li txhim kho lub zog kawg thiab tawg tsis kam ntawm mortar. Cov kev tshawb fawb tau pom tias lub zog compressive thiab durability ntawm mortar nrog rau qhov tsim nyog ntawm HPMC ntxiv yog feem ntau zoo dua li cov uas tsis muaj HPMC nyob rau hauv lub sij hawm ntev hardening txheej txheem.

 

3. Cov nyhuv ntawm HPMC rau qhov tawg tsis kam ntawm cov cement mortar
Cov kab nrib pleb yog ib qho teeb meem uas cuam tshuam rau qhov zoo ntawm cov cement mortar, tshwj xeeb tshaj yog nyob rau hauv kev cuam tshuam ntawm cov yam ntxwv xws li ziab shrinkage, kub hloov, thiab sab nraud quab yuam, mortar yog qhov ua rau tawg. Qhov sib ntxiv ntawm HPMC tuaj yeem txhim kho qhov tawg tsis kam ntawm mortar, feem ntau los ntawm cov hauv qab no:

Txhim kho qhov elasticity thiab plasticity ntawm mortar: HPMC muaj qee yam elasticity thiab plasticity, uas tuaj yeem txo qhov kev ntxhov siab los ntawm kev ziab kom qhuav thaum lub sij hawm kho cov tshuaj khib, yog li txo qhov tshwm sim ntawm cov kab nrib pleb.
Ua kom cov adhesion thiab tensile lub zog ntawm mortar: HPMC tuaj yeem txhim kho qhov adhesion thiab tensile lub zog ntawm mortar, tshwj xeeb tshaj yog thaum lub substrate nto tsis sib xws los yog lub substrate adhesion tsis zoo.
Tswj cov cement hydration npaum li cas: Los ntawm kev tswj cov cement hydration tus nqi, HPMC tuaj yeem ncua qhov poob dej ntau hauv cov cement mortar thiab txo qhov kev ntxhov siab los ntawm cov dej evaporation sai, yog li inhibiting qhov tshwm sim ntawm cov kab nrib pleb.

 

4. Cov nyhuv ntawm HPMC rau lub zog thiab kav ntev ntawm cov cement mortar
Thaum txhim kho kev ua haujlwm thiab tawg tsis kam ntawm cov cement mortar, HPMC kuj muaj qee yam cuam tshuam rau nws lub zog thiab kav ntev. Txawm hais tias qhov sib ntxiv ntawm HPMC yuav txo qis lub zog thaum ntxov ntawm cov mortar vim nws cov qauv molecular occupies ib feem ntawm cov dej uas yuav tsum tau rau cement hydration, nyob rau hauv lub sij hawm ntev, HPMC pab kom tiav hydration ntawm cement, yog li txhim kho qhov kawg lub zog ntawm mortar.

Tsis tas li ntawd, HPMC tuaj yeem txhim kho qhov permeability tsis kam ntawm cov cement mortar, txo qhov yaig ntawm mortar los ntawm dej los yog tshuaj, thiab txhim kho nws cov kav ntev. Qhov no ua rau cov mortar nrog HPMC ntxiv muaj kev ua tau zoo mus sij hawm ntev nyob rau hauv ntub dej los yog corrosive ib puag ncig, tshwj xeeb tshaj yog haum rau sab nrauv phab ntsa kho kom zoo nkauj, pem teb paving thiab lwm yam teb.

 

5. Daim ntawv thov kev cia siab ntawm HPMC hauv cov khoom siv cement-based
Nrog rau qhov kev thov loj zuj zus rau kev ua haujlwm siab hauv kev tsim kho kev lag luam, HPMC, uas yog ib qho tseem ceeb ntxiv, tau pom dav daim ntawv thov kev cia siab hauv cov khoom siv cement-based. Ntxiv nrog rau kev siv ib txwm siv xws li phab ntsa plastering thiab hauv pem teb mortar, HPMC kuj tuaj yeem siv rau hauv kev tsim cov mortar tus kheej, kho mortar, qhuav-siv mortar thiab lwm yam khoom los txhim kho kev ua tau zoo ntawm mortar.

Nrog rau kev txhim kho cov kev cai rau kev tsim kev tiv thaiv ib puag ncig thiab kev ruaj ntseg, cov pa phem thiab tsis tshua muaj VOC (volatile organic compound) cov yam ntxwv ntawm HPMC kuj ua rau nws muaj peev xwm zoo rau kev siv hauv cov khoom siv ntsuab. Nyob rau tib lub sijhawm, nrog rau kev txhim kho txuas ntxiv ntawm cov thev naus laus zis ntsig txog, kev hloov kho thiab daim ntawv thov ntawm HPMC yuav ua kom muaj ntau haiv neeg, muab kev muaj peev xwm ntau dua rau kev tsim kho tshiab thiab kev tsim cov khoom siv cement-based.

 

Raws li ib qho tseem ceeb ntawm cov cement mortar modifier, hydroxypropyl methylcellulose (HPMC) ho txhim kho kev tsim kho kev ua haujlwm thiab siv cov khoom siv cement-based los ntawm kev txhim kho cov dej ntws, dej tuav, tawg ua hauj lwm thiab lub zog ntawm mortar. Nrog rau kev txhim kho txuas ntxiv ntawm cov khoom siv hauv tsev, daim ntawv thov ntawm HPMC yuav nthuav dav ntxiv, dhau los ua ib qho tseem ceeb hauv kev txhawb nqa kev tsim cov khoom siv hauv tsev niaj hnub.