Yuav ua li cas txhim kho cov dej tuav ntawm hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose yog feem ntau siv additive nyob rau hauv qhuav hmoov mortar. Cellulose ether plays lub luag haujlwm tseem ceeb hauv cov hmoov qhuav mortar. Tom qab cov cellulose ether nyob rau hauv lub mortar yog yaj, qhov kev ua si saum npoo yuav xyuas kom meej tias cov cementitious cov ntaub ntawv yog zoo sib npaug zos faib, thiab cellulose ether, raws li ib tug tiv thaiv colloid, "wraps" khoom hais thiab tsim ib txheej ntawm lubricating zaj duab xis rau nws sab nrauv. nto, ua rau cov mortar system ruaj khov thiab txhim kho qhov ntws ntawm cov mortar thaum lub sij hawm sib tov cov khoom thiab smoothness ntawm kev tsim kho.

Hydroxypropyl methylcellulose HPMC muaj cov dej tuav zoo heev, uas tuaj yeem tiv thaiv cov dej hauv cov khib nyiab ntub los ntawm evaporating ntxov ntxov los yog absorbed los ntawm lub hauv paus txheej, xyuas kom meej tias cov cement yog tag nrho hydrated, yog li thaum kawg ua kom cov khoom siv ntawm cov tshuaj khib, uas yog tshwj xeeb tshaj yog pab tau. rau nyias txheej Mortar thiab absorbent puag los yog mortar siv nyob rau hauv high kub thiab qhuav tej yam kev mob. Cov dej tuav cov nyhuv ntawm hydroxypropyl methylcellulose ether tuaj yeem hloov cov txheej txheem tsim kho thiab txhim kho kev tsim kho. Piv txwv li, plastering kev tsim kho tuaj yeem nqa tawm ntawm cov dej-absorbing substrates yam tsis muaj pre-wetting.

Lub viscosity, ntau npaum, ambient kub thiab molecular qauv ntawm hydroxypropyl methylcellulose HPMC muaj kev cuam tshuam zoo rau nws cov dej tuav kev ua haujlwm. Nyob rau tib lub sijhawm, qhov ntau dua qhov viscosity ntawm cellulose ether, qhov dej tuav tau zoo dua; qhov ntau npaum li cas, qhov zoo dua cov dej tuav. Feem ntau, ib qho me me ntawm cellulose ether tuaj yeem txhim kho cov dej tuav ntawm mortar. Thaum qhov ntau npaum li cas nce mus txog qhov tseeb Thaum cov qib siab, cov dej tuav tau nce qeeb; Thaum qhov kub thiab txias nce, cov dej tuav ntawm cellulose ether feem ntau txo qis, tab sis qee qhov hloov kho cellulose ethers kuj muaj cov dej tuav zoo dua nyob rau hauv qhov kub thiab txias; cellulose nrog qib qis ntawm kev hloov Ether khaws cov dej zoo dua.

Cov pab pawg hydroxyl ntawm HPMC molecule thiab cov pa atom ntawm ether daim ntawv cog lus yuav koom nrog cov dej molecule los tsim ib daim ntawv cog lus hydrogen, tig cov dej dawb rau hauv cov dej khi, yog li ua lub luag haujlwm zoo hauv kev tuav dej; dej molecules thiab cellulose Lub interdiffusion ntawm ether molecular chains enables dej molecules nkag mus rau sab hauv ntawm lub loj chains ntawm cellulose ether thiab muaj zog binding rog, yog li tsim dej dawb thiab entangled dej, uas txhim kho cov dej tuav cov av nkos; cellulose ether txhim kho cov dej tuav ntawm cov khoom sib xyaw tshiab Cov khoom siv rheological, cov qauv ntxeem tau network thiab osmotic siab ntawm cov cement paste lossis cov yeeb yaj kiab tsim cov khoom ntawm cellulose ether cuam tshuam cov dej ntws. Txawm li cas los xij, vim tias cov dej tsis txaus ntseeg ntawm cov cellulose ether tam sim no, cov tshuaj khib nyiab muaj kev sib txuam tsis zoo thiab kev tsim kho tsis zoo, thiab cov tshuaj khib nyiab tuaj yeem tawg, hollowing thiab ntog tawm tom qab kev tsim kho.