Cov nyhuv ntawm HPMC nrog cov viscosities sib txawv ntawm kev ua tau zoo ntawm cov pob zeb

Hydroxypropyl methylcellulose (HPMC)yog ib qho cellulose ether uas tsis yog ionic siv dav hauv cov ntaub ntawv tsim kho, tshwj xeeb tshaj yog hauv cov mortar qhuav thiab cov pob zeb sib xyaw, uas ua lub luag haujlwm ntawm kev khaws dej, ua kom tuab, thiab txhim kho kev ua haujlwm ntawm kev tsim kho. Kev ua tau zoo ntawm HPMC raug cuam tshuam loj heev los ntawm nws cov viscosity, thiab muaj qhov sib txawv pom tseeb hauv lub luag haujlwm ntawm HPMC nrog cov viscosities sib txawv hauv cov pob zeb.

1. Lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm HPMC

HPMC yog cov polymer uas yaj tau hauv dej uas tuaj yeem tsim cov kua nplaum lossis colloid hauv dej. Nws lub hauv paus tseem ceeb ntawm kev ua haujlwm suav nrog:

Kev khaws dej: HPMC tuaj yeem xauv dej dawb thaum ntxov ntawm kev ua kom cov cement hydration, tiv thaiv kev poob dej, thiab xyuas kom meej tias kev nce qib ntawm cov tshuaj tiv thaiv hydration.

Cov nyhuv ua kom tuab: HPMC tuaj yeem ua rau kom cov viscosity ntawm cov slurry thiab txhim kho qhov kev tiv thaiv kev sib cais thiab kev npliag ntawm cov pob zeb.

Cov nyhuv tsim zaj duab xis: HPMC tuaj yeem tsim ib zaj duab xis txuas ntxiv mus rau saum npoo thaum lub sijhawm ziab, uas pab txhim kho lub zog sib txuas ntawm cov interfacial.

HPMC nrog cov viscosities sib txawv muaj kev ua tau zoo sib txawv hauv cov teebmeem saum toj no, uas muaj ntau yam cuam tshuam rau kev ua tau zoo ntawm cov pob zeb ua vaj tse.

2. Cov teebmeem tshwj xeeb ntawm HPMC viscosity rau kev ua tau zoo ntawm cov pob zeb

2.1. Cov nyhuv rau kev khaws dej

Kev khaws dej yog ib qho ntawm cov khoom tseem ceeb tshaj plaws ntawm HPMC. HPMC uas muaj viscosity tsawg (piv txwv li, tsawg dua 50,000 mPa·s) muaj kev khaws dej tsawg thiab tsim nyog rau cov kab ke uas xav tau kev tso dej sai dua, xws li cov plaster mortar. HPMC uas muaj viscosity nruab nrab thiab viscosity siab (piv txwv li, 100,000 txog 200,000 mPa·s) qhia txog kev khaws dej zoo dua hauv cov pob zeb ua vaj tse, uas tuaj yeem tiv thaiv kev nqus dej thiab kev ua kom dej tsis tu ncua, yog li ua kom cov cement noo tas mus li. Tshwj xeeb, kev siv HPMC uas muaj viscosity siab hauv cov chaw qhuav lossis cov hauv paus uas nqus tau zoo tuaj yeem txhim kho qhov kev tiv thaiv shrinkage thiab kev txhim kho lub zog thaum ntxov ntawm cov pob zeb ua vaj tse.

2.2. Cov nyhuv rau kev ua haujlwm tau zoo

HPMC tuaj yeem txhim kho qhov plasticity thiab workability ntawm cov pob zeb ua vaj tse. Vim nws cov nqi yaj sai, HPMC uas muaj viscosity qis tuaj yeem tawg sai hauv lub kaw lus, uas pab txhim kho qhov fluidity ntawm cov khoom sib tov hauv lub sijhawm luv luv; tab sis nws txoj kev txhim kho hauv lub sijhawm txij nkawm fluidity tsis zoo li cov khoom muaj viscosity siab. HPMC uas muaj viscosity siab muaj qhov cuam tshuam loj heev rau qhov tuab. Nws tuaj yeem txhim kho qhov sib xyaw ua ke ntawm cov khoom sib tov hauv cov pob zeb ua vaj tse, txo qhov los ntshav thiab kev sib cais, tab sis viscosity siab dhau kuj tseem tuaj yeem ua rau qhov fluidity ntawm cov pob zeb ua vaj tse txo qis, thiab nws yooj yim ua rau muaj teeb meem xws li lo rau lub thoob thiab nce kev tiv thaiv twj tso kua mis thaum lub sijhawm tsim kho. Yog li ntawd, hauv daim ntawv thov, nws yog qhov tsim nyog los xaiv cov khoom HPMC nrog viscosity tsim nyog raws li txoj kev tsim kho (xws li kev pleev xim tes, txau, thiab twj tso kua mis).

2.3. Kev cuam tshuam rau lub sijhawm teeb tsa

HPMC kuj muaj qee qhov kev ncua sijhawm rau lub sijhawm teeb tsa ntawm cov pob zeb ua vaj tse, tshwj xeeb tshaj yog cov khoom lag luam nruab nrab thiab siab viscosity, uas muaj zog encapsulation ntawm cov khoom cement, tiv thaiv kev tso tawm ntawm hydration cua sov, thiab ncua cov txheej txheem cement hydration. Feem ntau, raws li viscosity ntawm HPMC nce, nws qhov kev nyiam ncua sijhawm teeb tsa yog qhov tseem ceeb dua. Hauv kev tsim kho tiag tiag, qhov kev ncua sijhawm no yog qhov zoo rau kev nce lub sijhawm ua haujlwm ntawm cov pob zeb ua vaj tse, tab sis cov koob tshuaj yuav tsum tau tswj hwm thaum lub caij ntuj no lossis qhov kub qis kom tsis txhob muaj sijhawm teeb tsa ntau dhau uas cuam tshuam rau kev nce qib ntawm qhov project.

2.4. Kev cuam tshuam rau kev loj hlob ntawm lub zog

HPMC nws tus kheej tsis koom nrog hauv cov tshuaj tiv thaiv cement hydration, thiab nws qhov cuam tshuam rau lub zog ntawm cov pob zeb feem ntau pom tseeb hauv theem pib ntawm kev txhim kho lub zog. Txawm hais tias HPMC nrog viscosity siab dua muaj kev khaws cia dej zoo, nws yuav ncua qhov tshuaj tiv thaiv hydration, uas yuav ua rau lub zog thaum ntxov txo qis. Txawm li cas los xij, nyob rau theem tom qab, vim tias HPMC txhim kho cov xwm txheej hydration thiab ua rau cov cement hydrate ntau dua, lub zog tom qab feem ntau ruaj khov lossis txawm tias txhim kho. Yog li ntawd, kev xaiv tsim nyog ntawm HPMC nruab nrab-viscosity tuaj yeem xav txog ob qho tib si lub zog thaum ntxov thiab kev khaws cia dej zoo, uas yog qhov kev xaiv zoo dua.

2.5. Kev cuam tshuam rau cov khoom sib txuas

HPMCkuj tseem tuaj yeem txhim kho nws lub zog sib txuas nrog lub hauv paus hauv cov pob zeb lossis mortar. Qhov no yog ib feem vim nws cov khoom tsim zaj duab xis, thiab ib feem cuam tshuam nrog nws kev txhim kho ntawm slurry viscosity thiab cohesion. Feem ntau, siab-viscosity HPMC tuaj yeem tsim ib qho denser thiab txuas ntxiv bonding interface, yog li txhim kho lub zog sib txuas. Txawm li cas los xij, hauv kev siv ua haujlwm, yuav tsum tau them sai sai rau kev sib npaug nws qhov cuam tshuam rau kev ua haujlwm ntawm kev tsim kho kom tsis txhob muaj teeb meem hauv kev khawb vim muaj viscosity ntau dhau.

HPMCs ntawm cov viscosities sib txawv muaj lawv tus kheej qhov zoo thiab qhov tsis zoo hauv cov pob zeb ua vaj tse. Feem ntau:

HPMC viscosity qis: kev yaj sai, ua haujlwm tau zoo, tab sis kev khaws dej tsawg thiab cov teebmeem tuab;

HPMC viscosity nruab nrab (xws li 70,000-150,000 mPa · s): xav txog kev khaws dej, thickening thiab workability, nws yog hom siv dav tshaj plaws tam sim no;

HPMC viscosity siab (saum toj no 200,000 mPa · s): khaws dej zoo heev, tab sis muaj feem cuam tshuam ntau dua rau kev npliag, tsim nyog rau cov xwm txheej ua haujlwm nrog cov kev xav tau siab rau kev tswj dej ntws, xws li cov mortar saum npoo av thiab cov nplaum pobzeb hauv qab kev tsim kho kub lossis huab cua qhuav.