Cov khoom siv cement, xws li cov pob zeb ua vaj tse, cov av nplaum, thiab lwm yam khoom siv hauv tsev, yog siv dav hauv cov tsev niaj hnub. Cellulose ethers (xws li hydroxypropyl methylcellulose (HPMC), hydroxyethyl methylcellulose (HEMC), thiab lwm yam) yog cov khoom ntxiv tseem ceeb uas tuaj yeem txhim kho kev ua tau zoo ntawm cov khoom siv cement. Yuav kom ua tiav cov yam ntxwv zoo no, nws yog qhov tseem ceeb heev rau kev tswj hwm thiab tswj hwm kev ua tau zoo ntawm cellulose ethers.
1. Cov khoom yooj yim thiab cov haujlwm ntawm cellulose ethers
Cellulose ethers yog ib chav kawm ntawm cov tshuaj lom neeg ntawm cov cellulose ntuj, uas pawg hydroxyl raug hloov pauv ib feem los ntawm pawg ether los ntawm kev ua etherification. Ntau hom cellulose ethers tuaj yeem tsim tau raws li hom thiab tus lej ntawm cov substituents, thiab txhua hom muaj lub luag haujlwm sib txawv hauv cov khoom cement.
Viscosity ntawm cellulose ethers:
Qhov viscosity ntawm cellulose ethers cuam tshuam ncaj qha rau rheology thiab kev ruaj khov ntawm cov cement paste. Cov cellulose ethers uas muaj viscosity siab tuaj yeem txhim kho qhov kev khaws dej thiab lub zog sib txuas ntawm cov paste, tab sis tej zaum yuav txo nws cov fluidity. Cov cellulose ethers uas muaj viscosity qis pab txhim kho kev ua haujlwm thiab kev fluidity.
Qib ntawm kev hloov pauv (DS) thiab kev hloov pauv molar (MS):
Qhov degree ntawm kev hloov pauv thiab molar hloov pauv ntawm cellulose ethers txiav txim siab nws cov solubility thiab viscosity ntawm cov tshuaj. Qib siab ntawm kev hloov pauv thiab molar hloov pauv feem ntau tuaj yeem txhim kho qhov kev khaws cia dej thiab kev ruaj khov ntawm cellulose ethers.
Kev yaj ntawm cellulose ethers:
Qhov nrawm thiab solubility ntawm cellulose ethers cuam tshuam rau qhov sib xws ntawm cov cement paste. Cellulose ethers nrog solubility zoo tuaj yeem tsim cov tshuaj sib xws sai dua, yog li ua kom muaj kev sib xws thiab ruaj khov ntawm cov tshuaj nplaum.
2. Xaiv cov cellulose ethers uas tsim nyog
Cov xwm txheej siv sib txawv muaj cov kev cai ua tau zoo sib txawv rau cellulose ethers. Kev xaiv hom thiab qhov tshwj xeeb ntawm cellulose ether zoo tuaj yeem txhim kho kev ua tau zoo ntawm cov khoom cement:
Cov ntawv khi:
Hauv cov ntawv thov xws li cov nplaum pobzeb thiab cov plaster mortars, cov cellulose ethers uas muaj viscosity siab (xws li HPMC) tuaj yeem muab kev nplaum zoo dua thiab kev ntub dej ntev, yog li txhim kho kev ua haujlwm ntawm kev tsim kho thiab lub zog sib txuas kawg.
Cov ntaub ntawv khaws dej:
Hauv cov mortars uas nws tus kheej leveling thiab cov nplaum cement-based vuas, cellulose ethers uas muaj dej khaws cia siab (xws li HEMC). Cov dej khaws cia siab pab tiv thaiv kev poob dej ua ntej lub sijhawm, yog li ua kom muaj kev cuam tshuam txaus thiab lub sijhawm ua haujlwm ntev dua.
Cov ntaub ntawv txhawb zog:
Cov cellulose ethers siv los txhim kho lub zog ntawm cov khoom cement yuav tsum muaj kev sib kis zoo thiab viscosity nruab nrab los txhim kho qhov sib xws thiab lub zog ntawm lub matrix.
3. Txhim kho txoj kev ntxiv
Kev tswj hwm txoj kev ntxiv cellulose ether hauv cov khoom cement yog qhov tseem ceeb heev rau kev ua kom nws ua haujlwm tau zoo tshaj plaws. Cov hauv qab no yog ntau txoj hauv kev ua kom zoo tshaj plaws:
Txoj kev sib xyaw ua ntej:
Sib tov cellulose ether nrog lwm cov hmoov qhuav ua ntej. Txoj kev no tuaj yeem tiv thaiv kev tsim cov cellulose ether tom qab sib cuag ncaj qha nrog dej, yog li ua kom nws cov khoom sib xyaw ua ke hauv cov slurry.
Txoj kev sib tov ntub dej:
Maj mam ntxiv cov cellulose ether rau hauv cov cement slurry. Txoj kev no haum rau qhov xwm txheej uas cellulose ether yaj sai thiab pab tsim kom muaj kev sib xyaw ruaj khov.
Txoj kev ntxiv cais:
Thaum lub sijhawm npaj cov cement slurry, ntxiv cellulose ether hauv cov ntu tuaj yeem ua kom nws cov khoom sib npaug thoob plaws hauv cov txheej txheem npaj thiab txo cov agglomeration.
4. Tswj cov yam sab nraud
Cov yam sab nraud xws li kub, pH tus nqi, thiab qhov nrawm sib xyaw muaj feem cuam tshuam loj rau kev ua haujlwm ntawm cellulose ether.
Kev tswj kub:
Qhov solubility thiab viscosity ntawm cellulose ether yog rhiab heev rau qhov kub thiab txias. Qhov kub siab dua pab cellulose ether kom yaj sai, tab sis kuj tseem yuav ua rau qhov viscosity ntawm cov tshuaj kom txo qis. Qhov kub yuav tsum tau kho raws li qhov xwm txheej ntawm daim ntawv thov tshwj xeeb kom ntseeg tau tias muaj kev ua haujlwm zoo tshaj plaws thiab kev ua tau zoo.
Kev kho pH: Tus nqi pH ntawm cov cement paste feem ntau yog nyob rau hauv qhov ntau alkaline siab, thaum lub solubility thiab viscosity ntawm cellulose ether hloov pauv nrog qhov kev hloov pauv ntawm tus nqi pH. Kev tswj tus nqi pH hauv qhov ntau yam tsim nyog tuaj yeem ua kom ruaj khov ntawm kev ua haujlwm ntawm cellulose ether.
Kev sib xyaw ceev: Kev sib xyaw ceev cuam tshuam rau qhov cuam tshuam ntawm cellulose ether hauv cov cement paste. Kev sib xyaw ceev dhau yuav ua rau huab cua nkag thiab sib sau ua ke ntawm cellulose ether, thaum kev sib xyaw ceev nruab nrab pab kom sib npaug thiab yaj cellulose ether.
5. Kev tshuaj xyuas cov ntaub ntawv thiab cov lus qhia ua tau zoo
Los ntawm kev tshuaj xyuas qhov tseeb, peb tuaj yeem nkag siab ntxiv txog kev siv thiab kev ua kom zoo dua ntawm cellulose ether hauv cov khoom sib txawv ntawm cov cement:
Cov nplaum rau pobzeb ua haujlwm tau zoo: Thaum ib lub tuam txhab tsim cov nplaum rau pobzeb ua haujlwm tau zoo, pom tias qhov khaws dej ntawm cov khoom qub tsis txaus, ua rau lub zog sib txuas txo qis tom qab kev tsim kho. Los ntawm kev qhia txog HEMC uas khaws dej tau zoo thiab kho nws cov nyiaj ntxiv thiab txoj kev ntxiv (siv txoj kev sib xyaw ua ntej), qhov khaws dej thiab lub zog sib txuas ntawm cov nplaum rau pobzeb tau zoo dua.
Cov khoom siv hauv pem teb uas siv rau hauv ib qho project muaj qhov tsis zoo thiab qhov chaw tsis tiaj tus tom qab kev tsim kho. Los ntawm kev xaiv HPMC uas tsis muaj viscosity thiab ua kom zoo dua qhov nrawm thiab kev tswj kub, qhov ua tau zoo ntawm cov slurry thiab kev tsim kho tau zoo dua, ua rau qhov chaw hauv pem teb kawg du dua.
Kev tswj hwm kev ua tau zoo ntawm cellulose ether hauv cov khoom cement yog qhov tseem ceeb rau kev txhim kho kev ua tau zoo ntawm cov khoom siv thiab kev tsim kho zoo. Los ntawm kev xaiv hom cellulose ether zoo, kev ua kom zoo dua ntawm txoj kev ntxiv, thiab kev tswj hwm cov yam ntxwv sab nraud, cov khoom tseem ceeb ntawm cov khoom cement xws li kev khaws dej, kev nplaum, thiab kev ntws tuaj yeem txhim kho tau zoo heev. Hauv kev siv ua haujlwm, nws yog qhov tsim nyog los txhim kho thiab kho qhov kev siv cellulose ether raws li qhov xav tau tshwj xeeb thiab cov xwm txheej ntawm daim ntawv thov kom ua tiav cov txiaj ntsig zoo tshaj plaws.
Lub sijhawm tshaj tawm: Lub Rau Hli-26-2024