Taw qhia
Hydroxypropyl Methylcellulose (HPMC) yog non-ionic cellulose ether muab los ntawm ntuj cellulose. Nws tau dhau los ua ib qho tseem ceeb ntxiv hauv kev tsim kho kev lag luam, tshwj xeeb hauv kev tsim cov cement mortar. HPMC txhim kho cov khoom ntawm mortar, pab txhawb kev txhim kho kev ua haujlwm, dej tuav, adhesion, thiab txhua yam muaj zog.
Kev sib xyaw thiab cov khoom ntawm HPMC
HPMC yog tsim los ntawm etherification ntawm cellulose nrog methyl chloride thiab propylene oxide. Cov txiaj ntsig polymer yog tus cwj pwm los ntawm nws cov dej solubility siab, viscosity-hloov zog, thiab muaj peev xwm ua yeeb yaj kiab. Cov yam ntxwv no ua rau HPMC yog ib qho zoo tshaj plaws ntxiv rau kev hloov kho cov khoom rheological ntawm cov khoom siv cement.
Cov txiaj ntsig ntawm HPMC hauv Cement Mortar
1. Txhim kho kev ua haujlwm
Ib qho ntawm cov txiaj ntsig tseem ceeb ntawm HPMC hauv cov cement mortar yog nws lub peev xwm los txhim kho kev ua haujlwm. HPMC ua cov roj nplua nyeem ntawm cov cement hais, txo kev sib txhuam thiab tso cai rau kev ua haujlwm zoo dua. Qhov kev txhim kho kev ua haujlwm no ua kom yooj yim sib kis thiab qib ntawm cov tshuaj khib nyiab, qhov tseem ceeb rau kev ua tiav ib qho kev ua tiav.
2. Txhim khu kev tuav dej
HPMC txhim kho cov dej tuav lub peev xwm ntawm cov cement mortar. Kev tuav dej yog qhov tseem ceeb thaum lub sij hawm kho cov txheej txheem vim nws ua kom muaj dej txaus ntawm cov cement hais, ua rau kev txhim kho lub zog zoo dua. Los ntawm khaws cov dej, HPMC tiv thaiv kom qhuav ntxov ntxov thiab txo qhov kev pheej hmoo ntawm cov kab nrib pleb thiab shrinkage nyob rau hauv mortar.
3. Ntxiv Adhesion
Adhesion yog qhov tseem ceeb rau kev ua haujlwm ntev thiab kev ua haujlwm ntawm cov cement mortar. HPMC txhim kho cov khoom nplaum ntawm mortar los ntawm kev txhim kho nws lub zog sib txuas rau ntau yam substrates, xws li cib, pob zeb, thiab pob zeb. Qhov no adhesion nce ntxiv kom ntseeg tau tias cov mortar tseem nyob hauv qhov kev ntxhov siab thiab ib puag ncig.
4. Mechanical zog
Kev koom ua ke ntawm HPMC hauv cov cement mortar pab txhawb rau nws cov neeg kho tshuab lub zog. Los ntawm kev ua kom zoo dua cov txheej txheem hydration thiab txhim kho microstructure ntawm mortar, HPMC pab ua kom muaj zog dua compressive thiab flexural zog. Qhov kev txhim kho no yog qhov tseem ceeb rau kev siv cov qauv uas muaj peev xwm thauj khoom muaj kev txhawj xeeb.
Mechanisms ntawm HPMC Action hauv Cement Mortar
1. Kev hloov kho viscosity
HPMC hloov kho cov viscosity ntawm cov tshuaj mortar sib tov, ua kom nws cohesive thiab yooj yim rau lis. Cov saw hlau polymer ntawm HPMC cuam tshuam nrog cov dej molecules, tsim cov qauv zoo li gel uas ua rau kom cov viscosity ntawm cov theem aqueous. Cov nyhuv gelation no pab tswj cov homogeneity ntawm mortar thiab tiv thaiv kev sib cais ntawm cov khoom.
2. Kev tuav dej
HPMC's hydrophilic xwm tso cai rau nws nqus thiab khaws cov dej ntau. Thaum ntxiv rau cov cement mortar, HPMC tsim ib qho thaiv uas txo cov evaporation ntawm cov dej. Lub sijhawm ntev ntawm cov dej no ua kom cov dej tsis tu ncua ntawm cov cement hais, uas yog qhov tseem ceeb rau kev txhim kho lub zog thiab kav ntev hauv cov mortar.
3. Zaj duab xis tsim
Thaum ziab, HPMC tsim cov yeeb yaj kiab txuas ntxiv, hloov tau yooj yim nyob rau hauv mortar matrix. Cov yeeb yaj kiab no txhim kho kev sib raug zoo ntawm cov cement paste thiab aggregates, txhim kho tag nrho kev ncaj ncees ntawm cov mortar. Cov yeeb yaj kiab kuj tseem txhawb nqa lub mortar tiv thaiv dej infiltration thiab huab cua.
Kev txiav txim siab zoo hauv kev siv HPMC
1. Kev noj tshuaj
Kev pom zoo ntawm HPMC nyob rau hauv cov cement mortar sib txawv nyob ntawm seb cov ntawv thov tshwj xeeb thiab cov khoom xav tau. Feem ntau, qhov ntau npaum li cas ntawm 0.1% mus rau 0.5% los ntawm qhov hnyav ntawm cov cement. Cov koob tshuaj ntau dua tuaj yeem xav tau rau cov ntawv thov tshwj xeeb, xws li tus kheej-leveling mortars lossis pobzeb adhesives.
2. Cov txheej txheem sib xyaw
Cov txheej txheem sib xyaw kom raug yog qhov tseem ceeb los xyuas kom meej qhov sib txawv ntawm HPMC nyob rau hauv mortar. Kev sib xyaw qhuav ntawm HPMC nrog lwm cov khoom xyaw hmoov ua ntej ntxiv dej yog pom zoo. Qhov no ua kom ntseeg tau tias cov polymer sib npaug sib npaug thiab qhib thaum sib cuag nrog dej.
3. Compatibility nrog lwm yam additives
HPMC yog sib xws nrog ntau yam ntawm lwm yam additives siv nyob rau hauv cement mortars, xws li superplasticizers, accelerators, thiab retarders. Txawm li cas los xij, nws yog ib qho tseem ceeb uas yuav tsum tau ua qhov kev ntsuam xyuas kev sib raug zoo los xyuas kom meej tias qhov sib xyaw ua ke ntawm ntau cov tshuaj ntxiv tsis cuam tshuam rau kev ua haujlwm ntawm cov tshuaj khib nyiab.
Kev siv ntawm HPMC nyob rau hauv ntau hom Cement mortars
1. Pobzeb Adhesive
Hauv cov nplais nplaum, HPMC txhim kho lub sijhawm qhib, plam ua haujlwm, thiab lub zog adhesion. Kev txhim kho dej tuav kom ntseeg tau tias cov nplaum nplaum tseem ua haujlwm tau ntev dua, tso cai rau kev tso cov pobzeb meej.
2. Render thiab plaster mortars
Rau render thiab plaster mortars, HPMC muab kev ua haujlwm zoo heev thiab txo qhov kev pheej hmoo ntawm sagging. Kev txhim kho adhesion thiab dej khaws cia ua rau kom du, ruaj khov.
3 Self-Leveling mortars
Self-leveling mortars tau txais txiaj ntsig los ntawm viscosity-hloov cov khoom ntawm HPMC, uas ua kom lub ntsej muag zoo ib yam. Cov polymer pab tswj cov kua dej ntawm cov mortar thaum tiv thaiv kev sib cais thiab los ntshav.
4. Kho mortars
Hauv kev kho mortars, HPMC txhim kho adhesion rau cov substrates uas twb muaj lawm thiab txhim kho cov khoom siv kho tshuab ntawm thaj chaw kho. Lub peev xwm khaws dej ntawm HPMC ua kom muaj kev kho kom zoo thiab ua haujlwm ntev.
HPMC yog cov khoom siv ntau yam ntxiv uas ua rau muaj txiaj ntsig zoo ntawm cov cement mortars. Nws cov txiaj ntsig, suav nrog kev txhim kho kev ua haujlwm, dej tuav, adhesion, thiab lub zog siv tshuab, ua rau nws yog ib qho tseem ceeb hauv kev siv ntau yam kev tsim kho. Nkag siab txog cov txheej txheem ntawm HPMC kev nqis tes ua thiab xav txog cov tswv yim zoo xws li kev siv ntau npaum li cas thiab kev sib raug zoo yog qhov tseem ceeb rau kev ua kom zoo dua nws siv hauv cov cement mortars. Raws li kev tsim kho kev lag luam txuas ntxiv mus, daim ntawv thov ntawm HPMC zoo li yuav nthuav dav, tsav kev nce qib hauv qhov zoo thiab ruaj khov ntawm cov khoom siv cement.
Post lub sij hawm: May-24-2024