Lub npe Suav ntawm HPMC yog hydroxypropyl methylcellulose. Nws yog non-ionic thiab feem ntau siv ua tus neeg sawv cev khaws dej hauv cov mortar qhuav sib xyaw. Nws yog cov khoom siv khaws dej feem ntau siv hauv mortar.
Cov txheej txheem tsim khoom ntawm HPMC feem ntau yog cov khoom lag luam ether raws li polysaccharide tsim los ntawm alkalization thiab etherification ntawm paj rwb fiber (hauv tsev). Nws tsis muaj nqi nws tus kheej, tsis teb nrog cov ions them hauv cov khoom siv gelling, thiab muaj kev ua haujlwm ruaj khov. Tus nqi kuj qis dua lwm hom cellulose ethers, yog li nws siv dav hauv cov mortar qhuav.
Kev Ua Haujlwm ntawm hydroxypropyl methylcellulose: Nws tuaj yeem ua rau cov mortar sib xyaw tshiab tuab kom muaj qee qhov viscosity ntub thiab tiv thaiv kev sib cais. (Ua kom tuab) Kev khaws dej kuj yog qhov tseem ceeb tshaj plaws, uas pab tswj cov dej dawb hauv cov mortar, yog li tom qab cov mortar raug tsim, cov khoom siv cementitious muaj sijhawm ntau dua los hydrate. (Kev khaws dej) Nws muaj cov khoom siv cua-entraining, uas tuaj yeem qhia cov npuas cua zoo sib xws thiab zoo los txhim kho kev tsim kho ntawm mortar.
Qhov siab dua qhov viscosity ntawm hydroxypropyl methylcellulose ether, qhov zoo dua qhov kev ua tau zoo ntawm kev khaws dej. Viscosity yog ib qho tseem ceeb ntawm HPMC kev ua tau zoo. Tam sim no, cov chaw tsim khoom HPMC sib txawv siv ntau txoj kev thiab cov cuab yeej los ntsuas qhov viscosity ntawm HPMC. Cov txheej txheem tseem ceeb yog HaakeRotovisko, Hoppler, Ubbelohde thiab Brookfield.
Rau cov khoom tib yam, cov txiaj ntsig viscosity ntsuas los ntawm ntau txoj kev sib txawv yog txawv heev, thiab qee qhov txawm tias muaj ob npaug sib txawv. Yog li ntawd, thaum piv viscosity, nws yuav tsum tau ua tiav ntawm tib txoj kev sim, suav nrog kub, rotor, thiab lwm yam. Hais txog qhov loj me ntawm cov khoom me me, cov khoom me me, qhov zoo dua qhov khaws cia dej. Tom qab cov khoom loj ntawm cellulose ether nkag mus rau hauv dej, qhov chaw tam sim ntawd yaj thiab tsim cov gel los qhwv cov khoom kom tiv thaiv cov dej molecules los ntawm kev txuas ntxiv mus rau hauv. Qee zaum nws tsis tuaj yeem sib xyaw thiab yaj txawm tias tom qab ntev do, tsim cov kua flocculent lossis agglomeration. Nws cuam tshuam loj heev rau kev khaws cia dej ntawm cellulose ether, thiab solubility yog ib qho ntawm cov yam tseem ceeb rau kev xaiv cellulose ether.
Qhov zoo kuj yog ib qho tseem ceeb ntawm kev ua tau zoo ntawm methyl cellulose ether. MC siv rau cov hmoov qhuav mortar yuav tsum yog hmoov, nrog cov dej tsawg, thiab qhov zoo kuj xav tau 20% ~ 60% ntawm qhov loj me ntawm cov khoom me me kom tsawg dua 63um. Qhov zoo cuam tshuam rau qhov solubility ntawm hydroxypropyl methylcellulose ether. MC loj feem ntau yog granular, thiab nws yooj yim yaj hauv dej yam tsis muaj agglomeration, tab sis qhov nrawm yaj qeeb heev, yog li nws tsis haum rau siv rau hauv cov hmoov qhuav mortar.
Hauv cov hmoov qhuav mortar, MC raug faib rau ntawm cov khoom siv cementing xws li aggregate, filler zoo thiab cement, thiab tsuas yog cov hmoov zoo txaus thiaj li zam tau methyl cellulose ether agglomeration thaum sib tov nrog dej. Thaum ntxiv MC nrog dej kom yaj cov agglomerates, nws nyuaj heev rau disperse thiab yaj. Qhov ntxhib fineness ntawm MC tsis yog tsuas yog pov tseg xwb, tab sis kuj txo qhov muaj zog ntawm cov mortar. Thaum cov hmoov qhuav mortar zoo li no raug siv rau hauv thaj chaw loj, qhov ceev ntawm cov hmoov qhuav mortar hauv zos yuav raug txo qis, thiab cov kab nrib pleb yuav tshwm sim vim yog lub sijhawm kho sib txawv. Rau cov mortar tsuag nrog kev tsim kho tshuab, qhov xav tau rau fineness yog siab dua vim yog lub sijhawm sib tov luv dua. Feem ntau hais lus, qhov siab dua viscosity, qhov zoo dua qhov cuam tshuam ntawm dej. Txawm li cas los xij, qhov siab dua viscosity thiab qhov siab dua molecular hnyav ntawm MC, qhov txo qis hauv nws cov solubility yuav muaj qhov cuam tshuam tsis zoo rau lub zog thiab kev ua haujlwm ntawm cov mortar.
Qhov siab dua qhov viscosity, qhov ntau dua qhov thickening effect ntawm cov mortar, tab sis nws tsis yog proportional ncaj qha. Qhov siab dua qhov viscosity, qhov ntau dua viscosity ntawm cov ntub mortar yuav yog, uas yog, thaum lub sijhawm tsim kho, nws yog manifested li lo rau ntawm scraper thiab siab adhesion rau lub substrate. Tab sis nws tsis pab kom nce lub zog ntawm cov ntub mortar nws tus kheej. Qhov ntawd yog, thaum lub sijhawm tsim kho, qhov kev ua tau zoo tiv thaiv-sag tsis pom tseeb. Ntawm qhov tsis sib xws, qee qhov nruab nrab thiab qis viscosity tab sis hloov kho methyl cellulose ethers muaj kev ua tau zoo heev hauv kev txhim kho lub zog ntawm cov ntub mortar.
Qhov kev khaws dej ntawm HPMC kuj muaj feem cuam tshuam nrog qhov kub thiab txias siv, thiab qhov kev khaws dej ntawm methyl cellulose ether txo qis nrog rau qhov kub thiab txias nce ntxiv. Txawm li cas los xij, hauv kev siv cov khoom siv tiag tiag, cov hmoov qhuav feem ntau siv rau cov khoom kub ntawm qhov kub siab (siab dua 40 degrees) hauv ntau qhov chaw, xws li kev pleev xim rau phab ntsa sab nraud hauv qab lub hnub thaum lub caij ntuj sov, uas feem ntau ua kom cov cement kho thiab ua kom cov hmoov qhuav tawv. Qhov kev poob qis ntawm qhov kev khaws dej ua rau muaj kev xav tias ob qho tib si ua haujlwm tau zoo thiab kev tiv thaiv tawg raug cuam tshuam, thiab nws yog qhov tseem ceeb heev kom txo qhov cuam tshuam ntawm cov yam ntxwv kub hauv qab qhov xwm txheej no.
Hauv qhov no, methyl hydroxyethyl cellulose ether additives tam sim no suav hais tias yog nyob rau pem hauv ntej ntawm kev txhim kho thev naus laus zis. Txawm hais tias qhov ntau ntawm methyl hydroxyethyl cellulose tau nce (lub caij ntuj sov mis), qhov ua haujlwm tau zoo thiab kev tiv thaiv tawg tseem tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv. Los ntawm qee qhov kev kho tshwj xeeb ntawm MC, xws li kev nce qib ntawm etherification, thiab lwm yam, cov dej khaws cia cov nyhuv tuaj yeem tswj tau ntawm qhov kub siab dua, yog li nws tuaj yeem muab kev ua tau zoo dua nyob rau hauv cov xwm txheej hnyav.
Cov koob tshuaj ntawm HPMC yuav tsum tsis txhob siab dhau, txwv tsis pub nws yuav ua rau cov dej ntawm cov mortar xav tau ntau ntxiv, nws yuav lo rau ntawm lub trowel, thiab lub sijhawm teeb tsa yuav ntev dhau, uas yuav cuam tshuam rau kev tsim kho. Cov khoom mortar sib txawv siv HPMC nrog cov viscosities sib txawv, thiab tsis txhob siv cov viscosity siab HPMC casually. Yog li ntawd, txawm hais tias cov khoom hydroxypropyl methylcellulose zoo, lawv tau qhuas thaum lawv siv zoo. Kev xaiv HPMC zoo yog lub luag haujlwm tseem ceeb ntawm cov neeg ua haujlwm hauv chaw kuaj mob. Tam sim no, ntau tus neeg muag khoom tsis muaj kev ntseeg siab tab tom sib xyaw HPMC, thiab qhov zoo tsis zoo. Thaum xaiv qee yam cellulose, lub chaw kuaj mob yuav tsum ua haujlwm zoo hauv kev sim kom ntseeg tau tias cov khoom mortar ruaj khov, thiab tsis txhob ntshaw rau pheej yig thiab ua rau poob tsis tsim nyog.
Lub sijhawm tshaj tawm: Tsib Hlis-04-2023