Cov hom admixtures feem ntau siv rau hauv kev tsim cov mortar qhuav-mixed, lawv cov yam ntxwv kev ua tau zoo, mechanism ntawm kev ua haujlwm, thiab lawv cov kev cuam tshuam rau kev ua tau zoo ntawm cov khoom mortar qhuav-mixed. Kev txhim kho cov nyhuv ntawm cov neeg sawv cev khaws dej xws li cellulose ether thiab starch ether, redispersible latex hmoov thiab cov ntaub ntawv fiber rau kev ua tau zoo ntawm cov mortar qhuav-mixed tau tham txog ntau yam.
Cov tshuaj ntxiv ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev ua haujlwm ntawm kev tsim cov tshuaj sib xyaw qhuav, tab sis kev ntxiv cov tshuaj sib xyaw qhuav ua rau tus nqi khoom siv ntawm cov khoom siv sib xyaw qhuav siab dua li cov tshuaj ib txwm muaj, uas suav txog ntau dua 40% ntawm tus nqi khoom siv hauv cov tshuaj sib xyaw qhuav. Tam sim no, ib feem loj ntawm cov tshuaj ntxiv yog muab los ntawm cov chaw tsim khoom txawv teb chaws, thiab cov koob tshuaj siv rau cov khoom kuj yog muab los ntawm tus neeg muag khoom. Yog li ntawd, tus nqi ntawm cov khoom siv sib xyaw qhuav tseem siab, thiab nws nyuaj rau kev ua kom nrov npe ntawm cov tshuaj masonry thiab plastering nrog ntau thiab thaj chaw dav; cov khoom lag luam siab kawg raug tswj hwm los ntawm cov tuam txhab txawv teb chaws, thiab cov chaw tsim khoom siv sib xyaw qhuav muaj cov txiaj ntsig qis thiab kev kam rau tus nqi tsis zoo; Tsis muaj kev tshawb fawb txog kev siv tshuaj, thiab cov qauv txawv teb chaws raug ua raws li qhov muag tsis pom.
Raws li cov laj thawj saum toj no, daim ntawv no tshuaj xyuas thiab piv qee cov khoom tseem ceeb ntawm cov admixtures uas feem ntau siv, thiab ntawm lub hauv paus no, kawm txog kev ua tau zoo ntawm cov khoom siv mortar qhuav siv cov admixtures.
1 tus neeg sawv cev khaws dej
Tus neeg sawv cev khaws dej yog cov khoom sib xyaw tseem ceeb los txhim kho kev ua tau zoo ntawm cov xuab zeb sib xyaw qhuav, thiab nws kuj yog ib qho ntawm cov khoom sib xyaw tseem ceeb los txiav txim siab tus nqi ntawm cov khoom siv xuab zeb sib xyaw qhuav.
1. Hydroxypropyl Methyl Cellulose Ether (HPMC)
Hydroxypropyl methylcellulose yog ib lo lus dav dav rau cov khoom tsim los ntawm cov tshuaj tiv thaiv ntawm alkali cellulose thiab etherifying agent nyob rau hauv qee qhov xwm txheej. Alkali cellulose raug hloov los ntawm cov neeg sawv cev etherifying sib txawv kom tau txais cov cellulose ethers sib txawv. Raws li cov khoom ionization ntawm cov substituents, cellulose ethers tuaj yeem muab faib ua ob pawg: ionic (xws li carboxymethyl cellulose) thiab non-ionic (xws li methyl cellulose). Raws li hom substituent, cellulose ether tuaj yeem muab faib ua monoether (xws li methyl cellulose) thiab sib xyaw ether (xws li hydroxypropyl methyl cellulose). Raws li kev yaj sib txawv, nws tuaj yeem muab faib ua dej-soluble (xws li hydroxyethyl cellulose) thiab organic solvent-soluble (xws li ethyl cellulose), thiab lwm yam. Cov mortar qhuav-mixed yog feem ntau dej-soluble cellulose, thiab dej-soluble cellulose yog muab faib ua instant hom thiab nto kho qeeb hom yaj.
Lub mechanism ntawm kev ua haujlwm ntawm cellulose ether hauv mortar yog raws li nram no:
(1) Hydroxypropyl methylcellulose yooj yim yaj hauv dej txias, thiab nws yuav ntsib teeb meem hauv kev yaj hauv dej kub. Tab sis nws qhov kub gelation hauv dej kub yog siab dua li ntawm methyl cellulose. Qhov solubility hauv dej txias kuj zoo dua piv rau methyl cellulose.
(2) Qhov viscosity ntawm hydroxypropyl methylcellulose muaj feem cuam tshuam nrog nws qhov hnyav molecular, thiab qhov loj dua qhov hnyav molecular, qhov siab dua qhov viscosity. Kub kuj cuam tshuam rau nws qhov viscosity, thaum kub nce, viscosity txo qis. Txawm li cas los xij, nws qhov viscosity siab muaj qhov kub qis dua li methyl cellulose. Nws cov kua ruaj khov thaum khaws cia rau hauv chav sov.
(3) Qhov khaws cia dej ntawm hydroxypropyl methylcellulose nyob ntawm nws qhov ntxiv, viscosity, thiab lwm yam, thiab nws qhov khaws cia dej nyob rau hauv tib qhov ntxiv yog siab dua li ntawm methyl cellulose.
(4) Hydroxypropyl methylcellulose ruaj khov rau cov kua qaub thiab alkali, thiab nws cov kua dej ruaj khov heev hauv pH = 2 ~ 12. Caustic soda thiab dej txiv qaub tsis muaj feem cuam tshuam rau nws cov kev ua tau zoo, tab sis alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity nce ntxiv. Hydroxypropyl methylcellulose ruaj khov rau cov ntsev feem ntau, tab sis thaum qhov concentration ntawm cov ntsev ntau, qhov viscosity ntawm hydroxypropyl methylcellulose kua feem ntau nce ntxiv.
(5) Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog cov polymer sib xyaw uas yaj tau hauv dej los ua cov kua nplaum uas sib xws thiab viscosity siab dua. Xws li polyvinyl cawv, hmoov txhuv nplej siab ether, cov roj zaub, thiab lwm yam.
(6) Hydroxypropyl methylcellulose muaj kev tiv thaiv enzyme zoo dua li methylcellulose, thiab nws cov kua tsis tshua muaj peev xwm raug rhuav tshem los ntawm cov enzymes dua li methylcellulose.
(7) Qhov nplaum ntawm hydroxypropyl methylcellulose rau kev tsim kho mortar siab dua li ntawm methylcellulose.
2. Methylcellulose (MC)
Tom qab cov paj rwb ua kom zoo lawm raug kho nrog alkali, cellulose ether raug tsim los ntawm ntau qhov kev sib xyaw nrog methane chloride ua tus neeg sawv cev etherification. Feem ntau, qib kev hloov pauv yog 1.6 ~ 2.0, thiab qhov solubility kuj txawv nrog ntau qib kev hloov pauv. Nws yog rau cov cellulose ether uas tsis yog ionic.
(1) Methylcellulose yaj tau hauv dej txias, thiab nws yuav nyuaj rau yaj hauv dej kub. Nws cov kua dej ruaj khov heev hauv pH = 3 ~ 12. Nws muaj kev sib raug zoo nrog cov hmoov txhuv nplej siab, cov roj hmab guar, thiab lwm yam thiab ntau yam surfactants. Thaum qhov kub ncav cuag qhov kub gelation, gelation tshwm sim.
(2) Qhov khaws dej ntawm methyl cellulose nyob ntawm nws qhov ntxiv ntau npaum li cas, viscosity, qhov zoo ntawm cov khoom me me thiab qhov nrawm ntawm kev yaj. Feem ntau, yog tias qhov ntxiv ntau npaum li cas, qhov zoo me me, thiab qhov viscosity loj, qhov nrawm ntawm kev khaws dej siab. Ntawm lawv, qhov nrawm ntawm kev ntxiv muaj qhov cuam tshuam loj tshaj plaws rau qhov nrawm ntawm kev khaws dej, thiab qib ntawm viscosity tsis ncaj qha rau qib ntawm kev khaws dej. Qhov nrawm ntawm kev yaj feem ntau nyob ntawm qib ntawm kev hloov pauv ntawm qhov chaw ntawm cov khoom me me cellulose thiab qhov zoo ntawm cov khoom me me. Ntawm cov cellulose ethers saum toj no, methyl cellulose thiab hydroxypropyl methyl cellulose muaj qhov nrawm ntawm kev khaws dej siab dua.
(3) Kev hloov pauv ntawm qhov kub thiab txias yuav cuam tshuam loj heev rau qhov ceev ntawm cov methyl cellulose uas khaws dej. Feem ntau, qhov kub siab dua, qhov kev khaws dej yuav phem dua. Yog tias qhov kub ntawm cov mortar tshaj 40 ° C, qhov kev khaws dej ntawm methyl cellulose yuav raug txo qis, cuam tshuam loj heev rau kev tsim cov mortar.
(4) Methyl cellulose muaj feem cuam tshuam loj rau kev tsim kho thiab kev nplaum ntawm cov mortar. Qhov "kev nplaum" ntawm no yog hais txog lub zog nplaum uas hnov ntawm tus neeg ua haujlwm lub cuab yeej thov thiab phab ntsa substrate, uas yog, qhov kev tiv thaiv shear ntawm cov mortar. Qhov kev nplaum yog siab, qhov kev tiv thaiv shear ntawm cov mortar yog loj, thiab lub zog uas cov neeg ua haujlwm xav tau hauv cov txheej txheem ntawm kev siv kuj loj, thiab kev ua haujlwm ntawm cov mortar tsis zoo. Methyl cellulose adhesion yog nyob rau theem nruab nrab hauv cov khoom cellulose ether.
3. Hydroxyethylcellulose (HEC)
Nws yog ua los ntawm paj rwb zoo, kho nrog alkali, thiab ua ke nrog ethylene oxide ua tus neeg sawv cev etherification nyob rau hauv lub xub ntiag ntawm acetone. Qib ntawm kev hloov pauv feem ntau yog 1.5 ~ 2.0. Nws muaj hydrophilicity muaj zog thiab yooj yim nqus dej noo.
(1) Hydroxyethyl cellulose yaj tau hauv dej txias, tab sis nws nyuaj rau yaj hauv dej kub. Nws cov tshuaj ruaj khov ntawm qhov kub siab tsis muaj gelling. Nws tuaj yeem siv tau ntev hauv qhov kub siab hauv mortar, tab sis nws cov dej khaws cia qis dua li ntawm methyl cellulose.
(2) Hydroxyethyl cellulose ruaj khov rau cov kua qaub thiab alkali. Alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity me ntsis. Nws cov dispersibility hauv dej yog qhov phem dua li ntawm methyl cellulose thiab hydroxypropyl methyl cellulose.
(3) Hydroxyethyl cellulose muaj kev ua tau zoo tiv thaiv kev qaug zog rau cov mortar, tab sis nws muaj lub sijhawm ntev dua rau cov cement.
(4) Kev ua tau zoo ntawm hydroxyethyl cellulose uas tsim los ntawm qee lub tuam txhab hauv tsev yog qhov qis dua li ntawm methyl cellulose vim nws cov dej ntau thiab cov tshauv ntau.
Hmoov txhuv nplej siab ether
Cov hmoov txhuv nplej siab siv rau hauv cov mortars yog hloov kho los ntawm cov polymers ntuj ntawm qee cov polysaccharides. Xws li qos yaj ywm, pob kws, cassava, taum guar thiab lwm yam.
1. Hmoov txhuv nplej hloov kho
Cov hmoov txhuv nplej siab ether hloov kho los ntawm qos yaj ywm, pob kws, cassava, thiab lwm yam muaj qhov khaws dej qis dua li cellulose ether. Vim muaj qib sib txawv ntawm kev hloov kho, qhov ruaj khov rau acid thiab alkali yog txawv. Qee cov khoom tsim nyog rau kev siv hauv gypsum-based mortars, thaum lwm tus tuaj yeem siv rau hauv cement-based mortars. Kev siv cov hmoov txhuv nplej siab ether hauv mortar feem ntau yog siv ua cov khoom tuab kom txhim kho cov khoom tiv thaiv kev sagging ntawm mortar, txo qhov kev nplaum ntawm cov mortar ntub, thiab ntev lub sijhawm qhib.
Cov hmoov txhuv nplej siab feem ntau siv ua ke nrog cellulose, yog li cov yam ntxwv thiab qhov zoo ntawm ob yam khoom no sib pab ua ke. Vim tias cov khoom hmoov txhuv nplej siab pheej yig dua li cellulose ether, kev siv cov hmoov txhuv nplej siab hauv cov tshuaj khib yuav ua rau tus nqi ntawm cov tshuaj khib txo qis.
2. Guar gum ether
Guar gum ether yog ib hom hmoov txhuv nplej siab ether nrog cov khoom tshwj xeeb, uas tau hloov kho los ntawm cov taum guar ntuj. Feem ntau los ntawm kev sib xyaw ua ke ntawm guar gum thiab acrylic functional group, ib qho qauv uas muaj 2-hydroxypropyl functional group tau tsim, uas yog cov qauv polygalactomannose.
(1) Piv nrog cellulose ether, guar gum ether yaj tau zoo dua hauv dej. Cov yam ntxwv ntawm pH guar ethers yeej tsis cuam tshuam dab tsi.
(2) Nyob rau hauv cov xwm txheej ntawm viscosity qis thiab tsawg dosage, guar gum tuaj yeem hloov cellulose ether hauv qhov sib npaug, thiab muaj cov dej khaws cia zoo sib xws. Tab sis qhov sib xws, tiv thaiv-sag, thixotropy thiab lwm yam tau pom tseeb zoo dua.
(3) Nyob rau hauv cov xwm txheej ntawm viscosity siab thiab koob tshuaj loj, guar gum tsis tuaj yeem hloov cellulose ether, thiab kev siv sib xyaw ntawm ob qho yuav ua rau muaj kev ua tau zoo dua.
(4) Kev siv cov roj hmab guar hauv cov gypsum-based mortar tuaj yeem txo qhov kev nplaum thaum lub sijhawm tsim kho thiab ua rau kev tsim kho du. Nws tsis muaj kev cuam tshuam tsis zoo rau lub sijhawm teeb tsa thiab lub zog ntawm gypsum mortar.
3. Cov khoom siv ua kom cov dej ntxhia uas tau hloov kho kom ruaj khov
Cov tshuaj ua kom dej noo uas ua los ntawm cov zaub mov ntuj tsim los ntawm kev hloov kho thiab sib xyaw tau siv rau hauv Suav teb. Cov zaub mov tseem ceeb uas siv los ua cov tshuaj ua kom dej noo yog: sepiolite, bentonite, montmorillonite, kaolin, thiab lwm yam. Cov zaub mov no muaj qee yam khoom ua kom dej noo thiab ua kom tuab los ntawm kev hloov kho xws li cov neeg sawv cev sib txuas. Hom tshuaj ua kom dej noo no siv rau hauv cov pob zeb muaj cov yam ntxwv hauv qab no.
(1) Nws tuaj yeem txhim kho qhov kev ua tau zoo ntawm cov tshuaj khib nyiab ib txwm muaj, thiab daws cov teeb meem ntawm kev ua haujlwm tsis zoo ntawm cov tshuaj khib nyiab cement, lub zog qis ntawm cov tshuaj khib nyiab sib xyaw, thiab kev tiv thaiv dej tsis zoo.
(2) Cov khoom siv mortar nrog ntau qib zog rau cov tsev lag luam dav dav thiab pej xeem tuaj yeem tsim tau.
(3) Tus nqi khoom siv qis dua li ntawm cellulose ether thiab starch ether.
(4) Qhov kev khaws cia dej qis dua li ntawm cov neeg sawv cev khaws cia dej organic, qhov nqi qhuav ntawm cov mortar npaj tau loj dua, thiab qhov sib koom ua ke txo qis.
Cov hmoov roj hmab polymer uas yaj tau dua tshiab
Cov hmoov roj hmab uas tawg tau dua yog ua los ntawm kev txau kom qhuav cov polymer emulsion tshwj xeeb. Thaum ua tiav, cov colloid tiv thaiv, cov neeg sawv cev tiv thaiv kev sib sau ua ke, thiab lwm yam yuav dhau los ua cov khoom ntxiv tseem ceeb. Cov hmoov roj hmab qhuav yog qee cov khoom me me uas muaj li ntawm 80 ~ 100 hli sib sau ua ke. Cov khoom me me no yaj tau hauv dej thiab tsim cov khoom tawg ruaj khov me ntsis loj dua li cov khoom me me emulsion qub. Cov khoom tawg no yuav tsim ib zaj duab xis tom qab ziab thiab ziab. Zaj duab xis no tsis hloov pauv tau zoo li cov zaj duab xis emulsion feem ntau, thiab yuav tsis tawg dua thaum nws ntsib dej. Cov khoom tawg.
Cov roj hmab hmoov uas tawg tau dua tuaj yeem muab faib ua: styrene-butadiene copolymer, tertiary carbonic acid ethylene copolymer, ethylene-acetate acetic acid copolymer, thiab lwm yam, thiab raws li qhov no, silicone, vinyl laurate, thiab lwm yam raug grafted los txhim kho kev ua tau zoo. Cov kev ntsuas hloov kho sib txawv ua rau cov roj hmab hmoov uas tawg tau dua muaj cov yam ntxwv sib txawv xws li kev tiv thaiv dej, kev tiv thaiv alkali, kev tiv thaiv huab cua thiab kev ywj pheej. Muaj vinyl laurate thiab silicone, uas tuaj yeem ua rau cov roj hmab hmoov muaj hydrophobicity zoo. Cov vinyl tertiary carbonate uas muaj ceg ntoo siab nrog tus nqi Tg qis thiab kev ywj pheej zoo.
Thaum cov hmoov roj hmab no siv rau ntawm cov pob zeb mortar, lawv txhua tus muaj qhov cuam tshuam rau lub sijhawm teeb tsa ntawm cov cement, tab sis qhov cuam tshuam qeeb dua li ntawm kev siv ncaj qha ntawm cov emulsions zoo sib xws. Piv txwv li, styrene-butadiene muaj qhov cuam tshuam loj tshaj plaws, thiab ethylene-vinyl acetate muaj qhov cuam tshuam me tshaj plaws. Yog tias cov tshuaj tsawg dhau, qhov cuam tshuam ntawm kev txhim kho kev ua tau zoo ntawm cov pob zeb mortar tsis pom tseeb.
Lub sijhawm tshaj tawm: Plaub Hlis-03-2023