Dispersible polymer hmoov thiab lwm yam inorganic adhesives (xws li cement, slaked txiv qaub, gypsum, av nplaum, thiab lwm yam) thiab ntau yam aggregates, fillers thiab lwm yam additives [xws li hydroxypropyl methylcellulose, polysaccharide ( starch ether), fiber ntau, thiab lwm yam.] yog lub cev. mix kom qhuav-mixed mortar.Thaum cov hmoov hmoov qhuav ntxiv rau hauv dej thiab nplawm, nyob rau hauv qhov kev txiav txim ntawm hydrophilic tiv thaiv colloid thiab mechanical shearing force, latex hmoov hais tau sai sai dispersed rau hauv dej, uas yog txaus los ua lub redispersible latex hmoov tag nrho zaj duab xis.Cov hmoov av roj hmab sib txawv, uas muaj kev cuam tshuam rau rheology ntawm mortar thiab ntau yam kev tsim kho: affinity ntawm latex hmoov rau dej thaum nws yog redispersed, qhov sib txawv viscosity ntawm latex hmoov tom qab dispersion, cov nyhuv ntawm lub huab cua cov ntsiab lus ntawm mortar thiab kev faib cov npuas, Kev sib cuam tshuam ntawm roj hmab hmoov thiab lwm yam additives ua rau cov hmoov sib txawv latex muaj cov dej num ntawm kev nce fluidity, nce thixotropy, thiab nce viscosity.
Nws yog feem ntau ntseeg hais tias lub mechanism uas redispersible latex hmoov txhim kho lub workability ntawm tshiab mortar yog cov latex hmoov, tshwj xeeb tshaj yog cov kev tiv thaiv colloid, muaj ib tug affinity rau dej thaum dispersed, uas ua rau kom lub viscosity ntawm slurry thiab txhim kho cov cohesion ntawm lub siv mortar.
Tom qab cov mortar tshiab uas muaj cov latex hmoov dispersion yog tsim, nrog rau kev nqus dej los ntawm lub hauv paus nto, kev noj cov tshuaj tiv thaiv hydration, thiab volatilization rau saum huab cua, cov dej maj mam txo, cov resin hais maj mam mus, lub interface maj blurs. , thiab cov resin maj mam fuses nrog ib leeg.Thaum kawg polymerized rau hauv zaj duab xis.Cov txheej txheem ntawm kev tsim cov yeeb yaj kiab polymer tau muab faib ua peb theem.Nyob rau hauv thawj theem, cov polymer hais txav dawb do nyob rau hauv daim ntawv ntawm Brownian motion nyob rau hauv thawj emulsion.Raws li cov dej evaporates, kev txav ntawm cov khoom yog ib txwm muaj kev txwv ntau dua, thiab qhov sib cuam tshuam ntawm cov dej thiab huab cua ua rau lawv maj mam ua ke.Hauv theem thib ob, thaum cov khoom pib sib cuag, cov dej hauv lub network evaporates los ntawm capillary, thiab siab capillary nro thov rau saum npoo ntawm cov khoom ua rau deformation ntawm cov latex spheres ua rau lawv fuse ua ke, thiab cov dej uas seem nyob puv lub pores, thiab zaj duab xis yog roughly tsim.Qhov thib peb thiab zaum kawg theem ua rau lub diffusion (qee zaum hu ua self-adhesion) ntawm cov polymer molecules los ua ib zaj duab xis txuas ntxiv.Thaum lub sij hawm tsim cov yeeb yaj kiab, cov khoom sib cais ntawm cov xov tooj ntawm tes latex sib sau ua ke rau hauv cov yeeb yaj kiab tshiab nyias uas muaj zog tensile siab.Obviously, nyob rau hauv kev txiav txim rau cov dispersible polymer hmoov yuav tsum tau tsim ib zaj duab xis nyob rau hauv lub rehardened mortar, qhov tsawg kawg nkaus zaj duab xis forming kub (MFT) yuav tsum tau guaranteed kom qis tshaj qhov curing kub ntawm lub mortar.
Colloids - polyvinyl cawv yuav tsum tau muab cais tawm ntawm cov txheej txheem polymer.Qhov no tsis yog teeb meem nyob rau hauv alkaline cement mortar system, vim hais tias polyvinyl cawv yuav saponified los ntawm alkali generated los ntawm cov cement hydration, thiab cov adsorption ntawm quartz khoom yuav maj mam cais cov polyvinyl cawv los ntawm lub system, tsis muaj hydrophilic tiv thaiv colloid. ., Cov zaj duab xis tsim los ntawm dispersing lub redispersible latex hmoov, uas yog insoluble nyob rau hauv dej, tsis tau tsuas yog ua hauj lwm nyob rau hauv qhuav tej yam kev mob, tab sis kuj nyob rau hauv lub sij hawm ntev dej immersion tej yam kev mob.Tau kawg, nyob rau hauv cov txheej txheem uas tsis yog-alkaline, xws li gypsum los yog cov tshuab uas tsuas yog muab tso rau, txij li thaum polyvinyl cawv tseem muaj qee qhov hauv cov yeeb yaj kiab polymer kawg, uas cuam tshuam rau cov dej tsis kam ntawm cov yeeb yaj kiab, thaum cov tshuab no tsis siv rau cov dej mus ntev. immersion, thiab cov polymer tseem muaj nws cov yam ntxwv txhua yam khoom, dispersible polymer hmoov tseem tuaj yeem siv rau hauv cov tshuab no.
Nrog rau qhov kawg tsim ntawm cov yeeb yaj kiab polymer, cov txheej txheem tsim los ntawm inorganic thiab organic binders yog tsim nyob rau hauv cov mortar kho, uas yog, ib tug nkig thiab tawv pob txha pob txha muaj li ntawm hydraulic cov ntaub ntawv, thiab redispersible polymer hmoov yog tsim nyob rau hauv qhov sib txawv thiab cov khoom nto.hloov tau yooj yim network.Lub zog tensile thiab cohesion ntawm polymer resin zaj duab xis tsim los ntawm latex hmoov yog txhim kho.Vim qhov yooj yim ntawm cov polymer, lub peev xwm deformation ntau dua li cov qauv nruj ntawm cov cement pob zeb, qhov kev ua tau zoo ntawm cov mortar yog txhim kho, thiab cov nyhuv ntawm dispersing kev nyuaj siab yog zoo heev, yog li txhim kho qhov tawg tsis kam ntawm mortar. .
Nrog rau qhov nce ntawm cov ntsiab lus ntawm dispersible polymer hmoov, tag nrho cov txheej txheem tsim los ntawm yas.Nyob rau hauv cov ntaub ntawv ntawm cov ntsiab lus siab ntawm latex hmoov, lub polymer theem nyob rau hauv lub kho mortar maj mam tshaj lub inorganic hydration cov khoom theem, lub mortar yuav hloov zoo thiab ua ib tug elastomer, thiab hydration khoom ntawm cement yuav ua "filler" ".Lub zog tensile, elasticity, saj zawg zog thiab sealing zog ntawm mortar hloov nrog dispersible polymer hmoov tau txhim kho.Kev koom ua ke ntawm dispersible polymer hmoov tso cai rau ib tug polymer zaj duab xis (latex zaj duab xis) tsim thiab tsim ib feem ntawm lub pore phab ntsa, yog li sealing lub heev ntxeem tau qauv ntawm lub mortar.Lub latex membrane muaj ib tug self-stretching mechanism uas siv nro rau nws anchorage nrog lub mortar.Los ntawm cov zog sab hauv, cov tshuaj khib yog tuav tag nrho, yog li ua kom lub zog cohesive ntawm mortar.Lub xub ntiag ntawm cov khoom siv tau yooj yim thiab cov khoom siv elastic zoo txhim kho qhov yooj thiab elasticity ntawm cov tshuaj khib nyiab.Cov txheej txheem rau kev nce hauv kev ntxhov siab thiab tsis ua haujlwm lub zog yog raws li hauv qab no: thaum siv lub zog, microcracks qeeb vim qhov kev txhim kho hauv kev yooj yim thiab elasticity, thiab tsis tsim kom txog thaum muaj kev ntxhov siab ntau dua.Tsis tas li ntawd, interwoven polymer domains kuj cuam tshuam kev sib koom ua ke ntawm microcracks mus rau hauv-tawg.Yog li ntawd, dispersible polymer hmoov tsub kom qhov tsis ua hauj lwm kev nyuaj siab thiab tsis ua hauj lwm strain ntawm cov khoom.
Polymer zaj duab xis nyob rau hauv lub polymer-hloov mortar muaj ib qho tseem ceeb heev rau lub hardening ntawm lub mortar.Lub redispersible polymer hmoov muab faib rau ntawm lub interface plays lwm lub luag hauj lwm tseem ceeb tom qab dispersed thiab tsim rau hauv ib zaj duab xis, uas yog ua rau kom cov adhesion rau cov ntaub ntawv nyob rau hauv kev sib cuag.Nyob rau hauv lub microstructure ntawm thaj chaw sib txuas ntawm cov hmoov polymer-hloov cov nplais pobzeb sib txuas ntawm cov mortar thiab cov pobzeb ceramic, cov yeeb yaj kiab tsim los ntawm cov ntaub ntawv polymer ua tus choj ntawm cov pobzeb vitrified ceramic nrog cov dej tsis tshua muaj dej thiab cov cement mortar matrix.Qhov chaw sib cuag ntawm ob cov ntaub ntawv sib txawv yog qhov tshwj xeeb muaj kev pheej hmoo siab qhov chaw uas shrinkage tawg thiab ua rau poob ntawm adhesion.Yog li ntawd, lub peev xwm ntawm cov yeeb yaj kiab latex los kho cov kab nrib pleb ua rau lub luag haujlwm tseem ceeb hauv cov nplais nplaum.
Nyob rau tib lub sij hawm, cov respersible polymer hmoov uas muaj ethylene muaj ib tug tseem ceeb adhesion rau cov organic substrates, tshwj xeeb tshaj yog cov ntaub ntawv zoo sib xws, xws li polyvinyl chloride thiab polystyrene.Ib qho piv txwv zoo ntawm
Post lub sij hawm: Oct-31-2022