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 sib xyaw ua kom qhuav-sib xyaw. 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 roj hmab hmoov 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 cov huab cua cov ntsiab lus ntawm mortar thiab faib cov npuas, cov kev sib cuam tshuam ntawm roj hmab hmoov hmoov thiab lwm yam additives muaj zog ntxiv. thixotropy, thiab nce viscosity.
Nws yog feem ntau ntseeg hais tias lub mechanism uas redispersible latex hmoov txhim kho kev ua hauj lwm 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 tsub kom lub viscosity ntawm slurry thiab txhim kho cov cohesion ntawm cov tshuaj 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. Nyob rau theem 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 cov deformation ntawm cov latex spheres ua rau lawv fuses ua ke, thiab cov dej seem nyob rau hauv lub pores, thiab cov 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 ib qho 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 cov khoom siv quartz yuav maj mam cais cov polyvinyl cawv ntawm lub cev, 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, hauv cov tshuab tsis muaj alkaline, xws li gypsum lossis cov tshuab uas muaj cov khoom siv nkaus xwb, vim tias 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 kev tso dej rau lub sijhawm ntev, thiab cov polymer tseem muaj nws cov yam ntxwv ntawm cov khoom siv, dispersible polymer hmoov tseem siv tau 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 yog ntau dua li cov qauv nruj ntawm cov cement pob zeb, qhov deformation kev ua tau zoo ntawm cov mortar yog txhim kho, thiab cov nyhuv ntawm dispersing kev nyuaj siab yog heev txhim kho, 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 khoom theem, lub mortar yuav hloov zoo thiab dhau los ua ib tug elastomer, thiab cov khoom hydration ntawm cov cement yuav dhau los ua "filler" ". Lub zog tensile, elasticity, saj zawg zog thiab sealing zog ntawm mortar hmoov hloov tau hloov kho nrog polymer dispersible. tso cai rau ib zaj duab xis polymer (latex zaj duab xis) tsim thiab tsim ib feem ntawm cov phab ntsa pore, yog li sealing cov qauv ntxeem tau ntawm cov mortar Lub latex membrane muaj ib tug self-stretching mechanism uas siv nro rau nws anchorage nrog cov mortar los ntawm cov internal rog, lub mortar yog tuav raws li ib tug tag nrho, yog li ua kom lub siab elasticity ntawm lub xub ntiag thiab elasticity ntawm mortar Lub mechanism rau kev nce nyob rau hauv yield kev nyuaj siab thiab tsis ua hauj lwm lub zog yog raws li nram no: thaum ib tug quab yuam yog siv, microcracks yog ncua vim kev txhim kho nyob rau hauv yooj thiab elasticity, thiab tsis txhob tsim kom txog rau thaum lub zog siab 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 faib rau ntawm lub interface plays lwm lub luag hauj lwm tseem ceeb tom qab dispersed thiab tsim nyob 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 cov mortar thiab cov nplais pobzeb, cov yeeb yaj kiab tsim los ntawm cov polymer ua ib tus choj ntawm cov pobzeb vitrified ceramic uas tsis tshua muaj dej nqus 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