Mechanism yeRedispersible Emulsion Powder mune Dry Mix Mortar

Redispersible latex poda uye mamwe ma inorganic adhesives (semende, slaked lime, gypsum, ivhu, etc.) uye akasiyana aggregates, fillers uye zvimwe zvinowedzera [zvakadai sehydroxypropyl methylcellulose, polysaccharide (starch ether), fiber Fiber, nezvimwewo] zvinogadzirwa. mudhaka yakaoma-yakasanganiswa nekusanganiswa kwemuviri. Kana iyo yakaoma poda dhaka inowedzerwa kumvura uye yakabvongodzwa, pasi pekuita kwehydrophilic inodzivirira colloid uye mechanical shear simba, latex powder particles inogona kukurumidza kuparadzirwa mumvura, iyo inokwana kuumba zvizere redispersible latex powder mu film. Kuumbwa kwehupfu yerabha kune zvakasiyana-siyana pane rheological properties yedhaka uye zvakasiyana-siyana zvekuvaka zvivakwa: kuwirirana kwelatex powder kumvura kana yaparadzirwa, zvakasiyana-siyana zvehupfu hwe latex mushure mekupararira, kukanganisa kwemhepo. yedhaka uye kugoverwa kwemabhuru emhepo, Kudyidzana pakati pehupfu yerabha uye zvimwe zvinowedzera zvinoita kuti zvakasiyana-siyana latex powders zvive nemigumisiro yekuwedzera fluidity, kuwedzera thixotropy, uye kuwedzera viscosity.

Zvinowanzotendwa kuti nzira ye redispersible latex powder yekuvandudza kushanda kwedhaka itsva ndeye: kuwirirana kwelatex powder, kunyanya inodzivirira colloid, kumvura kana yakaparadzirwa, inowedzera viscosity ye slurry, uye inovandudza kubatana kwe dhaka rekuvaka.

Mushure meiyo ichangobva kusanganiswa dhaka ine latex poda dispersion yakaumbwa, nekutorwa kwemvura nechepasi, kushandiswa kwe hydration reaction, uye kuvhuvhuta kumhepo, mvura inodzikira zvishoma nezvishoma, zvidimbu zve resin zvichaswedera zvishoma nezvishoma, iyo interface. ichasviba zvishoma nezvishoma, uye resin inozobatana zvishoma nezvishoma. pakupedzisira polymerized kuita firimu. Maitiro ekuumbwa kwemafirimu epolymer akakamurwa kuita matanho matatu. Muchikamu chekutanga, zvikamu zvepolymer zvinofamba zvakasununguka muchimiro cheBrownian motion mune yekutanga emulsion. Sezvo mvura ichinyungudika, kufamba kwezvimedu kunowanzova kwakaganhurirwa, uye kusawirirana kwezviso pakati pemvura nemhepo kunomanikidza kuti zviwirirane zvishoma nezvishoma. Muchikamu chechipiri, kana zvimedu zvasangana, mvura iri mumambure inoputika kuburikidza necapillary tubes, uye kushushikana kwakanyanya kwecapillary kunoiswa pamusoro pezvimedu kunoita kuti deformation ye latex spheres isanganise pamwechete, uye mvura yakasara inozadza pores, uye firimu inenge yakaumbwa. Yechitatu, nhanho yekupedzisira inobvumira kupararira (dzimwe nguva kunonzi kuzvidzora) kwemamorekuru epolymer kuumba firimu rechokwadi rinoenderera. Munguva yekugadzira firimu, yakasarudzika nharembozha latex masisitimu anobatana kuita chikamu chitsva chefirimu chine kushushikana kwakanyanya. Zviripachena, kuitira kuti iyo redispersible polymer poda igadzire firimu mudhaka rakaomeswa, zvinodikanwa kuve nechokwadi chekuti tembiricha yekuumba firimu (MFT) yakadzikira pane tembiricha yekurapa yedhaka.

Colloids - polyvinyl doro rinofanira kuparadzaniswa kubva kune polymer film system. Iri harisi dambudziko mu alkaline simenti mortar system, nekuti iyo polyvinyl doro ichave saponified nealkali inogadzirwa nesamende hydration, uye adsorption yeiyo quartz zvinhu zvishoma nezvishoma ichaparadzanisa polyvinyl doro kubva muhurongwa, pasina iyo hydrophilic inodzivirira colloid. , Iyo firimu inoumbwa nekamwe-nguva kupararira kwe redispersible latex powder, iyo pachayo isingasviki mumvura, inogona kushanda kwete mumamiriro ezvinhu akaoma chete, asiwo mumamiriro ekunyudzwa kwemvura kwenguva refu. Ehe, mune dzisiri-alkaline masisitimu, senge gypsum kana filler-chete masisitimu, nekuti polyvinyl doro richiripo muchikamu chekupedzisira chepolymer firimu, iyo inokanganisa kudzivirira kwemvura kwefirimu, kana masisitimu aya asingashandisi kwenguva refu yemvura. kunyudzwa, uye iyo polymer ichine yayo yakasarudzika michina, uye iyo redispersible polymer poda inogona kushandiswa mune aya masisitimu.

Nekuumbwa kwekupedzisira kweiyo polymer firimu, sisitimu inoumbwa neinorganic uye organic binder zvimiro inoumbwa mudhaka rakaporeswa, kureva, brittle uye yakaoma skeleton inoumbwa nezvinhu zvehydraulic, uye inodhindwazve latex poda inoumba firimu pakati pegomba neiyo. nzvimbo yakasimba. flexible network. Kusimba kwekusimba uye kubatana kwepolymer resin firimu inogadzirwa nelatex poda inowedzerwa. Nekuda kwekuchinjika kwepolymer, iyo deformation kugona kwakakwira zvakanyanya kupfuura iyo yedombo resimende rakaomarara chimiro, iyo deformation kuita kwedhaka inovandudzwa, uye mhedzisiro yekuparadzira kushushikana inovandudzwa zvakanyanya, nekudaro ichivandudza kutsemuka kwedhaka. .

Nekuwedzera kwezviri mukati redispersible latex poda, iyo system yese inokura yakananga kupurasitiki. Kana iri yakakwira latex poda yemukati, chikamu chepolymer mudhaka yakarapirwa zvishoma nezvishoma chinodarika inorganic hydration chigadzirwa chikamu, uye dhaka richaita shanduko yemhando uye ive elastomer, nepo hydration chigadzirwa chesimende ichiva "yekuzadza". “. Kusimba kwesimba, elasticity, kuchinjika uye kuvharika kwedhaka rakagadziridzwa neredispersible latex poda zvese zvinovandudzwa. Kusanganiswa kwelatex poda inodzokororwa inobvumira iyo polymer firimu (latex film) kuumba uye kuita chikamu chemadziro epore, nekudaro ichivhara iyo yakanyanya porous chimiro chedhaka. Latex membrane ine inozvitwasanudza yega iyo inoita tension painosungirirwa padhaka. Kuburikidza nemasimba aya emukati, dhaka rinochengetedzwa sese, nokudaro richiwedzera kusimba kwakabatana kwedhaka. Kuvapo kwemapolymer anochinjika uye ane elastic zvakanyanya anovandudza kuchinjika uye elasticity yedhaka.

Iyo nzira yekuwedzera kwekunetseka kwegoho uye simba rekukundikana ndeiyi inotevera: kana simba rinoshandiswa, microcracks inononoka kusvikira kushushikana kwakanyanya kwasvika nekuda kwekuvandudza kushanduka uye elasticity. Pamusoro pezvo, iyo interwoven polymer domains zvakare inotadzisa kubatana kwema microcracks mukupinda mukati. Naizvozvo, iyo redispersible polymer poda inovandudza kutadza kushushikana uye kutadza dhizaini yechinhu.

Iyo polymer firimu mupolymer yakagadziridzwa dhaka ine yakakosha mhedzisiro pakuomesa dhaka. Iyo redispersible latex poda yakagoverwa pachiratidziro inoita rimwe basa rakakosha mushure mekuparadzirwa uye firimu-kugadzira, iri kuwedzera kunamatira kune zvakabatikana zvinhu. Mune iyo microstructure yepoda polima yakagadziridzwa tile bonding mortar uye tile interface, iyo firimu inoumbwa nepolymer inoumba zambuko pakati pemataira ane vitrified ane yakanyanya kuderera kunyura kwemvura uye simende yedhaka matrix. Nzvimbo yekubatana pakati pezvinhu zviviri zvakasiyana inzvimbo ine njodzi yakanyanya yekuputsika mitswe iumbe uye inotungamira mukurasikirwa kwekubatana. Nokudaro, kukwanisa kwemafirimu e latex kuporesa shrinkage kuputika kunokosha zvikuru kune matilesi ekunamatira.

Panguva imwecheteyo, iyo redispersible latex poda ine ethylene ine yakasarudzika yakanamatira kune organic substrates, kunyanya zvinhu zvakafanana, senge polyvinyl chloride uye polystyrene. Muenzaniso wakanaka ndewe kana zvasvika kumasiki.