Dispersible polima ufa ndi zomatira zina inorganic (monga simenti, slaked laimu, gypsum, dongo, etc.) ndi aggregates zosiyanasiyana, fillers ndi zina zina [monga hydroxypropyl methylcellulose, polysaccharide (wowuma efa), CHIKWANGWANI CHIKWANGWANI, etc.] ndi thupi kusakaniza kupanga matope osakaniza owuma. Pamene youma ufa matope ndi anawonjezera kuti madzi ndi analimbikitsa, pansi pa zochita za hydrophilic zoteteza colloid ndi makina akumeta ubweya mphamvu, ndi lalabala ufa particles akhoza mwamsanga omwazika m'madzi, zomwe ndi zokwanira kuti redispersible latex ufa mokwanira filimu. Mapangidwe a ufa wa mphira ndi wosiyana, womwe umakhudza rheology ya matope ndi zinthu zosiyanasiyana zomanga: kuyanjana kwa ufa wa latex wa madzi pamene umabalalitsidwa, kusiyana kwa kukhuthala kwa latex ufa pambuyo kubalalitsidwa, zotsatira zake pa mpweya zili mu matope ndi kugawa thovu, The kucheza pakati mphira ufa ndi zina zina zimapangitsa lalabala ufa osiyana ndi ntchito za kuwonjezeka fluidity, kuonjezera thixotropy, ndi kuwonjezeka. mamasukidwe akayendedwe.
Amakhulupirira kuti njira yomwe redispersible latex ufa imathandizira kuti matope atsopano azitha kugwira ntchito ndikuti ufa wa latex, makamaka colloid woteteza, umakhala ndi mgwirizano wamadzi akamwazikana, zomwe zimawonjezera kukhuthala kwa slurry ndikuwongolera kulumikizana kwamadzi. matope omanga.
Pambuyo matope atsopano okhala ndi latex powder dispersion apangidwa, ndi kuyamwa kwa madzi ndi pansi pamtunda, kumwa kwa hydration reaction, ndi kuphulika kwa mpweya, madzi amachepetsa pang'onopang'ono, tinthu tating'onoting'ono timayandikira pang'onopang'ono, mawonekedwewo amawonekera pang'onopang'ono. , ndipo utomoniwo umasakanikirana pang’onopang’ono. potsiriza polymerized mu filimu. Njira yopanga filimu ya polima imagawidwa m'magawo atatu. Mu gawo loyamba, polima particles kusuntha momasuka mu mawonekedwe a Brownian zoyenda mu koyamba emulsion. Madzi akamasanduka nthunzi, kusuntha kwa tinthu ting’onoting’ono kumakhala koletsedwa mwachibadwa, ndipo kukangana pakati pa madzi ndi mpweya kumachititsa kuti pang’onopang’ono agwirizane. Mu gawo lachiwiri, pamene particles ayamba kukhudzana wina ndi mzake, madzi mu maukonde amasanduka nthunzi kudzera capillary, ndi mkulu capillary mavuto ntchito pamwamba pa particles kumapangitsa mapindikidwe a latex spheres kuwapanga fuse pamodzi, ndi madzi otsala amadzaza pores, ndipo filimuyo imapangidwa mozungulira. Gawo lachitatu komanso lomaliza limathandizira kufalikira (nthawi zina kumatchedwa kudzimatira) kwa mamolekyu a polima kuti apange filimu yopitilira. Pakupanga filimu, tinthu tating'onoting'ono ta latex tating'onoting'ono timaphatikizana kukhala filimu yopyapyala yokhala ndi kupsinjika kwakukulu. Mwachiwonekere, kuti ufa wa polima wotayika ukhale wokhoza kupanga filimu mumatope opangidwanso, kutentha kochepa kwambiri kwa filimu (MFT) kuyenera kutsimikiziridwa kukhala kochepa kusiyana ndi kutentha kwa matope.
Colloids - mowa wa polyvinyl uyenera kulekanitsidwa ndi dongosolo la membrane wa polima. Ili si vuto mu dongosolo la matope a alkaline simenti, chifukwa mowa wa polyvinyl udzakhala saponified ndi alkali wopangidwa ndi simenti ya simenti, ndipo kutsekemera kwa zinthu za quartz kumalekanitsa pang'onopang'ono mowa wa polyvinyl ku dongosolo, popanda hydrophilic protective colloid. . , Kanema wopangidwa ndi kufalitsa ufa wa latex wopangidwanso, womwe susungunuka m'madzi, sungathe kugwira ntchito mumikhalidwe yowuma, komanso mumikhalidwe yomiza m'madzi kwa nthawi yayitali. Kumene, mu kachitidwe sanali zamchere, monga gypsum kapena kachitidwe ndi fillers okha, popeza polyvinyl mowa akadali pang'ono alipo mu chomaliza polima filimu, zomwe zimakhudza madzi kukana filimu, pamene machitidwe amenewa si ntchito madzi kwa nthawi yaitali. kumizidwa, ndipo polima akadali ndi mawonekedwe ake amakanika katundu, dispersible polima ufa angagwiritsidwebe ntchito machitidwe awa.
Ndi mapangidwe omaliza a filimu ya polima, dongosolo lopangidwa ndi zomangira ndi organic binders limapangidwa mumatope ochiritsidwa, ndiko kuti, chigoba chophwanyika ndi cholimba chomwe chimapangidwa ndi zipangizo zama hydraulic, ndi redispersible polima ufa amapangidwa mu kusiyana ndi pamwamba olimba. flexible network. Kulimba kwamphamvu komanso kulumikizana kwa filimu ya utomoni wa polima yopangidwa ndi ufa wa latex kumakulitsidwa. Chifukwa cha kusinthasintha kwa polima, mphamvu yopindika ndiyokwera kwambiri kuposa mawonekedwe olimba a mwala wa simenti, magwiridwe antchito a matope amawongoleredwa, ndipo zotsatira za kubalalitsa kupsinjika zimakhala bwino kwambiri, potero kuwongolera kukana kwa matope. .
Ndi kuchuluka kwa zili dispersible polima ufa, dongosolo lonse akufotokozera pulasitiki. Pankhani ya ufa wambiri wa latex, gawo la polima mumatope ochiritsidwa pang'onopang'ono limadutsa gawo la mankhwala a hydration, matopewo adzasintha bwino ndikukhala elastomer, ndipo hydration mankhwala a simenti adzakhala "filler" ". Kulimba kwamphamvu, kusinthasintha, kusinthasintha ndi kusindikiza katundu wa matope osinthidwa ndi ufa wa polima wotayika unasinthidwa. Kuphatikizika kwa ufa wa polima wotayika kumapangitsa filimu ya polima (filimu ya latex) kuti ipange ndi kupanga gawo la makoma a pore, potero kusindikiza mawonekedwe otsekemera kwambiri a matope. Nembanemba ya latex imakhala ndi njira yodzitambasulira yokha yomwe imagwiritsa ntchito kukhazikika kwake ndi matope. Kupyolera mu mphamvu zamkati izi, matope amagwiridwa lonse, motero amawonjezera mphamvu yogwirizana ya matope. Kukhalapo kwa ma polima osinthika kwambiri komanso zotanuka kwambiri kumapangitsa kuti matopewo asasunthike komanso kusinthasintha. Njira yowonjezeretsa kupsinjika kwa zokolola ndi kulephera mphamvu ndi motere: pamene mphamvu ikugwiritsidwa ntchito, ma microcracks amachedwa chifukwa cha kusintha kwa kusinthasintha ndi kusungunuka, ndipo samapanga mpaka kupanikizika kwakukulu kukufika. Kuphatikiza apo, madera ophatikizika a polima amalepheretsanso kuphatikiza kwa ma microcracks kukhala ming'alu. Choncho, dispersible polima ufa kumawonjezera kulephera kupsinjika ndi kulephera kwa zinthu.
Filimu ya polima mumatope opangidwa ndi polima imakhala ndi zotsatira zofunikira kwambiri pakuumitsa matope. The redispersible polima ufa anagawira pa mawonekedwe amasewera mbali ina yofunika pambuyo omwazikana ndi kupanga filimu, amene ndi kuonjezera adhesion kwa zipangizo kukhudzana. Mu microstructure ya malo olumikizirana pakati pa ufa wa polima-wosinthidwa wa ceramic matailosi omangira matope ndi matailosi a ceramic, filimu yopangidwa ndi polima imapanga mlatho pakati pa matailosi a ceramic okhala ndi mayamwidwe otsika kwambiri amadzi ndi masanjidwewo a matope a simenti. Malo ogwirizanitsa pakati pa zipangizo ziwiri zosiyana ndi malo apadera omwe ali ndi chiopsezo chachikulu chomwe ming'alu ya shrinkage imapanga ndipo imayambitsa kutayika kwa adhesion. Choncho, kuthekera kwa mafilimu a latex kuchiritsa ming'alu ya shrinkage kumagwira ntchito yofunika kwambiri pazitsulo zomatira.
Pa nthawi yomweyo, redispersible polima ufa munali ethylene ali odziwika kwambiri adhesion kwa magawo organic, makamaka zipangizo zofanana, monga polyvinyl kolorayidi ndi polystyrene. Chitsanzo chabwino cha
Nthawi yotumiza: Oct-31-2022