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 osakaniza kuti youma wothira matope. 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. The zikuchokera mphira ufa ndi wosiyana, amene zimakhudza rheology a matope ndi zosiyanasiyana zomangamanga katundu: ndi kuyanjana kwa latex ufa madzi pamene anabalalitsidwa, osiyana mamasukidwe akayendedwe a lalabala ufa pambuyo kubalalitsidwa, zotsatira pa mpweya zili matope ndi kugawa thovu, Kugwirizana pakati pa mphira ufa ndi zina zowonjezera zimapangitsa kuti ntchito zosiyanasiyana za latex ufa mamasukidwe akayendedwe.
Amakhulupirira kuti njira yomwe redispersible latex ufa imathandizira kugwira ntchito kwa matope atsopano ndikuti ufa wa latex, makamaka colloid woteteza, uli ndi mgwirizano wa madzi pamene umwazikana, womwe umawonjezera kukhuthala kwa slurry ndikuwongolera mgwirizano wa matope omanga.
Pambuyo matope atsopano okhala ndi latex powder kubalalitsidwa apangidwa, ndi kuyamwa kwa madzi ndi m'munsi pamwamba, kumwa hydration reaction, ndi volatilization mlengalenga, madzi amachepetsa pang'onopang'ono, utomoni particles pang'onopang'ono kuyandikira, mawonekedwe pang'onopang'ono blulls, ndi utomoni pang'onopang'ono amalumikizana wina ndi mzake. 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 ukuphwera kudzera capillary, ndi mkulu capillary mavuto ntchito pamwamba pa particles kumapangitsa mapindikidwe a latex spheres kuwapanga fuse pamodzi, ndi otsala madzi amadzaza pores, ndi filimu pafupifupi anapanga. 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 hydration, 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 lilipo mu chomaliza polima filimu, amene amakhudza kukana madzi filimu, pamene machitidwe amenewa si ntchito kwa nthawi yaitali kumiza m'madzi , ndi polima akadali khalidwe lake makina katundu, dispersible polima ufa angagwiritsidwe ntchito mu 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 ndi kulumikizana kwa filimu ya utomoni wa polima yopangidwa ndi ufa wa latex kumakulitsidwa. Chifukwa cha kusinthasintha kwa polima, mphamvu yopindika ndiyokwera kwambiri kuposa momwe mwala wokhazikika wa simenti umagwirira ntchito, kusinthika kwa matope kumatheka, ndipo zotsatira za kupsinjika kwamwala zimakula kwambiri, potero kuwongolera kukana kwa matope.
Ndi kuchuluka kwa zili dispersible polima ufa, dongosolo lonse akufotokozera pulasitiki. Pankhani ya mkulu zili lalabala ufa, ndi polima gawo mu matope anachiritsa pang`onopang`ono kuposa zochita kupanga hydration mankhwala gawo, matope adzakhala kusintha khalidwe ndi kukhala elastomer, ndi hydration mankhwala a simenti adzakhala "filler". filimu ya polima (filimu ya latex) kuti ipange ndi kupanga gawo la makoma a pore, potero amasindikiza mawonekedwe a porous kwambiri a matope a latex ali ndi njira yodzitambasula yomwe imagwiritsa ntchito kugwedezeka kwa anchorage ndi matope amkati, matope amagwiridwa lonse, potero akuwonjezera mphamvu yogwirizana ya matope ndi kusinthasintha kwakukulu kwa matope a polymer. 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