Pogwiritsa ntchitohydroxypropyl methyl cellulose HPMC, nthawi zambiri timapeza kuti imagawidwa m'mitundu iwiri: kusungunuka mwachangu ndi kusungunuka pang'onopang'ono. Tiyeni timvetse kusiyana pakati pa kusungunuka mwachangu ndi kusungunuka pang'onopang'ono kwa hydroxypropyl methyl cellulose.
HPMC ya Instant imatanthauza kugwiritsa ntchito cholumikizira cholumikizira pamwamba pa ntchito yopanga, kotero kuti HPMC ikhoza kufalikira mwachangu m'madzi ozizira, koma osati yankho lenileni, kudzera mu kusakaniza kofanana, kukhuthala kumakwera pang'onopang'ono, ndiko kuti, kusungunuka;
HPMC yosungunuka pang'onopang'ono ingathenso kutchedwa zinthu zosungunuka zotentha. Madzi ozizira akapezeka, amatha kufalikira mwachangu m'madzi otentha. Mwa kusakaniza mofanana, kutentha kwa yankho kudzatsika kufika pa kutentha kwina. (Kutentha kwa gel yathu ndi pafupifupi 60°C), kukhuthala kudzawoneka pang'onopang'ono mpaka gel yowonekera komanso yomata itapangidwa.
Apa pali kusiyana pakati pa yankho lachangu ndi yankho lochedwa. Ngati muli ndi mafunso okhudza chidziwitsochi, mutha kutifunsanso.
Hydroxypropyl methyl celluloseHPMCkuchedwetsa madzi a simenti
Kuwonjezera hydroxypropyl methyl cellulose ku simenti kumachepetsa kuchuluka kwa madzi m'thupi. Ndiye mukudziwa chiyani za momwe imagwirira ntchito? Tiyeni tiwone hydroxypropyl methyl cellulose kuti tichepetse kuchuluka kwa madzi m'thupi. Mfundo yaikulu.
1. Lingaliro la vuto la kayendedwe ka ayoni
Tinaganiza kuti hydroxypropyl methyl cellulose ingawonjezere kukhuthala kwa mayankho a pore, kulepheretsa kuyenda kwa ionic, ndikuchedwetsa kusungunuka kwa simenti. Komabe, ma ether a cellulose omwe ali ndi kukhuthala kochepa mu mayesowa anali ndi mphamvu yayikulu yochedwetsa kusungunuka kwa simenti. Chifukwa chake, lingaliro ili ndi losavomerezeka. Pourchez et al. nawonso akukayikira lingaliro ili. Ndipotu, nthawi yosuntha kapena kusamuka kwa ma ion ndi yochepa kwambiri, mwachiwonekere siyosiyana ndi kuchedwa kwa kusungunuka kwa simenti.
2. Kuwonongeka kwa alkali
Ma polysaccharides amawonongeka mosavuta pansi pa mikhalidwe ya alkaline kuti apange ma hydroxyl carboxylic acids omwe amachedwetsa hydration ya simenti. Chifukwa chake, kuchedwa kwa hydration ya hydroxypropyl methyl cellulose kungakhale chifukwa cha kuwonongeka kwake mu slurries ya simenti ya alkaline kuti apange ma hydroxycarboxylic acids. Komabe, Pourchez et al. adapeza kuti ma ether a cellulose anali okhazikika kwambiri pansi pa mikhalidwe ya alkaline, amawonongeka pang'ono chabe, ndipo zinthu zomwe zimawonongeka sizinakhudze kwambiri kuchedwa kwa hydration ya simenti.
3, kuyamwa
Kulowetsa madzi kungakhale hydroxypropyl methyl cellulose block simenti hydration chifukwa chenicheni ndichakuti zowonjezera zambiri zachilengedwe zidzalowetsedwa pa tinthu ta simenti ndi zinthu zothira madzi, kuletsa kusungunuka kwa tinthu ta simenti ndi crystallization ya zinthu zothira madzi, kotero kuti kuchedwetsa kusungunuka ndi kuzizira kwa simenti. Pourchez et al. adapeza kuti ma cellulose ethers amalowetsedwa mosavuta pamwamba pa zinthu zothira madzi monga calcium hydroxide, CSH gel ndi calcium aluminate hydrate, koma osati mosavuta kulowetsedwa ndi ettringite ndi magawo osasungunuka madzi. Komanso, pankhani ya cellulose ether, mphamvu ya adsorption ya HEC ndi yamphamvu kuposa ya kutupa kwa MC. Kutsika kwa hydroxyethyl mu HEC kapena hydroxypropyl muHPMC, mphamvu ya adsorption ikakhala yolimba: ponena za zinthu zothira madzi, mphamvu ya adsorption ya calcium hydroxide imakhala yolimba kuposa ya CSH. Kusanthula kwina kukuwonetsanso kuti mphamvu ya adsorption ya zinthu zothira madzi ndi cellulose ether ikugwirizana ndi kuchedwa kwa simenti: adsorption ikakhala yolimba, kuchedwa kumaonekera bwino, koma ettringite adsorption ya cellulose ether ndi yofooka, koma mapangidwe ake ndi ofooka, koma izi zimachedwa kwambiri. cellulose ether ya tricalcium silicate ndi zinthu zake zothira madzi zimakhala ndi adsorption yamphamvu, mwachionekere imachedwetsa njira ya hydration ya gawo la silicate, kuchuluka kwa adsorption kwa ettringite ndi kochepa kwambiri, koma mapangidwe a ettringite ochedwa ndi odziwikiratu, chifukwa cha kuchedwa kwa ettringite kupanga kumakhudzidwa ndi Ca2 + balance mu yankho, ndi kukulitsa kwa ether ya cellulose. Kuchedwa kwa silicate hydration kunapitilira.
Izi ndi mfundo ya hydroxypropyl methyl cellulose delay cement hydration. Tikukhulupirira kuti chidziwitsochi chithandiza aliyense kumvetsetsa momwe mankhwalawa amagwirira ntchito ndikugwiritsa ntchito bwino.
Nthawi yotumizira: Epulo-26-2024