Mukugwiritsa ntchitohydroxypropyl methyl cellulose HPMC, nthawi zambiri timapeza kuti imagawidwa m'magulu awiri: kusungunuka mwamsanga komanso pang'onopang'ono. Tiyeni timvetsetse kusiyana pakati pa kusungunuka mwachangu ndi kusungunuka pang'onopang'ono kwa hydroxypropyl methyl cellulose.
Instant HPMC imatanthawuza kugwiritsa ntchito njira yolumikizirana yolumikizirana yopangira chithandizo chapamwamba popanga, kuti HPMC itha kumwazikana mwachangu m'madzi ozizira, koma osati yankho lenileni, kudzera muzoyambitsa yunifolomu, kukhuthala pang'onopang'ono kuwuka, ndiko kuti, kuvunda;
Pang'onopang'ono sungunuka HPMC amathanso kutchedwa zotentha zosungunuka. Madzi ozizira akakumana, amatha kumwazikana mwachangu m'madzi otentha. Pogwedeza mofanana, kutentha kwa yankho kumatsika mpaka kutentha kwina. (Kutentha kwa gel osakaniza ndi pafupifupi 60 ° C), kukhuthala kumawonekera pang'onopang'ono mpaka gel yowonekera komanso yomata itapangidwa.
Pano pali kusiyana pakati pa yankho lachangu ndi yankho lapang'onopang'ono. Ngati muli ndi mafunso okhudza chidziwitsochi, mutha kutifunsanso.
Hydroxypropyl methyl celluloseMtengo wa HPMCkuchedwetsa simenti hydration
Kuonjezera hydroxypropyl methyl cellulose ku simenti kumachepetsa kuyamwa kwake. Ndiye mukudziwa chiyani za momwe zimagwirira ntchito? Tiyeni tiwone hydroxypropyl methyl cellulose kuchedwetsa simenti hydration. Mfundo yofunika.
1. Ion movement disorder hypothesis
Tinkaganiza kuti hydroxypropyl methyl cellulose ingawonjezere kukhuthala kwa ma pore, kulepheretsa kusuntha kwa ma ionic, ndikuchedwetsa kuyatsa kwa simenti. Komabe, m'munsi mamasukidwe akayendedwe cellulose etha mu mayeso anali ndi mphamvu yamphamvu kuchedwetsa simenti hydration. Choncho, kulingalira kumeneku n’kolakwika. Pourchez et al. ndikukaikiranso lingaliro ili. M'malo mwake, nthawi yakusamuka kwa ion kapena kusamuka ndi yaifupi kwambiri, mwachiwonekere sikusiyana ndi kuchedwa kwa simenti ya simenti.
2. Kuwonongeka kwa alkaline
Ma polysaccharides amawonongeka mosavuta pansi pamikhalidwe yamchere kuti apange ma hydroxyl carboxylic acid omwe amachedwetsa kuyamwa kwa simenti. Chifukwa chake, kuchedwetsedwa kwa hydration ya hydroxypropyl methyl cellulose kungakhale chifukwa cha kuwonongeka kwake mu slurries ya simenti ya alkaline kupanga ma hydroxycarboxylic acid. Komabe, Pourchez et al. anapeza kuti ma cellulose ethers anali okhazikika kwambiri pansi pa zinthu za alkaline, amangowonongeka pang'ono, ndipo zinthu zowonongeka zinali ndi zotsatira zochepa pa kuchedwa kwa simenti hydration.
3, adsorption
Adsorption ikhoza kukhala hydroxypropyl methyl cellulose chipika simenti hydration chifukwa chenicheni ndi chakuti zina zambiri organic adzakhala adsorbed pa particles simenti ndi mankhwala hydration, kupewa Kutha kwa particles simenti ndi crystallization wa mankhwala hydration, kuti achedwetse hydration ndi condensation wa simenti. Pourchez et al. anapeza kuti ma cellulose ethers amadsorbed mosavuta pazinthu za hydration monga calcium hydroxide, CSH gel ndi calcium aluminate hydrate, koma osati mosavuta adsorbed ndi ettringite ndi unhydrated magawo. Komanso, pankhani ya cellulose ether, mphamvu ya adsorption ya HEC ndi yamphamvu kuposa ya kutupa kwa MC. Kuchepetsa zomwe zili mu hydroxyethyl mu HEC kapena hydroxypropyl muMtengo wa HPMC, mphamvu ya adsorption yamphamvu: ponena za mankhwala a hydration, mphamvu ya adsorption ya calcium hydroxide ndi yamphamvu kuposa ya CSH. Kusanthula kwina kumasonyezanso kuti mphamvu ya adsorption ya mankhwala a hydration ndi cellulose ether ikugwirizana ndi kuchedwa kwa simenti ya hydration: mphamvu ya adsorption, ndi yoonekeratu kuchedwa, koma ettringite adsorption ya cellulose ether ndi yofooka, koma mapangidwe ake, koma izi zimachedwa kwambiri. cellulose efa wa tricalcium silicate ndi mankhwala ake hydration ali adsorption amphamvu, izo mwachionekere akuchedwa hydration ndondomeko silicate gawo, adsorption kuchuluka kwa ettringite ndi otsika kwambiri, koma anachedwa ettringite mapangidwe n'zoonekeratu, chifukwa kuchedwa ettringite mapangidwe amakhudzidwa ndi Ca 2 + bwino mu njira yothetsera, ndi kutambasuka kwa cellulose ether. Mochedwa silicate hydration anapitiriza.
Awa ndi hydroxypropyl methyl cellulose kuchedwa simenti hydration mfundo. Tikukhulupirira kuti chidziwitsochi chithandiza aliyense kumvetsetsa momwe mankhwalawa amagwirira ntchito ndikuzigwiritsa ntchito bwino.
Nthawi yotumiza: Apr-26-2024