Ekusetyenzisweni kweihydroxypropyl methyl cellulose HPMC, ngokuqhelekileyo sifumanisa ukuba yahlulwe ngokwesiseko kwiindidi ezimbini: ukupheliswa kwangoku kunye nokucothayo. Masiwuqonde umahluko phakathi kokupheliswa ngokukhawuleza kunye nokuchithwa kancinci kwe-hydroxypropyl methyl cellulose.
I-HPMC ekhawulezileyo ibhekisa kusetyenziso lwe-arhente yomnqamlezo yonyango lomphezulu kwinkqubo yemveliso, ukuze i-HPMC isasazwe ngokukhawuleza emanzini abandayo, kodwa ingabi yisisombululo sokwenene, ngokuvuselela iyunifomu, i-viscosity inyuka ngokucothayo, oko kukuthi, ukuchithwa;
I-HPMC enyibilikayo ecothayo inokubizwa ngokuba ziimveliso ezinyibilikayo ezishushu. Xa amanzi abandayo edibana, anokusasazwa ngokukhawuleza emanzini ashushu. Ngokuvuselela ngokulinganayo, ukushisa kwesisombululo kuya kuhla kwiqondo lokushisa elithile. (Iqondo lokushisa lejeli yethu li malunga ne-60 ° C), i-viscosity iya kubonakala ngokukhawuleza de i-gel ebonakalayo kunye ne-sticky yenziwe.
Nanku umahluko phakathi kwesisombululo esikhawulezileyo kunye nesisombululo esicothayo. Ukuba unayo nayiphi na imibuzo malunga nolu lwazi, unokuqhagamshelana nathi.
I-Hydroxypropyl methyl celluloseHPMCulibazisa ukuhanjiswa kwesamente
Ukongeza i-hydroxypropyl methyl cellulose kwisamente kunciphisa ukuhanjiswa kwayo. Yintoni ke oyaziyo malunga nendlela esebenza ngayo? Makhe sijonge kwi-hydroxypropyl methyl cellulose ukulibazisa ukuhanjiswa kwesamente. Umgaqo.
1. I-ion movement disorder hypothesis
Siye sacinga ukuba i-hydroxypropyl methyl cellulose iya kwandisa i-viscosity yezisombululo ze-pore, ithintele isantya sokuhamba kwe-ionic, kunye nokulibazisa ukuhanjiswa kwesamente. Nangona kunjalo, i-ethers ye-viscosity cellulose ephantsi kolu vavanyo yayinamandla amakhulu okulibazisa ukuchithwa kwesamente. Ngoko ke, le ngcinga ayisebenzi. Pourchez et al. kwakhona ukuthandabuza le ngqikelelo. Enyanisweni, ixesha lokufuduka kwe-ion okanye ukufuduka lifutshane kakhulu, ngokucacileyo alifani nokulibaziseka kwe-cement hydration.
2. Ukuthotywa kwealkaline
Iipolysaccharides zithotywa ngokulula phantsi kweemeko zealkaline ukuvelisa i-hydroxyl carboxylic acids ebambezela ukugcwala kwesamente. Ke ngoko, ukulibaziseka kwe-hydration ye-hydroxypropyl methyl cellulose inokuba ngenxa yokuthotywa kwayo kwi-alkaline slurries yesamente ukwenza i-hydroxycarboxylic acids. Nangona kunjalo, uPourchez et al. yafumanisa ukuba i-cellulose ethers yayizinzile kakhulu phantsi kweemeko ze-alkaline, iyancipha nje kancinci, kwaye iimveliso zokunciphisa zinempembelelo encinci ekulibazisekeni kwe-cement hydration.
3, i-adsorption
I-Adsorption ingaba yi-hydroxypropyl methyl cellulose ibhlokhi ye-cement hydration esona sizathu kukuba izongezo ezininzi zezinto eziphilayo ziya kubhengezwa kwiincinci zesamente kunye neemveliso ze-hydration, zithintele ukuchithwa kweengqungquthela ze-samente kunye ne-crystallization yeemveliso ze-hydration, ukwenzela ukulibazisa i-hydration kunye ne-condensation ye-cement. Pourchez et al. bafumanise ukuba i-cellulose ethers ibhengezwa ngokulula kwindawo yeemveliso ze-hydration ezifana ne-calcium hydroxide, ijeli ye-CSH kunye ne-calcium aluminate hydrate, kodwa ingabhengezwa ngokulula ngezigaba ze-ettringite kunye ne-unhydrated. Ngaphezu koko, kwimeko ye-cellulose ether, umthamo we-adsorption we-HEC unamandla kune-MC yokuvuvukala. Ukunciphisa umxholo we-hydroxyethyl kwi-HEC okanye i-hydroxypropyl kwiHPMC, amandla e-adsorption anamandla: malunga neemveliso ze-hydration, i-adsorption capacity ye-calcium hydroxide yomelele kune-CSH. Uhlalutyo olongezelelweyo lukwabonisa ukuba umthamo we-adsorption wemveliso ye-hydration kunye ne-ether cellulose inxulumene nokulibaziseka kwe-samente hydration: i-adsorption yomelele, i-adsorption icacile, kodwa i-ettringite adsorption ye-cellulose ether ibuthathaka, kodwa ukubunjwa kwayo, kodwa oku kubambezeleka kakhulu. I-cellulose ether ye-tricalcium silicate kunye nemveliso yayo ye-hydration ine-adsorption enamandla, ngokucacileyo ibambezela inkqubo ye-hydration yesigaba se-silicate, inani le-adsorption ye-ettringite liphantsi kakhulu, kodwa ukulibaziseka ukubunjwa kwe-ettringite kubonakala, ngenxa yokulibaziseka ukubunjwa kwe-ettringite kuchatshazelwa yi-Ca 2 + ibhalansi kwisisombululo, kukwandiswa kwe-cellulose ether. I-silicate hydration kade iqhubekile.
Ezi ziyi-hydroxypropyl methyl cellulose ukulibaziseka kwesamente hydration umgaqo. Siyathemba ukuba olu lwazi luya kwenza wonke umntu aqonde indlela imveliso esebenza ngayo kwaye ayisebenzise ngcono.
Ixesha lokuposa: Apr-26-2024