MC ndi methyl cellulose, yomwe imapezeka pochiza thonje woyengedwa ndi alkali, pogwiritsa ntchito methyl chloride ngati etherifying agent, ndikupanga cellulose ether kudzera muzochita zingapo. Nthawi zambiri, kuchuluka kwa m'malo ndi 1.6 ~ 2.0, ndipo kusungunuka kwake kumasiyananso ndi magawo osiyanasiyana olowa m'malo. Ndi ya non-ionic cellulose ether.
(1) Kusunga madzi amethyl cellulosezimatengera kuwonjezera kuchuluka kwake, mamasukidwe akayendedwe, tinthu fineness ndi kuvunda mlingo. Kawirikawiri, ngati kuchuluka kwa kuwonjezereka kuli kwakukulu, fineness ndi yaying'ono, ndipo mamasukidwe akayendedwe ndi aakulu, mlingo wosungira madzi ndi wapamwamba. Pakati pawo, kuchuluka kwa kuonjezera kumakhala ndi chikoka chachikulu pa mlingo wosungira madzi, ndipo msinkhu wa viscosity suli wofanana ndi mlingo wa kusunga madzi. The Kusungunuka mlingo makamaka zimadalira mlingo wa padziko kusinthidwa kwa mapadi particles ndi fineness wa particles. Pakati pa ma cellulose ethers omwe ali pamwambawa, methyl cellulose ndi hydroxypropyl methyl cellulose ali ndi milingo yochuluka yosungira madzi.
(2) Methylcellulose imasungunuka m'madzi ozizira, koma ovuta kusungunuka m'madzi otentha, ndipo njira yake yamadzimadzi imakhala yokhazikika pa pH = 3 ~ 12. Iwo ali ngakhale bwino ndi wowuma, guar chingamu, etc. ndi surfactants ambiri. Kutentha kukafika pa kutentha kwa gelation, zochitika za gelation zimachitika.
(3) Kusintha kwa kutentha kudzakhudza kwambiri kuchuluka kwa kusunga madzi kwa methyl cellulose. Nthawi zambiri, kutentha kumapangitsa kuti madzi asamasungidwe kwambiri. Ngati kutentha kwa matope kupitirira 40 ° C, kusungidwa kwa madzi kwa methyl cellulose kudzakhala koipa kwambiri, zomwe zidzakhudza kwambiri kugwira ntchito kwa matope.
(4) Methyl cellulose imakhudza kwambiri magwiridwe antchito komanso kumamatira kwamatope. “Kumatira” apa akutanthauza kumamatira komwe kumamveka pakati pa chida cha wogwiritsa ntchito ndi gawo lapansi la khoma, ndiko kuti, kukana kukameta ubweya wa matope. Kumamatira ndi kwakukulu, kukana kukameta ubweya wa matope ndi kwakukulu, ndipo mphamvu yofunikira ndi ogwira ntchito pakugwiritsa ntchito imakhalanso yaikulu, ndipo kumanga matope ndi osauka. Methylcellulose adhesion ali pamlingo wapakatikati muzinthu za cellulose ether.
HPMC ndi hydroxypropyl methyl cellulose, yomwe ndi cellulose yopanda ionic yosakanikirana ndi thonje yoyengedwa pambuyo pa mankhwala a alkali, pogwiritsa ntchito propylene oxide ndi methyl chloride ngati etherifying agents, komanso kudzera muzochita zingapo. Mlingo wolowa m'malo nthawi zambiri ndi 1.2 mpaka 2.0. Makhalidwe ake amasiyana malinga ndi kuchuluka kwa methoxyl ndi hydroxypropyl.
(1) Hydroxypropyl methylcellulose imasungunuka mosavuta m'madzi ozizira, koma imakumana ndi zovuta pakusungunuka m'madzi otentha. Koma kutentha kwake kwa gelation m'madzi otentha ndikokwera kwambiri kuposa kwa methyl cellulose. Kusungunuka m'madzi ozizira kumakhalanso bwino kwambiri poyerekeza ndi methyl cellulose.
(2) Kukhuthala kwa hydroxypropyl methylcellulose kumagwirizana ndi kukula kwa kulemera kwake kwa mamolekyulu, ndipo kukula kwake kwa molekyulu, kumapangitsa kukhuthala kwake. Kutentha kumakhudzanso kukhuthala kwake, pamene kutentha kumawonjezeka, kukhuthala kumachepa. Koma kukhuthala kwake sikukhudzidwa kwambiri ndi kutentha kwambiri kuposa methyl cellulose. Yankho lake ndi khola pa yosungirako firiji.
(3) Hydroxypropyl methylcellulose ndi yokhazikika ku asidi ndi alkali, ndipo njira yake yamadzimadzi imakhala yokhazikika pa pH = 2 ~ 12. Madzi a caustic ndi laimu sakhala ndi zotsatira zochepa pa ntchito yake, koma alkali amatha kufulumizitsa kusungunuka kwake ndikuwonjezera kukhuthala kwake. Hydroxypropyl methylcellulose ndi yokhazikika ku mchere wamba, koma pamene mchere wa mchere uli wambiri, kukhuthala kwa hydroxypropyl methylcellulose solution kumawonjezeka.
(4) Kusunga madzihydroxypropyl methylcellulosezimatengera kuchuluka kwake, kukhuthala, etc. Mlingo wosungira madzi pansi pa kuchuluka komweko ndi wapamwamba kuposa wa methyl cellulose.
(5) Hydroxypropyl methylcellulose akhoza kusakaniza ndi madzi sungunuka polima mankhwala kupanga njira ndi yunifolomu ndi apamwamba mamasukidwe akayendedwe. Monga polyvinyl mowa, wowuma ether, masamba chingamu, etc.
(6) Kumamatira kwa hydroxypropyl methylcellulose pakupanga matope ndikokwera kuposa methylcellulose.
(7) Hydroxypropyl methylcellulose imalimbana bwino ndi michere kuposa methylcellulose, ndipo yankho lake la enzymatic degradation mwina ndilotsika kuposa la methylcellulose.
Nthawi yotumiza: Apr-28-2024