HPMC ndi hydroxypropyl methylcellulose, amene si aionic mapadi wosanganiza efa wopangidwa kuchokera thonje woyengeka pambuyo alkalization, ntchito propylene okusayidi ndi methyl kolorayidi monga etherification wothandizira, ndi kudzera angapo zochita. Mlingo wolowa m'malo nthawi zambiri ndi 1.2 ~ 2.0. Katundu wake ndi wosiyana chifukwa cha kuchuluka kwa methoxyl ndi hydroxypropyl.
MC ndi methyl cellulose, yomwe imapangidwa ndicellulose etherpochiza thonje woyengedwa ndi alkali, kugwiritsa ntchito methane chloride ngati etherification agent, ndikudutsamo 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.
Kufananiza magwiridwe antchito pakati pa awiriwa:
(1) Hydroxypropyl methylcellulose imasungunuka mosavuta m'madzi ozizira, ndipo 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. 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.
Methylcellulose imasungunukanso m'madzi ozizira, ndipo zimakhala zovuta kusungunuka m'madzi otentha. Njira yake yamadzimadzi imakhala yokhazikika pa pH = 3 ~ 12. Iwo ali ngakhale bwino ndi wowuma, guar chingamu, etc. ndi surfactants ambiri. Pamene kutentha kufika kutentha kwa gelation, gelation imachitika.
(2) Kukhuthala kwa hydroxypropyl methylcellulose kumakhudzana ndi kulemera kwake kwa mamolekyulu, ndipo kukula kwake kwa molekyulu kumapangitsa kukhuthala kwamphamvu. Kutentha kumakhudzanso kukhuthala kwake, pamene kutentha kumawonjezeka, kukhuthala kumachepa. Komabe, kukhuthala kwake kwakukulu kumakhala ndi kutentha kochepa kuposa methyl cellulose. Yankho lake ndi lokhazikika likasungidwa kutentha.
Methylcellulose amakhudza kwambiri workability ndi adhesion wa matope. “Kumatira” pano kukutanthauza mphamvu yomatira yomwe imamveka pakati pa chida cha wogwiritsa ntchito ndi gawo lapansi la khoma, ndiko kuti, kukana kukameta ubweya wa matope. Kumamatira kumakhala kwakukulu, kukana kukameta ubweya wa matope ndi kwakukulu, ndipo mphamvu zomwe ogwira ntchito amafunikira pakugwiritsa ntchito zimakhala zazikulu, ndipo ntchito yomanga matope ndi yosauka. Methyl cellulose adhesion ali pamlingo wocheperako muzinthu za cellulose ether.
(3) Kusungidwa kwa madzi kwa hydroxypropyl methylcellulose kumadalira kuchuluka kwake, kukhuthala kwake, ndi zina zambiri, ndipo kuchuluka kwake komwe kumasungira madzi pansi pa kuchuluka komweko ndikokwera kuposa kwa methyl cellulose.
Kusungidwa kwa madzi kwa methylcellulose kumadalira kuchuluka kwake, kukhuthala, kukongola kwa tinthu ndi kusungunuka kwake. Nthawi zambiri, ngati kuchuluka kwake kuli kwakukulu, fineness ndi yaying'ono, ndipo mamasukidwe ake ndiakuluakulu, kuchuluka kwa kusunga madzi kumakhala kwakukulu. Pakati pawo, kuchuluka kwa kuwonjezera kumakhudza kwambiri kuchuluka kwa kusungirako madzi, ndipo msinkhu wa viscosity suli wofanana mwachindunji ndi mlingo wa kusunga madzi. The Kusungunuka mlingo makamaka zimadalira mlingo wa padziko kusinthidwa kwa mapadi particles ndi tinthu fineness. Pakati pa ma cellulose ethers omwe ali pamwambawa, methyl cellulose ndi hydroxypropyl methyl cellulose ali ndi milingo yayikulu yosungira madzi.
(4) Hydroxypropyl methylcellulose akhoza kusakaniza ndi madzi sungunuka polima mankhwala kupanga yunifolomu ndi apamwamba mamasukidwe akayendedwe njira. Monga polyvinyl mowa, wowuma etere, masamba chingamu, etc. The adhesion wa hydroxypropyl methylcellulose kumanga matope ndi apamwamba kuposa methylcellulose.
Hydroxypropyl methylcellulose imakhala ndi kukana bwino kwa enzyme kuposa methylcellulose, ndipo yankho lake silingawonongeke ndi michere kuposa methylcellulose.
Kusintha kwa kutentha kumatha kukhudza kwambiri kusungidwa kwa madzi a methyl cellulose. Nthawi zambiri, kutentha kumapangitsa kuti madzi asamasungidwe kwambiri. Ngati kutentha kwa matope kupitirira 40 ° C, kusungirako madzi kwa methyl cellulose kudzachepetsedwa kwambiri, zomwe zimakhudza kwambiri kupanga matope. Kutentha kukakhala kokwera, yesani kusankha hydroxypropyl methylcellulose.
Nthawi yotumiza: Dec-20-2022