Kawirikawiri, mu kapangidwe kahydroxypropyl methylcellulose, cellulose yoyengedwa bwino imachiritsidwa ndi yankho la alkali pa 35-40°C kwa theka la ola, kufinyidwa, cellulose imaphwanyidwa, ndikusungidwa bwino pa 35°C, kuti ulusi wa alkali womwe wapezeka ukhale wa polymerized mulingo womwe ulipo. Ikani ulusi wa alkali mu ketulo ya etherification, onjezerani propylene oxide ndi methyl chloride motsatizana, ndikutenthetsa pa 50-80 ℃ kwa maola 5 mpaka mphamvu yayikulu ya pafupifupi 1.8 MPa. Kenako onjezerani kuchuluka koyenera kwa hydrochloric acid ndi oxalic acid m'madzi otentha pa 90°C kuti mutsuke zinthuzo kuti muwonjezere voliyumu. Sungunulani ndi centrifuge. Tsukani mpaka madzi atakhala osalowererapo, pamene kuchuluka kwa madzi m'zinthuzo kuli kochepera 60%, muumitse ndi mpweya wotentha pa 130°C mpaka pansi pa 5%.
Alkalization: Thonje loyeretsedwa ndi ufa likatsegulidwa limawonjezeredwa mu chosungunulira chosagwira ntchito, ndipo limayatsidwa ndi madzi a alkali ndi ofewa kuti liwonjezere kristalo la thonje loyeretsedwa, zomwe zimathandiza kuti mamolekyu a etherifying agent alowemo ndikuwonjezera kufanana kwa etherification reaction. Alkali yomwe imagwiritsidwa ntchito mu alkaliization ndi hydroxide yachitsulo kapena maziko achilengedwe. Kuchuluka kwa alkali komwe kumawonjezeredwa (ndi kulemera, komwe kuli pansipa) ndi kuwirikiza 0.1-0.6 kuposa thonje loyeretsedwa, ndipo kuchuluka kwa madzi ofewa ndi kuwirikiza 0.3-1.0 kuposa thonje loyeretsedwa; chosungunulira chosagwira ntchito ndi chisakanizo cha mowa ndi hydrocarbon, ndipo kuchuluka kwa chosungunulira chosagwira ntchito komwe kumawonjezeredwa ndi thonje loyeretsedwa. Nthawi 7-15: chosungunulira chosagwira ntchito chingakhalenso mowa wokhala ndi maatomu 3-5 a kaboni (monga mowa, propanol), acetone. Ikhozanso kukhala aliphatic hydrocarbons ndi aromatic hydrocarbons; kutentha kuyenera kulamulidwa mkati mwa 0-35°C panthawi ya alkaliization; nthawi ya alkaliization ndi pafupifupi ola limodzi. Kusintha kwa kutentha ndi nthawi kumatha kudziwika malinga ndi zofunikira za zinthu ndi chinthucho.
Kuyeretsedwa kwa Ether: Pambuyo pa chithandizo cha alkalizing, pansi pa vacuum conditions, etherification imachitika powonjezera etherifying agent, ndipo etherifying agent ndi propylene oxide. Pofuna kuchepetsa kugwiritsa ntchito etherifying agent, etherifying agent inawonjezedwa kawiri panthawi ya etherification.
Nthawi yotumizira: Epulo-28-2024