Ngokuvamile, ku-synthesis yei-hydroxypropyl methylcellulose, i-cellulose kakotini ecolisisiwe iphathwa ngesisombululo se-alkali ku-35-40 ° C isigamu sehora, icindezelwe, i-cellulose ihlutshiwe, futhi iguge ngokufanele ku-35 ° C, ukuze imicu ye-alkali etholiwe i-polymerized degree ingaphakathi kwesidingo esidingekayo. ububanzi. Faka i-alkali fibre eketelani le-etherification, engeza i-propylene oxide ne-methyl chloride ngokushintshana, bese ufaka i-etherify ku-50-80 ℃ amahora angu-5 kuya kungcindezi ephezulu cishe engu-1.8 MPa. Bese wengeza inani elifanele le-hydrochloric acid ne-oxalic acid emanzini ashisayo ku-90 ° C ukuze ugeze izinto zokwandisa ivolumu. Dehydrate nge-centrifuge. Geza kuze kube yilapho ungathathi hlangothi, lapho okuqukethwe kwamanzi okubalulekile kungaphansi kuka-60%, yomise ngokugeleza komoya oshisayo ku-130 ° C kuya ngaphansi kuka-5%.
I-Alkalization: Ukotini ocolisisiwe oyimpushana ngemva kokuvula wengezwa kuncibiliki esingasebenzi, futhi usebenze nge-alkali namanzi athambile ukuze kuvuvuke i-crystal lattice kakotini ocolisisiwe, osiza ekungeneni kwama-ejenti e-etherifying futhi uthuthukise ukufana kokusabela kwe-etherification. . I-alkali esetshenziswa ku-alkalization iyi-hydroxide yensimbi noma isisekelo se-organic. Inani le-alkali elengeziwe (ngobuningi, okufanayo ngezansi) liphindwe izikhathi ezingu-0.1-0.6 kunekotini elicwengekile, futhi inani lamanzi athambile liphindwe izikhathi ezingu-0.3-1.0 kunekotini elicwengekile; i-solvent ye-inert iyinhlanganisela yotshwala ne-hydrocarbon, futhi inani le-solvent ye-inert eyengeziwe iwukotini ohlungiwe. Izikhathi ezingu-7-15: i-solvent inert ingaba notshwala obunama-athomu e-carbon angu-3-5 (njengotshwala, i-propanol), i-acetone. Kungaba futhi i-aliphatic hydrocarbons nama-hydrocarbon anephunga elimnandi; izinga lokushisa kufanele lilawulwe ngaphakathi kwe-0-35 ° C ngesikhathi se-alkalization; isikhathi se-alkalization cishe ihora elingu-1. Ukulungiswa kwezinga lokushisa nesikhathi kunganqunywa ngokuvumelana nezidingo zezinto kanye nomkhiqizo.
I-Etherification: Ngemva kokwelashwa kwe-alkalization, ngaphansi kwezimo ze-vacuum, i-etherification yenziwa ngokungeza i-etherifying agent, futhi i-etherifying agent i-propylene oxide. Ukuze kuncishiswe ukusetshenziswa kwe-ejenti ye-etherifying, i-ejenti ye-etherifying yengezwe kabili phakathi nenqubo yokufaka i-etherification.
Isikhathi sokuthumela: Apr-28-2024