Ngokuvamile, ekuhlanganisweni kwei-hydroxypropyl methylcellulose, i-cellulose yekotini ecolisisiwe iphathwa ngesisombululo se-alkali ku-35-40°C isigamu sehora, icindezelwe, i-cellulose iyacolwa, futhi ivuthwe ngokufanele ku-35°C, ukuze imicu ye-alkali etholiwe ibe yi-polymerized ngokwesilinganiso. Faka i-alkali fiber eketheni ye-etherification, engeza i-propylene oxide kanye ne-methyl chloride ngokulandelana, bese uyi-etherify ku-50-80 ℃ amahora ama-5 kumfutho ophezulu ongaba ngu-1.8 MPa. Bese ufaka inani elifanele le-hydrochloric acid kanye ne-oxalic acid emanzini ashisayo ku-90°C ukuze ugeze izinto ukuze wandise ivolumu. Khipha amanzi nge-centrifuge. Geza kuze kube yilapho kungathathi hlangothi, lapho okuqukethwe kwamanzi kungaphansi kuka-60%, komise ngokugeleza komoya oshisayo ku-130°C kuya ngaphansi kuka-5%.
I-Alkalization: Ukotini ocociwe ngophuphu ngemva kokuvulwa ufakwa ku-solvent engasebenzi, bese uvuselelwa ngamanzi e-alkali nathambile ukuze kuvuvuke i-crystal lattice yekotini ecociwe, okusiza ekungeneni kwama-molecule e-etherifying agent futhi kuthuthukise ukufana kokusabela kwe-etherification. I-alkali esetshenziswa ku-alkalization iyi-hydroxide yensimbi noma isisekelo se-organic. Inani le-alkali elingeziwe (ngesisindo, elifanayo ngezansi) liphindwe izikhathi ezingu-0.1-0.6 kunekotini ecociwe, kanti inani lamanzi athambile liphindwe izikhathi ezingu-0.3-1.0 kunekotini ecociwe; i-solvent engasebenzi iyinhlanganisela yotshwala ne-hydrocarbon, kanti inani le-solvent engasebenzi elingeziwe likotini ecociwe. Izikhathi ezingu-7-15: i-solvent engasebenzi ingaba yi-alcohol enama-athomu e-carbon angu-3-5 (njenge-alcohol, i-propanol), i-acetone. Kungaba futhi yi-aliphatic hydrocarbons nama-hydrocarbon aromatic; izinga lokushisa kufanele lilawulwe ngaphakathi kuka-0-35°C ngesikhathi se-alkalization; isikhathi se-alkalization cishe siyihora eli-1. Ukulungiswa kwezinga lokushisa nesikhathi kunganqunywa ngokuya ngezidingo zezinto ezibonakalayo nomkhiqizo.
Ukufakwa kwe-ether: Ngemva kokwelashwa kwe-alkalizing, ngaphansi kwezimo ze-vacuum, ukufakwa kwe-ether kwenziwa ngokufaka i-etherifying agent, kanti i-etherifying agent yi-propylene oxide. Ukuze kuncishiswe ukusetshenziswa kwe-etherifying agent, i-etherifying agent yengezwe kabili ngesikhathi senqubo ye-etherification.
Isikhathi sokuthunyelwe: Ephreli-28-2024