Kazhinji, mune synthesis yehydroxypropyl methylcellulose, iyo yakanatswa donje cellulose inobatwa nealkali solution pa 35-40 ° C kwehafu yeawa, yakasvinwa, cellulose inopwanyika, uye zvakakodzera kukwegura pa 35 ° C, kuitira kuti ma alkali fibers anowanikwa avhareji yepolymerized dhigirii iri mukati mehutano hunodiwa. Isa iyo alkali faibha muketero ye etherification, wedzera propylene oxide uye methyl chloride zvakare, uye etherify pa 50-80 ℃ kwemaawa mashanu kusvika pakumanikidzwa kwakanyanya kwe 1.8 MPa. Wobva wawedzera huwandu hwakakodzera hwehydrochloric acid uye oxalic acid kumvura inopisa pa90 ° C kushambidza zvinhu kuti uwedzere huwandu. Dehydrate ne centrifuge. Shamba kusvika kune kwausingarereki, kana mvura inenge iri muzvinyorwa zvisingasviki 60%, iomese nemhepo inopisa inoyerera pa130 ° C kusvika pasi pe5%.
Alkalization: Donje rakanatswa rakanatswa mushure mekuvhurwa rinowedzerwa muinert solvent, uye rinoitwa nealkali uye mvura yakapfava kuzvimba crystal lattice yedonje yakacheneswa, iyo inobatsira kupinda kweetherifying agent mamorekuru uye inovandudza kufanana kweiyo etherification reaction. Iyo alkali inoshandiswa mu alkalization isimbi hydroxide kana organic base. Nhamba yealkali yakawedzerwa (kuburikidza nehukuru, yakafanana pasi) ndeye 0.1-0.6 nguva yekotoni yakanatswa, uye huwandu hwemvura yakapfava ndeye 0.3-1.0 nguva yekotoni yakanatswa; iyo inert solvent isanganiswa yedoro uye hydrocarbon, uye chiyero cheinert solvent chakawedzerwa ikotoni yakanatswa. 7-15 nguva: iyo inert solvent inogonawo kuva doro ne 3-5 carbon atomu (zvakadai sedoro, propanol), acetone. Inogonawo kuva aliphatic hydrocarbons uye anonhuwirira hydrocarbons; tembiricha inofanira kudzorwa mukati 0-35 ° C panguva alkalization; nguva ye alkalization inenge 1hr. Kugadziriswa kwekushisa uye nguva kunogona kugadziriswa maererano nezvinodiwa zvezvinhu uye chigadzirwa.
Etherification: Mushure mekurapa kwe alkalization, pasi pemamiriro ekutsvaira, etherification inoitwa nekuwedzera etherifying agent, uye etherifying agent inonzi propylene oxide. Kuti uderedze kudyiwa kweiyo etherifying agent, iyo etherifying agent yakawedzerwa kaviri panguva ye etherification process.
Nguva yekutumira: Kubvumbi-28-2024