Uburyo bukoreshwa bwa hydroxypropyl methylcellulose

Mubisanzwe, muri synthesis yahydroxypropyl methylcellulose, ipamba itunganijwe neza ivurwa hamwe na alkali yumuti kuri 35-40 ° C mugihe cyigice cyisaha, irakanda, selile irasunikwa, kandi ifite imyaka ikwiye kuri 35 ° C, kuburyo fibre ya alkali yabonetse mubipimo bya polymerized biri murwego rusabwa. intera. Shira fibre ya alkali mumasafuriya ya etherification, ongeramo okiside ya propylene na methyl chloride, hanyuma etherify kuri 50-80 ℃ mumasaha 5 kumuvuduko mwinshi wa 1.8 MPa. Noneho shyiramo urugero rukwiye rwa acide hydrochloric na aside oxyde mumazi ashyushye kuri 90 ° C kugirango woze ibikoresho kugirango wagure amajwi. Umwuma hamwe na centrifuge. Karaba kugeza utabogamye, mugihe amazi arimo mubikoresho ari munsi ya 60%, yumisha hamwe numwuka ushushe kuri 130 ° C kugeza munsi ya 5%.

Alkalisation: Ifu yatunganijwe neza nyuma yo gufungura yongerwaho umusemburo wa inert, hanyuma igashyirwa mumazi ya alkali namazi yoroshye kugirango ikabyimba kasitori ya kirisiti ya pamba itunganijwe, ifasha kwinjira muri molekile ya etherifing kandi ikanahindura uburinganire bwimikorere ya etherification. . Alkali ikoreshwa muri alkalisation ni hydroxide yicyuma cyangwa shingiro kama. Ingano ya alkali yongeweho (kubwinshi, kimwe hepfo) irikubye inshuro 0.1-0,6 iy'ipamba inoze, naho amazi yoroshye akubye inshuro 0.3-1.0 z'ipamba inoze; umusemburo wa inert ni uruvange rwa alcool na hydrocarubone, kandi ingano ya inert solvent yongeweho ni ipamba nziza. Inshuro 7-15: inert solvent irashobora kandi kuba inzoga hamwe na atome ya karubone 3-5 (nka alcool, propanol), acetone. Irashobora kandi kuba hydrocarbone ya alifatique na hydrocarbone ya aromatic; ubushyuhe bugomba kugenzurwa muri 0-35 ° C mugihe cya alkalisation; igihe cya alkalisation ni nka 1h. Guhindura ubushyuhe nigihe birashobora kugenwa ukurikije ibisabwa nibikoresho nibicuruzwa.

Etherification: Nyuma yo kuvura alkalisation, mubihe bya vacuum, etherification ikorwa hongerwamo imiti ya etherifying, kandi agent ya etherifying ni okiside ya propylene. Kugirango ugabanye ikoreshwa rya agent ya etherifying, agent ya etherifying yongeyeho kabiri mugihe cya etherification.