Njira yopangira ya hydroxypropyl methylcellulose

Nthawi zambiri, mu kaphatikizidwe wahydroxypropyl methylcellulose, woyengedwa thonje mapadi mankhwala mankhwala ndi alkali solution pa 35-40 ° C kwa theka la ola, kufinyidwa, mapadi ndi pulverized, ndi moyenerera zaka 35 ° C, kuti analandira alkali ulusi ndi avareji polymerized digiri ndi mkati chofunika. osiyanasiyana. Ikani ulusi wa alkali mu ketulo ya etherification, onjezerani propylene oxide ndi methyl chloride nayenso, ndi etherify pa 50-80 ℃ kwa maola 5 mpaka kuthamanga kwakukulu kwa pafupifupi 1.8 MPa. Kenaka yikani mlingo woyenera wa hydrochloric acid ndi oxalic acid m'madzi otentha pa 90 ° C kuti musambe zinthuzo kuti muwonjezere voliyumu. Dehydrate ndi centrifuge. Sambani mpaka osalowerera ndale, pamene madzi omwe ali muzinthuzo ndi ochepera 60%, ziumeni ndi mpweya wotentha pa 130 ° C mpaka pansi pa 5%.

Alkalization: The ufa woyengedwa thonje pambuyo kutsegula anawonjezera mu zosungunulira inert, ndi adamulowetsa ndi alkali ndi madzi ofewa kutupa crystal lattice wa thonje woyengedwa, amene amathandiza kuti malowedwe a etherifying wothandizila mamolekyu ndi bwino yunifolomu wa etherification anachita. . The alkali ntchito alkalization ndi zitsulo hydroxide kapena organic maziko. Kuchuluka kwa alkali yowonjezeredwa (ndi misa, yomweyi pansipa) ndi 0.1-0.6 nthawi ya thonje yoyengedwa, ndipo kuchuluka kwa madzi ofewa ndi 0.3-1.0 nthawi ya thonje yoyengedwa; zosungunulira inert ndi chisakanizo cha mowa ndi hydrocarbon, ndipo kuchuluka kwa inert zosungunulira anawonjezera ndi woyengeka thonje. 7-15 nthawi: zosungunulira inert angakhalenso mowa ndi 3-5 maatomu mpweya (monga mowa, propanol), acetone. Itha kukhalanso ma hydrocarbon aliphatic ndi ma hydrocarbon onunkhira; kutentha kuyenera kuyendetsedwa mkati mwa 0-35 ° C panthawi ya alkalization; nthawi ya alkalization ndi pafupifupi 1hr. Kusintha kwa kutentha ndi nthawi kungadziwike molingana ndi zofunikira za zinthu ndi mankhwala.

Etherification: Pambuyo pa chithandizo cha alkalization, pansi pazimenezi, etherification ikuchitika powonjezera etherifying agent, ndi etherifying agent ndi propylene oxide. Pofuna kuchepetsa kumwa kwa etherifying wothandizira, wothandizira etherifying adawonjezeredwa kawiri panthawi ya etherification.