Ngokubanzi, kwi-synthesis yeihydroxypropyl methylcellulose, i-cotton cellulose ecocekileyo iphathwa ngesisombululo se-alkali kwi-35-40 ° C kwisiqingatha seyure, icinezelwe, i-cellulose ihlanjululwe, kwaye ikhulile ngokufanelekileyo kwi-35 ° C, ukwenzela ukuba iifayili ze-alkali ezifunyenweyo ziyi-avareji ye-polymerized degree ngaphakathi kwemfuneko efunekayo. uluhlu. Faka i-alkali fiber kwi-kettle ye-etherification, yongeza i-propylene oxide kunye ne-methyl chloride ngokuphindaphindiweyo, kwaye i-etherify kwi-50-80 ℃ iiyure ze-5 ukuya kuxinzelelo oluphezulu malunga ne-1.8 MPa. Emva koko faka inani elifanelekileyo le-hydrochloric acid kunye ne-oxalic acid kumanzi ashushu kwi-90 ° C ukuhlamba izinto zokwandisa umthamo. Dehydrate nge centrifuge. Geza ude ungathathi hlangothi, xa umthamo wamanzi kwizinto eziphathekayo ungaphantsi kwama-60%, uyomise ngokuhamba komoya oshushu kwi-130 ° C ukuya ngaphantsi kwe-5%.
I-alkalization: Umqhaphu osulungekisiweyo owenziwe ngumgubo emva kokuvula wongezwa kwi-solvent engasebenziyo, kwaye isebenze ngealkali kunye namanzi athambileyo ukudumba i-crystal lattice yomqhaphu osulungekisiweyo, onceda ekungeneni kwee-ajenti ze-etherifying iimolekyuli kunye nokuphucula ukufana kwe-etherification reaction. . I-alkali esetyenziswe kwi-alkalization yintsimbi ye-hydroxide okanye isiseko sezinto eziphilayo. Ubungakanani be-alkali eyongeziweyo (ngobunzima, obufana ngezantsi) yi-0.1-0.6 amaxesha e-cotton ecocekileyo, kunye nomthamo wamanzi athambileyo ngama-0.3-1.0 amaxesha ekotoni ecocekileyo; i-solvent inert ngumxube wotywala kunye ne-hydrocarbon, kwaye inani le-solvent ye-inert eyongeziweyo i-cotton ecocekileyo. Amaxesha angama-7-15: i-solvent ye-inert ingaba yi-alcohol kunye ne-3-5 i-athomu ye-carbon (njenge-alcohol, propanol), i-acetone. Isenokuba yi-aliphatic hydrocarbons kunye ne-aromatics hydrocarbons; iqondo lokushisa kufuneka lilawulwe ngaphakathi kwe-0-35 ° C ngexesha le-alkalization; ixesha alkalization malunga 1hr. Ukulungiswa kweqondo lokushisa kunye nexesha kunokumiselwa ngokweemfuno zezinto kunye nemveliso.
I-Etherification: Emva kokunyanga kwe-alkalization, phantsi kweemeko ze-vacuum, i-etherification iqhutyelwa ngokudibanisa i-etherifying agent, kunye ne-etherifying agent yi-propylene oxide. Ukuze kuncitshiswe ukusetyenziswa kwe-etherifying agent, i-agent etherifying yongezwa kabini ngexesha lenkqubo ye-etherification.
Ixesha lokuposa: Apr-28-2024