Hanyar roba ta hydroxypropyl methylcellulose

Kullum, a cikin kira nahydroxypropyl methylcellulose, da mai ladabi cellulose auduga ana bi da alkali bayani a 35-40 ° C na rabin sa'a, squeezed, da cellulose ne pulverized, da kuma dace da shekaru a 35 ° C, sabõda haka, samu alkali zaruruwa ne talakawan polymerized digiri ne a cikin da ake bukata. iyaka. Saka alkali fiber a cikin kettle etherification, ƙara propylene oxide da methyl chloride bi da bi, kuma etherify a 50-80 ℃ na 5 hours zuwa wani babban matsa lamba na kusan 1.8 MPa. Sa'an nan kuma ƙara adadin da ya dace na hydrochloric acid da oxalic acid zuwa ruwan zafi a 90 ° C don wanke kayan don faɗaɗa ƙarar. Dehydrate tare da centrifuge. Wanke har sai tsaka tsaki, lokacin da abun ciki na ruwa a cikin kayan ya kasance ƙasa da 60%, bushe shi tare da iska mai zafi a 130 ° C zuwa ƙasa da 5%.

Alkaki: Za a saka audugar da aka tace da ita bayan an bude ta a cikin wani abu mara kyau, sannan a kunna shi da alkali da ruwa mai laushi don kumbura tsinken crystal na auduga mai ladabi, wanda ke da amfani ga shigar da kwayoyin halitta masu lalata da kuma inganta daidaiton halayen etherification. . Alkali da aka yi amfani da shi a cikin alkalization shine karfe hydroxide ko tushen kwayoyin halitta. Adadin alkali da aka ƙara (ta taro, iri ɗaya a ƙasa) shine sau 0.1-0.6 na auduga mai ladabi, kuma adadin ruwa mai laushi shine sau 0.3-1.0 na auduga mai ladabi; Ƙunƙarar rashin ƙarfi shine cakuda barasa da hydrocarbon, kuma adadin ƙarancin ƙarancin da aka ƙara shine auduga mai ladabi. 7-15 sau: inert sauran ƙarfi kuma iya zama barasa tare da 3-5 carbon atom (kamar barasa, propanol), acetone. Yana kuma iya zama aliphatic hydrocarbons da aromatic hydrocarbons; ya kamata a sarrafa zafin jiki a cikin 0-35 ° C yayin alkalization; lokacin alkalization yana kusan 1hr. Ana iya ƙayyade daidaitawar zafin jiki da lokaci bisa ga buƙatun kayan da samfur.

Etherification: Bayan jiyya na alkalization, a ƙarƙashin yanayi mara kyau, ana aiwatar da etherification ta hanyar ƙara wani wakili na etherifying, kuma wakilin etherifying shine propylene oxide. Don rage yawan amfani da wakili na etherifying, an ƙara ma'auni na etherifying sau biyu a lokacin aikin etherification.