Sodium carboxymethyl cellulose, ake magana a kai a matsayin carboxymethyl cellulose (CMC) wani irin high-polymer fiber ether shirya ta sinadaran gyara na halitta cellulose. Tsarinsa shine naúrar D-glucose galibi ta hanyar β (1→4) Ana haɗa maɓallan tare.
CMC fari ne ko madara fari fibrous foda ko granules, tare da yawa na 0.5-0.7 g/cm3, kusan mara wari, m, da hygroscopic. A sauƙaƙe tarwatsa cikin ruwa don samar da maganin colloidal na gaskiya, wanda ba zai iya narkewa a cikin kaushi mai ƙarfi kamar ethanol. pH na 1% bayani mai ruwa shine 6.5-8.5, lokacin da pH> 10 ko <5, danko na mucilage yana raguwa sosai, kuma aikin shine mafi kyau lokacin pH = 7. Barga don zafi, danko yana tashi da sauri ƙasa da 20 ° C, kuma yana canzawa a hankali a 45 ° C. Dumama na dogon lokaci sama da 80 ° C na iya hana colloid kuma rage danko da aiki sosai. Yana da sauƙi mai narkewa a cikin ruwa kuma maganin yana bayyana; yana da tsayayye sosai a cikin maganin alkaline, amma yana da sauƙin ruwa lokacin da ya ci karo da acid, kuma zai yi hazo lokacin da ƙimar pH ya kai 2-3, kuma zai amsa da gishirin ƙarfe mai yawa.
Tsarin tsari: C6H7(OH)2OCH2COONa Tsarin kwayoyin halitta: C8H11O5Na
Babban halayen shine: cellulose na halitta da farko yana fuskantar amsawar alkalinization tare da NaOH, kuma tare da ƙari na chloroacetic acid, hydrogen akan ƙungiyar hydroxyl akan rukunin glucose yana jure yanayin maye gurbin tare da ƙungiyar carboxymethyl a cikin chloroacetic acid. Ana iya gani daga tsarin tsarin cewa akwai rukunin hydroxyl guda uku akan kowace rukunin glucose, wato, C2, C3, da C6 hydroxyl kungiyoyin. A hydrogen a kan kowane hydroxyl kungiyar da aka maye gurbinsu da carboxymethyl, wanda aka bayyana a matsayin mataki na maye gurbin 3. A mataki na maye gurbin CMC kai tsaye rinjayar solubility, emulsification, thickening, kwanciyar hankali, acid juriya da gishiri juriya naCMC .
An yi imani da cewa lokacin da digiri na maye gurbin ya kasance a kusa da 0.6-0.7, aikin emulsifying ya fi kyau, kuma tare da karuwar darajar maye gurbin, wasu kaddarorin suna inganta daidai. Lokacin da matakin maye gurbin ya fi 0.8, juriya na acid da juriya na gishiri suna haɓaka sosai. .
Bugu da ƙari, an kuma ambata a sama cewa akwai ƙungiyoyin hydroxyl guda uku a kowace raka'a, wato, ƙungiyoyin hydroxyl na biyu na C2 da C3 da kuma rukunin farko na hydroxyl na C6. A cikin ka'idar, aikin rukunin hydroxyl na farko ya fi na ƙungiyar hydroxyl na biyu, amma bisa ga tasirin isotopic na C, ƙungiyar -OH akan C2 Ya fi acidic, musamman a cikin yanayin alkali mai ƙarfi, aikinsa. yana da ƙarfi fiye da C3 da C6, don haka ya fi dacewa da halayen maye gurbin, wanda C6 ya biyo baya, kuma C3 shine mafi rauni.
A gaskiya ma, aikin CMC ba wai kawai yana da alaƙa da matakin maye gurbin ba, har ma da daidaituwar rarraba ƙungiyoyin carboxymethyl a cikin dukkanin kwayoyin cellulose da maye gurbin ƙungiyoyin hydroxymethyl a kowace naúrar tare da C2, C3, da C6. kowane kwayoyin halitta. alaka da uniformity. Tun da CMC wani fili ne na madaidaiciyar polymerized sosai, kuma ƙungiyar ta carboxymethyl tana da canji mara kyau a cikin kwayoyin halitta, ƙwayoyin suna da mabambantan mabanbanta lokacin da aka bar maganin a tsaye, kuma tsayin ƙwayar linzamin ya bambanta idan akwai ƙarfin ƙarfi a cikin maganin. . Ƙaƙwalwar tana da yanayin juyawa zuwa maɓuɓɓugar ruwa, kuma wannan hali ya zama mai karfi tare da karuwa na raguwa har sai an shirya yanayin karshe gaba daya. Wannan sifa ta CMC ana kiranta pseudoplasticity. The pseudoplasticity na CMC ne m ga homogenization da bututun sufuri, kuma shi ba zai dandana ma m a cikin ruwa madara, wanda shi ne m ga saki madara kamshin. .
Don amfani da samfuran CMC, muna buƙatar samun kyakkyawar fahimtar manyan sigogi kamar kwanciyar hankali, danko, juriya na acid, da danko. Sanin yadda muke zabar samfurin da ya dace.
Kayayyakin CMC masu ƙarancin danko suna da ɗanɗano mai daɗi, ƙarancin ɗanko, kuma kusan babu lokacin farin ciki. Ana amfani da su musamman a cikin miya da abubuwan sha na musamman. Ruwan lafiya na baka kuma zabi ne mai kyau.
Ana amfani da samfuran CMC masu matsakaicin danko a cikin abubuwan sha, abubuwan sha na furotin na yau da kullun da ruwan 'ya'yan itace. Yadda za a zaɓa ya dogara da halayen injiniyoyi na sirri. A cikin kwanciyar hankali na abubuwan sha, CMC ya ba da gudummawa mai yawa.
Samfuran CMC masu tsananin danko suna da ingantacciyar sararin aikace-aikace. Idan aka kwatanta da sitaci, guar gum, xanthan gum da sauran samfurori, kwanciyar hankali na CMC har yanzu yana da kyau a bayyane, musamman a cikin kayan nama, amfanin riƙewar ruwa na CMC ya fi bayyane! Daga cikin masu daidaitawa kamar ice cream, CMC shima zabi ne mai kyau.
Babban alamun don auna ingancin CMC sune digiri na maye gurbin (DS) da tsabta. Gabaɗaya, kaddarorin CMC sun bambanta idan DS ya bambanta; mafi girman matakin maye gurbin, mafi ƙarfi da ƙarfi, kuma mafi kyawun nuna gaskiya da kwanciyar hankali na mafita. A cewar rahotanni, nuna gaskiya na CMC ya fi kyau lokacin da matakin maye gurbin shine 0.7-1.2, kuma danko na maganin ruwa shine mafi girma lokacin da darajar pH ta kasance 6-9.
Don tabbatar da ingancinsa, ban da zaɓin wakili na etherification, dole ne a yi la'akari da wasu abubuwan da suka shafi matakin maye gurbin da tsabta, kamar alakar da ke tsakanin adadin alkali da etherification, lokacin etherification, abun ciki na ruwa a ciki. tsarin, zafin jiki, ƙimar DH, Magani Mai da hankali da gishiri da dai sauransu.
Ingancin samfuran ƙãre CMC ya dogara ne akan maganin samfurin. Idan bayani na samfurin ya bayyana a fili, akwai 'yan gel barbashi, free zaruruwa, da kuma baki spots na ƙazanta, shi ne m tabbatar da cewa ingancin CMC ne mai kyau. Idan an bar maganin na ƴan kwanaki, maganin ba zai bayyana ba. Fari ko turbid, amma har yanzu a bayyane yake, wannan shine mafi kyawun samfur!
Lokacin aikawa: Dec-14-2022