Methylcellulose (MC)
Tsarin kwayoyin halitta na methylcellulose (MC) shine:
[C6H7O2(OH)3-h(OCH3)n\]x
Tsarin samarwa shine don yin ether cellulose ta hanyar jerin halayen bayan an kula da auduga mai ladabi tare da alkali, kuma ana amfani da methyl chloride azaman wakili na etherification. Gabaɗaya, matakin maye gurbin shine 1.6 ~ 2.0, kuma solubility shima ya bambanta da digiri daban-daban na maye gurbin. Nasa ne ga wadanda ba ionic cellulose ether.
Methylcellulose yana narkewa a cikin ruwan sanyi, kuma zai yi wuya a narke cikin ruwan zafi. Maganin ruwan sa yana da ƙarfi sosai a cikin kewayon pH = 3 ~ 12.
Yana da kyau dacewa tare da sitaci, guar danko, da dai sauransu da yawa surfactants. Lokacin da zafin jiki ya kai ga zafin jiki na gelation, gelation yana faruwa.
Riƙewar ruwa na methylcellulose ya dogara da ƙarin adadinsa, danko, fineness barbashi da adadin rushewa.
Gabaɗaya, idan adadin ƙari yana da girma, ƙarancin ƙarancin ƙanƙara ne, kuma danko yana da girma, yawan riƙe ruwa yana da girma. Daga cikin su, adadin ƙarawa yana da tasiri mafi girma a kan yawan adadin ruwa, kuma matakin danko ba daidai ba ne kai tsaye zuwa matakin yawan ruwa. A rushe kudi yafi dogara a kan mataki na surface gyara na cellulose barbashi da barbashi fineness.
Daga cikin ethers cellulose da ke sama, methyl cellulose da hydroxypropyl methyl cellulose suna da ƙimar riƙe ruwa mafi girma.
Carboxymethylcellulose (CMC)
Carboxymethyl cellulose, kuma aka sani da sodium carboxymethyl cellulose, wanda aka fi sani da cellulose, cmc, da dai sauransu, shi ne anionic linear polymer, wani sodium gishiri na cellulose carboxylate, kuma shi ne sabunta da kuma m. Chemical albarkatun kasa.
Ana amfani da shi ne a masana'antar wanke-wanke, masana'antar abinci da kuma ruwan hako mai, kuma adadin da ake amfani da shi a cikin kayan shafawa ya kai kusan kashi 1%.
Ionic cellulose ether an yi shi ne daga filaye na halitta (auduga, da dai sauransu) bayan maganin alkali, ta yin amfani da sodium monochloroacetate a matsayin wakili na etherification, da kuma jurewa jerin jiyya.
Matsakaicin maye gaba ɗaya shine 0.4 ~ 1.4, kuma aikin sa yana tasiri sosai ta matakin maye gurbin.
CMC yana da kyakkyawan ikon ɗaurewa, kuma maganin sa na ruwa yana da kyakkyawan ikon dakatarwa, amma babu ainihin ƙimar nakasar filastik.
Lokacin da CMC ya narke, depolymerization yana faruwa a zahiri. Danko yana farawa yayin rushewa, ya wuce ta matsakaicin matsakaici, sannan ya faɗi zuwa tudu. Sakamakon danko yana da alaƙa da depolymerization.
Matsayin depolymerization yana da alaƙa da alaƙa da adadin ƙarancin ƙarfi (ruwa) a cikin tsari. A cikin tsarin rashin ƙarfi mara kyau, kamar man goge baki wanda ke ɗauke da glycerin da ruwa, CMC ba zai ƙare gaba ɗaya ba kuma zai kai ga ma'auni.
A cikin yanayin ƙaddamarwar ruwa da aka ba, mafi yawan hydrophilic da aka maye gurbin CMC ya fi sauƙi don ƙaddamarwa fiye da ƙananan CMC da aka maye gurbin.
Hydroxyethylcellulose (HEC)
Ana yin HEC ta hanyar yin maganin auduga mai ladabi tare da alkali, sannan a mayar da martani tare da ethylene oxide a matsayin wakili na etherification a gaban acetone. Matsakaicin maye gaba ɗaya shine 1.5 ~ 2.0. Yana da karfi hydrophilicity kuma yana da sauƙin sha danshi.
Hydroxyethyl cellulose yana narkewa a cikin ruwan sanyi, amma yana da wuya a narke cikin ruwan zafi. Maganin sa yana da ƙarfi a babban zafin jiki ba tare da gelling ba.
Yana da karko ga na kowa acid da tushe. Alkalis na iya hanzarta rushewar kuma ya dan ƙara danko. Rarrabuwar sa a cikin ruwa ya ɗan yi muni fiye da na methyl cellulose da hydroxypropyl methyl cellulose.
Hydroxypropyl Methyl Cellulose (HPMC)
Tsarin kwayoyin halittar HPMC shine:
[C6H7O2 (OH) 3-mn (OCH3) m, OCH2CH (OH) CH3 \] n \] x
Hydroxypropyl methylcellulose wani nau'in cellulose ne wanda fitarwa da amfaninsa ke karuwa cikin sauri.
Yana da ether wanda ba na ionic cellulose ba wanda aka yi daga auduga mai ladabi bayan alkalization, ta amfani da propylene oxide da methyl chloride a matsayin wakili na etherification, ta hanyar jerin halayen. Matsakaicin maye gaba ɗaya shine 1.2 ~ 2.0.
Kaddarorinsa sun bambanta saboda bambancin rabo na abun ciki na methoxyl da abun ciki na hydroxypropyl.
Hydroxypropyl methylcellulose yana da sauƙin narkewa a cikin ruwan sanyi, amma zai gamu da wahala wajen narkewa cikin ruwan zafi. Amma zafinsa na gelation a cikin ruwan zafi yana da girma fiye da na methyl cellulose. Solubility a cikin ruwan sanyi kuma yana inganta sosai idan aka kwatanta da methyl cellulose.
Dankowar hydroxypropyl methylcellulose yana da alaƙa da nauyin kwayoyin halitta, kuma mafi girman nauyin kwayoyin halitta, mafi girman danko. Hakanan yanayin zafi yana rinjayar danko, yayin da zafin jiki ya karu, danko yana raguwa. Duk da haka, babban danko yana da tasirin zafi fiye da methyl cellulose. Maganin sa yana da ƙarfi idan an adana shi a cikin zafin jiki.
Riƙewar ruwa na hydroxypropyl methylcellulose ya dogara ne akan ƙarin adadinsa, danko, da dai sauransu, kuma yawan ajiyar ruwa a daidai adadin adadin ya fi na methyl cellulose.
Hydroxypropyl methylcellulose yana da kwanciyar hankali ga acid da alkali, kuma maganin sa na ruwa yana da ƙarfi sosai a cikin kewayon pH = 2 ~ 12. Caustic soda da ruwan lemun tsami suna da ɗan tasiri akan aikin sa, amma alkali na iya hanzarta rushewar kuma yana ƙara danko.
Hydroxypropyl methylcellulose ya tsaya tsayin daka ga gishiri na kowa, amma lokacin da maida hankali na maganin gishiri ya yi girma, dankowar maganin hydroxypropyl methylcellulose yana kula da karuwa.
Hydroxypropyl methylcellulose za a iya haxa shi da ruwa mai narkewa polymer mahadi don samar da uniform da mafi girma danko bayani. Kamar polyvinyl barasa, sitaci ether, kayan lambu danko, da dai sauransu.
Hydroxypropyl methylcellulose yana da mafi kyawun juriya na enzyme fiye da methylcellulose, kuma maganinsa ba shi da yuwuwar lalatawar enzymatically fiye da methylcellulose.
Lokacin aikawa: Fabrairu-14-2023