Menene methylcellulose?

Methyl Cellulose (MC) Tsarin kwayoyin halitta \[C6H7O2 (OH) 3-h (OCH3) n1] x Ana kula da auduga mai ladabi da alkali, kuma ana amfani da methyl chloride azaman etherification. Bayan jerin halayen, ana gudanar da maganin ether cellulose. Gabaɗaya, matakin maye gurbin shine 1.6 ~ 2.0, kuma matakin maye ya bambanta. Nasa ne ga wadanda ba ionic cellulose ether.

1. Methylcellulose yana soluble a cikin ruwan sanyi, ruwan zafi zai fuskanci matsaloli, kuma pH kewayon maganin ruwa yana da kwanciyar hankali tsakanin 3/12. Sitaci, guar danko da sauran surufactants da yawa sun fi dacewa. Gelation yana faruwa lokacin da yawan zafin jiki ya kai yawan zafin jiki.

Riƙewar ruwa na methylcellulose ya dogara da adadin da aka ƙara, danko, fineness barbashi da adadin rushewa. Gabaɗaya girma, ƙarami, babban danko, babban riƙe ruwa. Daga cikin su, riƙewar ruwa yana da tasiri mafi girma, kuma matakin danko ba daidai ba ne kai tsaye ga riƙewar ruwa. A rushe kudi yafi dogara a kan mataki na surface gyara na cellulose barbashi da fineness na barbashi. Daga cikin ethers cellulose da ke sama, methyl cellulose da hydroxypropyl methyl cellulose suna da babban riƙewar ruwa.

Canje-canjen yanayin zafi na iya yin tasiri sosai akan riƙe ruwa na methyl cellulose. – Mafi girman zafin jiki, mafi muni da riƙewar ruwa. Idan yawan zafin jiki na turmi ya wuce 40 ° C, riƙewar ruwa na methyl cellulose zai ragu sosai, yana tasiri sosai ga ginin turmi.

Methylcellulose yana da tasiri mai mahimmanci akan iya aiki da mannewa na turmi. “Manne” a nan yana nufin mannewa tsakanin kayan aikin ma’aikaci da katangar bango, wato, juriyar juriyar turmi. Dankowa, ƙarfin turmi, da ƙarfin da ma'aikata ke buƙata suma suna da girma sosai, ginin turmi ba shi da kyau. Methylcellulose yana manne a matsakaicin matakan a cikin samfuran ether cellulose.

2. Hydroxypropyl methylcellulose (HPMC) [C 6 H 7 O 2 (OH) 3-mn (OCH 3) m, OCH 2 CH (OH) CH 3] n]] hydroxypropyl methyl cellulose A cikin 'yan shekarun nan, nau'in cellulose yana da ya karu da sauri. Yana da ether wanda ba shi da ionic cellulose wanda aka shirya ta jerin halayen bayan alkalization na alkali mai ladabi na auduga, wanda ake amfani da propylene oxide da methyl chloride a matsayin wakilai na etherification. Matsayin musanyawa yawanci 1.2/2.0. Kaddarorinsa sun bambanta bisa ga rabon abun ciki na methoxyl da abun ciki na hydroxypropyl.

1. Hydroxypropyl methylcellulose an raba shi zuwa nau'in zafi-narke da nau'in nan take. Yawan zafinsa na gelation a cikin ruwan zafi yana da mahimmanci fiye da na methylcellulose. Hakanan yana nuna babban cigaba akan methylcellulose lokacin da aka narkar da shi cikin ruwan sanyi.

Dankowar hydroxypropyl methylcellulose yana da alaƙa da nauyin kwayoyin halitta, kuma nauyin kwayoyin yana da girma. Hakanan yanayin zafi yana rinjayar danko, yayin da zafin jiki ya karu, danko yana raguwa. Koyaya, tasirin zafin jiki akan danko yana ƙasa da na methyl cellulose. Maganin yana da kwanciyar hankali a cikin zafin jiki.

3. Riƙewar ruwa na hydroxypropyl methylcellulose ya dogara da adadin adadinsa, danko, da dai sauransu, kuma yawan ajiyar ruwa na adadin wannan adadin ya fi na methyl cellulose.

4. Hydroxypropyl methylcellulose yana da kwanciyar hankali ga acid da alkali, kuma maganinsa na ruwa yana da tsayi sosai a cikin pH na 2/12. Ayyukan soda caustic da ruwan lemun tsami ba su da tasiri sosai, amma alkali na iya hanzarta rushewarta, kuma an 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 yakan ƙara ƙaruwa.

Ana iya haxa Hydroxypropyl methylcellulose tare da polymers masu narkewa da ruwa don samar da uniform, babban bayani mai danko. Kamar polyvinyl barasa, sitaci ether, kayan lambu danko, da dai sauransu.

Hydroxypropyl methylcellulose yana da mafi kyawun juriya na enzyme fiye da methylcellulose, yuwuwar lalatawar enzymatic na maganin sa yana ƙasa da na methylcellulose, kuma mannewar hydroxypropylmethylcellulose zuwa ginin turmi ya fi na methylcellulose girma. tushe cellulose.

Uku, hydroxyethyl cellulose (HEC) an yi shi daga auduga mai ladabi da aka yi da alkali, a gaban acetone, da ethylene oxide a matsayin wakili na etherification. Matsayinsa na sauyawa yawanci 1.5/2.0. Yana da karfi hydrophilicity kuma yana da sauƙin sha danshi.

1. Hydroxyethyl cellulose yana narkewa a cikin ruwan sanyi, amma yana da wuya a narke cikin ruwan zafi. Maganin yana da kwanciyar hankali a babban zafin jiki kuma ba shi da kayan gel. Ana iya amfani da shi na dogon lokaci a cikin turmi mai zafi mai zafi, amma riƙewar ruwa ya yi ƙasa da na methyl cellulose.

2. Hydroxyethyl cellulose ne barga zuwa general acid da alkali. Alkaki yana saurin rushewa, kuma dankowar sa yana karuwa kadan. Watsewarta a cikin ruwa ya ɗan yi muni fiye da na methyl cellulose da hydroxypropyl methyl cellulose.

3. Hydroxyethyl cellulose yana da kyau anti-rataye yi a turmi, amma na dogon lokaci, wasu gida samar hydroxyethyl cellulose yana da muhimmanci kasa aiki fiye da methyl cellulose saboda da babban ruwa abun ciki da kuma high ash abun ciki.

4. Carboxymethyl cellulose (CMC) \ [C6H7O2 (OH) 2och2COONa] (auduga, da dai sauransu) na halitta fiber ana bi da shi tare da alkali, kuma sodium chloroacetate ana amfani da matsayin etherification wakili, bayan jerin dauki jiyya, an sanya shi a cikin ionic. cellulose ether. Matsayin maye gaba ɗaya shine 0.4/1.4, kuma matakin maye gurbin yana da babban tasiri akan aiki.

Carboxymethyl cellulose yana da babban hygroscopicity, kuma yanayin ajiya na gabaɗaya ya ƙunshi ƙarin ruwa.

2. Maganin ruwa na Carboxymethyl cellulose ba ya samar da gel, danko yana raguwa lokacin da zafin jiki ya tashi, kuma danko ba zai iya jurewa ba lokacin da zafin jiki ya wuce 50 ° C.

Kwanciyarsa yana tasiri sosai ta pH. Gabaɗaya ana amfani da turmi na gypsum, ba don turmi siminti ba. A cikin yanayin babban alkalinity, zai rasa danko.

Riƙewar ruwansa ya yi ƙasa da na methyl cellulose. Turmi gypsum yana da sakamako mai raguwa, yana rage ƙarfi. Amma farashin carboxymethyl cellulose yana da ƙasa da ƙasa fiye da na methyl cellulose.