Hydroxyethyl Methyl Cellulose

Cellulose ether shine kayan sinadarai masu kyau na polymer da aka yi amfani da su da yawa waɗanda aka yi daga cellulose na polymer na halitta ta hanyar magani. Bayan ƙera cellulose nitrate da cellulose acetate a cikin karni na 19, masana kimiyya sun haɓaka jerin abubuwan da suka samo asali na cellulose ethers da yawa, kuma an ci gaba da gano sababbin filayen aikace-aikacen, wanda ya ƙunshi sassa na masana'antu da yawa. Cellulose ether kayayyakin irin su sodium carboxymethyl cellulose (CMC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl hydroxypropyl cellulose (MHEC) da methyl hydroxypropyl cellulose (MHPC) da sauran cellulose ethers an san su. "Masana'antu monosodium glutamate" kuma an yi amfani dashi sosai wajen hako mai, gini, sutura, abinci, magani da sinadarai na yau da kullun.

Hydroxyethylmethylcellulose(MHEC) wani farin foda ne mara wari, mara ɗanɗano, mara guba wanda za'a iya narkar da shi cikin ruwan sanyi don samar da ingantaccen bayani. Yana da halaye na thickening, dauri, dispersing, emulsifying, film-forming, suspending, adsorbing, gelling, surface aiki, rike danshi da kuma kare colloid. Saboda aikin aiki na farfajiya na maganin ruwa, ana iya amfani dashi azaman wakili mai kariya na colloidal, emulsifier da dispersant. Hydroxyethyl methylcellulose aqueous bayani yana da kyau hydrophilicity kuma shi ne ingantaccen ruwa mai riƙe da ruwa. Saboda hydroxyethyl methylcellulose ya ƙunshi ƙungiyoyin hydroxyethyl, yana da kyakkyawan ikon rigakafin ƙwayar cuta, kwanciyar hankali mai kyau da juriya na mildew yayin ajiya na dogon lokaci.

An shirya Hydroxyethyl methylcellulose (HEMC) ta hanyar gabatar da abubuwan maye gurbin ethylene oxide (MS 0.3 ~ 0.4) a cikin methylcellulose (MC), kuma juriya na gishiri ya fi na polymers da ba a canza su ba. Yawan zafin jiki na methylcellulose shima ya fi na MC.

Tsarin:

Siffa:

Babban halayen hydroxyethyl methylcellulose (HEMC) sune:

1. Solubility: Mai narkewa a cikin ruwa da wasu kaushi na halitta. Ana iya narkar da HEMC a cikin ruwan sanyi. Mafi girman maida hankalinsa ana ƙaddara ta danko ne kawai. Solubility ya bambanta da danko. Ƙananan danko, mafi girma da solubility.
2. Juriya na Gishiri: Abubuwan HEMC ba su ne ethers cellulose na ionic ba kuma ba polyelectrolytes ba, don haka suna da kwanciyar hankali a cikin mafita mai ruwa lokacin da salts na ƙarfe ko na lantarki ya kasance, amma ƙari mai yawa na electrolytes na iya haifar da gelation da hazo.
3. Ayyukan shimfidar wuri: Saboda aikin aiki na farfajiya na maganin ruwa, ana iya amfani da shi azaman wakili mai kariya na colloidal, emulsifier da dispersant.
4. Thermal gel: Lokacin da maganin ruwa na samfuran HEMC ya yi zafi zuwa wani zafin jiki, ya zama maras kyau, gels, da hazo, amma idan aka ci gaba da sanyaya shi, ya koma yanayin maganin asali, da zafin jiki wanda wannan gel da hazo Yana faruwa ne yafi Dangane da su man shafawa, suspending aids, m colloid, emulsifiers da dai sauransu.
5. Metabolism inert da rashin ƙamshi da ƙamshi: HEMC ana amfani dashi sosai a abinci da magani don ba za'a daidaita shi ba kuma yana da ƙarancin ƙamshi da ƙamshi.
6. Juriya na Mildew: HEMC yana da ingantacciyar juriya mai kyau da kwanciyar hankali mai kyau yayin ajiya na dogon lokaci.
7. PH kwanciyar hankali: Dankowar ruwa mai ruwa na samfuran HEMC ba shi da wahala acid ko alkali ya shafa, kuma ƙimar pH ba ta da ƙarfi a cikin kewayon 3.0 zuwa 11.0.

Aikace-aikace:

Hydroxyethyl methylcellulose za a iya amfani da a matsayin colloidal m wakili, emulsifier da dispersant saboda ta surface-aiki aiki a cikin ruwa bayani. Misalan aikace-aikacen sa sune kamar haka:

1. Tasirin hydroxyethyl methylcellulose akan aikin siminti. Hydroxyethyl methylcellulose wani wari ne, marar ɗanɗano, farin foda mara guba wanda za'a iya narkar da shi cikin ruwan sanyi don samar da bayani mai haske. Yana da halaye na thickening, dauri, dispersing, emulsifying, film-forming, suspending, adsorbing, gelling, surface aiki, rike danshi da kuma kare colloid. Tun da mai ruwa bayani yana da wani surface rayayye aiki, shi za a iya amfani da a matsayin colloidal m wakili, emulsifier da dispersant. Hydroxyethyl methylcellulose aqueous bayani yana da kyau hydrophilicity kuma shi ne ingantaccen ruwa mai riƙe da ruwa.
2. An shirya fenti mai taimako tare da babban sassauci, wanda aka yi da kayan albarkatu masu zuwa a sassa da nauyin nauyi: 150-200 g na ruwa mai tsabta; 60-70 g na acrylic emulsion mai tsabta; 550-650 g na alli mai nauyi; 70-90 g na talcum foda; 30-40 g tushe cellulose ruwa bayani; 10-20 g lignocellulose ruwa bayani; 4-6g taimakon samar da fim; 1.5-2.5 g na maganin antiseptik da bactericides; 1.8-2.2 g mai watsawa; 3.5-4.5 g; Ethylene glycol 9-11 g; Ana yin maganin ruwa na hydroxyethyl methylcellulose ta hanyar narkar da 2-4% hydroxyethyl methylcellulose a cikin ruwa; Ana yin maganin ruwa na lignocellulose na 1-3% Lignocellulose ana yin shi ta hanyar narkewa cikin ruwa.

Shiri:

Hanyar shiri na hydroxyethyl methylcellulose, hanyar ita ce yin amfani da auduga mai ladabi azaman albarkatun ƙasa da ethylene oxide azaman wakili na etherification don shirya hydroxyethyl methylcellulose. Matsakaicin sassa na albarkatun kasa don shirya hydroxyethyl methyl cellulose kamar haka: 700-800 sassa na toluene da isopropanol cakuda a matsayin sauran ƙarfi, 30-40 sassa na ruwa, 70-80 sassa na sodium hydroxide, 80-85 sassa na auduga mai ladabi. zobe 20-28 sassa na oxyethane, 80-90 sassa na methyl chloride, 16-19 sassa na glacial acetic acid; takamaiman matakai sune:

Mataki na farko, a cikin kettle dauki, ƙara toluene da cakuda isopropanol, ruwa, da sodium hydroxide, zafi har zuwa 60-80 ° C, dumi na minti 20-40;

Mataki na biyu, alkalization: sanyaya abubuwan da ke sama zuwa 30-50 ° C, ƙara auduga mai ladabi, fesa toluene da sauran kaushi na isopropanol, zuba shi zuwa 0.006Mpa, cika nitrogen don maye gurbin 3, sannan a aiwatar da bayan maye gurbin Alkalinization, Yanayin alkalization sune: lokacin alkalization shine sa'o'i 2, kuma yanayin zafin jiki shine 30 ° C zuwa 50 ° C;

Mataki na uku, etherification: bayan an gama alkalization, ana fitar da reactor zuwa 0.05-0.07MPa, kuma an ƙara ethylene oxide da methyl chloride na minti 30-50; mataki na farko na etherification: 40-60 ° C, 1.0-2.0 Hours, ana sarrafa matsa lamba tsakanin 0.15 da 0.3Mpa; mataki na biyu na etherification: 60～90 ℃, 2.0～2.5 hours, da matsa lamba da ake sarrafawa tsakanin 0.4 da 0.8Mpa;

Mataki na hudu, neutralization: Ƙara glacial acetic acid da aka auna a gaba a cikin kettle hazo, danna cikin kayan da aka cire don neutralization, tada zafin jiki zuwa 75-80 ° C don hazo, zafin jiki ya tashi zuwa 102 ° C, kuma pH darajar ita ce 6 A karfe 8, an gama lalatawa; tankin narkar da ruwa yana cike da ruwan famfo da na'urar osmosis na baya da aka bi da shi a 90 ° C zuwa 100 ° C;

Mataki na biyar, centrifugal wanka: kayan da ke cikin mataki na hudu an yi amfani da su ta hanyar centrifuge na kwance a kwance, kuma an canja kayan da aka raba zuwa wani tankin wanka da aka cika da ruwan zafi a gaba don wanke kayan;

Mataki na shida, bushewa na centrifugal: ana isar da kayan da aka wanke a cikin na'urar bushewa ta hanyar kwancen centrifuge a kwance, kuma an bushe kayan a 150-170 ° C, kuma busassun busassun an murƙushe su kuma an tattara su.

Idan aka kwatanta da fasahar samar da ether na cellulose, abin da aka kirkiro na yanzu yana amfani da ethylene oxide a matsayin wakili na etherification don shirya hydroxyethyl methyl cellulose, wanda yana da kyakkyawan ikon anti-mold saboda dauke da kungiyoyin hydroxyethyl. Yana da kyau danko kwanciyar hankali da mildew juriya a lokacin dogon lokacin ajiya. Ana iya amfani dashi maimakon sauran ethers cellulose.