Mayar da hankali kan ethers cellulose

Menene albarkatun kasa na hydroxypropyl methylcellulose (HPMC)

Hydroxypropyl methylcellulose (HPMC) wani muhimmin fili ne na ether cellulose na roba, wanda aka yi amfani dashi sosai a magani, kayan gini, abinci, sutura da sauran masana'antu. HPMC yana da mai kyau thickening, emulsification, film-forming, moisturizing, karfafawa da sauran kaddarorin, don haka yana da muhimmanci aikace-aikace darajar a da yawa filayen. Babban albarkatun kasa don samar da HPMC sun haɗa da cellulose, sodium hydroxide, propylene oxide, methyl chloride da ruwa.

1. Cellulose

Cellulose shine babban kayan asali na HPMC, yawanci ana samun su daga filayen shuka na halitta kamar auduga da itace. Cellulose shine mafi yawan nau'in polymer kwayoyin halitta a duniya. Tsarin kwayoyin halittarsa ​​shine polysaccharide mai tsayi mai tsayi wanda ya ƙunshi raka'o'in glucose wanda aka haɗa ta β-1,4-glycosidic bonds. Ita kanta Cellulose ba ta iya narkewa a cikin ruwa kuma ba ta da kyakkyawar amsawar sinadarai. Sabili da haka, ana buƙatar jerin hanyoyin gyare-gyaren sinadarai don haɓaka solubility da aiki don shirya samfuran ether na cellulose daban-daban.

2. Sodium hydroxide (NaOH)

Sodium hydroxide, wanda kuma aka sani da soda caustic, wani abu ne mai karfi na alkaline wanda ke taka muhimmiyar rawa a matsayin alkalizer a cikin samar da tsarin HPMC. A farkon matakin samarwa, cellulose yana amsawa tare da maganin sodium hydroxide don kunna ƙungiyoyin hydroxyl akan sarkar kwayoyin halitta ta cellulose, ta haka ne ke samar da wuraren amsawa don amsawar etherification na gaba. Wannan matakin kuma ana kiransa “alalization reaction”. Alkalized cellulose yana fuskantar wasu sauye-sauye na tsari, yana sauƙaƙa amsawa tare da reagents na sinadarai na gaba (kamar propylene oxide da methyl chloride).

3. Propylene oxide (C3H6O)

Propylene oxide yana ɗaya daga cikin maɓalli na etherifying a cikin samar da HPMC, galibi ana amfani dashi don canza ƙungiyoyin hydroxyl a cikin cellulose zuwa ƙungiyoyin hydroxypropyl. Musamman, cellulose alkalized yana amsawa tare da propylene oxide a ƙarƙashin wasu yanayin zafi da matsa lamba, kuma ƙungiyoyin epoxy masu aiki a cikin propylene oxide suna haɗe da sarkar kwayar halitta ta cellulose ta hanyar ƙarin amsawar buɗewa don samar da madadin hydroxypropyl. Wannan tsari yana ba HPMC kyakkyawar narkewar ruwa da iya yin kauri.

4. Methyl chloride (CH3Cl)

Methyl chloride wani muhimmin ma'anar etherifying da ake amfani da shi don canza ƙungiyoyin hydroxyl na cellulose zuwa ƙungiyoyin metoxyl. Methyl chloride yana amsawa tare da ƙungiyoyin hydroxyl akan sarkar kwayar halitta ta cellulose ta hanyar maye gurbin nucleophilic don samar da methyl cellulose. Ta hanyar wannan methylation dauki, HPMC samun mai kyau hydrophobicity, musamman nuna m solubility a wasu kwayoyin kaushi. Bugu da ƙari, ƙaddamar da ƙungiyoyin methoxy yana ƙara inganta kayan samar da fina-finai da kwanciyar hankali na sinadarai na HPMC.

5. Ruwa

Ruwa, a matsayin mai narkewa da matsakaiciyar amsawa, yana gudana ta cikin dukkan tsarin samarwa na HPMC. A cikin alkalization da etherification halayen, ruwa ba kawai yana taimakawa wajen narkar da sodium hydroxide da daidaita yanayin hydration na cellulose ba, amma kuma yana shiga cikin tsarin yanayin zafi don tabbatar da kula da zafin jiki a duk lokacin da ake aiwatarwa. Tsabtataccen ruwa yana da tasiri mai mahimmanci akan ingancin HPMC, kuma ana buƙatar ruwa mai tsabta mai tsabta ko ruwa mai tsabta.

6. Organic kaushi

A cikin tsarin samarwa na HPMC, wasu matakan tsari na iya buƙatar amfani da wasu kaushi na halitta, kamar methanol ko ethanol. Ana amfani da waɗannan kaushi a wasu lokuta don daidaita danko na tsarin amsawa, rage samuwar abubuwan da aka samu, ko haɓaka takamaiman halayen sinadarai. Zaɓin ƙauyen ƙwayoyin cuta yana buƙatar ƙaddara gwargwadon bukatun tsarin samarwa da aikace-aikacen samfurin ƙarshe.

7. Sauran kayan taimako

Baya ga manyan albarkatun ƙasa na sama, a cikin ainihin tsarin samarwa, ana iya amfani da wasu kayan taimako da ƙari, irin su masu haɓakawa, stabilizers, da sauransu, don haɓaka haɓakar halayen halayen, sarrafa ƙimar amsawa ko haɓaka kaddarorin jiki da sinadarai. na samfurin ƙarshe.

8. Babban matakai na tsarin samarwa

Babban matakan tsari don samar da HPMC za a iya raba kashi uku: alkalization, etherification da neutralization magani. Na farko, cellulose yana amsawa tare da sodium hydroxide zuwa alkalize don samar da alkali cellulose. Sa'an nan, etherification yana faruwa a cikin amsawar alkali cellulose tare da propylene oxide da methyl chloride don samar da hydroxypropyl da methoxy maye gurbin cellulose ethers. A ƙarshe, ta hanyar neutralization magani, wanke, bushewa da sauran matakai, HPMC kayayyakin da takamaiman solubility, danko da sauran halaye ana samun.

9. Sakamakon ingancin albarkatun kasa akan aikin samfuran HPMC

Daban-daban tushen albarkatun kasa da tsabta suna da tasiri mai mahimmanci akan inganci da aikin HPMC na ƙarshe. Alal misali, tsabta da nauyin nauyin kwayoyin halitta na kayan albarkatun cellulose zai shafi danko da solubility na HPMC; Matsakaicin sashi da yanayin halayen propylene oxide da methyl chloride zai ƙayyade matakin hydroxypropyl da maye gurbin methoxy, don haka yana shafar tasirin kauri da kaddarorin samar da fim na samfurin. Sabili da haka, zaɓi da kula da ingancin albarkatun ƙasa suna da mahimmanci yayin aikin samarwa.

Babban albarkatun kasa na hydroxypropyl methylcellulose (HPMC) sun hada da cellulose, sodium hydroxide, propylene oxide, methyl chloride da ruwa. Ta hanyar jerin hadaddun halayen sinadarai, waɗannan albarkatun ƙasa ana canza su zuwa kayan aiki tare da fa'idar ƙimar aikace-aikacen. Kewayon aikace-aikacen HPMC ya ƙunshi fannoni da yawa kamar magani, kayan gini, da abinci. Kyawawan halayensa na zahiri da sinadarai sun sa ya zama dole a masana'antu da yawa.


Lokacin aikawa: Satumba-30-2024
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