Focus on Cellulose ethers

Abubuwan sinadarai da haɗin gwiwar hydroxypropyl methylcellulose (HMPC)

Hydroxypropyl methylcellulose (HPMC) polymer roba ne wanda aka samo daga cellulose kuma ana amfani dashi azaman mai kauri, emulsifier, da stabilizer a masana'antu daban-daban kamar abinci, magunguna, da kayan kwalliya. HMPC wani nau'in hydroxypropylated ne na methylcellulose (MC), ether nonionic cellulose ether mai narkewa da ruwa wanda ya ƙunshi raka'o'in cellulose methoxylated da hydroxypropylated. Ana amfani da HMPC ko'ina azaman abin haɓakawa a cikin samfuran magunguna saboda rashin guba, rashin daidaituwa, da haɓakar halittu.

HMPC sinadaran Properties:

Abubuwan sinadarai na HMPC ana danganta su da kasancewar hydroxyl da ƙungiyoyin ether a cikin tsarin kwayoyin halitta. Ƙungiyoyin hydroxyl na cellulose za a iya aiki ta hanyar halayen sinadarai daban-daban, irin su etherification, esterification, da oxidation, don gabatar da ƙungiyoyi masu aiki daban-daban a cikin kashin baya na polymer. HMPC ya ƙunshi duka methoxy (-OCH3) da hydroxypropyl (-OCH2CHOHCH3) ƙungiyoyi, waɗanda za a iya sarrafawa don samar da kaddarorin daban-daban kamar solubility, danko da gelation.

HMPC yana da narkewa sosai a cikin ruwa, yana samar da bayyane, mafita mai ɗanɗano a ƙananan ƙima. Ana iya canza dankowar hanyoyin HMPC ta hanyar daidaita ma'aunin canji (DS) na ƙungiyoyin hydroxypropyl, wanda ke ƙayyade adadin wuraren da aka gyara hydroxyl a kowace naúrar glucose. Mafi girma da DS, ƙananan solubility kuma mafi girma da danko na HMPC bayani. Ana iya amfani da wannan kadarar don sarrafa sakin kayan aiki masu aiki daga magungunan magunguna.

HMPC kuma yana nuna halayen pseudoplastic, ma'ana cewa danko yana raguwa tare da haɓaka ƙimar ƙarfi. Wannan kadarar ta sa ta dace a matsayin mai kauri don ƙirar ruwa waɗanda ke buƙatar jure wa ƙarfin ƙarfi yayin aiki ko aikace-aikace.

HMPC yana da ƙarfi da ƙarfi har zuwa takamaiman zafin jiki, wanda ya fara raguwa. Zazzaɓin lalacewa na HMPC ya dogara da DS da ƙaddamarwar polymer a cikin bayani. An ba da rahoton kewayon ƙarancin zafin jiki na HMPC zuwa 190-330 ° C.

Tsarin HMPC:

HMPC an haɗa shi ta hanyar etherification dauki na cellulose tare da propylene oxide da methylethylene oxide a gaban wani alkaline mai kara kuzari. Halin yana faruwa a matakai biyu: na farko, ƙungiyoyin methyl na cellulose ana maye gurbinsu da propylene oxide, sa'an nan kuma ƙungiyoyin hydroxyl suna ƙara maye gurbinsu da methyl ethylene oxide. Ana iya sarrafa DS na HMPC ta hanyar daidaita ma'aunin molar propylene oxide zuwa cellulose yayin aikin haɗin gwiwa.

Yawanci ana yin maganin a cikin matsakaiciyar ruwa a matsanancin zafin jiki da matsa lamba. Ainihin mai kara kuzari yawanci sodium ko potassium hydroxide, wanda ke haɓaka reactivity na ƙungiyoyin cellulose hydroxyl zuwa ga zoben epoxide na propylene oxide da methylethylene oxide. Sa'an nan samfurin amsawa yana baci, wanke da bushe don samun samfurin HMPC na ƙarshe.

Hakanan ana iya haɗa HMPC ta hanyar amsa cellulose tare da propylene oxide da epichlorohydrin a gaban abubuwan haɓaka acid. Ana amfani da wannan hanyar, wanda aka sani da tsarin epichlorohydrin, don samar da abubuwan da suka samo asali na cellulose na cationic, waɗanda aka yi cajin gaske saboda kasancewar ƙungiyoyin ammonium quaternary.

a ƙarshe:

HMPC shine polymer multifunctional tare da kyawawan kaddarorin sinadarai masu dacewa da aikace-aikace daban-daban a cikin masana'antu daban-daban. Haɗin HMPC ya haɗa da amsawar etherification na cellulose tare da propylene oxide da methylethylene oxide a gaban alkaline mai kara kuzari ko mai kara kuzari. Ana iya daidaita kaddarorin HMPC ta hanyar sarrafa DS da maida hankali na polymer. Aminci da daidaituwar halittu na HMPC sun sa ya zama kyakkyawan zaɓi don ƙirar magunguna.


Lokacin aikawa: Satumba 18-2023
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