gabatar
Cellulose ethers ne anionic ruwa-soluble polymers samu daga cellulose. Wadannan polymers suna da aikace-aikace masu yawa a cikin masana'antu daban-daban kamar abinci, magunguna, kayan shafawa, da gine-gine saboda kaddarorin su kamar su thickening, gelling, film-forming, da emulsifying. Ɗaya daga cikin mahimman kaddarorin ethers cellulose shine zafin jiki na thermal gelation (Tg), yanayin zafin da polymer ke jujjuya canjin lokaci daga sol zuwa gel. Wannan kadarorin yana da mahimmanci wajen tantance aikin ethers cellulose a aikace-aikace daban-daban. A cikin wannan labarin, mun tattauna yanayin zafin jiki na thermal gelation na hydroxypropyl methylcellulose (HPMC), daya daga cikin ethers cellulose da aka fi amfani da su a cikin masana'antu.
Thermal gelation zafin jiki na HPMC
HPMC ne Semi-Synthetic cellulose ether da aka yi amfani da ko'ina a daban-daban aikace-aikace saboda ta musamman kaddarorin. HPMC yana da narkewa sosai a cikin ruwa, yana samar da ingantattun mafita na danko a ƙananan yawa. A mafi girma da yawa, HPMC yana samar da gels waɗanda ke juyawa akan dumama da sanyaya. Gelation na thermal na HPMC tsari ne na mataki biyu wanda ya haɗa da samuwar miceles tare da tara micelles don samar da hanyar sadarwar gel (Hoto 1).
Matsakaicin zafin jiki na thermal gelation na HPMC ya dogara da dalilai da yawa kamar digiri na maye gurbin (DS), nauyin kwayoyin halitta, maida hankali, da pH na maganin. Gabaɗaya, mafi girman DS da nauyin kwayoyin halitta na HPMC, mafi girma da zafin jiki na thermal gelation. Ƙaddamar da HPMC a cikin bayani kuma yana rinjayar Tg, mafi girman ƙaddamarwa, mafi girma Tg. Hakanan pH na maganin yana rinjayar Tg, tare da maganin acidic wanda ke haifar da ƙananan Tg.
Thermal Gelation na HPMC yana da jujjuyawar kuma ana iya shafa shi ta wasu abubuwan waje daban-daban kamar ƙarfi mai ƙarfi, zafin jiki, da tattara gishiri. Shear ya karya tsarin gel kuma yana rage Tg, yayin da yawan zafin jiki ya sa gel ya narke kuma ya rage Tg. Ƙara gishiri zuwa bayani kuma yana rinjayar Tg, kuma kasancewar cations kamar calcium da magnesium yana ƙara Tg.
Aikace-aikace na daban-daban Tg HPMC
Za'a iya keɓanta halayen thermogelling na HPMC don aikace-aikace daban-daban. Ana amfani da ƙananan Tg HPMCs a aikace-aikacen da ke buƙatar saurin gelation, kamar kayan zaki nan take, miya da tsarin miya. Ana amfani da HPMC tare da babban Tg a cikin aikace-aikacen da ke buƙatar jinkiri ko tsawaita gelation, kamar tsara tsarin isar da magunguna, dorewar allunan saki, da suturar rauni.
A cikin masana'antar abinci, ana amfani da HPMC azaman thickener, stabilizer da wakili na gelling. Ana amfani da Low Tg HPMC a cikin kayan zaki nan take wanda ke buƙatar saurin gelation don samar da nau'in da ake so da kuma bakin baki. Ana amfani da HPMC tare da babban Tg a cikin ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙiba inda ake son jinkiri ko tsawaita gelation don hana syneresis da kula da tsarin yadawa.
A cikin masana'antar harhada magunguna, ana amfani da HPMC azaman mai ɗaure, tarwatsawa da ɗorewa wakili na saki. Ana amfani da HPMC tare da babban Tg a cikin samar da allunan da aka tsawaita, inda ake buƙatar jinkiri ko tsawaita gelation don sakin miyagun ƙwayoyi na tsawon lokaci. Ana amfani da Low Tg HPMC wajen samar da allunan da ke wargaza baki, inda ake buƙatar tarwatsewa da sauri don samar da jin bakin da ake so da sauƙi na haɗiye.
a karshe
Zazzaɓin zafin jiki na thermal na HPMC shine maɓalli mai mahimmanci wanda ke ƙayyade halayen sa a aikace-aikace daban-daban. HPMC na iya daidaita Tg ɗin sa ta hanyar matakin maye gurbin, nauyin kwayoyin halitta, maida hankali da ƙimar pH na maganin don dacewa da aikace-aikace daban-daban. Ana amfani da HPMC tare da ƙaramin Tg don aikace-aikacen da ke buƙatar saurin gelation, yayin da ake amfani da HPMC tare da babban Tg don aikace-aikacen da ke buƙatar jinkiri ko tsawaita gelation. HPMC ne m kuma m cellulose ether tare da yawa m aikace-aikace a daban-daban masana'antu.
Lokacin aikawa: Agusta-24-2023