ethula
Ama-cellulose ether ama-polymers ancibilika emanzini a-anionic asuselwa ku-cellulose. Lawa ma-polymers anezicelo eziningi ezimbonini ezahlukahlukene ezifana nezokudla, ezemithi, izimonyo, nezokwakha ngenxa yezakhiwo zazo ezinjengokuqina, i-gelling, ukwenza amafilimu, kanye nokufaka i-emulsifying. Esinye sezici ezibaluleke kakhulu ze-cellulose ethers ukushisa kwazo kwe-thermal gelation (Tg), izinga lokushisa lapho i-polymer ingena khona ukuguquka kwesigaba kusuka ku-sol kuya kujeli. Lesi sakhiwo sibalulekile ekunqumeni ukusebenza kwama-cellulose ethers ezinhlelweni ezahlukene. Kulesi sihloko, sixoxa ngezinga lokushisa elishisayo le-gelation ye-hydroxypropyl methylcellulose (HPMC), enye ye-cellulose ethers esetshenziswa kakhulu embonini.
I-Thermal Gelation Temperature ye-HPMC
I-HPMC iyi-semi-synthetic cellulose ether esetshenziswa kabanzi ezinhlelweni ezihlukene ngenxa yezakhiwo zayo ezihlukile. I-HPMC incibilika kakhulu emanzini, yakha izixazululo ze-viscous ezicacile ekugxilweni okuphansi. Ezimweni eziphakeme, i-HPMC yenza amajeli ashintshekayo lapho kushiswa futhi kupholiswa. I-Thermal Gelation ye-HPMC iyisinyathelo esinezinyathelo ezimbili ezibandakanya ukwakheka kwama-micelles okulandelwa ukuhlanganiswa kwama-micelles ukwenza inethiwekhi yejeli (Umfanekiso 1).
Izinga lokushisa elishisayo le-gelation ye-HPMC lincike ezintweni ezimbalwa ezifana ne-degree of substitution (DS), isisindo samangqamuzana, ukugxilisa ingqondo, kanye ne-pH yesixazululo. Ngokuvamile, ukuphakama kwe-DS nesisindo samangqamuzana e-HPMC, izinga lokushisa elishisayo le-gelation liphezulu. Ukugxiliswa kwe-HPMC esixazululweni kuphinde kuthinte i-Tg, uma i-concentration iphezulu, iphezulu i-Tg. I-pH yesisombululo iphinde ithinte i-Tg, enezixazululo ezine-asidi eziholela ekunciphiseni kwe-Tg.
I-Thermal Gelation ye-HPMC iyabuyiseleka emuva futhi ingathinteka yizici ezihlukahlukene zangaphandle ezifana ne-shear force, izinga lokushisa, nokugxila kukasawoti. I-Shear iphula isakhiwo sejeli futhi yehlise i-Tg, kuyilapho izinga lokushisa elikhulayo libangela ukuthi ijeli lincibilike futhi lehlise i-Tg. Ukufaka usawoti esixazululweni nakho kuthinta i-Tg, futhi ukuba khona kwama-cations afana ne-calcium ne-magnesium kwandisa i-Tg.
Ukusetshenziswa kwe-Tg HPMC ehlukene
Ukuziphatha kwe-thermogelling kwe-HPMC kungahlelelwa izinhlelo zokusebenza ezahlukene. I-Low Tg HPMCs isetshenziswa ezinhlelweni ezidinga i-gelation esheshayo, njenge-dessert esheshayo, i-sauce ne-soup formulations. I-HPMC ene-Tg ephezulu isetshenziswa ezinhlelweni ezidinga ukulibaziseka noma ukugezwa isikhathi eside, njengokwakhiwa kwamasistimu okulethwa kwezidakamizwa, amaphilisi okukhululwa okuqhubekayo, namanxeba amanxeba.
Embonini yokudla, i-HPMC isetshenziswa njenge-thickener, stabilizer kanye ne-ejenti yokugaya. I-Low Tg HPMC isetshenziswa ekwenziweni kophudingi osheshayo okudinga ukugezwa ngokushesha ukuze kuhlinzekwe ukuthungwa okufunwayo kanye nokuzwakala komlomo. I-HPMC ene-Tg ephezulu isetshenziswa ekwakhiweni kokusatshalaliswa kwamafutha aphansi lapho i-gelation ebambezelekile noma enwetshiwe ifunwa ukuvimbela i-synersis nokugcina ukwakheka kokusabalalisa.
Embonini yezemithi, i-HPMC isetshenziswa njenge-binder, disintegrant kanye ne-ejenti yokukhululwa eqhubekayo. I-HPMC ene-Tg ephezulu isetshenziswa ekwakhiweni kwamaphilisi okukhishwa okunwetshiwe, lapho i-gelation ebambezelekile noma enwetshiwe idingeka ukuze kukhululwe umuthi isikhathi eside. I-Low Tg HPMC isetshenziswa ekwakhiweni kwamaphilisi ahlakazeka ngomlomo, lapho ukuhlakazeka okusheshayo kanye ne-gelation kuyadingeka ukuze kuhlinzekwe ukuzwa komlomo okufunayo kanye nokugwinya kalula.
Ekuphetheni
Izinga lokushisa elishisayo le-gelation le-HPMC liyindawo eyinhloko enquma ukuziphatha kwayo ezinhlelweni ezihlukahlukene. I-HPMC ingalungisa i-Tg yayo ngezinga lokushintsha, isisindo samangqamuzana, ukugxilisa ingqondo kanye nenani le-pH lesixazululo ukuze livumelane nezinhlelo zokusebenza ezahlukene. I-HPMC ene-Tg ephansi isetshenziselwa izinhlelo zokusebenza ezidinga i-gelation esheshayo, kuyilapho i-HPMC ene-Tg ephezulu isetshenziselwa izinhlelo zokusebenza ezidinga ukulibaziseka noma ukugezwa isikhathi eside. I-HPMC iyi-ether ye-cellulose eguquguqukayo enemisebenzi eminingi engase ibe khona ezimbonini ezihlukahlukene.
Isikhathi sokuthumela: Aug-24-2023