IHydroxypropylmethylcellulose (HPMC) iyinhlanganisela esiphenduke into esemqoka ezimbonini eziningi ngenxa yemisebenzi yayo eminingi. Ngokuvamile isetshenziswa njengesengezo sokudla, i-thickener ezimonyoni, ngisho nesithako sezokwelapha emithini eminingi. Impahla eyingqayizivele ye-HPMC ukuziphatha kwayo kwe-thixotropic, okuyivumela ukuthi iguqule izakhiwo ze-viscosity kanye nokugeleza ngaphansi kwezimo ezithile. Ngaphezu kwalokho, kokubili i-high-viscosity ne-low-viscosity HPMC inale ndawo, ebonisa i-thixotropy ngisho nangaphansi kwezinga lokushisa lejeli.
Thixotropy yenzeka ku-HPMC lapho isixazululo siba sigundi lapho kusetshenziswa ingcindezi noma inyakaziswa, okuholela ekwehleni kwe-viscosity. Lokhu kuziphatha kungabuye kuguqulwe; lapho ukucindezeleka kususwa futhi isisombululo sishiywe ukuze siphumule, i-viscosity ibuyela kancane kancane esimweni sayo esiphakeme. Lesi sakhiwo esiyingqayizivele senza i-HPMC ibe ingxenye ebalulekile ezimbonini eziningi njengoba ivumela ukusetshenziswa okushelelayo nokucubungula kalula.
Njenge-nonionic hydrocolloid, i-HPMC ikhukhumala emanzini ukuze yakhe ijeli. Izinga lokuvuvukala kanye ne-gelling lincike esisindweni samangqamuzana nokugxila kwe-polymer, i-pH kanye nezinga lokushisa lesisombululo. I-viscosity ephezulu I-HPMC ivamise ukuba nesisindo semolekyuli ephezulu futhi ikhiqiza ijeli ye-viscosity ephezulu, kuyilapho i-viscosity ephansi i-HPMC inesisindo esiphansi samangqamuzana futhi ikhiqiza ijeli ye-viscous encane. Nokho, naphezu kwalo mehluko ekusebenzeni, zombili izinhlobo ze-HPMC zibonisa i-thixotropy ngenxa yezinguquko zesakhiwo ezenzeka ezingeni lamangqamuzana.
Ukuziphatha kwe-thixotropic kwe-HPMC kuwumphumela wokuqondanisa kwamaketanga e-polymer ngenxa yengcindezi yokushear. Lapho ukucindezeleka kwe-shear kusetshenziswa ku-HPMC, amaketanga e-polymer aqondana nokuqondisa kokucindezeleka okusetshenzisiwe, okuholela ekubhujisweni kwesakhiwo senethiwekhi ye-three-dimensional eyayikhona ngaphandle kokucindezeleka. Ukuphazamiseka kwenethiwekhi kubangela ukuncipha kwe-viscosity yesixazululo. Lapho ukucindezeleka kususwa, amaketanga e-polymer ahlela kabusha ngokuma kwawo kwasekuqaleni, akhe kabusha inethiwekhi futhi abuyisele i-viscosity.
I-HPMC iphinde ibonise i-thixotropy ngaphansi kwezinga lokushisa le-gelling. Izinga lokushisa lejeli izinga lokushisa lapho amaketanga e-polymer enqamula khona ukuze akhe inethiwekhi enezinhlangothi ezintathu, akha ijeli. Kuncike ekugxilweni, isisindo samangqamuzana kanye ne-pH yesisombululo se-polymer. I-gel ephumela ine-viscosity ephezulu futhi ayishintshi ngokushesha ngaphansi kwengcindezi. Kodwa-ke, ngaphansi kwezinga lokushisa le-gelation, isixazululo se-HPMC sahlala siwuketshezi, kodwa sisabonisa ukuziphatha kwe-thixotropic ngenxa yokuba khona kwesakhiwo senethiwekhi esakhiwe kancane. Inethiwekhi eyakhiwe yilezi zingxenye idiliza ngaphansi kwengcindezi, okuholela ekunciphiseni kwe-viscosity. Lokhu kuziphatha kunenzuzo ezinhlelweni eziningi lapho izixazululo zidinga ukugeleza kalula uma zinyakaziswa.
I-HPMC iyikhemikhali eguquguqukayo enezici ezimbalwa ezihlukile, enye yazo ukuziphatha kwayo kwe-thixotropic. Kokubili ama-HPMC ane-viscosity ephezulu kanye ne-low-viscosity analesi sakhiwo, abonisa i-thixotropy ngisho nangaphansi kwezinga lokushisa lejeli. Lesi sici senza i-HPMC ibe ingxenye ebalulekile ezimbonini eziningi ezidinga izixazululo eziphatha ukugeleza okulula ukuze kuqinisekiswe ukusetshenziswa okubushelelezi. Naphezu komehluko wezakhiwo phakathi kwama-HPMC ane-viscosity ephezulu kanye ne-low-viscosity, ukuziphatha kwawo kwe-thixotropic kwenzeka ngenxa yokuqondanisa nokuphazamiseka kwesakhiwo senethiwekhi esakheke kancane. Ngenxa yezakhiwo zayo eziyingqayizivele, abacwaningi bahlala behlola izinhlelo zokusebenza ezihlukahlukene ze-HPMC, benethemba lokudala imikhiqizo emisha futhi banikeze izixazululo ezingcono kubathengi emhlabeni jikelele.
Isikhathi sokuthumela: Aug-23-2023