IHydroxypropyl methylcellulose (HPMC) iyinhlanganisela ye-polymer encibilika emanzini esetshenziswa kabanzi kwezokwelapha, ukudla, izinto zokwakha kanye neminye imikhakha. Ngenxa yokuqina kwayo okuhle, ukwakheka kwefilimu, i-emulsifying, ukubopha nezinye izakhiwo, isetshenziswa kabanzi njenge-thickener, stabilizer kanye ne-ejenti yokumisa. Izici ze-rheological ze-HPMC, ikakhulukazi ukusebenza kwayo emazingeni okushisa ahlukene, yizici ezibalulekile ezithinta umphumela wayo wokusebenzisa.
1. Uhlolojikelele lwe-HPMC Rheological Properties
Izakhiwo ze-Rheological ziwukubonakaliswa okuphelele kokuguquguquka nezici zokugeleza kwezinto ezingaphansi kwamandla angaphandle. Okwezinto ze-polymer, i-viscosity kanye nokuziphatha kwe-shear thinning yimingcele emibili evamile ye-rheological. Izakhiwo ze-rheological ze-HPMC zithinteka kakhulu yizici ezifana nesisindo samangqamuzana, ukugxila, izakhiwo ze-solvent kanye nezinga lokushisa. Njenge-ether ye-cellulose engeyona i-ionic, i-HPMC ibonisa i-pseudoplasticity kusisombululo esinamanzi, okungukuthi, i-viscosity yayo iyancipha ngokukhula kwesilinganiso sokugunda.
2. Umthelela Wezinga lokushisa ku-HPMC Viscosity
Izinga lokushisa lingenye yezinto ezibalulekile ezithinta izakhiwo ze-rheological ze-HPMC. Njengoba izinga lokushisa likhuphuka, i-viscosity yesisombululo se-HPMC ngokuvamile iyehla. Lokhu kungenxa yokuthi ukunyuka kwezinga lokushisa kwenza buthaka ukusebenzisana kwe-hydrogen bond phakathi kwama-molecule amanzi, ngaleyo ndlela kunciphisa amandla okusebenzelana phakathi kwamaketanga e-molecular HPMC, okwenza amaketanga e-molecular abe lula ukushelela nokugeleza. Ngakho-ke, emazingeni okushisa aphezulu, izixazululo ze-HPMC zibonisa i-viscosity ephansi.
Kodwa-ke, ukuguqulwa kwe-viscosity ye-HPMC akuwona ubudlelwano bomugqa. Uma izinga lokushisa likhuphuka ngokwezinga elithile, i-HPMC ingase ibe nenqubo yokuhlakazeka-yemvula. Ku-HPMC, ubudlelwano phakathi kwe-solubility kanye nezinga lokushisa bunzima kakhulu: ngaphakathi kwebanga elithile lokushisa, i-HPMC izokwehla kusukela kusixazululo, esibonakala njengokwenyuka okubukhali kwe-viscosity yesisombululo noma ukwakheka kwejeli. Lesi simo ngokuvamile senzeka uma sisondela noma sidlula izinga lokushisa lokuqedwa le-HPMC.
3. Umthelela wezinga lokushisa ekuziphatheni kwe-rheological kwesisombululo se-HPMC
Ukuziphatha kwe-rheological kwesisombululo se-HPMC ngokuvamile kubonisa umphumela wokunciphisa i-shear, okungukuthi, i-viscosity iyancipha lapho izinga lokugunda likhuphuka. Ukushintsha kwezinga lokushisa kunomthelela omkhulu kulo mphumela wokunciphisa i-shear. Ngokuvamile, njengoba izinga lokushisa likhuphuka, i-viscosity yesisombululo se-HPMC iyancipha, futhi umphumela wayo wokunciphisa i-shear uba sobala kakhulu. Lokhu kusho ukuthi emazingeni okushisa aphezulu, i-viscosity yesisombululo se-HPMC incike kakhulu kuzinga lokugunda, okungukuthi, ngesilinganiso esifanayo se-shear, isisombululo se-HPMC ekushiseni okuphezulu sigeleza kalula kunokushisa okuphansi.
Ngaphezu kwalokho, ukwanda kwezinga lokushisa nakho kuthinta i-thixotropy yesisombululo se-HPMC. Thixotropy ibhekisela endaweni ukuthi i-viscosity yesisombululo iyancipha ngaphansi kwesenzo samandla e-shear, futhi i-viscosity ilulama kancane kancane ngemva kokususwa kwe-shear force. Ngokuvamile, ukwanda kwezinga lokushisa kuholela ekwandeni kwe-thixotropy yesisombululo se-HPMC, okungukuthi, ngemva kokususwa kwe-shear force, i-viscosity ithola kancane kancane kunezimo eziphansi zokushisa.
4. Umthelela wezinga lokushisa ekuziphatheni kwe-gelation ye-HPMC
I-HPMC inendawo eyingqayizivele ye-thermal gelation, okungukuthi, ngemva kokushisa kumazinga athile okushisa (ijeli lokushisa), isisombululo se-HPMC sizoshintsha sisuka esimweni sesixazululo siye esimweni sejeli. Le nqubo ithintwa kakhulu izinga lokushisa. Njengoba izinga lokushisa likhuphuka, ukusebenzisana phakathi kwe-hydroxypropyl kanye ne-methyl substituent kuma-molecule e-HPMC kuyanda, okuholela ekubambeni kwamaketanga amangqamuzana, ngaleyo ndlela kwakhe ijeli. Lesi simo sibaluleke kakhulu embonini yemithi neyokudla ngoba singasetshenziswa ukulungisa ukuthungwa kanye nokukhulula izakhiwo zomkhiqizo.
5. Ukusetshenziswa kanye nokubaluleka okungokoqobo
Umthelela wezinga lokushisa ezindaweni ze-rheological ze-HPMC ubaluleke kakhulu ekusebenzeni okungokoqobo. Ukuze kusetshenziswe izixazululo ze-HPMC, njengamalungiselelo okukhululwa okuqhubekayo kwezidakamizwa, izingqimba zokudla, noma izilawuli zezinto zokwakha, umphumela wokushisa ezindaweni ze-rheological kufanele ucatshangelwe ukuze kuqinisekiswe ukuzinza nokusebenza komkhiqizo ngaphansi kwezimo ezihlukene zokushisa. Isibonelo, uma ulungiselela izidakamizwa ezizwela ukushisa, umthelela wokushintsha kwezinga lokushisa ku-viscosity nokuziphatha kwe-gelation ye-matrix ye-HPMC kudinga ukucatshangelwa ukuze kukhuliswe izinga lokukhishwa kwesidakamizwa.
Izinga lokushisa linomthelela omkhulu kuzakhiwo ze-rheological ze-hydroxypropyl methylcellulose. Ukushisa okwenyuka ngokuvamile kunciphisa i-viscosity yezixazululo ze-HPMC, kuthuthukisa umphumela wayo wokunciphisa i-shear-thinning kanye ne-thixotropy, futhi kungase kubangele i-gelation eshisayo. Ekusetshenzisweni okungokoqobo, ukuqonda nokulawula umthelela wezinga lokushisa ezindaweni ze-rheological ze-HPMC kuyisihluthulelo sokuthuthukisa ukusebenza komkhiqizo kanye nemingcele yokucubungula.
Isikhathi sokuthumela: Sep-05-2024