I-Hydroxypropyl methylcellulose (HPMC) iyinto yemvelo ye-polymer esetshenziswa kakhulu ekudleni, umuthi, izimonyo kanye nezinye izinkambu. I-viscosity yayo iyinkomba ebalulekile ethinta ukusebenza kwayo, okuvame ukuhlobana kakhulu nezinto ezifana nesisindo se-hpmc, ukugxilwa kwesixazululo, uhlobo lwe-solvent kanye lokushisa.
1. Isisindo molecular
Isisindo samangqamuzana se-HPMC singesinye sezinto ezibaluleke kakhulu ezithinta ukubonakala kwalo. Ngokuvamile, ubukhulu besisindo se-molecular, isikhathi eside uchungechunge lwamangqamuzana we-HPMC, okubi kakhulu koketshezi, kanye nokuphakama okuphezulu. Lokhu kungenxa yokuthi ukwakheka kwe-macromoleklartain chain kuhlinzeka ngokuxhumana okwengeziwe, okuholele ekumisweni okunamandla olwela uketshezi lwesixazululo. Ngakho-ke, ekuhluphisweni okufanayo, izixazululo ze-HPMC ezinezinsimbi ezinkulu zamangqamuzana zivame ukubonisa ama-viscosities aphezulu.
Ukwanda kwesisindo se-molecular kuthinta nezindawo ze-viscoelastic zesisombululo. Izisombululo ze-HPMC ezinezinsimbi eziphakeme zamangqamuzana zibonisa i-viscoeliastity enamandla ngamanani aphansi we-shear, ngenkathi amanani aphezulu e-shear angaziphatha njengoketshezi lweNewtonian. Lokhu kwenza i-HPMC ibe nokuziphatha okuyinkimbinkimbi okwenziwe izimbongi ezibucayi ezimweni ezihlukile zokusebenzisa.
2. Ukuhlushwa kwesisombululo
Ukuhlushwa kwekhambi kunomthelela omkhulu ekubonakaleni kwe-HPMC. Njengoba ukugcwala kwe-HPMC kukhuphuka, ukusebenzisana phakathi kwama-molecule ku-solution kukhuphuka, okuholele ekuphikiseni ukugeleza kokugeleza okwengeziwe futhi ngaleyo ndlela kwandise ukubonakala. Ngokuvamile, ukugcwaliseka kwe-HPMC kukhombisa ukukhula okungenangqondo ngaphakathi kwebanga elithile, okungukuthi, isilinganiso lapho i-viscosity inyuka kancane kancane yehle.
Ikakhulu ezixazululweni zokuhlushwa okuphezulu, ukuxhumana phakathi kwamaketanga ama-molefanelar kunamandla, futhi izinhlaka zenethiwekhi noma i-gelation kungenzeka, ezizothuthukisa kakhulu ukubonwa kwesixazululo. Ngakho-ke, ezihlolweni zezimboni, ukuze kufezeke ukulawulwa okuhle kwe-viscosity, kuvame kuyadingeka ukulungisa i-HPMC.
3. Uhlobo lwe-solvent
I-solubity kanye ne-viscosity ye-HPMC nayo ihlobene nohlobo lwe-solvent olusetshenzisiwe. I-HPMC ivame ukusebenzisa amanzi njenge-solvent, kepha ngaphansi kwemibandela ethile, amanye ama-sol afana ne-ethanol ne-acetone angasetshenziswa. Amanzi, njenge-solvent ye-polar, angasebenzisana ngokuqinile namaqembu we-hpdroxyl kanye ne-methyl kuma-molecule we-HPMC ukukhuthaza ukuchithwa kwawo.
I-polarity ye-solvent, izinga lokushisa, kanye nokuxhumana phakathi kwe-solvent kanye nama-molecule we-HPMC azothinta i-solubity kanye ne-viscosity ye-HPMC. Isibonelo, lapho kusetshenziswa i-solvent ephansi ye-polarity, i-solubility ye-HPMC iyancipha, okuholela ekubonakaleni okuphansi kwesisombululo.
4. Ukushisa
Umphumela wokushisa kokuvulelwa kwe-viscosity ye-HPMC futhi ubaluleke kakhulu. Ngokuvamile, ukubonakala kwesisombululo se-HPMC kunciphisa izinga lokushisa elikhulayo. Lokhu kungenxa yokuthi lapho izinga lokushisa likhuphuka, ukunyakaza kwe-molecular okushisayo kukhuphuka, okuholela ekutheni kube buthaka ngamandla okusebenzisana phakathi kwama-molecule, ngaleyo ndlela kunciphise ukubonwa.
Kumazinga athile okushisa, izakhiwo zesisombululo se-HPMC zibonisa indlela yokuziphatha ecace kakhudlwana, okungukuthi, i-viscosity ayithinteki kuphela yizinga le-shear, kepha futhi zithinteka kakhulu ngezinguquko zokushisa. Ngakho-ke, kuzinhlelo zokusebenza ezisebenzayo, izinguquko zokushisa zokulawula zingenye yezindlela ezisebenzayo zokuguqula i-viscosic ye-HPMC.
5. I-Shear isilinganiso
I-viscosity yesixazululo se-HPMC ayithinteki kuphela yizici ezi-static, kodwa futhi ngesilinganiso se-shear. I-HPMC iyi-fluid engeyona neyeNewtonian, futhi i-viscosity yayo ishintsha ngokushintsha kwesilinganiso se-Shear. Ngokuvamile, isixazululo se-HPMC sibonisa ukubonakala okuphezulu ezindaweni eziphansi ze-shear, ngenkathi i-visa inciphisa kakhulu kumanani aphezulu we-shear. Le nto ibizwa ngokuthi yi-shear conning.
Umphumela wezinga le-Shear ekubonakaleni kwesisombululo se-HPMC ngokuvamile kuhlobene nokuziphatha kwamaketanga amamolekyuli. Emazingeni aphansi we-shear, amaketanga amangqamuzana athambekele ekubambeni ndawonye, okuholele ekubonakaleni okuphezulu; Emazingeni aphezulu e-shear, ukuxhumana phakathi kwamaketanga amangqamuzana aphukile futhi i-viscosity iphansi.
6 Inani le-PH
I-Viscosity ye-HPMC nayo ihlobene nenani le-PH lekhambi. Ama-molecule we-HPMC aqukethe ama-hydroxyproppropyl aguqukayo kanye namaqembu we-methyl, kanti isimo senkokhiso salawa maqembu siyathinteka kuPh. Kwezinye izindlela ze-PH, ama-molecule we-HPMC angahle afune ama-gels, ngaleyo ndlela eshintsha i-viscosity yesisombululo.
Ngokuvamile, ezindaweni ezi-acidic noma ze-alkali, ukwakheka kwe-HPMC kungashintsha, kuthinte ukuxhumana kwayo ngama-molecule e-solvent futhi, nakho, okuthinta ukubonana. Kumanani ahlukene we-PH, ukuqina kanye nokuqina kwezixazululo ze-HPMC nakho kungahluka, ngakho-ke ukunakwa okukhethekile kufanele kukhokhwe kulawulo lwe-PH ngenkathi lusetshenziswa.
7. Umphumela Wezengezo
Ngaphezu kwalezi zinto ezingenhla, izengezo ezithile ezifana nosawoti kanye nama-surfactants kungathinta nokubonakala kwe-HPMC. Ukungezwa kosawoti kuvame ukuguqula amandla we-ionic wesisombululo, ngaleyo ndlela kuthinte ukugcwala kanye nokubonakaliswa kwama-molecule we-HPMC. Ama-surfactants angashintsha ukwakheka kwamangqamuzana kwe-HPMC ngokushintsha ukuxhumana phakathi kwama-molecule, ngaleyo ndlela eshintsha ukubonakala kwawo.
I-viscosity ye-HPMC ithintekile yizici eziningi, kufaka phakathi isisindo samangqamuzana, ukugxila kwesixazululo, uhlobo lwe-solvent, izinga lokushisa, izinga lokushisa, inani le-shear, i-pH. Ukuze ulawule izici ze-viscosity ze-HPMC, lezi zinto zidinga ukulungiswa kahle ngokuya ngezidingo zangempela zohlelo lokusebenza. Ngokuqonda lezi zinto ezinethonya, ukusebenza kwe-HPMC kungenziwa kwenziwe kahle ekukhiqizeni okuhlukile nasezimweni zokusetshenziswa ukuze kuqinisekiswe ukuqina nokusebenza kwayo ezinhlelweni ezahlukahlukene.
Isikhathi sePosi: Feb-15-2025