I-Hydroxypropyl methylcellulose (HPMC) iyinhlanganisela ye-polymer engeyona i-ionic emanzini etholakala ngokuguqulwa kwamakhemikhali kwe-cellulose yemvelo. Isetshenziswa kabanzi ezimbonini zokudla, zemithi, zezimonyo kanye nezokwakha, ikakhulukazi njenge-adhesive, thickener, emulsifier kanye ne-ejenti yokumisa ekulungiseleleni imithi. Enqubweni yokufaka isicelo, izici ze-viscosity zesisombululo samanzi se-HPMC zibalulekile ekusebenzeni kwayo emikhakheni ehlukene.
1. Isakhiwo kanye nezakhiwo ze-hydroxypropyl methylcellulose
Isakhiwo samangqamuzana e-HPMC siqukethe amaqembu amabili abambele, i-hydroxypropyl (-CH₂CHOHCH₃) kanye ne-methyl (-OCH₃), okwenza kube nokuncibilika okuhle kwamanzi kanye nekhono lokuguqula. Iketango lamangqamuzana e-HPMC linesakhiwo esithile esiqinile, kodwa futhi lingakha isakhiwo senethiwekhi esinezinhlangothi ezintathu esixazululweni esinamanzi, okuholela ekwandeni kwe-viscosity. Isisindo sayo samangqamuzana, uhlobo lokuthatha indawo kanye nezinga lokushintsha (okungukuthi, izinga le-hydroxypropyl kanye nokushintshwa kwe-methyl kweyunithi ngayinye) kunethonya elibalulekile ku-viscosity yesixazululo.
2. Izici ze-viscosity zesisombululo esinamanzi
Izici ze-viscosity zesisombululo samanzi se-HPMC zihlobene eduze nezici ezifana nokugxilisa ingqondo, isisindo samangqamuzana, izinga lokushisa kanye nenani le-pH le-solvent. Ngokuvamile, i-viscosity yesisombululo samanzi se-HPMC iyanda ngokukhula kokugxila kwayo. I-viscosity yayo ibonisa ukuziphatha okungezona kwe-Newtonian rheological, okungukuthi, njengoba izinga le-shear likhula, i-viscosity yesisombululo iyancipha kancane kancane, ikhombisa isenzakalo sokunciphisa i-shear.
(1) Umphumela wokugxilisa ingqondo
Kunobudlelwano obuthile phakathi kwe-viscosity yesisombululo samanzi se-HPMC nokugxila kwayo. Njengoba ukugxila kwe-HPMC kwanda, ukusebenzisana kwamangqamuzana esixazululweni se-aqueous kuyathuthukiswa, futhi ukubopha nokuxhumanisa kwamaketanga amangqamuzana kwanda, okuholela ekwandeni kwe-viscosity yesisombululo. Emazingeni aphansi, i-viscosity yesisombululo se-aqueous se-HPMC ikhula ngokuhambisana nokwanda kokugxila, kodwa ekugxilweni okuphezulu, ukukhula kwe-viscosity yesisombululo kuvame ukuba isicaba futhi kufinyelele inani elizinzile.
(2) Umphumela wesisindo samangqamuzana
Isisindo samangqamuzana e-HPMC sithinta ngqo i-viscosity yesisombululo sayo esinamanzi. I-HPMC enesisindo esiphezulu samangqamuzana inamaketanga amangqamuzana amade futhi ingakha isakhiwo senethiwekhi esinezinhlangothi ezintathu esiyinkimbinkimbi esixazululweni samanzi, okuholela ekubonakaleni okuphezulu. Ngokuphambene, i-HPMC enesisindo esiphansi samangqamuzana inesakhiwo senethiwekhi esixegayo kanye ne-viscosity ephansi ngenxa yamaketanga ayo amangqamuzana amafushane. Ngakho-ke, uma ufaka isicelo, kubaluleke kakhulu ukukhetha i-HPMC enesisindo esifanelekile samangqamuzana ukuze kuzuzwe umphumela omuhle we-viscosity.
(3) Umphumela wezinga lokushisa
Izinga lokushisa liyisici esibalulekile esithinta i-viscosity yesisombululo samanzi se-HPMC. Njengoba izinga lokushisa likhuphuka, ukunyakaza kwama-molecule amanzi kuyaqina futhi i-viscosity yesisombululo ngokuvamile iyancipha. Lokhu kungenxa yokuthi lapho izinga lokushisa likhuphuka, inkululeko yochungechunge lwamangqamuzana e-HPMC iyanda futhi ukuxhumana phakathi kwama-molecule kuba buthaka, ngaleyo ndlela kunciphisa i-viscosity yesisombululo. Kodwa-ke, impendulo ye-HPMC evela kumaqoqo ahlukene noma izinhlobo zohlobo lokushisa nayo ingahluka, ngakho-ke izimo zokushisa zidinga ukulungiswa ngokuya ngezidingo ezithile zohlelo lokusebenza.
(4) Umthelela yenani le-pH
I-HPMC ngokwayo iyinhlanganisela engeyona i-ionic, futhi i-viscosity yesisombululo sayo se-aqueous izwela izinguquko ku-pH. Nakuba i-HPMC ibonisa izici ze-viscosity ezinzile uma kuqhathaniswa ezindaweni ezine-acidic noma ezingathathi hlangothi, ukunyibilika kanye ne-viscosity ye-HPMC kuzothinteka ezindaweni ezine-acidic ngokwedlulele noma ezine-alkali. Isibonelo, ngaphansi kwe-asidi eqinile noma izimo ze-alkaline ezinamandla, ama-molecule e-HPMC angase onakaliswe kancane, ngaleyo ndlela ehlise i-viscosity yesisombululo sayo esinamanzi.
3. Ukuhlaziywa kwe-Rheological of viscosity izici ze-HPMC isixazululo samanzi
Ukuziphatha kwe-rheological kwesisombululo samanzi se-HPMC ngokuvamile kubonisa izici ezingezona ze-Newtonian fluid, okusho ukuthi i-viscosity yayo ayihlobene nje nezici ezifana nokuhlushwa kwesisombululo kanye nesisindo samangqamuzana, kodwa futhi nesilinganiso se-shear. Ngokuvamile, ngamanani aphansi we-shear, isixazululo samanzi se-HPMC sibonisa i-viscosity ephakeme, kuyilapho izinga lokugunda likhuphuka, i-viscosity iyancipha. Lokhu kuziphatha kubizwa ngokuthi "ukugunda phuca" noma "ukugunda ukugunda" futhi kubaluleke kakhulu ekusebenzeni okuningi okusebenzayo. Isibonelo, emikhakheni yezingubo zokugqoka, ukulungiswa kwemithi, ukucubungula ukudla, njll., izici ze-shear thinning ze-HPMC zingaqinisekisa ukuthi i-viscosity ephezulu igcinwa ngesikhathi sezicelo zejubane eliphansi, futhi ingageleza kalula ngaphansi kwezimo ze-shear zesivinini esikhulu.
4. Ezinye izici ezithinta i-viscosity yesisombululo samanzi se-HPMC
(1) Umphumela kasawoti
Ukwengezwa kwezixube zikasawoti (njenge-sodium chloride) kungakhuphula i-viscosity yesisombululo samanzi se-HPMC. Lokhu kungenxa yokuthi usawoti ungathuthukisa ukusebenzisana phakathi kwama-molecule ngokushintsha amandla e-ionic esixazululo, ukuze ama-molecule e-HPMC akhe isakhiwo senethiwekhi esihlangene, ngaleyo ndlela andise i-viscosity. Kodwa-ke, umphumela wohlobo lukasawoti kanye nokugxila ku-viscosity nakho kudinga ukulungiswa ngokuya ngezimo ezithile.
(2) Umthelela wezinye izithasiselo
Ukwengeza ezinye izithasiselo (njengama-surfactants, ama-polymers, njll.) kusixazululo samanzi se-HPMC nakho kuzothinta i-viscosity. Isibonelo, ama-surfactants anganciphisa i-viscosity ye-HPMC, ikakhulukazi uma ukugxiliswa kwe-surfactant kuphezulu. Ngaphezu kwalokho, ama-polymers athile noma izinhlayiya zingaphinde zihlanganyele ne-HPMC futhi ziguqule izakhiwo ze-rheological zesisombululo sayo.
Izici ze-viscosity zei-hydroxypropyl methylcellulose isixazululo esinamanzi sithintwa izici eziningi, okuhlanganisa ukugxilisa ingqondo, isisindo samangqamuzana, izinga lokushisa, inani le-pH, njll. Isixazululo samanzi se-HPMC ngokuvamile sibonisa izakhiwo ze-rheological ezingezona ze-Newtonian, sinezakhiwo ezinhle zokujiya kanye ne-shear thinning, futhi sisetshenziswa kabanzi emikhakheni ehlukahlukene yezimboni neyemithi. Ukuqonda kanye nokwenza kahle lezi zici ze-viscosity kuzosiza ukuthuthukisa ukusetshenziswa kwe-HPMC ezinhlelweni ezahlukene. Kuzicelo ezingokoqobo, uhlobo olufanele lwe-HPMC nezimo zenqubo kufanele zikhethwe ngokuya ngezidingo ezithile ukuze kutholwe i-viscosity ekahle kanye nezakhiwo ze-rheological.
Isikhathi sokuthumela: Mar-01-2025