I-Hydroxypropyl methylcellulose (HPMC) iyinhlanganisela ye-polymer encibilikayo emanzini engeyona i-ionic etholakala ngokuguqulwa kwamakhemikhali kwe-cellulose yemvelo. Isetshenziswa kabanzi embonini yokudla, yezokwelapha, yezimonyo kanye neyokwakha, ikakhulukazi njenge-glue, i-thickener, i-emulsifier kanye ne-alamu yokumiswa ekulungiseleleni imithi. Enkambisweni yokufaka, izici ze-viscosity zesisombululo samanzi se-HPMC zibalulekile ekusebenzeni kwayo emikhakheni ehlukene.
1. Isakhiwo kanye nezakhiwo ze-hydroxypropyl methylcellulose
Isakhiwo sama-molecule se-HPMC siqukethe amaqembu amabili athatha indawo, i-hydroxypropyl (-CH2)₂I-CHOHCH₃) kanye ne-methyl (-OCH₃), okwenza kube nokuncibilika kwamanzi okuhle kanye nekhono lokuguqula. Uchungechunge lwama-molecule lwe-HPMC lunesakhiwo esithile esiqinile, kodwa lungakha futhi isakhiwo senethiwekhi esinezilinganiso ezintathu kusisombululo samanzi, okuholela ekwandeni kwe-viscosity. Isisindo salo sama-molecule, uhlobo lwe-substituent kanye nezinga lokushintsha (okungukuthi, izinga le-hydroxypropyl kanye ne-methyl substitution yeyunithi ngayinye) kunethonya elibalulekile ekuqineni kwesisombululo.
2. Izici zokuqina kwesisombululo samanzi
Izici ze-viscosity zesisombululo samanzi se-HPMC zihlobene eduze nezici ezifana nokuhlushwa, isisindo sama-molecule, izinga lokushisa kanye nenani le-pH le-solvent. Ngokuvamile, i-viscosity yesisombululo samanzi se-HPMC iyanda ngokwanda kokuhlushwa kwayo. I-viscosity yayo ibonisa ukuziphatha kwe-rheological okungeyona i-Newtonian, okungukuthi, njengoba izinga lokushefa likhuphuka, i-viscosity yesisombululo iyancipha kancane kancane, okubonisa into yokuncipha kwe-shear.
(1) Umphumela wokugxilisa ingqondo
Kukhona ubudlelwano obuthile phakathi kwe-viscosity yesisombululo samanzi se-HPMC kanye nokuhlushwa kwaso. Njengoba ukuhlushwa kwe-HPMC kwanda, ukusebenzisana kwama-molecule esixazululweni samanzi kuyakhula, futhi ukunamathelana nokuxhumanisa kwamaketanga ama-molecule kuyanda, okuholela ekwandeni kwe-viscosity yesisombululo. Ekuhlushweni okuphansi, i-viscosity yesisombululo samanzi se-HPMC iyanda ngokulandelana nokwanda kokuhlushwa, kodwa ekuhlushweni okuphezulu, ukukhula kwe-viscosity yesisombululo kuvame ukuba yisicaba futhi kufinyelele inani elizinzile.
(2) Umphumela wesisindo sama-molecule
Isisindo sama-molecule se-HPMC sithinta ngqo i-viscosity yesisombululo sayo samanzi. I-HPMC enesisindo sama-molecule esiphezulu inamaketanga amade ama-molecule futhi ingakha isakhiwo senethiwekhi esiyinkimbinkimbi kakhulu esinezinhlangothi ezintathu esixazululweni samanzi, okuholela ekuqineni okuphezulu. Ngokuphambene nalokho, i-HPMC enesisindo sama-molecule esiphansi inesakhiwo senethiwekhi esikhululekile kanye ne-viscosity ephansi ngenxa yamaketanga ama-molecule ayo amafushane. Ngakho-ke, lapho usebenzisa, kubaluleke kakhulu ukukhetha i-HPMC enesisindo sama-molecule esifanele ukuze kufezwe umphumela omuhle we-viscosity.
(3) Umphumela wokushisa
Izinga lokushisa liyisici esibalulekile esithinta ukujiya kwesisombululo samanzi se-HPMC. Njengoba izinga lokushisa landa, ukunyakaza kwama-molecule amanzi kuyaqina futhi ukujiya kwesisombululo kuvame ukwehla. Lokhu kungenxa yokuthi lapho izinga lokushisa likhuphuka, inkululeko yochungechunge lwama-molecule e-HPMC iyanda futhi ukusebenzisana phakathi kwama-molecule kuyabuthaka, ngaleyo ndlela kunciphisa ukujiya kwesisombululo. Kodwa-ke, impendulo ye-HPMC evela kumaqoqo noma amabhrendi ahlukene kuya ekushiseni nayo ingahluka, ngakho-ke izimo zokushisa zidinga ukulungiswa ngokuya ngezidingo ezithile zokusetshenziswa.
(4) Umphumela wenani le-pH
I-HPMC ngokwayo iyinhlanganisela engeyona i-ionic, futhi i-viscosity yesisombululo sayo samanzi iyazwela ezinguqukweni ze-pH. Nakuba i-HPMC ibonisa izici ze-viscosity ezizinzile ezindaweni ezine-acidic noma ezingathathi hlangothi, ukuncibilika kanye ne-viscosity ye-HPMC kuzothinteka ezindaweni ezine-acidic noma ezine-alkaline kakhulu. Isibonelo, ngaphansi kwezimo ze-acidic noma ezine-alkaline eqinile, ama-molecule e-HPMC angase anciphe kancane, ngaleyo ndlela kuncishiswe i-viscosity yesisombululo sayo samanzi.
3. Ukuhlaziywa kwe-Rheological kwezimpawu ze-viscosity zesisombululo samanzi se-HPMC
Ukuziphatha kwe-rheological kwesisombululo samanzi se-HPMC kuvame ukukhombisa izici zoketshezi olungeyona i-Newtonian, okusho ukuthi i-viscosity yayo ayihlobene nje kuphela nezici ezifana nokuhlushwa kwesisombululo kanye nesisindo sama-molecule, kodwa futhi nesilinganiso sokusika. Ngokuvamile, ngamanani aphansi okusika, isixazululo samanzi se-HPMC sibonisa i-viscosity ephezulu, kuyilapho njengoba izinga lokusika likhuphuka, i-viscosity iyancipha. Lokhu kuziphatha kubizwa ngokuthi "ukusika i-shear" noma "ukusika i-shear" futhi kubaluleke kakhulu ezisetshenzisweni eziningi ezisebenzayo. Isibonelo, emikhakheni yokumboza, ukulungiselela imithi, ukucubungula ukudla, njll., izici zokusika i-shear ze-HPMC zingaqinisekisa ukuthi i-viscosity ephezulu igcinwa ngesikhathi sokusetshenziswa kwesivinini esiphansi, futhi ingageleza kalula ngaphansi kwezimo zokusika ngesivinini esikhulu.
4. Ezinye izinto ezithinta i-viscosity yesisombululo samanzi se-HPMC
(1) Umphumela kasawoti
Ukwengezwa kwezinyibilikisi zikasawoti (njenge-sodium chloride) kungandisa i-viscosity yesisombululo samanzi se-HPMC. Lokhu kungenxa yokuthi usawoti ungathuthukisa ukusebenzisana phakathi kwama-molecule ngokushintsha amandla e-ionic esisombululo, ukuze ama-molecule e-HPMC akhe isakhiwo senethiwekhi esincanyana, ngaleyo ndlela andise i-viscosity. Kodwa-ke, umphumela wohlobo lukasawoti kanye nokuhlushwa kwe-viscosity nakho kudinga ukulungiswa ngokuya ngezimo ezithile.
(2) Umphumela wezinye izithasiselo
Ukwengeza ezinye izithasiselo (ezifana nama-surfactants, ama-polymers, njll.) kusisombululo samanzi se-HPMC nakho kuzothinta i-viscosity. Isibonelo, ama-surfactants anganciphisa i-viscosity ye-HPMC, ikakhulukazi lapho ukuhlushwa kwe-surfactant kuphezulu. Ngaphezu kwalokho, ama-polymers noma izinhlayiya ezithile zingasebenzisana ne-HPMC futhi zishintshe izakhiwo ze-rheological zesisombululo sayo.
Izici ze-viscosity zei-hydroxypropyl methylcellulose Isixazululo samanzi sithinteka yizici eziningi, okuhlanganisa ukuhlushwa, isisindo sama-molecule, izinga lokushisa, inani le-pH, njll. Isixazululo samanzi se-HPMC sivame ukubonisa izakhiwo ze-rheological ezingezona eze-Newtonian, sinezakhiwo ezinhle zokujiya kanye nokunciphisa ukusika, futhi sisetshenziswa kabanzi emikhakheni ehlukahlukene yezimboni neyemithi. Ukuqonda nokuqonda lezi zici ze-viscosity kuzosiza ukuthuthukisa ukusetshenziswa kwe-HPMC ezinhlotsheni ezahlukene zokusebenza. Ezinhlotsheni ezisebenzayo, uhlobo lwe-HPMC olufanele kanye nezimo zenqubo kufanele kukhethwe ngokuya ngezidingo ezithile ukuze kutholakale izakhiwo ze-viscosity kanye ne-rheological ezifanele.
Isikhathi sokuthunyelwe: Mashi-01-2025