I-HPMC (Hydroxypropyl Methylcellulose) iyi-polysaccharide eyi-semi-synthetic polymer esetshenziswa kakhulu kwezokwelapha, ekudleni, embonini yamakhemikhali nakweminye imikhakha. Izici zayo zokuhlakazeka zingenye yezindawo ezishisayo ocwaningweni nasekusetshenzisweni kwayo.
1. Isakhiwo samangqamuzana nezici zokuncibilika kwe-HPMC
I-HPMC iyinhlanganisela ye-polymer encibilika emanzini etholwe ngokuguqulwa kwe-etherification ye-cellulose. Iyunithi yayo yesakhiwo i-β-D-glucose, exhunywe ngamabhondi angu-1,4-glycosidic. Isakhiwo seketango eliyinhloko le-HPMC lisuselwa ku-cellulose yemvelo, kodwa ingxenye yamaqembu ayo e-hydroxyl ithathelwa indawo amaqembu e-methoxy (-OCH₃) namaqembu e-hydroxypropyl (-CH₂CH(OH)CH₃), ngakho-ke ikhombisa ukuziphatha kokuhlakazeka okuhlukile kulokho kwe-cellulose yemvelo.
Isakhiwo samangqamuzana e-HPMC sinomthelela omkhulu ekuncibilikeni kwayo. Izinga lokushintsha (i-DS, i-Degree of Substitution) kanye nokushintshwa kwe-molar (MS, I-Molar Substitution) ye-HPMC amapharamitha abalulekile anquma izici zayo zokuncibilika. Uma izinga lokushintshwa liphakeme, amaqembu e-hydroxyl engeziwe ku-molecule athathelwa indawo yi-hydrophobic methoxy noma amaqembu e-hydroxypropyl, akhuphula ukunyibilika kwe-HPMC kuzinyibilikisi zemvelo futhi kwehlise ukunyibilika emanzini. Ngokuphambene nalokho, lapho izinga lokushintsha liphansi, i-HPMC inamandla kakhulu emanzini futhi izinga layo lokuqedwa liyashesha.
2. Indlela yokuchithwa kwe-HPMC
Ukuncibilika kwe-HPMC emanzini kuyinqubo eyinkimbinkimbi ngokomzimba namakhemikhali, futhi indlela yayo yokuhlakazeka ihlanganisa ikakhulukazi lezi zinyathelo ezilandelayo:
Isiteji sokumanzisa: Uma i-HPMC ihlangana namanzi, ama-molecule amanzi azoqale akhe ifilimu ye-hydration ebusweni be-HPMC ukuze asonge izinhlayiya ze-HPMC. Kule nqubo, ama-molecule amanzi asebenzisana namaqembu e-hydroxyl kanye ne-methoxy kuma-molecule e-HPMC ngamabhondi e-hydrogen, okubangela ukuthi ama-molecule e-HPMC acwile kancane kancane.
Isiteji sokuvuvukala: Ngokungena kwama-molecule amanzi, izinhlayiya ze-HPMC ziqala ukumunca amanzi futhi zikhukhumale, ivolumu iyanda, futhi amaketanga e-molecular ayaxega kancane kancane. Ikhono lokuvuvukala le-HPMC lithintwa isisindo sayo samangqamuzana nezinto ezithatha indawo. Isisindo samangqamuzana sikhulu, isikhathi sokuvuvukala siba side; lapho i-hydrophilicity ye-substitute inamandla, izinga lokuvuvukala likhulu.
Isigaba sokuhlakazeka: Lapho ama-molecule e-HPMC emunca amanzi anele, amaketanga e-molecular aqala ukuhlehla ezinhlayiyeni futhi kancane kancane ahlakazeke esixazululweni. Ijubane lale nqubo lithintwa yizici ezifana nezinga lokushisa, izinga lokunyakazisa kanye nezakhiwo ze-solvent.
I-HPMC ngokuvamile ibonisa ukuncibilika okuhle emanzini, ikakhulukazi ekamelweni lokushisa. Kodwa-ke, kufanele kuqashelwe ukuthi lapho izinga lokushisa likhuphuka lifika ezingeni elithile, i-HPMC izobonisa into "ye-thermal gel", okungukuthi, i-solubility iyancipha njengoba izinga lokushisa likhuphuka. Lokhu kubangelwa ukunyakaza okuqinisiwe kwama-molecule amanzi emazingeni okushisa aphezulu kanye nokusebenzisana okuthuthukisiwe kwe-hydrophobic phakathi kwama-molecule e-HPMC, okuholela ekuhlanganiseni kwe-intermolecular kanye nokwakhiwa kwesakhiwo sejeli.
3. Izinto ezithinta ukunyibilika kwe-HPMC
I-solubility ye-HPMC ithintwa izici eziningi, okuhlanganisa izakhiwo zayo ezingokomzimba namakhemikhali nezimo zangaphandle. Izinto eziyinhloko zihlanganisa:
Izinga lokushintsha: Njengoba kushiwo ngenhla, uhlobo nenani labangene esikhundleni se-HPMC kuthinta ngokuqondile ukunyibilika kwayo. Ama-substitute amaningi, amaqembu ambalwa e-hydrophilic ku-molecule futhi kubi kakhulu ukuncibilika. Ngokuphambene nalokho, uma kukhona okushintshile okumbalwa, i-hydrophilicity ye-HPMC iyathuthukiswa futhi ukunyibilika kuba ngcono.
Isisindo samangqamuzana: Isisindo samangqamuzana e-HPMC silingana ngokuqondile nesikhathi saso sokuqedwa. Isisindo samangqamuzana sikhulu, inqubo yokuqedwa ihamba kancane. Lokhu kungenxa yokuthi iketango lamangqamuzana e-HPMC elinesisindo esikhulu samangqamuzana lide futhi ama-molecule abambene kakhulu, okwenza kube nzima ukuthi ama-molecule wamanzi angene, okuholela ekuvuvukeni nokuncibilika kancane.
Izinga lokushisa lesixazululo: Izinga lokushisa lingenye yezinto ezibalulekile ezithinta ukunyibilika kwe-HPMC. I-HPMC incibilika ngokushesha emazingeni okushisa aphansi, kuyilapho emazingeni okushisa aphakeme ingase yakhe ijeli futhi yehlise ukunyibilika kwayo. Ngakho-ke, i-HPMC ivame ukulungiswa emanzini aphansi okushisa ukuze igweme i-gelation emazingeni okushisa aphezulu.
Uhlobo lwe-solvent: I-HPMC ayincibiliki emanzini kuphela, kodwa futhi iyancibilika kuzincibilikisi ezithile eziphilayo, njenge-ethanol, i-isopropyl alcohol, njll. Ukuncibilika kuzincibilikisi zemvelo kuncike ohlotsheni nokusatshalaliswa kwezithako ezihlukile. Ngaphansi kwezimo ezijwayelekile, i-HPMC ayinakuncibilika kahle kuzincibilikisi zemvelo, futhi inani elifanele lamanzi lidinga ukungezwa ukusiza ukuncibilika.
Inani le-pH: I-HPMC inokubekezelela okuthile enaluni ye-pH yesisombululo, kodwa ngaphansi kwezimo eziyingozi kakhulu ze-asidi ne-alkali, ukunyibilika kwe-HPMC kuzothinteka. Ngokuvamile, i-HPMC inokunyibilika okungcono kububanzi be-pH obungu-3 ukuya ku-11.
4. Ukusetshenziswa kwe-HPMC emikhakheni ehlukene
I-solubility ye-HPMC iyenza ibe wusizo emikhakheni eminingi:
Inkambu yezemithi: I-HPMC ivamise ukusetshenziswa njengezinto zokunameka, izinto zokunamathisela kanye nama-ejenti akhipha isikhathi eside kumaphilisi emithi. Ezingxenyeni zezidakamizwa, i-HPMC ingakha ifilimu efanayo ukuze ithuthukise ukuzinza kwesidakamizwa; ekwakhiweni kokukhishwa okuqhubekayo, i-HPMC ilawula izinga lokukhululwa komuthi ngokulawula izinga lokuqedwa kwawo, ngaleyo ndlela kuzuzwe ukulethwa kwezidakamizwa okuhlala isikhathi eside.
Imboni yokudla: Ekudleni, i-HPMC isetshenziswa njenge-thickener, emulsifier and stabilizer. Ngenxa yokuthi i-HPMC inokunyibilika okuhle kwamanzi nokuzinza kokushisa, inganikeza ukuthungwa okufanelekile nokunambitha ekudleni okuhlukahlukene. Ngesikhathi esifanayo, imvelo engeyona i-ionic ye-HPMC iyivimbela ukuthi isabele nezinye izithako zokudla futhi igcine ukuzinza ngokomzimba namakhemikhali kokudla.
Imboni yamakhemikhali yansuku zonke: I-HPMC ivamise ukusetshenziswa njenge-thickener ne-emulsifier emikhiqizweni efana ne-shampoo, i-conditioner kanye nokhilimu wobuso. Ukuncibilika kwayo okuhle emanzini kanye nomphumela wokujiya kuyivumela ukuthi inikeze ulwazi oluhle kakhulu lokusebenzisa. Ngaphezu kwalokho, i-HPMC ingasebenzisana nezinye izithako ezisebenzayo ukuthuthukisa ukusebenza komkhiqizo.
Izinto zokwakha: Embonini yezokwakha, i-HPMC isetshenziswa njenge-ejenti yokuqina kanye ne-ejenti yokugcina amanzi odakeni lukasimende, izinto zokunamathisela zamathayili kanye nezingubo zokugqoka. I-HPMC ingathuthukisa ngempumelelo ukusebenza kwalezi zinto, inwebise isikhathi sazo sokusebenzisa, futhi ithuthukise ukumelana kwazo nokuqhekeka.
Njengomsebenzi we-polymer onokuncibilika okuhle, ukuziphatha kokuncibilika kwe-HPMC kuthintwa izici eziningi, njengesakhiwo samangqamuzana, izinga lokushisa, inani le-pH, njll. Ezinkambini zohlelo lokusebenza ezihlukene, ukunyibilika kwe-HPMC kungathuthukiswa ngokulungisa lezi zici ukuze kuhlangatshezwane nezidingo ezihlukene. I-solubility ye-HPMC ayigcini nje ngokunquma ukusebenza kwayo ezixazululweni ezinamanzi, kodwa futhi ithinta ngokuqondile imisebenzi yayo ezimbonini zemithi, zokudla, zamakhemikhali zansuku zonke nezokwakha.
Isikhathi sokuthumela: Oct-14-2024