Focus on Cellulose ethers

Iyini i-HPMC?Yini i-MC?

Iyini i-HPMC?Yini i-MC?

I-HPMC iyi-hydroxypropyl methylcellulose, okuyi-ether engeyona i-ionic cellulose eyenziwe ngokotini ocolisisiwe ngemva kokwenziwa kwe-alkalization, kusetshenziswa i-propylene oxide ne-methyl chloride njengama-etherification agents, futhi ngochungechunge lokusabela.Izinga lokushintsha ngokuvamile liyi-1.2 ~ 2.0.Izakhiwo zayo zihlukile ngenxa yezilinganiso ezihlukene zokuqukethwe kwe-methoxyl nokuqukethwe kwe-hydroxypropyl.

I-MC i-methyl cellulose, eyenziwe nge-cellulose ether ngokwelapha ukotini ocolisisiwe nge-alkali, kusetshenziswa i-methane chloride njenge-etherification agent, futhi idlula ochungechungeni lokusabela.Ngokuvamile, izinga lokushintsha lingu-1.6~2.0, futhi ukunyibilika nakho kuhlukile ngamazinga ahlukene okushintsha.Kungokwe-non-ionic cellulose ether.

(1) IHydroxypropyl methylcellulose incibilika kalula emanzini abandayo, futhi izohlangabezana nobunzima ekuncibilikeni emanzini ashisayo.Kodwa izinga lokushisa layo le-gelation emanzini ashisayo liphakeme kakhulu kunalelo le-methyl cellulose.I-solubility emanzini abandayo nayo ithuthuke kakhulu uma iqhathaniswa ne-methyl cellulose.I-Hydroxypropyl methylcellulose izinzile ku-asidi ne-alkali, futhi isixazululo sayo samanzi sizinze kakhulu kububanzi be-pH=2~12.I-Caustic soda namanzi e-lime anethonya elincane ekusebenzeni kwawo, kodwa i-alkali ingasheshisa ukuchithwa kwayo futhi ikhulise ukubukeka kwayo.IHydroxypropyl methylcellulose izinzile kusawoti ovamile, kodwa lapho ukuhlangana kwesixazululo sikasawoti kuphezulu, i-viscosity ye-hydroxypropyl methylcellulose solution ivame ukwanda.

I-Methylcellulose nayo iyancibilika emanzini abandayo, futhi kuyoba nzima ukuyihlakaza emanzini ashisayo.Isixazululo saso esinamanzi sizinzile kakhulu ebangeni le-pH=3~12.Inokuhambisana okuhle nesitashi, i-guar gum, njll. kanye nama-surfactants amaningi.Lapho izinga lokushisa lifinyelela izinga lokushisa le-gelation, i-gelation iyenzeka.

(2) I-viscosity ye-hydroxypropyl methylcellulose ihlobene nesisindo sayo samangqamuzana, futhi uma sikhulu isisindo samangqamuzana, i-viscosity iphakama.Ukushisa nakho kuthinta i-viscosity yayo, njengoba izinga lokushisa likhuphuka, i-viscosity iyancipha.Kodwa-ke, i-viscosity yayo ephezulu inomphumela ophansi wokushisa kune-methyl cellulose.Isixazululo saso sizinzile uma sigcinwe ekamelweni lokushisa.

I-Methylcellulose inomthelela omkhulu ekusebenzeni nasekubambeleleni kodaka.Igama elithi “adhesion” lapha libhekisela emandleni okunamathela azwakala phakathi kwethuluzi lokufaka isicelo lesisebenzi kanye ne-substrate yodonga, okungukuthi, ukumelana nokugunda kodaka.I-adhesiveness iphakeme, ukumelana kwe-shear kodaka kukhulu, futhi amandla adingwa ngabasebenzi ngesikhathi sokusebenzisa nawo makhulu, futhi ukusebenza kokwakhiwa kodaka kumpofu.I-Methyl cellulose adhesion isezingeni elilinganiselwe emikhiqizweni ye-cellulose ether.

(3) Ukugcinwa kwamanzi kwe-hydroxypropyl methylcellulose kuncike enanini layo elingeziwe, i-viscosity, njll., futhi izinga layo lokugcinwa kwamanzi ngaphansi kwenani elifanayo lokwengezwa lingaphezulu kwele-methyl cellulose.

Ukugcinwa kwamanzi kwe-methylcellulose kuncike enanini layo elingeziwe, i-viscosity, ukucoleka kwezinhlayiyana nezinga lokuqedwa.Ngokuvamile, uma inani elingeziwe likhulu, ukucoleka kuncane, futhi i-viscosity inkulu, izinga lokugcinwa kwamanzi liphezulu.Phakathi kwazo, inani lokwengeza linomthelela omkhulu kakhulu ekugcinweni kwamanzi, futhi izinga le-viscosity alilingani ngokuqondile nezinga lokugcinwa kwamanzi.Izinga lokuhlakazeka lincike kakhulu ezingeni lokuguqulwa kwendawo yezinhlayiya ze-cellulose kanye nokucoleka kwezinhlayiyana.Phakathi kwama-cellulose ether angenhla, i-methyl cellulose ne-hydroxypropyl methyl cellulose anamazinga aphezulu okugcina amanzi.

(4) I-Hydroxypropyl methylcellulose ingaxutshwa nezinhlanganisela ze-polymer ezincibilika emanzini ukuze zenze isisombululo esifanayo nesiphezulu se-viscosity.Okufana ne-polyvinyl alcohol, isitashi ether, i-vegetable gum, njll. Ukunamathela kwe-hydroxypropyl methylcellulose ekwakhiweni kodaka kuphakeme kunaleyo ye-methylcellulose.

I-Hydroxypropyl methylcelluloseI-HPMCinokumelana ne-enzyme okungcono kune-methylcellulose, futhi isisombululo sayo mancane amathuba okuthi sonakaliswe ama-enzyme kune-methylcellulose.

Ukushintsha kwezinga lokushisa kungathinta kakhulu ukugcinwa kwamanzi kwe-methyl cellulose.Ngokuvamile, lapho izinga lokushisa liphezulu, kuba kubi nakakhulu ukugcinwa kwamanzi.Uma izinga lokushisa lodaka lidlula i-40 ° C, ukugcinwa kwamanzi kwe-methyl cellulose kuzoncishiswa kakhulu, okuthinta kakhulu ukwakhiwa kodaka.Uma izinga lokushisa liphezulu uma kuqhathaniswa, zama ukukhetha i-hydroxypropyl methylcellulose.


Isikhathi sokuthumela: Jan-20-2023
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