I-Methylcellulose (MC)
Ifomula yama-molecule ye-methylcellulose (MC) ithi:
[C6H7O2(OH)3-h(OCH3)n\]x
Inqubo yokukhiqiza ukwenza i-cellulose ether ngokusebenzisa uchungechunge lwezimpendulo ngemva kokuba ukotini ocolisisiwe uphathwe nge-alkali, bese kusetshenziswa i-methyl chloride njenge-etherification. Ngokuvamile, izinga lokushintsha lingu-1.6 ~ 2.0, kanti ukuncibilika nakho kuhlukile ngamazinga ahlukene okushintsha. Kungokwe-non-ionic cellulose ether.
I-Methylcellulose iyancibilika emanzini abandayo, futhi kuzoba nzima ukuyincibilika emanzini ashisayo. Isixazululo sayo samanzi sizinzile kakhulu ku-pH=3~12.
Ihambisana kahle nesitashi, i-guar gum, njll. kanye nama-surfactants amaningi. Lapho izinga lokushisa lifinyelela izinga lokushisa le-gelation, kwenzeka i-gelation.
Ukugcinwa kwamanzi kwe-methylcellulose kuncike enanini layo lokwengeza, i-viscosity, ubuncane bezinhlayiya kanye nesilinganiso sokuncibilika.
Ngokuvamile, uma inani lokwengeza likhulu, ubucwebe buncane, kanti ubucwebe bukhulu, izinga lokugcina amanzi liphezulu. Phakathi kwazo, inani lokwengeza linomthelela omkhulu kakhulu esilinganisweni sokugcina amanzi, futhi izinga lobuningi alilingani ngqo nezinga lokugcinwa kwamanzi. Izinga lokuncibilika lincike kakhulu ezingeni lokuguqulwa kobuso bezinhlayiya ze-cellulose kanye nobucwebe bezinhlayiya.
Phakathi kwama-ether e-cellulose angenhla, i-methyl cellulose kanye ne-hydroxypropyl methyl cellulose zinamazinga aphezulu okugcinwa kwamanzi.
I-Carboxymethylcellulose (CMC)
I-Carboxymethyl cellulose, eyaziwa nangokuthi i-sodium carboxymethyl cellulose, eyaziwa kakhulu ngokuthi i-cellulose, i-cmc, njll., iyi-polymer eqondile ye-anionic, usawoti we-sodium we-cellulose carboxylate, futhi ivuseleleka futhi ayipheli. Izinto zokusetshenziswa zamakhemikhali.
Isetshenziswa kakhulu embonini yensipho, embonini yokudla kanye noketshezi lokubhoboza uwoyela, kanti inani elisetshenziswa ezimonyweni libalelwa cishe ku-1%.
I-ether ye-cellulose ye-Ionic yenziwe ngemicu yemvelo (ukotini, njll.) ngemva kokwelashwa nge-alkali, kusetshenziswa i-sodium monochloroacetate njenge-etherification agent, futhi idlula ochungechungeni lwezindlela zokwelapha zokusabela.
Izinga lokushintsha ngokuvamile lingu-0.4 ~ 1.4, futhi ukusebenza kwalo kuthinteka kakhulu yizinga lokushintsha.
I-CMC inekhono elihle kakhulu lokubopha, kanti isixazululo sayo samanzi sinekhono elihle lokumisa, kodwa ayikho inani langempela lokuguqulwa kwepulasitiki.
Lapho i-CMC incibilika, empeleni i-depolymerization iyenzeka. I-viscosity iqala ukukhuphuka ngesikhathi sokuncibilika, idlule ku-maximum, bese yehlela ethafeni. I-viscosity ephumelayo ihlobene ne-depolymerization.
Izinga lokususwa kwe-polymerization lihlobene eduze nenani le-solvent empofu (amanzi) ekwakhiweni. Ohlelweni lwe-solvent olubi, njenge-toothpaste equkethe i-glycerin namanzi, i-CMC ngeke isuswe ngokuphelele futhi izofinyelela iphuzu lokulingana.
Uma kunesidingo sokuhlushwa kwamanzi, kulula ukususa i-CMC efakwe emanzini amaningi kune-CMC efakwe emanzini amaningi.
I-Hydroxyethylcellulose (HEC)
I-HEC yenziwa ngokwelapha ukotini ocolisisiwe nge-alkali, bese isabela nge-ethylene oxide njenge-etherification agent lapho kukhona i-acetone. Izinga lokushintshana ngokuvamile lingu-1.5 ~ 2.0. Inamandla okushintsha amanzi futhi kulula ukuyimunca umswakama.
I-Hydroxyethyl cellulose iyancibilika emanzini abandayo, kodwa kunzima ukuyincibilika emanzini ashisayo. Isixazululo sayo sizinzile ekushiseni okuphezulu ngaphandle kokufaka i-gelling.
Izinzile kuma-asidi avamile kanye nezisekelo. Ama-alkali angasheshisa ukuncibilika kwawo futhi andise kancane i-viscosity yawo. Ukuhlakazeka kwawo emanzini kubi kancane kunokwe-methyl cellulose kanye ne-hydroxypropyl methyl cellulose.
I-Hydroxypropyl Methyl Cellulose (HPMC)
Ifomula yama-molecule ye-HPMC yile:
\[C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3\]n\]x
I-Hydroxypropyl methylcellulose uhlobo lwe-cellulose olukhiqizwa futhi lusetshenziswa kakhulu.
Kuyi-ether exubile ye-cellulose engeyona i-ionic eyenziwe ngokotini ocwengekile ngemva kokuhlanganiswa kwe-alkali, kusetshenziswa i-propylene oxide kanye ne-methyl chloride njenge-etherification agent, ngokusebenzisa uchungechunge lwezimpendulo. Izinga lokushintshana ngokuvamile lingu-1.2 ~ 2.0.
Izakhiwo zayo zihlukile ngenxa yezilinganiso ezahlukene zokuqukethwe kwe-methoxyl kanye nokuqukethwe kwe-hydroxypropyl.
I-hydroxypropyl methylcellulose incibilika kalula emanzini abandayo, kodwa izobhekana nobunzima ekuncibilikeni emanzini ashisayo. Kodwa izinga lokushisa layo le-gelation emanzini ashisayo liphakeme kakhulu kunele-methyl cellulose. Ukuncibilika emanzini abandayo nakho kuthuthuke kakhulu uma kuqhathaniswa ne-methyl cellulose.
Ukuqina kwe-hydroxypropyl methylcellulose kuhlobene nesisindo sayo sama-molecule, futhi uma isisindo sama-molecule sikhulu, kulapho ukuqina kwayo kukhuphuka khona. Izinga lokushisa lithinta nokuqina kwayo, njengoba izinga lokushisa likhuphuka, ukuqina kwayo kwehla. Kodwa-ke, ukuqina kwayo okuphezulu kunomphumela wokushisa ophansi kune-methyl cellulose. Isixazululo sayo sizinzile uma sigcinwe ekushiseni kwegumbi.
Ukugcinwa kwamanzi kwe-hydroxypropyl methylcellulose kuncike enanini layo lokwengeza, i-viscosity, njll., futhi izinga layo lokugcinwa kwamanzi enanini elifanayo lokwengeza liphakeme kunele-methyl cellulose.
I-Hydroxypropyl methylcellulose izinzile ku-asidi kanye ne-alkali, futhi isixazululo sayo samanzi sizinzile kakhulu ku-pH=2~12. I-Caustic soda kanye namanzi e-lime awathinti kakhulu ukusebenza kwayo, kodwa i-alkali ingasheshisa ukuncibilika kwayo futhi yandise i-viscosity yayo.
I-hydroxypropyl methylcellulose izinzile kusawoti ovamile, kodwa uma ukuhlushwa kwesisombululo sikasawoti kuphezulu, i-viscosity yesisombululo se-hydroxypropyl methylcellulose ivame ukwanda.
I-hydroxypropyl methylcellulose ingaxutshwa nama-polymer compounds ancibilika emanzini ukuze kwakheke isixazululo esifanayo nesinobuthi obuphezulu. Njenge-polyvinyl alcohol, i-starch ether, i-vegetable gum, njll.
I-hydroxypropyl methylcellulose inokumelana okungcono kwama-enzyme kune-methylcellulose, futhi isixazululo sayo cishe asikwazi ukuwohloka ngama-enzyme kune-methylcellulose.
Isikhathi sokuthunyelwe: Feb-14-2023