I-Methylcellulose (MC)
I-molecule ye-methylcellulose (MC) yile:
[C6H7O2(OH)3-h(OCH3)n\]x
Inqubo yokukhiqiza iwukwenza i-cellulose ether ngochungechunge lokusabela ngemva kokuba ukotini ocolisisiwe ulashwe nge-alkali, futhi i-methyl chloride isetshenziswa njenge-etherification agent.Ngokuvamile, izinga lokushintsha lingu-1.6~2.0, futhi ukunyibilika nakho kuhlukile ngamazinga ahlukene okushintsha.Kungokwe-non-ionic cellulose ether.
I-Methylcellulose 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.
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 ikakhulukazi 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.
I-Carboxymethylcellulose (CMC)
I-Carboxymethyl cellulose, eyaziwa nangokuthi i-sodium carboxymethyl cellulose, evame ukubizwa ngokuthi i-cellulose, i-cmc, njll., i-anionic linear polymer, usawoti we-sodium we-cellulose carboxylate, futhi ivuseleleka futhi ayishi.Izinto zokusetshenziswa zamakhemikhali.
Isetshenziswa kakhulu embonini yokuhlanza, imboni yokudla kanye noketshezi lokumba lwenkundla kawoyela, futhi inani elisetshenziswa ezimonyoni libalelwa ku-1%.
I-ionic cellulose ether yenziwa ngemicu yemvelo (ukotini, njll.) ngemva kokwelashwa kwe-alkali, kusetshenziswa i-sodium monochloroacetate njenge-etherification agent, futhi kwenziwa uchungechunge lwemithi yokwelapha.
Izinga lokushintsha ngokuvamile lingu-0.4~1.4, futhi ukusebenza kwakho kuthintwa kakhulu izinga lokushintsha.
I-CMC inekhono elihle kakhulu lokubopha, futhi isisombululo sayo esinamanzi sinekhono elihle lokumisa okwesikhashana, kodwa alikho inani langempela lokuguquguquka kwepulasitiki.
Lapho i-CMC incibilika, ukukhishwa kwe-depolymerization kwenzeka ngempela.I-viscosity iqala ukukhuphuka ngesikhathi sokuhlakazeka, idlule ngobuningi, bese yehlela ethafeni.I-viscosity ewumphumela ihlobene ne-depolymerization.
Izinga le-depolymerization lihlobene eduze nenani le-solvent (amanzi) empofu ekwakhiweni.Kuhlelo lokuncibilikisa olubi, olufana nomuthi wokuxubha amazinyo oqukethe i-glycerin namanzi, i-CMC ngeke iqede ukungcola futhi izofinyelela iphuzu lokulinganisa.
Esimeni sokugxiliswa kwamanzi okunikeziwe, i-CMC efakwe endaweni ephezulu ene-hydrophilic kulula ukuyisusa kune-CMC efakwe endaweni ephansi.
I-Hydroxyethylcellulose (HEC)
I-HEC yenziwa ngokwelapha ukotini ocolisisiwe nge-alkali, bese isabela nge-ethylene oxide njenge-etherification agent phambi kwe-acetone.Izinga lokushintsha ngokuvamile liyi-1.5 ~ 2.0.Ine-hydrophilicity eqinile futhi kulula ukumunca umswakama.
I-Hydroxyethyl cellulose iyancibilika emanzini abandayo, kodwa kunzima ukuyincibilika emanzini ashisayo.Isixazululo saso sizinzile ekushiseni okuphezulu ngaphandle kwe-gelling.
Iqinile kuma-asidi avamile nezisekelo.Ama-alkali angasheshisa ukuqedwa kwawo futhi andise kancane i-viscosity yawo.Ukuhlakazeka kwayo emanzini kubi kakhulu kunaleyo ye-methyl cellulose ne-hydroxypropyl methyl cellulose.
IHydroxypropyl Methyl Cellulose (HPMC)
I-molecular formula ye-HPMC yile:
\[C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3\]n\]x
I-Hydroxypropyl methylcellulose iwuhlobo lwe-cellulose okukhipha kanye nokusetshenziswa kwalo kukhuphuka ngokushesha.
I-ether engeyona i-ionic cellulose exutshwe ukotini ocolisisiwe ngemva kokwenziwa kwe-alkalization, kusetshenziswa i-propylene oxide ne-methyl chloride njenge-etherification agent, ngochungechunge lokusabela.Izinga lokushintsha ngokuvamile liyi-1.2 ~ 2.0.
Izakhiwo zayo zihlukile ngenxa yezilinganiso ezihlukene zokuqukethwe kwe-methoxyl nokuqukethwe kwe-hydroxypropyl.
IHydroxypropyl methylcellulose incibilika kalula emanzini abandayo, kodwa 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-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.
Ukugcinwa kwamanzi kwe-hydroxypropyl methylcellulose kuncike enanini layo elingeziwe, i-viscosity, njll., futhi izinga layo lokugcinwa kwamanzi ngenani elifanayo lokwengezwa lingaphezulu kwele-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.
IHydroxypropyl methylcellulose ingaxutshwa nezinhlanganisela ze-polymer ezincibilika emanzini ukuze kwakhiwe isixazululo esifana nese-viscosity esiphezulu.Okufana ne-polyvinyl alcohol, isitashi ether, ushingamu wemifino, njll.
IHydroxypropyl methylcellulose inokumelana kangcono ne-enzyme kune-methylcellulose, futhi isisombululo sayo mancane amathuba okuthi sonakaliswe ngokwe-enzymatic kune-methylcellulose.
Isikhathi sokuthumela: Feb-14-2023