Ukwethulwa kwama-cellulose ether amaningana avamile

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 ukuyincibilika 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 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.

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 esinamanzi 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.