Methylcellulose (MC)
Foromo ea limolek'hule ea methylcellulose (MC) ke:
[C6H7O2(OH)3-h(OCH3)n\]x
Ts'ebetso ea tlhahiso ke ho etsa ether ea cellulose ka letoto la liketso kamora hore k'hothone e hloekisitsoeng e phekoloe ka alkali, 'me methyl chloride e sebelisoa e le moemeli oa etherification. Ka kakaretso, tekanyo ea phetolo ke 1.6 ~ 2.0, 'me ho qhibiliha ho boetse ho fapane ka maemo a fapaneng a phetolo. Ke ea ether ea cellulose e seng ea ionic.
Methylcellulose e qhibiliha metsing a batang, 'me ho tla ba thata ho e qhibilihisa metsing a chesang. Tharollo ea eona ea metsi e tsitsitse haholo maemong a pH=3~12.
E tsamaisana hantle le starch, gum ea guar, jj. le li-surfactants tse ngata. Ha mocheso o fihla mochesong oa gelation, gelation e etsahala.
Ho boloka metsi ha methylcellulose ho itshetlehile ka bongata ba yona ba ho e eketsa, ho teteana, ho ba botenya ha dikarolwana le sekgahla sa ho qhibiliha.
Ka kakaretso, haeba tekanyo ea ho eketsa e le kholo, botenya bo bonyenyane, 'me botenya bo boholo, sekhahla sa ho boloka metsi se phahame. Har'a tsona, tekanyo ea ho eketsa e na le tšusumetso e kholo ka ho fetisisa sekhahla sa ho boloka metsi, 'me boemo ba botenya ha bo lekane ka ho toba le boemo ba sekhahla sa ho boloka metsi. Sekhahla sa ho qhibiliha se itšetlehile haholo ka tekanyo ea phetoho ea bokaholimo ba likaroloana tsa cellulose le botenya ba likaroloana.
Har'a li-ether tsa cellulose tse ka holimo, methyl cellulose le hydroxypropyl methyl cellulose li na le sekhahla se phahameng sa ho boloka metsi.
Carboxymethylcellulose (CMC)
Carboxymethyl cellulose, e tsejoang hape e le sodium carboxymethyl cellulose, e tsejoang haholo e le cellulose, cmc, jj., ke polymer e otlolohileng ea anionic, letsoai la sodium la cellulose carboxylate, 'me e nchafatsoa ebile ha e che. Lisebelisoa tse tala tsa lik'hemik'hale.
E sebelisoa haholo indastering ea sesepa, indastering ea lijo le mokelikeli oa ho cheka oli masimong, 'me bongata bo sebelisoang litlolong bo etsa hoo e ka bang 1%.
Ether ea cellulose ea ionic e entsoe ka likhoele tsa tlhaho (k'hothone, jj.) kamora kalafo ea alkali, ho sebelisoa sodium monochloroacetate e le moemeli oa etherification, 'me e ntse e phekoloa ka letoto la mekhoa ea karabelo.
Tekanyo ea ho nkela sebaka hangata ke 0.4 ~ 1.4, 'me ts'ebetso ea eona e angoa haholo ke tekanyo ea ho nkela sebaka.
CMC e na le bokhoni bo botle ba ho tlama, 'me tharollo ea eona ea metsi e na le bokhoni bo botle ba ho emisa, empa ha ho na boleng ba 'nete ba ho fetoha ha polasetiki.
Ha CMC e qhibiliha, ho tlosoa ha polima hoa etsahala. Ho teteana ho qala ho nyoloha nakong ea ho qhibiliha, ho feta ka tekanyo e phahameng, ebe ho theohela sebakeng se phahameng. Ho teteana ho hlahang ho amana le ho tlosoa ha polima.
Tekanyo ea ho tlosoa ha polymerization e amana haufi-ufi le bongata ba solvent e fokolang (metsi) e entsoeng. Tsamaisong e fokolang ea solvent, joalo ka sesepa sa meno se nang le glycerin le metsi, CMC e ke ke ea tlosoa ka botlalo 'me e tla fihla ntlheng ea tekano.
Tabeng ea metsi a mangata a nang le metsi a mangata, ho bonolo ho a tlosa ho polymer ho feta CMC e nang le metsi a mangata.
Hydroxyethylcellulose (HEC)
HEC e etsoa ka ho phekola k'hothone e hloekisitsoeng ka alkali, ebe e arabela ka ethylene oxide e le moemeli oa etherification ha ho na le acetone. Tekanyo ea ho nkeloa sebaka hangata ke 1.5 ~ 2.0. E na le philicity e matla ea hydrophilicity 'me e bonolo ho monya mongobo.
Hydroxyethyl cellulose e qhibiliha metsing a batang, empa ho thata ho e qhibilihisa metsing a chesang. Tharollo ea eona e tsitsitse mochesong o phahameng ntle le ho hlapolla.
E tsitsitse ho li-acid le metheo e tloaelehileng. Li-alkali li ka potlakisa ho qhibiliha ha eona le ho eketsa viscosity ea eona hanyane. Ho qhalana ha eona metsing ho mpe hanyane ho feta ha methyl cellulose le hydroxypropyl methyl cellulose.
Hydroxypropyl Methyl Cellulose (HPMC)
Foromo ea limolek'hule ea HPMC ke:
\[C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3\]n\]x
Hydroxypropyl methylcellulose ke mofuta oa cellulose oo tlhahiso le tšebeliso ea oona li ntseng li eketseha ka potlako.
Ke ether e tsoakiloeng ea cellulose e seng ea ionic e entsoeng ka k'hothone e hloekisitsoeng ka mor'a alkalization, e sebelisang propylene oxide le methyl chloride e le moemeli oa etherification, ka letoto la liketso. Tekanyo ea ho nkeloa sebaka ka kakaretso ke 1.2 ~ 2.0.
Thepa ea eona e fapane ka lebaka la likarolelano tse fapaneng tsa methoxyl le hydroxypropyl.
Hydroxypropyl methylcellulose e qhibiliha habonolo metsing a batang, empa e tla ba le bothata ba ho qhibiliha ka metsing a chesang. Empa mocheso oa gelation ea eona metsing a chesang o phahame haholo ho feta oa methyl cellulose. Ho qhibiliha ha eona metsing a batang le hona ho ntlafetse haholo ha ho bapisoa le methyl cellulose.
Ho teteana ha hydroxypropyl methylcellulose ho amana le boima ba eona ba limolek'hule, 'me ha boima ba limolek'hule bo le boholo, ho teteana ho ba holimo. Mocheso le oona o ama ho teteana ha eona, ha mocheso o ntse o eketseha, ho teteana hoa fokotseha. Leha ho le joalo, ho teteana ha eona ho phahameng ho na le phello e tlase ea mocheso ho feta methyl cellulose. Tharollo ea eona e tsitsitse ha e bolokoa mochesong oa kamore.
Ho boloka metsi ha hydroxypropyl methylcellulose ho itshetlehile ka bongata ba yona ba ho eketsa, viscosity, jj., mme sekgahla sa yona sa ho boloka metsi ka bongata bo lekanang ba ho eketsa se hodimo ho feta sa methyl cellulose.
Hydroxypropyl methylcellulose e tsitsitse ho ea ho asiti le alkali, 'me tharollo ea eona ea metsi e tsitsitse haholo ho pH=2~12. Caustic soda le metsi a lime ha li na tšusumetso e kholo ts'ebetsong ea eona, empa alkali e ka potlakisa ho qhibiliha ha eona le ho eketsa viscosity ea eona.
Hydroxypropyl methylcellulose e tsitsitse ho matswai a tlwaelehileng, empa ha mahloriso a tharollo ya letswai a le hodimo, viscosity ya tharollo ya hydroxypropyl methylcellulose e atisa ho eketseha.
Hydroxypropyl methylcellulose e ka kopanngoa le metsoako ea polymer e qhibilihang ka metsing ho etsa tharollo e tšoanang le e nang le viscosity e phahameng. Joalo ka polyvinyl alcohol, starch ether, vegetable gum, jj.
Hydroxypropyl methylcellulose e na le khanyetso e betere ea li-enzyme ho feta methylcellulose, 'me tharollo ea eona ha e na monyetla oa ho senyeha ka mokhoa oa enzymatic ho feta methylcellulose.
Nako ea poso: Hlakola-14-2023