Methylcellulose (MC)
Foromo ea molek'hule ea methylcellulose (MC) ke:
[C6H7O2(OH)3-h(OCH3)n\]x
Mokhoa oa tlhahiso ke ho etsa cellulose ether ka letoto la liketso ka mor'a hore k'hothone e hloekisitsoeng e phekoloe ka alkali, 'me methyl chloride e sebelisoa e le etherification agent. Ka kakaretso, tekanyo ea ho fetola ke 1.6 ~ 2.0, 'me solubility e boetse e fapane le likhato tse fapaneng tsa ho fetola. Ke ea non-ionic cellulose ether.
Methylcellulose e qhibiliha ka metsing a batang, 'me ho tla ba thata ho qhibiliha ka metsing a chesang. Tharollo ea eona ea metsi e tsitsitse haholo maemong a pH = 3 ~ 12.
E na le tumellano e ntle le starch, guar gum, joalo-joalo le li-surfactants tse ngata. Ha mocheso o fihla mocheso oa gelation, gelation e etsahala.
Ho boloka metsi a methylcellulose ho ipapisitse le palo ea eona ea tlatsetso, viscosity, botle ba likaroloana le sekhahla sa ho qhibiliha.
Ka kakaretso, haeba palo ea tlatsetso e le kholo, botle bo nyane, 'me viscosity e kholo, sekhahla sa ho boloka metsi se phahame. Har'a bona, palo ea ho eketsoa e na le tšusumetso e kholo ka ho fetisisa ho tekanyo ea ho boloka metsi, 'me boemo ba viscosity ha bo lekane ka ho toba le tekanyo ea ho boloka metsi. Sekhahla sa ho qhibiliha haholo-holo se itšetlehile ka tekanyo ea phetoho ea bokaholimo ba likaroloana tsa cellulose le botle ba likaroloana.
Har'a li-ether tsa cellulose tse ka holimo, methyl cellulose le hydroxypropyl methyl cellulose li na le litekanyetso tse phahameng tsa ho boloka metsi.
Carboxymethylcellulose (CMC)
Carboxymethyl cellulose, eo hape e tsejoang e le sodium carboxymethyl cellulose, eo hangata e tsejoang e le cellulose, cmc, joalo-joalo, ke anionic linear polymer, letsoai la sodium ea cellulose carboxylate, 'me e ka nchafatsoa ebile ha e che. Lisebelisoa tsa lik'hemik'hale.
E sebelisoa haholo indastering ea litlolo, indastering ea lijo le mokelikeli oa ho cheka masimong a oli, 'me chelete e sebelisoang ho litlolo e etsa hoo e ka bang 1%.
Ionic cellulose ether e entsoe ka likhoele tsa tlhaho (cotton, joalo-joalo) kamora kalafo ea alkali, ho sebelisoa sodium monochloroacetate joalo ka etherification agent, le ho etsa letoto la liphekolo tsa karabelo.
Tekanyo ea ho kenya sebaka ka kakaretso ke 0.4 ~ 1.4, 'me ts'ebetso ea eona e angoa haholo ke tekanyo ea ho kenya 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 polasetiki.
Ha CMC e qhibiliha, depolymerization e hlile e etsahala. Viscosity e qala ho phahama nakong ea ho qhibiliha, e feta ka holimo, ebe e theohela sehlabeng. Viscosity e hlahisoang e amana le depolymerization.
Tekanyo ea depolymerization e amana haufi-ufi le palo ea mokelikeli o fokolang (metsi) ha ho etsoa. Tsamaisong e futsanehileng ea solvent, joalo ka sesepa sa meno se nang le glycerin le metsi, CMC e ke ke ea senya ka ho feletseng 'me e tla fihla boemong ba ho lekana.
Tabeng ea khatello ea metsi e fanoeng, CMC e nkeloang sebaka haholo ke hydrophilic ho bonolo ho e tlosa ho feta CMC e nkeloang sebaka e tlase.
Hydroxyethylcellulose (HEC)
HEC e entsoe ka ho phekola k'hothone e hloekisitsoeng ka alkali, ebe e itšoara ka ethylene oxide e le moemeli oa etherification ka pel'a acetone. Tekanyo ea ho nka sebaka ka kakaretso ke 1.5 ~ 2.0. E na le hydrophilicity e matla 'me e bonolo ho monya mongobo.
Hydroxyethyl cellulose e qhibiliha ka metsing a batang, empa ho thata ho qhibiliha ka metsing a chesang. Tharollo ea eona e tsitsitse mocheso o phahameng ntle le gelling.
E tsitsitse ho li-acids tse tloaelehileng le metheo. Alkalis e ka potlakisa ho qhibiliha ha eona 'me ea eketsa viscosity hanyenyane. Ho qhalana ha eona metsing ho mpe ho feta ea methyl cellulose le hydroxypropyl methyl cellulose.
Hydroxypropyl Methyl Cellulose (HPMC)
Foromo ea molek'hule ea HPMC ke:
\[C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3\]n\]x
Hydroxypropyl methylcellulose ke mofuta oa cellulose eo tlhahiso le tšebeliso ea eona li ntseng li eketseha ka potlako.
Ke selulose e seng ionic e tsoakiloeng e entsoeng ka k'hothone e hloekisitsoeng ka mor'a alkalization, e sebelisa propylene oxide le methyl chloride e le etherification agent, ka letoto la liketso. Tekanyo ea ho nka sebaka ka kakaretso ke 1.2 ~ 2.0.
Thepa ea eona e fapane ka lebaka la likarohano tse fapaneng tsa litaba tsa methoxyl le litaba tsa hydroxypropyl.
Hydroxypropyl methylcellulose e qhibiliha habonolo metsing a batang, empa e tla kopana le bothata ba ho qhibiliha metsing a chesang. Empa mocheso oa eona oa gelation metsing a chesang o phahame haholo ho feta oa methyl cellulose. Ho qhibiliha ha metsi a batang ho boetse ho ntlafala haholo ha ho bapisoa le methyl cellulose.
Viscosity ea hydroxypropyl methylcellulose e amana le boima ba eona ba molek'hule, 'me ha boima ba molek'hule bo le boholo, ho ba le viscosity e phahameng. Mocheso o boetse o ama viscosity ea eona, ha mocheso o ntse o eketseha, viscosity e fokotseha. Leha ho le joalo, viscosity ea eona e phahameng e na le phello e tlase ea mocheso ho feta methyl cellulose. Tharollo ea eona e tsitsitse ha e bolokiloe mocheso oa kamore.
Palo ea metsi ea hydroxypropyl methylcellulose e ipapisitse le palo ea eona ea tlatsetso, viscosity, joalo-joalo, mme sekhahla sa eona sa ho boloka metsi ka tekanyo e tšoanang ea tlatsetso e phahame ho feta ea methyl cellulose.
Hydroxypropyl methylcellulose e tsitsitse ho acid le alkali, 'me tharollo ea eona ea metsi e tsitsitse haholo ka pH = 2 ~ 12. Caustic soda le metsi a lime ha li na phello e fokolang ts'ebetsong ea eona, empa alkali e ka potlakisa ho qhibiliha ha eona le ho eketsa viscosity ea eona.
Hydroxypropyl methylcellulose e tsitsitse ho matsoai a tloaelehileng, empa ha motsoako oa motsoako oa letsoai o phahame, viscosity ea hydroxypropyl methylcellulose tharollo e atisa ho eketseha.
Hydroxypropyl methylcellulose e ka kopanngoa le metsoako ea polymer e qhibilihang ka metsing ho etsa tharollo e tšoanang le e phahameng ea viscosity. Joalo ka joala ba polyvinyl, starch ether, boka ba meroho, joalo-joalo.
Hydroxypropyl methylcellulose e na le khanyetso e ntle ea 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: Feb-14-2023