Cellulose ether ke lentsoe le akaretsang bakeng sa letoto la lihlahisoa tse hlahisoang ke karabelo ea alkali cellulose le etherifying agent tlasa maemo a itseng. Alkali cellulose e nkeloa sebaka ke lisebelisoa tse fapaneng tsa etherifying ho fumana li-ether tse fapaneng tsa cellulose. Ho ea ka thepa ea ionization ea li-substituent, cellulose ethers e ka aroloa ka mekhahlelo e 'meli: ionic (joalo ka carboxymethyl cellulose) le nonionic (joalo ka methyl cellulose). Ho latela mofuta oa substituent, cellulose ether e ka aroloa ka monoether (joalo ka methyl cellulose) le ether e tsoakiloeng (joalo ka hydroxypropyl methyl cellulose). Ho ea ka solubility e fapaneng, e ka aroloa ka ho qhibiliha ha metsi (joalo ka hydroxyethyl cellulose) le organic solvent solubility (joalo ka ethyl cellulose). Seretse se kopantsoeng le metsi haholo-holo ke selulose e qhibilihang ka metsing, 'me selulose e qhibilihang ka metsing e arotsoe ka mofuta oa hang-hang le mofuta oa ho qhibiliha o alafshoang ka holim'a metsi.
Mokhoa oa ts'ebetso ea cellulose ether ka seretse ke ka tsela e latelang:
(1) Ka mor'a hore cellulose ether ka seretse e qhibilihe ka metsing, kabo e sebetsang le e ts'oanang ea thepa ea samente tsamaisong e tiisitsoe ka lebaka la mosebetsi oa holim'a metsi, 'me cellulose ether, e le colloid e sireletsang, "e phuthela" e tiileng. likaroloana le A lera la lubricating filimi e thehoa holim'a eona ka ntle, e leng se etsang hore tsamaiso ea seretse e be e tsitsitseng haholoanyane, hape e ntlafatsa ho phalla ha seretse nakong ea ho kopanya le ho boreleli ha kaho.
(2) Ka lebaka la litšobotsi tsa eona tsa sebopeho sa limolek'hule, tharollo ea cellulose ether e etsa hore mongobo o seretse o se ke oa lahleheloa ke bonolo, 'me butle-butle o o lokolla ka nako e telele, o fa seretse ho boloka metsi hantle le ho sebetsa hantle.
1. Methylcellulose: (MC)
Ka mor'a hore k'hothone e hloekisitsoeng e phekoloe ka alkali, cellulose ether e hlahisoa ka letoto la liketso ka methane chloride 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.
(1) 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.
(2) Ho boloka metsi a methyl cellulose 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.
(3) Liphetoho tsa mocheso li tla ama ka botebo tekanyo ea ho boloka metsi ea methyl cellulose. Ka kakaretso, ha thempereichara e phahame, ho mpefala ha metsi ho boloka metsi. Haeba mocheso oa seretse o feta 40 ° C, ho boloka metsi a methyl cellulose ho tla fokotseha haholo, ho ama ka ho teba ho hahoa ha seretse.
(4) Methyl cellulose e na le phello e kholo mohahong le momahaneng oa seretse. "Ho khomarela" mona ho bolela matla a tlamahano pakeng tsa sesebelisoa sa mosebetsi le karoloana ea lebota, ke hore, ho hanyetsa ho kuta ha seretse. Sekhomaretsi se phahame, khanyetso ea ho kuta ea seretse e kholo, 'me matla a hlokoang ke basebetsi ha a ntse a sebelisoa le ona a maholo,' me ts'ebetso ea kaho ea seretse e futsanehile. Khokahano ea methyl cellulose e maemong a mahareng ho lihlahisoa tsa ether ea cellulose.
2. Hydroxypropyl methyl cellulose (HPMC):
Hydroxypropyl methylcellulose ke mofuta oa cellulose oo tlhahiso le tšebeliso ea tsona li ntseng li eketseha ka potlako lilemong tsa morao tjena. 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 fapana ho latela karolelano ea methoxyl ho hydroxypropyl content.
(1) Hydroxypropyl methylcellulose e qhibiliha habonolo metsing a batang, 'me e tla kopana le mathata a 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.
(2) 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, tšusumetso ea viscosity ea eona e phahameng le mocheso o tlase ho feta oa methyl cellulose. Tharollo ea eona e tsitsitse ha e bolokiloe mocheso oa kamore.
(3) Ho bolokoa ha metsi a hydroxypropyl methylcellulose ho itšetlehile ka palo ea eona ea tlatsetso, viscosity, joalo-joalo, 'me sekhahla sa eona sa ho boloka metsi tlas'a chelete e tšoanang ea tlatsetso e phahame ho feta ea methyl cellulose.
(4) Hydroxypropyl methylcellulose e tsitsitse ho acid le alkali, 'me tharollo ea eona ea metsi e tsitsitse haholo ka har'a 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 'me ea eketsa viscosity ea eona hanyenyane. 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.
(5) 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.
(6) Hydroxypropyl methylcellulose e na le khanyetso e ntle ea enzyme ho feta methylcellulose, 'me monyetla oa ho senyeha ha enzymatic ea tharollo ea eona o tlase ho feta oa methylcellulose.
(7) Ho khomarela ha hydroxypropyl methylcellulose mohahong oa seretse ho phahame ho feta methylcellulose.
3. Hydroxyethyl cellulose (HEC):
E entsoe ka k'hothone e hloekisitsoeng e tšoaroang ka alkali, 'me e itšoara ka ethylene oxide e le etherification agent ka pel'a acetone. Tekanyo ea eona ea ho fetola hangata ke 1.5 ~ 2.0. E na le hydrophilicity e matla 'me e bonolo ho monya mongobo.
(1) 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 ka sebelisoa nako e telele tlas'a mocheso o phahameng ka har'a seretse, empa ho boloka metsi a eona ho tlaase ho feta methyl cellulose.
(2) Hydroxyethyl cellulose e tsitsitse ho acid e akaretsang le alkali. Alkali 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. .
(3) Hydroxyethyl cellulose e na le ts'ebetso e ntle ea anti-sag bakeng sa seretse, empa e na le nako e telele ea ho chechisa samente.
(4) Ts'ebetso ea hydroxyethyl cellulose e hlahisoang ke likhoebo tse ling tsa malapeng e tlase haholo ho feta ea methyl cellulose ka lebaka la metsi a mangata le molora o mongata.
4. Carboxymethyl cellulose (CMC):
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.
(1) Carboxymethyl cellulose e na le hygroscopic, 'me e tla ba le metsi a mangata ha a bolokiloe tlas'a maemo a tloaelehileng.
(2) Carboxymethyl cellulose aqueous solution e ke ke ea hlahisa gel, 'me viscosity e tla fokotseha ka ho eketseha ha mocheso. Ha mocheso o feta 50 ° C, viscosity ha e fetohe.
(3) Ho tsitsa ha eona ho ameha haholo ke PH. Ka kakaretso, e ka sebelisoa seretseng se thehiloeng ho gypsum, empa eseng ka seretseng sa samente. Ha e le alkaline e ngata, e tla lahleheloa ke viscosity.
(4) Palo ea eona ea metsi e tlase haholo ho feta ea methyl cellulose. E na le phello e sitisang seretse se thehiloeng ho gypsum mme e fokotsa matla a eona. Leha ho le joalo, theko ea carboxymethyl cellulose e tlase haholo ho feta ea methyl cellulose.
Nako ea poso: Feb-27-2023