Cellulose ether ke sehlopha sa bohlokoa sa metsoako ea polymer, e sebelisoang haholo kahong, meriana, lijo le masimo a mang. Har'a tsona, HPMC (hydroxypropyl methylcellulose), MC (methylcellulose), HEC (hydroxyethyl cellulose) le CMC (carboxymethyl cellulose) ke li-ether tse 'nè tse tloaelehileng tsa cellulose.
Methyl cellulose (MC):
MC e qhibiliha ka metsing a batang 'me ho thata ho qhibiliha ka metsing a chesang. Tharollo ea metsi e tsitsitse haholo ka pH = 3 ~ 12, e na le tumellano e ntle, 'me e ka kopanngoa le mefuta e fapaneng ea li-surfactants tse kang starch le guar gum. Ha mocheso o fihla mocheso oa gelation, gelation e etsahala.
Palo ea metsi ea MC e ipapisitse le palo ea eona ea tlatsetso, viscosity, botle ba likaroloana le sekhahla sa ho qhibiliha. Ka kakaretso, tekanyo ea ho boloka metsi e phahame ha palo ea ho eketsoa e le khōlō, likaroloana li le ntle le viscosity e phahameng. Har'a tsona, palo ea ho eketsoa e na le phello e kholo ka ho fetisisa tekanyong ea ho boloka metsi, 'me boemo ba viscosity ha bo lekane le tekanyo ea ho boloka metsi. Sekhahla sa ho qhibiliha se itšetlehile haholo ka tekanyo ea phetoho ea holim'a metsi le bokhabane ba likaroloana tsa cellulose.
Liphetoho tsa mocheso li tla ama haholo ho bolokoa ha metsi ho MC. 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 MC ho tla fokotseha haholo, ho ama ka botebo ts'ebetso ea kaho ea seretse.
MC e na le tšusumetso e kholo mosebetsing oa kaho le ho khomarela seretse. Mona, "ho khomarela" ho bolela ho khomarela pakeng tsa lisebelisoa tsa kaho tsa mosebeletsi le substrate ea lerako, ke hore, ho hanyetsa ho kuta ha seretse. Ha ho khomarela ho hoholo, ho na le khanyetso e kholo ea ho kuta ha seretse, matla a mangata a hlokahalang ke mosebeletsi nakong ea tšebeliso, le ts'ebetso e mpe ea kaho ea seretse. Ho khomarela MC ho boemong bo bohareng har'a lihlahisoa tsa cellulose ether.
Hydroxypropyl methylcellulose (HPMC):
HPMC e qhibiliha habonolo ka metsing, empa ho ka ba thata ho qhibiliha ka metsing a chesang. Leha ho le joalo, mocheso oa eona oa gelation metsing a chesang o phahame haholo ho feta oa MC, 'me ho qhibiliha ha oona metsing a batang ho boetse ho molemo ho feta oa MC.
The viscosity ea HPMC e amana le boima ba molek'hule, 'me viscosity e phahame ha boima ba molek'hule bo le boholo. Mocheso o boetse o ama viscosity ea eona, 'me viscosity e fokotseha ha mocheso o ntse o eketseha, empa mocheso oo viscosity ea oona e fokotsehang o tlaase ho feta oa MC. Tharollo ea eona e tsitsitse mocheso oa kamore.
Palo ea metsi ea HPMC e ipapisitse le palo e ekelitsoeng le viscosity, joalo-joalo. Sekhahla sa ho boloka metsi ka chelete e tšoanang ea tlatsetso e phahame ho feta ea MC.
HPMC e tsitsitse ho li-acids le alkalis, 'me tharollo ea eona ea metsi e tsitsitse haholo ka pH mefuta e 2 ~ 12. Caustic soda le metsi a lime ha li na phello e fokolang ts'ebetsong ea eona, empa alkali e ka potlakisa sekhahla sa ho qhibiliha le ho eketsa viscosity. HPMC e tsitsitse ho matsoai a akaretsang, empa ha motsoako oa tharollo ea letsoai o phahame, viscosity ea tharollo ea HPMC e atisa ho eketseha.
HPMC e ka tsoakoa le metsoako ea polymer e qhibilihang ka metsing ho etsa junifomo, tharollo e phahameng ea viscosity, joalo ka joala ba polyvinyl, starch ether, gum ea meroho, joalo-joalo.
HPMC e na le khanyetso e ntle ea enzyme ho feta MC, 'me tharollo ea eona ha e kotsing ea ho senyeha ha enzymatic ho feta MC. HPMC e na le mamarelo a betere ho seretse ho feta MC.
Hydroxyethyl cellulose (HEC):
HEC e qhibiliha ka metsing a batang 'me ho thata ho e qhibiliha ka metsing a chesang. Tharollo e tsitsitse mocheso o phahameng mme ha e na thepa ea gel. E ka sebelisoa ka seretse nako e telele mocheso o phahameng, empa ho boloka metsi ho tlase ho feta MC.
HEC e tsitsitse ho li-acids le li-alkali ka kakaretso, alkali e ka potlakisa ho qhibiliha ha eona le ho eketsa viscosity hanyenyane, 'me ho senyeha ha eona metsing ho tlaase ho feta MC le HPMC.
HEC e na le ts'ebetso e ntle ea ho emisoa bakeng sa seretse, empa samente e na le nako e telele ea ho lieha.
HEC e hlahisoang ke likhoebo tse ling tsa lehae e na le ts'ebetso e tlase ho feta MC ka lebaka la metsi a eona a mangata le molora.
Carboxymethyl cellulose (CMC):
CMC ke ionic cellulose ether e lokisitsoeng ke letoto la kalafo karabelo ka mor'a hore likhoele tsa tlhaho (tse kang k'hothone) li tšoaroe ka alkali le chloroacetic acid e sebelisoa e le etherifying agent. Tekanyo ea ho nka sebaka ka kakaretso e pakeng tsa 0.4 le 1.4, 'me ts'ebetso ea eona e angoa haholo ke tekanyo ea ho kenya sebaka.
CMC e na le litlamorao tsa ho tsitsisa le emulsification, 'me e ka sebelisoa linong tse nang le oli le protheine ho bapala karolo ea emulsification stabilization.
CMC e na le phello ea ho boloka metsi. Lihlahisoang tsa nama, bohobe, li-buns tse halikiloeng le lijo tse ling, li ka bapala karolo ea ntlafatso ea lisele, 'me li ka etsa hore metsi a se ke a fetoha, a eketsa chai ea lihlahisoa le ho eketsa tatso.
CMC e na le phello ea gelling mme e ka sebelisoa ho etsa jelly le jeme.
CMC e ka etsa filimi holim'a lijo, e nang le phello e itseng ea tšireletso holim'a litholoana le meroho 'me e lelefatsa bophelo ba sethala sa litholoana le meroho.
Li-ether tsena tsa cellulose li na le thepa ea tsona e ikhethang le libaka tsa ts'ebeliso. Khetho ea lihlahisoa tse loketseng e hloka ho khethoa ho latela litlhoko tse khethehileng tsa kopo le maemo a tikoloho.
Nako ea poso: Oct-29-2024