MC ke methyl cellulose, e entsoeng ka cellulose ether ka ho phekola k'hothone e hloekisitsoeng ka alkali, ho sebelisa methane chloride e le etherification agent, le ho latela letoto la liketso. 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) 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.
(2) 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.
(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 ho khomarela seretse. "Ho khomarela" mona ho bolela matla a sekhomaretsi a utloahalang pakeng tsa sesebelisoa sa mosebetsi le karoloana ea lebota, ke hore, ho hanyetsa 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. Methyl cellulose adhesion e boemong bo itekanetseng lihlahisoa tsa cellulose ether.
HPMC ke hydroxypropyl methylcellulose, e leng selulose e seng ionic e tsoakiloeng ka k'hothone e hloekisitsoeng ka mor'a alkalization, e sebelisa propylene oxide le methyl chloride e le li-etherification agents, le 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.
(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, 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.
(3) 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 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.
(4) 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.
(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) Ho khomarela ha hydroxypropyl methylcellulose mohahong oa seretse ho phahame ho feta methylcellulose.
(7) Hydroxypropyl methylcellulose e na le khanyetso e ntle ea enzyme ho feta methylcellulose, 'me tharollo ea eona ha e khone ho senyeha ka li-enzyme ho feta methylcellulose.
Nako ea poso: Apr-17-2023