MC ke methyl cellulose, e fumanoang ka ho phekola k'hothone e hloekisitsoeng ka alkali, ho sebelisoa methyl chloride e le moemeli oa etherifying, le ho etsa cellulose ether ka letoto la liketso. 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.
(1) Ho boloka metsi haselulose ea methylho itshetlehile ka bongata ba yona ba ho eketsa, ho teteana, ho teteana ha dikarolwana le sekgahla sa ho qhalana. Ka kakaretso, haeba bongata ba ho eketsa bo le boholo, ho teteana ho le honyenyane, mme ho teteana ho le hoholo, sekgahla sa ho boloka metsi se hodimo. Har'a tsona, bongata ba ho eketsa bo na le tshusumetso e kgolo hodima sekgahla sa ho boloka metsi, mme boemo ba ho teteana ha bo lekane le boemo ba sekgahla sa ho boloka metsi. Sekgahla sa ho qhaqha se itshetlehile haholo-holo ka tekanyo ya phetoho ya bokahodimo ba dikarolwana tsa cellulose le ho teteana ha dikarolwana. Har'a di-ether tsa cellulose tse ka hodimo, methyl cellulose le hydroxypropyl methyl cellulose di na le sekgahla se hodimo sa ho teteana ha metsi.
(2) Methylcellulose e qhibiliha metsing a batang, empa ho thata ho e qhibilihisa metsing a chesang, 'me tharollo ea eona ea metsi e tsitsitse haholo maemong a pH=3~12. E lumellana hantle le starch, gum ea guar, jj. le li-surfactants tse ngata. Ha mocheso o fihla mochesong oa gelation, ketsahalo ea gelation e etsahala.
(3) Phetoho ea mocheso e tla ama sekhahla sa ho boloka metsi sa methyl cellulose ka botebo. Ka kakaretso, ha mocheso o phahame, ho boloka metsi ho mpefala. Haeba mocheso oa seretse o feta 40 °C, ho boloka metsi ha methyl cellulose ho tla mpefala haholo, e leng se tla ama ho sebetsa ha seretse ka botebo.
(4) Methyl cellulose e na le phello e kholo ho sebetseng le ho khomareleng ha seretse. “Ho khomarela” mona ho bolela ho khomarela ho utloahalang pakeng tsa sesebelisoa sa sesebelisoa sa mosebetsi le substrate ea lebota, ke hore, ho hanyetsa ho kuta ha seretse. Ho khomarela ho hoholo, ho hanyetsa ho kuta ha seretse ho hoholo, 'me matla a hlokahalang ke basebetsi ts'ebetsong ea ts'ebeliso le 'ona a maholo, 'me kaho ea seretse ha e ntle. Ho khomarela ha Methylcellulose ho boemong bo itekanetseng lihlahisoa tsa ether tsa cellulose.
HPMC ke hydroxypropyl methyl cellulose, e leng ether e tsoakiloeng ea cellulose e seng ionic e entsoeng ka k'hothone e hloekisitsoeng ka mor'a kalafo ea alkali, ho sebelisoa propylene oxide le methyl chloride e le li-ether tse futhumatsang, le ka letoto la liketso. Tekanyo ea ho nkeloa sebaka ka kakaretso ke 1.2 ho isa ho 2.0. Thepa ea eona e fapana ho latela karolo ea methoxyl le hydroxypropyl.
(1) Hydroxypropyl methylcellulose e qhibiliha habonolo metsing a batang, empa e tla tobana le mathata ha e qhibiliha ka metsing a chesang. Empa mocheso oa gelation ea eona metsing a chesang o phahame haholo ho feta oa methyl cellulose. Ho qhibiliha ka metsing a batang le hona ho ntlafetse haholo ha ho bapisoa le methyl cellulose.
(2) Ho teteana ha hydroxypropyl methylcellulose ho amana le boholo ba 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. Empa ho teteana ha eona ha ho amehe haholo ke mocheso o phahameng ho feta methyl cellulose. Tharollo ea eona e tsitsitse ha e bolokoa mochesong oa kamore.
(3) Hydroxypropyl methylcellulose e tsitsitse ho ea ho asiti le alkali, 'me tharollo ea eona ea metsi e tsitsitse haholo ho tloha ho pH=2 ~ 12. Caustic soda le metsi a lime ha li na phello e kholo ts'ebetsong ea eona, empa alkali e ka potlakisa ho qhibiliha ha eona le ho eketsa viscosity. Hydroxypropyl methylcellulose e tsitsitse ho ea ho letsoai le tloaelehileng, empa ha mahloriso a tharollo ea letsoai a le holimo, viscosity ea tharollo ea hydroxypropyl methylcellulose e atisa ho eketseha.
(4) Ho boloka metsi hahydroxypropyl methylcelluloseho itshetlehile ka bongata ba yona ba ho eketsa, ho teteana, jj. Sekgahla sa ho boloka metsi tlasa bongata bo tshwanang ba ho eketsa se hodimo ho feta sa methyl cellulose.
(5) Hydroxypropyl methylcellulose e ka kopanngoa le metsoako ea polymer e qhibilihang ka metsing ho etsa tharollo e nang le viscosity e tšoanang le e phahameng. Joalo ka polyvinyl alcohol, starch ether, vegetable gum, jj.
(6) Ho khomarela ha hydroxypropyl methylcellulose kahong ea seretse ho phahame ho feta ha methylcellulose.
(7) Hydroxypropyl methylcellulose e na le khanyetso e betere ho dienzyme ho feta methylcellulose, mme monyetla wa ho senyeha ha enzymatic wa tharollo ya yona o tlase ho feta wa methylcellulose.
Nako ea poso: Mmesa-28-2024