A:
MC ke methyl cellulose: e hloekisitsoe k'hothone ka mor'a phekolo ea alkali, methane chloride e le etherifying agent, ka letoto la liketso ho etsa cellulose ether. Ka kakaretso, tekanyo ea ho fetola ke 1.6 ~ 2.0, 'me ho qhibiliha ho fapana ho ea ka tekanyo ea ho kenya sebaka. Ke ea nonionic 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 eketsa palo e kholo, fineness e nyane, viscosity, sekhahla sa ho boloka metsi se phahame. Palo ea li-additives e na le tšusumetso e kholo ho tekanyo ea ho boloka metsi, 'me viscosity ha e lekane le tekanyo ea ho boloka metsi. Sekhahla sa ho qhibiliha se itšetlehile haholo ka tekanyo ea phetoho ea holim'a metsi le boleng ba likaroloana tsa likaroloana tsa cellulose. Ho li-ether tse 'maloa tse kaholimo tsa cellulose, sekhahla sa ho boloka metsi sa methyl cellulose le HPMC hydroxypropyl methyl cellulose se phahame.
(2) Methyl cellulose e qhibiliha ka metsing a batang, ao ho leng thata ho qhibiliha ka metsing a chesang. Tharollo ea eona ea metsi e tsitsitse haholo ka hare ho pH = 3 ~ 12. E lumellana hantle le starch, guanidine gum le li-surfactants tse ngata. Gelation e etsahala ha mocheso o fihla mocheso oa gelation.
(3) Phetoho ea mocheso e tla ama ka botebo sekhahla sa ho boloka metsi sa methyl cellulose. Ka kakaretso, ha thempereichara e phahame, ho mpefala ha metsi ho boloka metsi. Haeba mocheso oa seretse o feta 40 ℃, ho bolokoa ha metsi a methyl cellulose ho tla mpefala haholo, e leng ho amang ho aha ha seretse ka botebo.
(4) Methyl cellulose e na le tšusumetso e hlakileng mabapi le ho hahoa le ho khomarela seretse. "Adhesion" mona e bolela ho khomarela ho utluoa ke mosebeletsi pakeng tsa sesebelisoa le lerako la lerako, e leng ho hanyetsa ho kuta ha seretse. Ho khomarela ho hoholo, ho hanyetsa ho kuta ha seretse ho hoholo, matla a hlokoang ke basebetsi ha a ntse a sebelisoa le ona a maholo, 'me ho hahoa ha seretse ho futsanehile. Ka lihlahisoa tsa cellulose ether, ho khomarela ha methyl cellulose ho boemong bo itekanetseng.
HPMC ke hydroxypropyl methyl cellulose: e entsoe ka k'hothone e hloekisitsoeng ka mor'a phekolo ea alkali, e nang le propylene oxide le chloromethane e le etherifying agent, ka letoto la liketso le ho etsoa ka selulose e seng ea ionic e kopantsoeng le ether. Tekanyo ea ho nka sebaka ka kakaretso ke 1.2 ~ 2.0. Thepa ea eona e fapana ho latela karolo ea methoxy le hydroxypropyl content.
(1) HPMC hydroxypropyl methyl cellulose e qhibiliha habonolo metsing a batang, ao ho leng thata ho a qhibiliha ka metsing a chesang. Leha ho le joalo, mocheso oa eona oa gelation metsing a chesang ho hlakile hore o phahame ho feta oa methyl cellulose. Ho qhibiliha ha methyl cellulose metsing a batang le hona ho ile ha ntlafatsoa haholo.
(2) Viscosity ea HPMC hydroxypropyl methyl cellulose e amana le boima ba eona ba molek'hule, 'me ha boima ba limolek'hule bo phahame, ho ba le viscosity e phahameng. Mocheso o boetse o ama viscosity. Viscosity ea fokotseha ha mocheso o ntse o eketseha. Empa phello ea eona ea mocheso o phahameng oa viscosity e tlase ho feta ea methyl cellulose. Tharollo e tsitsitse ha e bolokiloe mocheso oa kamore.
(3) HPMC hydroxypropyl methyl cellulose e tsitsitse ho acid le setsi, 'me tharollo ea eona ea metsi e tsitsitse haholo ka pH = 2 ~ 12. Soda ea caustic le metsi a lime ha li na phello e fokolang ho thepa ea eona, empa alkali e ka potlakisa sekhahla sa ho qhibiliha le ho ntlafatsa viscosity. HPMC hydroxypropyl methyl cellulose e tsitsitse ho matsoai a akaretsang, empa ha motsoako oa motsoako oa letsoai o phahame, viscosity ea HPMC hydroxypropyl methyl cellulose tharollo e atisa ho eketseha.
(4) Poloko ea metsi ea HPMC hydroxypropyl methyl cellulose e itšetlehile ka tekanyo ea eona le viscosity, 'me sekhahla sa ho boloka metsi sa HPMC hydroxypropyl methyl cellulose se phahame ho feta sa methyl cellulose ka tekanyo e tšoanang.
(5) HPMC hydroxypropyl methyl cellulose e ka tsoakoa le metsoako ea polymer e qhibilihang ka metsing hore e be tharollo e tšoanang, e phahameng ea viscosity. Joalo ka joala ba polyvinyl, starch ether, sekhomaretsi sa meroho joalo-joalo.
(6) Ho khomarela ha HPMC hydroxypropyl methyl cellulose mohahong oa seretse ho phahame ho feta methyl cellulose.
(7) HPMC hydroxypropyl methyl cellulose e na le khanyetso e ntle ea enzyme ho feta methyl cellulose, 'me monyetla oa ho senyeha ha enzyme ea eona o tlase ho feta oa methyl cellulose.
Nako ea poso: May-26-2022