Methylcellulose (MC) ke mofuta oa cellulose ether. Cellulose ether compounds ke lintho tse nkiloeng ka ho fetola lik'hemik'hale tsa selulose ea tlhaho, 'me methylcellulose ke motsoako oa bohlokoa oa selulose o entsoeng ke methylating (methyl substitution) karolo ea hydroxyl ea selulose. Ka hona, methylcellulose ha se feela motsoako oa cellulose, empa hape ke ether e tloaelehileng ea cellulose.
1. Tokisetso ea methylcellulose
Methylcellulose e lokisoa ka ho arabela selulose ka methylating agent (e kang methyl chloride kapa dimethyl sulfate) tlas'a maemo a alkaline ho methylate karolo ea hydroxyl ea selulose. Boitšoaro bona bo hlaha haholo ho lihlopha tsa hydroxyl sebakeng sa C2, C3 le C6 sa selulose ho etsa methylcellulose ka likhato tse fapaneng tsa ho fetola. The reaction process ke e latelang:
Cellulose (polysaccharide e entsoeng ka likarolo tsa tsoekere) e qala ho sebetsa tlas'a maemo a alkaline;
Ebe ho hlahisoa moemeli oa methylating ho etsa karabelo ea etherification ho fumana methylcellulose.
Mokhoa ona o ka hlahisa lihlahisoa tsa methylcellulose tse nang le li-viscosities tse fapaneng le thepa ea ho qhibiliha ka ho laola maemo a karabelo le tekanyo ea methylation.
2. Thepa ea methylcellulose
Methylcellulose e na le lintho tse latelang tse ka sehloohong:
Solubility: Ho fapana le cellulose ea tlhaho, methylcellulose e ka qhibiliha metsing a batang empa eseng metsing a chesang. Lebaka ke hore ho hlahisoa ha li-substituents tsa methyl ho senya maqhama a hydrogen pakeng tsa limolek'hule tsa cellulose, ka hona ho fokotsa khanya ea eona. Methylcellulose e etsa tharollo e pepeneneng ka metsing 'me e bonts'a litšobotsi tsa gelation ka mocheso o phahameng, ke hore, tharollo e teteaneng ha e futhumala' me e khutlisa metsi ka mor'a ho pholile.
Non-toxicity: Methylcellulose ha e na chefo 'me ha e monoe ke tsamaiso ea lijo tsa motho. Ka hona, hangata e sebelisoa lijong le li-additives tsa meriana e le motenya, emulsifier le stabilizer.
Taolo ea viscosity: Methylcellulose e na le thepa e ntle ea taolo ea viscosity, mme viscosity ea eona ea tharollo e amana le tharollo ea mahloriso le boima ba limolek'hule. Ka ho laola tekanyo ea ho kenya sebaka karabelong ea etherification, lihlahisoa tsa methylcellulose tse nang le mefuta e fapaneng ea viscosity li ka fumanoa.
3. Tšebeliso ea methylcellulose
Ka lebaka la thepa ea eona e ikhethang ea 'mele le lik'hemik'hale, methylcellulose e sebelisitsoe haholo liindastering tse ngata.
3.1 Indasteri ea lijo
Methylcellulose ke tlatsetso e tloaelehileng ea lijo e sebelisoang mefuteng e fapaneng ea phepelo ea lijo, haholo-holo e le motenya, emulsifier le stabilizer. Kaha methylcellulose e ka halefa ha e futhumala 'me ea tsosolosa metsi ka mor'a ho pholile, hangata e sebelisoa lijong tse leqhoa, thepa e halikiloeng le sopho. Ho phaella moo, tlhaho ea methylcellulose e tlaase ea khalori e etsa hore e be motsoako oa bohlokoa mefuteng e meng ea lijo tse tlaase.
3.2 Liindasteri tsa meriana le tsa bongaka
Methylcellulose e sebelisoa haholo indastering ea meriana, haholo-holo tlhahiso ea letlapa, e le e thusang le ho kopanya. Ka lebaka la bokhoni ba eona bo botle ba ho fetola li-viscosity, e ka ntlafatsa ka katleho matla a mochine le thepa ea ho arohana ea matlapa. Ho feta moo, methylcellulose e boetse e sebelisoa e le karolo ea maiketsetso ea likhapha ho ophthalmology ho phekola mahlo a omileng.
3.3 Indasteri ea kaho le thepa
Har'a thepa ea kaho, methylcellulose e sebelisoa haholo ka samente, gypsum, li-coatings le li-adhesives e le motenya, ho boloka metsi le filimi ea pele. Ka lebaka la ho boloka metsi hantle, methylcellulose e ka ntlafatsa metsi le ho sebetsa ha thepa ea kaho le ho qoba ho hlahisa mapetsong le li-voids.
3.4 Indasteri ea litlolo
Methylcellulose e boetse e sebelisoa hangata indastering ea litlolo e le motenya le stabilizer ho thusa ho theha li-emulsion le li-gel tse tšoarellang nako e telele. E ka ntlafatsa maikutlo a sehlahisoa le ho ntlafatsa phello ea moisturizing. Ke hypoallergenic ebile e bonolo, 'me e loketse letlalo le bonolo.
4. Papiso ea methylcellulose le tse ling tsa cellulose ethers
Li-cellulose ethers ke lelapa le leholo. Ntle le methylcellulose, ho boetse ho na le ethyl cellulose (EC), hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC) le mefuta e meng. Phapang ea bona e ka sehloohong e itšetlehile ka mofuta le tekanyo ea ho kenya sebaka sa li-substituent molek'hule ea cellulose, e khethollang ho solubility, viscosity le libaka tsa kopo.
Methylcellulose vs Hydroxypropyl Methylcellulose (HPMC): HPMC ke mofuta o ntlafalitsoeng oa methylcellulose. Ntle le sebaka sa methyl, hydroxypropyl e boetse e hlahisoa, e etsang hore ho qhibiliha ha HPMC ho fapane haholo. HPMC e ka qhibiliha ka har'a mocheso o pharaletseng, 'me mocheso oa eona oa mocheso oa mocheso o phahame ho feta oa methylcellulose. Ka hona, indastering ea thepa ea moaho le ea meriana, HPMC e na le mefuta e mengata ea lits'ebetso.
Methylcellulose vs Ethyl Cellulose (EC): Ethyl cellulose ha e qhibilihe ka metsing, empa e qhibiliha ka har'a metsoako ea tlhaho. Hangata e sebelisoa ho lisebelisoa tsa membrane tse sa khaotseng bakeng sa ho roala le lithethefatsi. Methyl cellulose e qhibiliha ka metsing a batang 'me e sebelisoa haholo-holo e le ntho e thibelang metsi le ho boloka metsi. Libaka tsa ts'ebeliso ea eona li fapane le tsa ethyl cellulose.
5. Mokhoa oa nts'etsopele ea li-cellulose ethers
Ka tlhokahalo e ntseng e eketseha ea lisebelisoa tse tšoarellang le lik'hemik'hale tse tala, metsoako ea cellulose ether, ho kenyelletsa le methyl cellulose, butle-butle e fetoha karolo ea bohlokoa ea thepa e bolokang tikoloho. E tsoa ho likhoele tsa tlhaho tsa limela, e ka nchafatsoa, 'me ka tlhaho e ka senyeha tikolohong. Nakong e tlang, libaka tsa ts'ebeliso ea li-cellulose ethers li ka 'na tsa atolosoa ka ho eketsehileng, tse kang matla a macha, mehaho e tala le biomedicine.
Joaloka mofuta oa cellulose ether, methyl cellulose e sebelisoa haholo liindastering tse ngata ka lebaka la thepa ea eona e ikhethang ea 'mele le lik'hemik'hale. Ha se feela hore e na le solubility e ntle, e se nang chefo, le bokhoni bo botle ba ho fetola viscosity, empa hape e phetha karolo ea bohlokoa lijong, meriana, kaho le litlolo. Nakong e tlang, ka tlhoko e ntseng e eketseha ea lisebelisoa tse baballang tikoloho, menyetla ea ts'ebeliso ea methyl cellulose e tla ba kholo.
Nako ea poso: Oct-23-2024