Potso e potlakileng mabapi le li-cellulose ethers

Li-cellulose ethers ke lihlopha tse fapaneng tsa metsoako ea lik'hemik'hale tse nkiloeng ho selulose, e leng polymer e ngata ka ho fetisisa lefatšeng. Lik'hemik'hale tsena li fumane tšebeliso e atileng liindastering tse fapaneng ka lebaka la thepa ea tsona e ikhethang le lits'ebetso tse fapaneng.

Sebopeho le Thepa eaCellulose Ethers
Cellulose, polysaccharide e nang le likaroloana tse pheta-phetoang tsa tsoekere tse hokahantsoeng ke β(1→4) glycosidic bond, e sebetsa e le karolo ea mantlha ea sebopeho maboteng a lisele tsa limela. Li-cellulose ethers li entsoe ka ho fetola lik'hemik'hale lihlopha tsa hydroxyl (-OH) tse teng ka molek'hule ea selulose. Mefuta e atileng haholo ea li-cellulose ethers e kenyelletsa methyl cellulose (MC), hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), le ethyl hydroxyethyl cellulose (EHEC).

Ho nkeloa sebaka ha lihlopha tsa hydroxyl ka selulose ka lihlopha tse fapaneng tse sebetsang ho fetola thepa ea sephetho sa cellulose ethers. Mohlala, ho hlahisoa ha lihlopha tsa methyl ho ntlafatsa ho qhibiliha ha metsi le thepa ea ho etsa lifilimi, ho etsa hore MC e lokele lits'ebetso tsa meriana, lihlahisoa tsa lijo le thepa ea kaho. Ka mokhoa o ts'oanang, ho kenyelletsoa ha lihlopha tsa hydroxyethyl kapa hydroxypropyl ho ntlafatsa ho boloka metsi, bokhoni ba ho tiisa, le ho khomarela, ho etsa hore HEC le HPC li be le li-additives tsa bohlokoa lihlahisoa tsa tlhokomelo ea botho, lipente le li-adhesives. Carboxymethyl cellulose, e hlahisoang ka ho kenya lihlopha tsa hydroxyl le lihlopha tsa carboxymethyl, e bonts'a ho boloka metsi hantle, botsitso le thepa e teteaneng, e e etsa hore e sebelisoe haholo indastering ea lijo, meriana, le joalo ka tlatsetso ea mokelikeli oa ho cheka lekaleng la oli le khase.

The degree of substitution (DS), e bonts'ang palo-hare ea palo ea lihlopha tsa hydroxyl tse nkeloang sebaka ka yuniti ea tsoekere ka selulose, e susumetsa haholo litšobotsi tsa cellulose ethers. Litekanyetso tse phahameng tsa DS hangata li fella ka ho qhibiliha ho eketsehileng, viscosity, le botsitso, empa ho nkela sebaka ho feteletseng ho ka senya biodegradability le litšobotsi tse ling tse lakatsehang tsa cellulose ethers.

Synthesis ea Cellulose Ethers
Tšimoloho ea li-cellulose ethers e kenyelletsa liphetoho tsa lik'hemik'hale tse hlahisang lihlopha tse ling mokokotlong oa cellulose. E 'ngoe ea mekhoa e tloaelehileng ea ho hlahisa li-cellulose ethers ke etherification ea selulose ho sebelisa li-reagents tse loketseng tlas'a maemo a laoloang.

Mohlala, motsoako oa methyl cellulose hangata o kenyelletsa karabelo ea selulose ka alkali metal hydroxides ho hlahisa alkali cellulose, e lateloe ke kalafo ka methyl chloride kapa dimethyl sulfate ho kenyelletsa lihlopha tsa methyl ketane ea cellulose. Ka mokhoa o ts'oanang, hydroxypropyl cellulose le hydroxyethyl cellulose li entsoe ka ho arabela selulose ka propylene oxide kapa ethylene oxide, ka ho latellana, ka pel'a li-catalysts tsa alkali.

Carboxymethyl cellulose e hlahisoa ka karabelo ea selulose ka sodium hydroxide le chloroacetic acid kapa letsoai la eona la sodium. Ts'ebetso ea carboxymethylation e etsahala ka sebaka sa nucleophilic, moo sehlopha sa hydroxyl sa cellulose se arabelang ka chloroacetic acid ho theha khokahano ea carboxymethyl ether.

Kakaretso ea li-cellulose ethers e hloka taolo e hlokolosi ea maemo a karabelo, joalo ka mocheso, pH, le nako ea karabelo, ho fihlela boemo bo lakatsehang ba phetisetso le thepa ea sehlahisoa. Ho feta moo, mehato ea tlhoekiso e atisa ho sebelisoa ho tlosa lihlahisoa le litšila, ho netefatsa boleng le ho tsitsisa ha cellulose ethers.

Lisebelisoa tsa Cellulose Ethers
Li-cellulose ethers li fumana lits'ebetso tse atileng liindastering tse fapaneng ka lebaka la thepa le ts'ebetso ea tsona e fapaneng. Tse ling tsa lisebelisoa tsa bohlokoa li kenyelletsa:

Indasteri ea Lijo:Li-cellulose ethersjoalo ka carboxymethyl cellulose hangata e sebelisoa joalo ka li-thickening agents, stabilizers, le emulsifiers lihlahisoa tsa lijo joalo ka li-sauces, dressings le ice cream. Li ntlafatsa sebopeho, viscosity le botsitso ba sethala ha li ntse li ntlafatsa molomo le tatso.

Litlhare: Methyl cellulose le hydroxypropyl cellulose li sebelisoa haholo mefuteng ea meriana e le li-binders, disintegrants, le li-agent tse laoloang tse lokolloang matlapeng, li-capsules le li-topical formulations. Li-cellulose ether tsena li ntlafatsa phano ea lithethefatsi, bioavailability, le ho latela melao ea mokuli.

Lisebelisuoa tsa Kaho: Methyl cellulose le hydroxyethyl cellulose li sebelisoa indastering ea kaho e le li-additives ka seretse se entsoeng ka samente, li-plaster le li-adhesives tsa lithaele ho matlafatsa ts'ebetso, ho boloka metsi le thepa ea ho khomarela. Li ntlafatsa momahano, li fokotsa ho peperana, le ho ntlafatsa ts'ebetso ea thepa ea kaho.

Lihlahisoa tsa Tlhokomelo ea Motho: Hydroxyethyl cellulose le hydroxypropyl cellulose ke metsoako e tloaelehileng lihlahisoa tsa tlhokomelo ea motho joalo ka li-shampoo, lotions, le litlolo tse loketseng.

o matla a bona, ho tsitsisa le ho etsa lifilimi. Li ntlafatsa ts'ebetso ea sehlahisoa, sebopeho, le letlalo la letlalo ha li ntse li matlafatsa botsitso ba sebopeho.

Lipente le Liaparo: Li-cellulose ethers li sebetsa e le li-rheology modifiers, thickeners, le stabilizer ka lipente, liphahlo le li-adhesives, ho ntlafatsa thepa ea kopo, boitšoaro ba ho phalla le ho thehoa ha filimi. Li ntlafatsa taolo ea viscosity, ho hanyetsa ho sag, le botsitso ba mebala mefuteng e thehiloeng metsing.

Indasteri ea Oli le Khase: Carboxymethyl cellulose e sebelisoa e le sesebelisoa sa viscosity modifier le se laolang tahlehelo ea mokelikeli marong a ho cheka bakeng sa tlhahlobo ea oli le khase le tlhahiso. E ntlafatsa rheology ea mokelikeli, ho hloekisa likoti, le botsitso ba hantle ha e ntse e thibela tšenyo ea sebopeho.

Indasteri ea Masela: Li-cellulose ethers li sebelisoa ho hatisa masela, ho daea le ho phethela mekhoa ea ho ntlafatsa tlhaloso ea khatiso, tlhahiso ea mebala le bonolo ba masela. Li thusa ho hasana ha pigment, ho khomarela likhoele, 'me li hlatsoa ka potlako lisebelisoa tsa masela.

Li-cellulose ethersemela sehlopha se fapaneng sa metsoako ea lik'hemik'hale e nkiloeng ho selulose, e fanang ka mefuta e mengata ea thepa le ts'ebetso bakeng sa lits'ebetso tse fapaneng tsa indasteri. Ka liphetoho tse laoloang tsa lik'hemik'hale tsa mokokotlo oa selulose, li-cellulose ethers li bonts'a litšobotsi tse lakatsehang tse kang ho qhibiliha ha metsi, taolo ea viscosity le botsitso, e leng se etsang hore e be li-additives tsa bohlokoa liindastering ho tloha ho lijo le meriana ho ea ho haha ​​​​le masela. Ha tlhoko ea thepa e tšoarellang le e baballang tikoloho e ntse e hola, li-cellulose ethers li mothating oa ho bapala karolo ea bohlokoa ho fihlela litlhoko tse tsoelang pele tsa indasteri ea sejoale-joale ha li ntse li fokotsa tšusumetso ea tikoloho.