I-Methylcellulose (MC) iwuhlobo lwe-cellulose ether. Izinhlanganisela ze-cellulose ether ziwukuphuma okutholwe ngokuguqulwa kwamakhemikhali ku-cellulose yemvelo, futhi i-methylcellulose iwumphumela ophuma ku-cellulose obalulekile owakhiwa i-methylating (i-methyl substitution) ingxenye ye-hydroxyl ye-cellulose. Ngakho-ke, i-methylcellulose ayiyona nje i-cellulose derivative, kodwa futhi i-ether ye-cellulose evamile.
1. Ukulungiswa kwe-methylcellulose
I-Methylcellulose ilungiswa ngokuphendula i-cellulose nge-ejenti ye-methylating (njenge-methyl chloride noma i-dimethyl sulfate) ngaphansi kwezimo ze-alkaline ukuze i-methylate ingxenye ye-hydroxyl ye-cellulose. Lokhu kusabela kwenzeka ikakhulukazi emaqenjini e-hydroxyl endaweni ye-C2, C3 kanye ne-C6 ye-cellulose ukuze akhe i-methylcellulose enamazinga ahlukene okushintsha. Inqubo yokusabela imi kanje:
I-cellulose (i-polysaccharide eyakhiwe amayunithi e-glucose) iqala ukusebenza ngaphansi kwezimo ze-alkaline;
Bese kwethulwa i-ejenti ye-methylating ukuze ibhekane ne-etherification reaction ukuze ithole i-methylcellulose.
Le ndlela ingakhiqiza imikhiqizo ye-methylcellulose ene-viscosity ehlukene kanye nezindawo zokuncibilika ngokulawula izimo zokusabela kanye nezinga le-methylation.
2. Izakhiwo ze-methylcellulose
I-Methylcellulose inezindawo ezilandelayo eziyinhloko:
Ukunyibilika: Ngokungafani ne-cellulose yemvelo, i-methylcellulose ingancibilika emanzini abandayo kodwa hhayi emanzini ashisayo. Lokhu kungenxa yokuthi ukwethulwa kwama-substituents e-methyl kubhubhisa izibopho ze-hydrogen phakathi kwama-molecule e-cellulose, ngaleyo ndlela kunciphisa ukucwebezela kwayo. I-Methylcellulose yakha isixazululo esisobala emanzini futhi ikhombisa izici ze-gelation emazingeni okushisa aphezulu, okungukuthi, isisombululo siyashuba lapho sishiswa futhi siphinde sithole uketshezi ngemuva kokupholisa.
Ukungewona ubuthi: I-methylcellulose ayinabo ubuthi futhi ayimuncwa uhlelo lokugaya ukudla komuntu. Ngakho-ke, kuvame ukusetshenziselwa izithasiselo zokudla kanye nemithi njenge-thickener, emulsifier kanye ne-stabilizer.
Ukulawulwa kwe-viscosity: I-Methylcellulose inezici ezinhle zokulawula i-viscosity, futhi i-viscosity yayo yesisombululo ihlobene nokuhlushwa kwesisombululo kanye nesisindo samangqamuzana. Ngokulawula izinga lokushintsha ekuphenduleni kwe-etherification, imikhiqizo ye-methylcellulose enamabanga ahlukene e-viscosity ingatholwa.
3. Ukusetshenziswa kwe-methylcellulose
Ngenxa yezakhiwo zayo eziyingqayizivele zomzimba namakhemikhali, i-methylcellulose isetshenziswe kabanzi ezimbonini eziningi.
3.1 Imboni yokudla
I-Methylcellulose iyisengezo sokudla esivamile esisetshenziswa ezinhlobonhlobo zokucubungula ukudla, ikakhulukazi njenge-thickener, emulsifier kanye ne-stabilizer. Njengoba i-methylcellulose ingaba ijeli lapho ishiswa futhi ibuyisela uketshezi ngemva kokupholisa, ivame ukusetshenziswa ekudleni okufriziwe, izimpahla ezibhakwayo kanye nesobho. Ngaphezu kwalokho, imvelo ephansi yekhalori ye-methylcellulose yenza kube isithako esibalulekile kwamanye amafomula okudla anekhalori ephansi.
3.2 Izimboni zemithi nezokwelapha
I-Methylcellulose isetshenziswa kabanzi embonini yezemithi, ikakhulukazi ekukhiqizeni amaphilisi, njenge-excipient ne-binder. Ngenxa yekhono layo elihle lokulungisa i-viscosity, ingathuthukisa ngempumelelo amandla emishini kanye nezakhiwo zokuhlakazeka zamaphilisi. Ngaphezu kwalokho, i-methylcellulose iphinde isetshenziswe njengengxenye yezinyembezi zokwenziwa ku-ophthalmology ukwelapha amehlo omile.
3.3 Imboni yezokwakha kanye nezinto zokwakha
Phakathi kwezinto zokwakha, i-methylcellulose isetshenziswa kakhulu kusimende, i-gypsum, i-coatings kanye ne-adhesives njenge-thickener, i-retainer yamanzi kanye nefilimu yangaphambili. Ngenxa yokugcinwa kwayo kahle kwamanzi, i-methylcellulose ingathuthukisa uketshezi nokusebenza kwezinto zokwakha futhi igweme ukukhiqizwa kwemifantu kanye nama-voids.
3.4 Imboni yezimonyo
I-Methylcellulose iphinde isetshenziswe embonini yezimonyo njenge-thickener kanye ne-stabilizer ukusiza ukwakha ama-emulsion nama-gel ahlala isikhathi eside. Ingathuthukisa umuzwa womkhiqizo futhi ithuthukise umphumela wokuthambisa. I-hypoallergenic futhi imnene, futhi ifanele isikhumba esibucayi.
4. Ukuqhathaniswa kwe-methylcellulose namanye ama-cellulose ether
I-Cellulose ethers umndeni omkhulu. Ngaphandle kwe-methylcellulose, kukhona ne-ethyl cellulose (EC), i-hydroxypropyl methylcellulose (HPMC), i-hydroxyethyl cellulose (HEC) nezinye izinhlobo. Umehluko wabo oyinhloko usehlotsheni kanye nezinga lokufakwa esikhundleni se-molecule ye-cellulose, enquma ukunyibilika kwabo, i-viscosity kanye nezindawo zokusebenzisa.
I-Methylcellulose vs Hydroxypropyl Methylcellulose (HPMC): I-HPMC inguqulo ethuthukisiwe ye-methylcellulose. Ngokungeziwe esikhundleni se-methyl, i-hydroxypropyl nayo yethulwa, okwenza ukunyibilika kwe-HPMC kuhluke kakhulu. I-HPMC ingancibilika ebangeni lokushisa elibanzi, futhi izinga lokushisa elishisayo le-gelation liphezulu kunalelo le-methylcellulose. Ngakho-ke, ezimbonini zokwakha kanye nezimboni zemithi, i-HPMC inohlu olubanzi lwezinhlelo zokusebenza.
I-Methylcellulose vs Ethyl Cellulose (EC): I-Ethyl cellulose ayincibiliki emanzini, kodwa incibilika kuzincibilikisi zemvelo. Isetshenziswa kaningi ezintweni ezisetshenziswayo zokukhishwa kwe-membrane zokumboza nezidakamizwa. I-Methyl cellulose iyancibilika emanzini abandayo futhi isetshenziswa kakhulu njenge-thickener kanye ne-ejenti egcina amanzi. Izindawo ezisetshenziswayo zihlukile kulezo ze-ethyl cellulose.
5. Indlela yokuthuthuka yama-cellulose ethers
Ngokukhula kwesidingo sezinto ezisimeme namakhemikhali aluhlaza, izinhlanganisela ze-cellulose ether, kuhlanganise ne-methyl cellulose, kancane kancane ziba ingxenye ebalulekile yezinto ezithinta imvelo. Isuselwa emiculweni yezitshalo yemvelo, iyavuseleleka, futhi ingonakaliswa ngokwemvelo endaweni ezungezile. Ngokuzayo, izindawo zokusetshenziswa kwe-cellulose ethers zingase zinwetshwe ngokuqhubekayo, njengamandla amasha, izakhiwo eziluhlaza kanye ne-biomedicine.
Njengohlobo lwe-cellulose ether, i-methyl cellulose isetshenziswa kabanzi ezimbonini eziningi ngenxa yezakhiwo zayo ezihlukile zomzimba namakhemikhali. Ayinayo nje kuphela i-solubility enhle, i-non-toxicity, kanye nekhono elihle lokulungiswa kwe-viscosity, kodwa futhi idlala indima ebalulekile ekudleni, emithini, ekwakhiweni nasezimonyoni. Ngokuzayo, ngesidingo esandayo sezinto zokwakha ezinobungani bemvelo, amathuba okufakwa kwe-methyl cellulose azoba banzi.
Isikhathi sokuthumela: Oct-23-2024