I-Methylcellulose (MC) luhlobo lwe-cellulose ether. Iikhompawundi ze-cellulose ether zifunyenwe ngokuguqulwa kweekhemikhali ze-cellulose yendalo, kwaye i-methylcellulose yinto ebalulekileyo ye-cellulose derivative eyenziwe yi-methylating (i-methyl substitution) inxalenye ye-hydroxyl ye-cellulose. Ngoko ke, i-methylcellulose ayisiyiyo kuphela i-cellulose derivative, kodwa kunye ne-ether ye-cellulose eqhelekileyo.
1. Ukulungiswa kwe-methylcellulose
I-Methylcellulose ilungiswe ngokuphendula i-cellulose kunye ne-agent ye-methylating (efana ne-methyl chloride okanye i-dimethyl sulfate) phantsi kweemeko ze-alkali kwi-methylate inxalenye ye-hydroxyl ye-cellulose. Oku kusabela kwenzeka ikakhulu kumaqela e-hydroxyl kwi-C2, i-C3 kunye ne-C6 izikhundla ze-cellulose ukwenza i-methylcellulose kunye needigri ezahlukeneyo zokutshintshwa. Inkqubo yokusabela imi ngolu hlobo lulandelayo:
I-cellulose (i-polysaccharide eyakhiwe ngeeyunithi ze-glucose) iqala ukusebenza phantsi kweemeko ze-alkaline;
Emva koko i-agent ye-methylating yaziswa ukuba ingene kwi-etherification reaction ukuze ifumane i-methylcellulose.
Le ndlela inokuvelisa iimveliso ze-methylcellulose ezine-viscosities ezahlukeneyo kunye neempawu ze-solubility ngokulawula iimeko zokusabela kunye neqondo le-methylation.
2. Iipropati ze-methylcellulose
I-Methylcellulose ineempawu eziphambili ezilandelayo:
Ukunyibilika: Ngokungafaniyo ne-cellulose yendalo, i-methylcellulose inokunyibilika emanzini abandayo kodwa kungekhona emanzini ashushu. Oku kungenxa yokuba ukuqaliswa kwe-methyl substituents kutshabalalisa iibhondi ze-hydrogen phakathi kwee-molecule ze-cellulose, ngaloo ndlela kunciphisa i-crystallinity yayo. I-Methylcellulose yenza isisombululo esicacileyo emanzini kwaye ibonisa iimpawu ze-gelation kumaqondo okushisa aphezulu, oko kukuthi, isisombululo siyaqina xa sishushu kwaye siphinde siphinde sifumane umbane emva kokupholisa.
I-non-toxicity: I-Methylcellulose ayinayo ityhefu kwaye ayifuntshwa yinkqubo yokugaya ukutya komntu. Ngoko ke, isetyenziswa rhoqo kwizongezo zokutya kunye neyeza njenge-thickener, emulsifier kunye ne-stabilizer.
Ukulawulwa kwe-Viscosity: I-Methylcellulose ineempawu ezintle zokulawula i-viscosity, kunye ne-viscosity yayo yesisombululo ihambelana nesisombululo soxinzelelo kunye nobunzima be-molecular. Ngokulawula iqondo lokutshintshwa kwi-etherification reaction, iimveliso ze-methylcellulose ezinoluhlu oluhlukeneyo lwe-viscosity zingafumaneka.
3. Ukusetyenziswa kwe-methylcellulose
Ngenxa yeempawu zayo ezizodwa kunye neekhemikhali, i-methylcellulose isetyenziswe ngokubanzi kumashishini amaninzi.
3.1 Ishishini lokutya
I-Methylcellulose sisongezo sokutya esiqhelekileyo esisetyenziswa kwiindidi ezahlukeneyo zokutya, ngokukodwa njenge-thickener, emulsifier kunye ne-stabilizer. Ekubeni i-methylcellulose inokuthi ifakwe i-gel xa ishushu kwaye ibuyisele ubumanzi emva kokupholisa, ihlala isetyenziselwa ukutya okufriziwe, izinto ezibhakiweyo kunye neesuphu. Ukongezelela, i-calori ephantsi ye-methylcellulose yenza ukuba ibe yinto ebalulekileyo kwezinye iifomyula zokutya eziphantsi kweekhalori.
3.2 Amashishini amayeza kunye nezonyango
I-Methylcellulose isetyenziswa ngokubanzi kwishishini lamachiza, ngakumbi kwimveliso yethebhulethi, njenge-excipient kunye ne-binder. Ngenxa yobuchule bayo bokuhlengahlengiswa kwe-viscosity, inokuphucula ngokufanelekileyo amandla omatshini kunye neempawu zokuqhekeka kwamacwecwe. Ukongeza, i-methylcellulose ikwasetyenziswa njengecandelo leenyembezi ezenziweyo kwi-ophthalmology ukunyanga amehlo omileyo.
3.3 Ishishini lokwakha kunye nemathiriyeli
Phakathi kwezinto zokwakha, i-methylcellulose isetyenziswa ngokubanzi kwi-samente, i-gypsum, i-coatings kunye ne-adhesives njenge-thickener, ukugcinwa kwamanzi kunye nefilimu yangaphambili. Ngenxa yokugcinwa kwamanzi kakuhle, i-methylcellulose inokuphucula umbane kunye nokusebenza kwezinto zokwakha kunye nokuphepha ukuveliswa kweentanda kunye ne-voids.
3.4 Ishishini lezithambiso
I-Methylcellulose isetyenziswa ngokuqhelekileyo kwishishini lezinto zokuthambisa njenge-thickener kunye ne-stabilizer ukunceda ukwenza i-emulsions ehlala ixesha elide kunye neegels. Inokuphucula ukuvakalelwa kwemveliso kunye nokwandisa umphumo wokuthambisa. I-hypoallergenic kwaye ithambile, kwaye ifanelekile kwesikhumba esibucayi.
4. Ukuthelekiswa kwe-methylcellulose kunye nezinye i-cellulose ethers
I-cellulose ethers yintsapho enkulu. Ukongeza kwi-methylcellulose, kukho kwakhona i-ethyl cellulose (EC), i-hydroxypropyl methylcellulose (HPMC), i-hydroxyethyl cellulose (HEC) kunye nezinye iintlobo. Umahluko wabo omkhulu ulele kuhlobo kunye neqondo lokutshintshwa kwezinto ezithatha indawo kwi-molecule ye-cellulose, emisela ukunyibilika kwabo, i-viscosity kunye neendawo zokusebenza.
I-Methylcellulose vs Hydroxypropyl Methylcellulose (HPMC): I-HPMC yinguqulelo ephuculweyo ye-methylcellulose. Ukongeza kwi-methyl substituent, i-hydroxypropyl nayo yaziswa, eyenza ukunyibilika kwe-HPMC kuhluke ngakumbi. I-HPMC inokunyibilika kuluhlu olubanzi lobushushu, kwaye ubushushu bayo be-thermal gelation buphezulu kunolo lwe-methylcellulose. Ngoko ke, kwizinto zokwakha kunye namashishini amayeza, i-HPMC inoluhlu olubanzi lwezicelo.
I-Methylcellulose vs Ethyl Cellulose (EC): I-Ethyl cellulose ayinyibiliki emanzini, kodwa i-soluble kwi-organic solvents. Ihlala isetyenziselwa ukukhutshwa kwe-membrane yezixhobo ezizinzileyo zokugquma kunye neziyobisi. I-Methyl cellulose iyanyibilika emanzini abandayo kwaye isetyenziswa ikakhulu njengento etyebisayo kunye nokugcina amanzi. Iindawo zayo zokusetyenziswa zihluke kwezo ze-ethyl cellulose.
5. Indlela yokuphuhlisa i-cellulose ethers
Ngokunyuka kwemfuno yezinto ezizinzileyo kunye neekhemikhali eziluhlaza, iikhompawundi ze-cellulose ether, ezibandakanya i-methyl cellulose, ngokuthe ngcembe ziba yinxalenye ebalulekileyo yezinto ezihambelana nokusingqongileyo. Ithatyathwe kwimicu yendalo yezityalo, iyahlaziyeka, kwaye inokonakala ngokwendalo kwimekobume. Kwixesha elizayo, iindawo zokusetyenziswa kwe-cellulose ethers zinokwandiswa ngakumbi, njengamandla amatsha, izakhiwo eziluhlaza kunye ne-biomedicine.
Njengodidi lwe-cellulose ether, i-methyl cellulose isetyenziswa ngokubanzi kumashishini amaninzi ngenxa yeempawu zayo ezizodwa kunye neekhemikhali. Ayinayo kuphela i-solubility efanelekileyo, i-non-toxicity, kunye nobuchule obuhle bokulungelelanisa i-viscosity, kodwa idlala indima ebalulekileyo ekutyeni, amayeza, ukwakhiwa kunye nezithambiso. Kwixesha elizayo, ngokunyuka kwemfuno yezinto ezihambelana nokusingqongileyo, amathuba okusetyenziswa kwe-methyl cellulose aya kuba banzi.
Ixesha lokuposa: Oct-23-2024