Umbuzo osheshayo mayelana nama-cellulose ethers

I-cellulose ethers iyiqembu elihlukahlukene lenhlanganisela yamakhemikhali etholakala ku-cellulose, okuyi-polymer ephilayo eningi kakhulu eMhlabeni. Lezi zinhlanganisela zithole ukusetshenziswa okubanzi ezimbonini ezahlukahlukene ngenxa yezakhiwo zazo ezihlukile kanye nezicelo eziguquguqukayo.

Isakhiwo kanye Nezakhiwo zeI-Cellulose Ethers
I-Cellulose, i-polysaccharide ehlanganisa amayunithi e-glucose aphindaphindayo axhunywe ngamabhondi e-β(1→4) e-glycosidic, isebenza njengengxenye yesakhiwo eyinhloko ezindongeni zamaseli ezitshalo. Ama-cellulose ethers ahlanganiswa ngokushintsha amakhemikhali amaqembu e-hydroxyl (-OH) akhona ku-molecule ye-cellulose. Izinhlobo ezivame kakhulu ze-cellulose ethers zihlanganisa i-methyl cellulose (MC), i-hydroxypropyl cellulose (HPC), i-hydroxyethyl cellulose (HEC), i-carboxymethyl cellulose (CMC), ne-ethyl hydroxyethyl cellulose (EHEC).

Ukufakwa esikhundleni kwamaqembu e-hydroxyl ku-cellulose ngamaqembu ahlukahlukene asebenzayo kushintsha izakhiwo ze-cellulose ethers eziwumphumela. Isibonelo, ukwethulwa kwamaqembu e-methyl kuthuthukisa ukuncibilika kwamanzi kanye nezakhiwo zokwakha amafilimu, okwenza i-MC ifanelekele ukusetshenziswa kwemithi, imikhiqizo yokudla, nezinto zokwakha. Ngokufanayo, ukufakwa kwamaqembu e-hydroxyethyl noma e-hydroxypropyl kuthuthukisa ukugcinwa kwamanzi, ikhono lokuqina, nokunamathela, okwenza i-HEC ne-HPC izithasiselo ezibalulekile emikhiqizweni yokunakekelwa komuntu siqu, amapende, nama-adhesives. I-Carboxymethyl cellulose, ekhiqizwe ngokufaka amaqembu e-hydroxyl esikhundleni samaqembu e-carboxymethyl, ikhombisa ukugcinwa kwamanzi okuhle kakhulu, ukuzinza, kanye nezindawo ezijiyayo, ikwenze isetshenziswe kabanzi embonini yokudla, kwezemithi, nanjengesengezo soketshezi lokumba emkhakheni kawoyela negesi.

I-Degree of substitution (DS), ebonisa inani eliphakathi nendawo lamaqembu e-hydroxyl eyunithi ngayinye ye-glucose ku-cellulose, lithonya ngokuphawulekayo izici ze-cellulose ethers. Amanani aphezulu e-DS ngokuvamile aphumela ekwenyukeni kokuncibilika, i-viscosity, kanye nokuzinza, kodwa ukufaka esikhundleni ngokweqile kungase kubeke engcupheni i-biodegradability nezinye izici ezifiselekayo zama-cellulose ether.

Ukuhlanganiswa kwe-Cellulose Ethers
Ukuhlanganiswa kwe-cellulose ethers kuhilela ukusabela kwamakhemikhali okwethula amaqembu angena esikhundleni kumgogodla we-cellulose. Enye yezindlela ezivame kakhulu zokukhiqiza ama-cellulose ethers i-etherification ye-cellulose kusetshenziswa ama-reagents afanelekile ngaphansi kwezimo ezilawulwayo.

Isibonelo, ukuhlanganiswa kwe-methyl cellulose ngokuvamile kuhilela ukusabela kwe-cellulose nge-alkali metal hydroxides ukuze kukhiqizwe i-alkali cellulose, okulandelwa ukwelashwa nge-methyl chloride noma i-dimethyl sulfate ukwethula amaqembu e-methyl ochungechungeni lwe-cellulose. Ngokufanayo, i-hydroxypropyl cellulose ne-hydroxyethyl cellulose ahlanganiswa ngokuphendula i-cellulose nge-propylene oxide noma i-ethylene oxide, ngokulandelana, phambi kwama-catalysts e-alkali.

I-Carboxymethyl cellulose ikhiqizwa ngokusabela kwe-cellulose nge-sodium hydroxide ne-chloroacetic acid noma usawoti wayo we-sodium. Inqubo ye-carboxymethylation yenzeka ngokufaka esikhundleni se-nucleophilic, lapho iqembu le-hydroxyl le-cellulose lisabela ne-chloroacetic acid ukwakha ukuxhumana kwe-carboxymethyl ether.

Ukuhlanganiswa kwama-cellulose ethers kudinga ukulawula ngokucophelela izimo zokusabela, njengezinga lokushisa, i-pH, nesikhathi sokusabela, ukuze kuzuzwe izinga elifiswayo lokushintsha kanye nezakhiwo zomkhiqizo. Ukwengeza, izinyathelo zokuhlanza zivame ukusetshenziswa ukuze kukhishwe imikhiqizo egayiwe kanye nokungcola, kuqinisekiswe ikhwalithi nokuvumelana kwama-cellulose ethers.

Izicelo zeCellulose Ethers
Ama-cellulose ether athola ukusetshenziswa okusabalele kuzo zonke izimboni ezihlukahlukene ngenxa yezakhiwo nokusebenza kwawo okuhlukahlukene. Ezinye zezinhlelo zokusebenza ezibalulekile zifaka:

Imboni Yokudla:Ama-cellulose ethersnjenge-carboxymethyl cellulose ivamise ukusetshenziswa njengama-thickening agents, iziqinisi, nama-emulsifiers emikhiqizweni yokudla efana namasoso, okokugqoka, nama-ayisikhilimu. Bathuthukisa ukuthungwa, i-viscosity, nokuzinza kweshalofu ngenkathi bethuthukisa ukukhishwa komlomo nokunambitheka.

Ezemithi: I-Methyl cellulose ne-hydroxypropyl cellulose asetshenziswa kakhulu ekwenziweni kwemithi njengama-binders, ama-disintegrants, nama-ejenti akhululwayo alawulwayo kumaphilisi, amaphilisi, kanye nokwakhiwa kwezihloko. Lawa ma-cellulose ethers athuthukisa ukulethwa kwezidakamizwa, i-bioavailability, nokuthobela isiguli.

Izinto Zokwakha: I-methyl cellulose ne-hydroxyethyl cellulose zisetshenziswa embonini yezokwakha njengezithasiselo odakeni olusekelwe kusimende, amapulastele, nama-adhesive anamathelayo ukuze kuthuthukiswe ukusebenza, ukugcinwa kwamanzi, kanye nezakhiwo zokunamathela. Bathuthukisa ukubumbana, banciphise ukuqhekeka, futhi bathuthukise ukusebenza kwezinto zokwakha.

Imikhiqizo Yokunakekela Umuntu: I-Hydroxyethyl cellulose kanye ne-hydroxypropyl cellulose yizithako ezivamile emikhiqizweni yokunakekelwa komuntu siqu njengama-shampoos, ama-lotions, nama-creams okufanele t.

o ukujiya kwawo, ukuzinzisa, nokwenza amafilimu. Zithuthukisa ukungaguquguquki komkhiqizo, ukuthungwa, nokuzwakala kwesikhumba ngenkathi zithuthukisa ukwakheka kokuqina.

Amapende Nezingubo: Ama-cellulose ethers asebenza njengama-rheology modifiers, thickeners, nama-stabilizer kumapende, ama-coatings, nama-adhesives, athuthukisa izakhiwo zohlelo lokusebenza, ukuziphatha kokugeleza, nokwakheka kwefilimu. Bathuthukisa ukulawulwa kwe-viscosity, ukumelana ne-sag, nokuzinza kombala ekwakhiweni okusekelwe emanzini.

Imboni Kawoyela Negesi: I-Carboxymethyl cellulose isetshenziswa njenge-viscosity modifier kanye ne-ejenti yokulawula ukulahlekelwa uketshezi ekumbelweni koketshezi lokuhlola nokukhiqizwa kukawoyela negesi. Ithuthukisa i-rheology yoketshezi, ukuhlanzwa kwemigodi, nokuzinza kwe-wellbore ngenkathi ivimbela ukulimala kokwakheka.

Imboni Yezindwangu: Ama-cellulose ether asetshenziswa ekuphrinteni izindwangu, ukudaya, kanye nezinqubo zokuqeda ukuze kuthuthukiswe ukuchazwa kokuphrinta, ukuvela kombala, kanye nokuthamba kwendwangu. Benza lula ukuhlakazeka kwe-pigment, ukunamathela kumafayibha, futhi bageze ukushesha kokufakwa kwendwangu.

Ama-cellulose etherszimelela iqembu elihlukahlukene lezinhlanganisela zamakhemikhali atholakala ku-cellulose, enikeza inhlobonhlobo yezakhiwo nokusebenza kwezinhlelo zokusebenza ezihlukahlukene zezimboni. Ngokuguqulwa kwamakhemikhali okulawulwayo komgogodla we-cellulose, ama-ether e-cellulose abonisa izici ezifiselekayo ezifana nokuncibilika kwamanzi, ukulawulwa kwe-viscosity, nokuzinza, okubenza babe izithasiselo ezibalulekile ezimbonini ezisukela ekudleni nemithi kuya kwezokwakha nezindwangu. Njengoba isidingo sezinto ezisimeme nezinobungani kwemvelo siqhubeka sikhula, ama-cellulose ether akulungele ukudlala indima ebalulekile ekuhlangabezaneni nezidingo ezithuthukayo zezimboni zesimanje kuyilapho enciphisa umthelela wendawo.