Umbuzo okhawulezayo malunga ne-cellulose ethers

I-Cellulose ethers liqela elihlukeneyo leekhemikhali zemichiza ephuma kwi-cellulose, eyona nto ininzi i-polymer eziphilayo emhlabeni. Ezi khompawundi zifumene ukusetyenziswa ngokubanzi kumashishini ahlukeneyo ngenxa yeepropathi zazo ezizodwa kunye nezicelo eziguquguqukayo.

Ubume kunye neePropati zeI-Cellulose Ethers
I-Cellulose, i-polysaccharide equka ukuphindaphinda iiyunithi ze-glucose ezidityaniswe yi-β (1→ 4) iibhondi ze-glycosidic, isebenza njengenxalenye yesakhiwo esisisiseko kwiindonga zeeseli zezityalo. I-cellulose ethers yenziwe ngokuguqulwa kweekhemikhali amaqela e-hydroxyl (-OH) akhoyo kwi-molecule ye-cellulose. Iintlobo eziqhelekileyo ze-cellulose ethers ziquka i-methyl cellulose (MC), i-hydroxypropyl cellulose (HPC), i-hydroxyethyl cellulose (HEC), i-carboxymethyl cellulose (CMC), kunye ne-ethyl hydroxyethyl cellulose (EHEC).

Ukutshintshwa kwamaqela e-hydroxyl kwi-cellulose kunye namaqela ahlukeneyo asebenzayo kuguqula iimpawu ze-ether ze-cellulose ezibangelwayo. Ngokomzekelo, ukungeniswa kwamaqela e-methyl kwandisa ukunyibilika kwamanzi kunye neempawu zokwenza ifilimu, okwenza i-MC ifaneleke kwizicelo kumachiza, iimveliso zokutya kunye nezinto zokwakha. Ngokufanayo, ukufakwa kwamaqela e-hydroxyethyl okanye e-hydroxypropyl kuphucula ukugcinwa kwamanzi, amandla okuqina, kunye nokunamathela, okwenza i-HEC kunye ne-HPC izongezo ezixabisekileyo kwiimveliso zokunyamekela, iipeyinti, kunye ne-adhesives. I-Carboxymethyl cellulose, eveliswe ngokutshintsha amaqela e-hydroxyl ngamaqela e-carboxymethyl, ibonisa ukugcinwa kwamanzi okugqwesileyo, uzinzo, kunye neempawu ezityebileyo, eziyenza isetyenziswe ngokubanzi kushishino lokutya, amayeza, kunye nesongezo solwelo lokomba kwicandelo leoli kunye negesi.

Iqondo lokuthatha indawo (DS), elibonisa inani eliphakathi lamaqela e-hydroxyl afakwe endaweni nganye kwiyunithi ye-glucose kwi-cellulose, ichaphazela kakhulu iipropati ze-cellulose ethers. Amaxabiso aphezulu e-DS akholisa ukukhokelela ekwandeni kokunyibilika, ukuqaqamba kwe-viscosity, kunye nokuzinza, kodwa ukutshintshwa okugqithisileyo kunokubeka esichengeni ukonakaliswa kwezinto eziphilayo kunye nezinye iimpawu ezinqwenelekayo ze-cellulose ethers.

Ukuhlanganiswa kweCellulose Ethers
Ukwenziwa kwe-cellulose ethers kubandakanya ukusabela kweekhemikhali ezizisa amaqela abambeleyo kwi-cellulose backbone. Enye yeendlela eziqhelekileyo zokuvelisa i-cellulose ethers yi-etherification ye-cellulose usebenzisa i-reagents efanelekileyo phantsi kweemeko ezilawulwayo.

Umzekelo, i-synthesis ye-methyl cellulose ibandakanya ukusabela kweselulosi kunye ne-alkali metal hydroxides ukuvelisa i-alkali cellulose, ilandelwa lunyango nge-methyl chloride okanye i-dimethyl sulfate ukwazisa amaqela e-methyl kwikhonkco leselulosi. Ngokufanayo, i-hydroxypropyl cellulose kunye ne-hydroxyethyl cellulose zenziwe ngokuphendula i-cellulose kunye ne-propylene oxide okanye i-ethylene oxide, ngokulandelanayo, phambi kwe-alkali catalysts.

I-Carboxymethyl cellulose iveliswa ngokusabela kweselulosi kunye ne-sodium hydroxide kunye ne-chloroacetic acid okanye ityuwa yesodium. Inkqubo ye-carboxymethylation yenzeke ngokusebenzisa i-nucleophilic substitution, apho iqela le-hydroxyl le-cellulose liphendula nge-chloroacetic acid ukwenza i-carboxymethyl ether linkage.

Ukudityaniswa kwe-cellulose ethers kufuna ulawulo olululo lweemeko zokusabela, ezifana nobushushu, i-pH, kunye nexesha lokuphendula, ukuphumeza iqondo elinqwenelekayo lokutshintsha kunye neempawu zemveliso. Ukongezelela, amanyathelo okucoca ahlala esetyenziselwa ukususa imveliso kunye nokungcola, ukuqinisekisa umgangatho kunye nokuhambelana kwe-cellulose ethers.

Ukusetyenziswa kweCellulose Ethers
I-Cellulose ethers ifumana ukusetyenziswa okuxhaphakileyo kuwo wonke amashishini ahlukeneyo ngenxa yeepropathi zazo ezahlukeneyo kunye nokusebenza kwazo. Ezinye zezicelo eziphambili ziquka:

Ishishini lokutya:I-cellulose ethersezifana ne-carboxymethyl cellulose zidla ngokusetyenziswa njengee-agent ezityebisayo, izizinzi, kunye ne-emulsifiers kwiimveliso zokutya ezinje ngeesosi, iilokhwe, kunye ne-ice creams. Baphucula ukuthungwa, i-viscosity, kunye nokuzinza kweshelufu ngelixa bephucula umlomo kunye nokukhululwa kwencasa.

I-Pharmaceuticals: I-Methyl cellulose kunye ne-hydroxypropyl cellulose zisetyenziswe ngokubanzi kwiifomyula zamachiza njengezibophelelo, i-disintegrants, kunye ne-controlled-release agents kwiipilisi, ii-capsules, kunye ne-topical formulations. Ezi cellulose ethers ziphucula ukuhanjiswa kwamachiza, bioavailability, kunye nokuthotyelwa kwesigulane.

Izinto zokwakha: I-Methyl cellulose kunye ne-hydroxyethyl cellulose zisetyenziswa kwishishini lokwakha njengezongezo kwi-samente-based mortars, i-plasters, kunye ne-adhesives ye-tile ukuphucula ukusebenza, ukugcinwa kwamanzi kunye neempawu zokubambelela. Baphucula umanyano, banciphise ukuqhekeka, kwaye baphucule ukusebenza kwemathiriyeli yokwakha.

Iimveliso zokhathalelo lobuqu: Iselulosi ye-Hydroxyethyl kunye ne-hydroxypropyl cellulose zizithako eziqhelekileyo kwiimveliso zokhathalelo lomntu ezifana neshampu, iilotion, kunye neekhrimu ngenxa ye-t.

o Ukutyeba, ukuzinzisa, kunye neempawu zabo zokwenza ifilim. Baphucula ukuhambelana kwemveliso, ukuthungwa, kunye nokuziva kwesikhumba ngelixa bephucula ukuzinza kokwakheka.

Iipeyinti kunye neeNgxoxo: I-cellulose ethers isebenza njenge-rheology modifiers, i-thickeners, kunye ne-stabilizers kwiipende, iingubo, kunye ne-adhesives, ukuphucula iimpawu zesicelo, ukuziphatha kokuhamba, kunye nokwakheka kwefilimu. Baphucula ukulawulwa kwe-viscosity, ukuxhathisa kwe-sag, kunye nokuzinza kombala kwiindlela ezisekelwe emanzini.

Umzi-mveliso we-oyile negesi: I-Carboxymethyl cellulose isetyenziswa njenge-viscosity modifier kunye ne-arhente yokulawula ilahleko yolwelo kulwelo lokomba lwe-oyile negesi yokuhlola nokuveliswa. Iphucula i-rheology yolwelo, ukucocwa komngxuma, kunye nokuzinza kwe-wellbore ngelixa ukhusela umonakalo wokwakheka.

Umzi-mveliso weMilaphu: Ii-ether ze-Cellulose zisetyenziswa ekushicileleni amalaphu, ukudaya, kunye nokugqiba iinkqubo zokuphucula ukuchazwa koshicilelo, isivuno sombala, kunye nokuthamba kwelaphu. Baququzelela ukusasazwa kwe-pigment, ukunamathela kwiintsinga, kunye nokuhlamba ukukhawuleza kwi-application yelaphu.

I-cellulose etherszimele iqela elihlukeneyo leekhemikhali zemichiza ephuma kwi-cellulose, enikezela uluhlu olubanzi lweepropati kunye nokusebenza kwezicelo ezahlukeneyo zoshishino. Ngokusebenzisa ukuguqulwa kweekhemikhali ezilawulwayo ze-cellulose backbone, i-cellulose ethers ibonisa iimpawu ezinqwenelekayo ezifana nokunyibilika kwamanzi, ukulawulwa kwe-viscosity, kunye nokuzinza, okwenza zibe izongezo ezixabisekileyo kumashishini avela kukutya kunye namayeza ukuya kulwakhiwo kunye neendwangu. Njengoko imfuno yezinto ezizinzileyo kunye nezokusingqongileyo ziqhubeka zikhula, i-cellulose ethers ikulungele ukudlala indima ebalulekileyo ekuhlangabezaneni neemfuno eziguqukayo zamashishini anamhlanje ngelixa kuncitshiswa impembelelo yokusingqongileyo.