Umbuzo omfutshane malunga nee-ether ze-cellulose

Ii-ether ze-Cellulose liqela elahlukeneyo lee-compounds zeekhemikhali ezivela kwi-cellulose, eyona polymer ininzi kakhulu eMhlabeni. Ezi compounds zifunyenwe ngokubanzi kumashishini ahlukeneyo ngenxa yeempawu zazo ezikhethekileyo kunye nokusetyenziswa kwazo ngeendlela ezahlukeneyo.

Ulwakhiwo kunye neempawu zeIi-Ether zeCellulose
I-Cellulose, i-polysaccharide equlathe iiyunithi zeglucose eziphindaphindayo ezidityaniswe ziibhondi ze-glycosidic ze-β(1→4), isebenza njengesakhi esiphambili kwiindonga zeseli zezityalo. Ii-ether ze-Cellulose zenziwa ngokuguqula amaqela e-hydroxyl (-OH) akhoyo kwimolekyuli ye-cellulose. Iintlobo eziqhelekileyo zee-ether ze-cellulose 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 ngamaqela ahlukeneyo asebenzayo kutshintsha iipropati ze-cellulose ethers ezivelayo. Umzekelo, ukungeniswa kwamaqela e-methyl kuphucula ukunyibilika kwamanzi kunye neepropati zokwenza ifilimu, okwenza i-MC ifaneleke ukusetyenziswa kumayeza, iimveliso zokutya, kunye nezixhobo zokwakha. Ngokufanayo, ukufakwa kwamaqela e-hydroxyethyl okanye e-hydroxypropyl kuphucula ukugcinwa kwamanzi, amandla okuqina, kunye nokunamathela, okwenza izongezo ze-HEC kunye ne-HPC zibe zezona zibalulekileyo kwiimveliso zokhathalelo lomntu, iipeyinti, kunye nezincamathelisi. I-Carboxymethyl cellulose, eveliswa ngokufaka amaqela e-hydroxyl endaweni yamaqela e-carboxymethyl, ibonisa iipropati zokugcina amanzi, ukuzinza, kunye nokuqina, okwenza ukuba isetyenziswe kakhulu kushishino lokutya, kumayeza, nakwisongezo solwelo lokubhola kwicandelo leoyile negesi.

Iqondo lokutshintshwa (DS), elibonisa inani eliqhelekileyo lamaqela e-hydroxyl atshintshiweyo ngeyunithi yeglucose kwi-cellulose, lichaphazela kakhulu iipropati ze-cellulose ethers. Amaxabiso aphezulu e-DS adla ngokubangela ukwanda kokunyibilika, ukuxinana, kunye nokuzinza, kodwa ukutshintsha okugqithisileyo kunokubeka emngciphekweni ukubola kwezinto eziphilayo kunye nezinye iimpawu ezinqwenelekayo ze-cellulose ethers.

Ukwenziwa kwee-Ether zeCellulose
Ukwenziwa kwee-cellulose ethers kubandakanya ii-chemical reactions ezizisa amaqela atshintshayo kwi-cellulose backbone. Enye yezona ndlela zixhaphakileyo zokuvelisa ii-cellulose ethers kukwenza i-cellulose ibe ether kusetyenziswa ii-reagents ezifanelekileyo phantsi kweemeko ezilawulwayo.

Umzekelo, ukwenziwa kwe-methyl cellulose kudla ngokubandakanya ukusabela kwe-cellulose kunye ne-alkali metal hydroxides ukuvelisa i-alkali cellulose, kulandele unyango nge-methyl chloride okanye i-dimethyl sulfate ukungenisa amaqela e-methyl kwi-cellulose chain. Ngokufanayo, i-hydroxypropyl cellulose kunye ne-hydroxyethyl cellulose zenziwa ngokuphendula i-cellulose nge-propylene oxide okanye i-ethylene oxide, ngokulandelanayo, xa kukho ii-alkali catalysts.

I-carboxymethyl cellulose iveliswa ngokuphendula kwe-cellulose nge-sodium hydroxide kunye ne-chloroacetic acid okanye ityuwa yayo ye-sodium. Inkqubo ye-carboxymethylation yenzeka ngokutshintshwa kwe-nucleophilic, apho iqela le-hydroxyl le-cellulose lisabela kunye ne-chloroacetic acid ukwenza i-carboxymethyl ether linkage.

Ukwenziwa kwee-cellulose ethers kufuna ulawulo olucokisekileyo lweemeko zokusabela, ezifana nobushushu, i-pH, kunye nexesha lokusabela, ukuze kufezekiswe inqanaba elifunekayo lokutshintshwa kunye neempawu zemveliso. Ukongeza, amanyathelo okucoca adla ngokusetyenziswa ukususa iimveliso ezingasemva kunye nokungcola, ukuqinisekisa umgangatho kunye nokuhambelana kwee-cellulose ethers.

Ukusetyenziswa kweCellulose Ethers
Ii-cellulose ethers zifumana usetyenziso oluxhaphakileyo kumashishini ahlukeneyo ngenxa yeempawu zazo ezahlukeneyo kunye nemisebenzi yazo. Ezinye zezona zicelo ziphambili ziquka:

Ishishini lokutya:Ii-ether ze-celluloseEzifana ne-carboxymethyl cellulose zihlala zisetyenziswa njengezinto eziqinisayo, izinto ezizinzisayo, kunye nezixutyisi kwiimveliso zokutya ezifana neesosi, ii-dressings, kunye ne-ayisikhrim. Ziphucula ukuthungwa, i-viscosity, kunye nokuzinza kweshelufu ngelixa ziphucula ukuziva komlomo kunye nokukhululwa kwencasa.

Amayeza: I-Methyl cellulose kunye ne-hydroxypropyl cellulose zisetyenziswa kakhulu kwi-pharmaceutical formulations njenge-binders, disintegrants, kunye ne-controlled-release agents kwiipilisi, ii-capsules, kunye ne-topical formulations. Ezi ethers ze-cellulose ziphucula ukuhanjiswa kwamayeza, ukufumaneka kwe-bioavailability, kunye nokuthobela imiqathango yesigulane.

Izixhobo zokwakha: I-Methyl cellulose kunye ne-hydroxyethyl cellulose zisetyenziswa kushishino lokwakha njengezongezo kwiimortars ezisekwe kwisamente, iiplaster, kunye nee-adhesive zethayile ukuphucula ukusebenza kakuhle, ukugcinwa kwamanzi, kunye neempawu zokuncamathelisa. Ziphucula ukuhlangana, zinciphisa ukuqhekeka, kwaye ziphucula ukusebenza kwezixhobo zokwakha.

Iimveliso zoNyango lobuqu: I-Hydroxyethyl cellulose kunye ne-hydroxypropyl cellulose zizithako eziqhelekileyo kwiimveliso zononophelo lobuqu ezifana neeshampu, iiloshini, kunye neekhrimu ezifunekayo.

iipropati zazo zokutyeba, ukuzinzisa, kunye nokwenza ifilimu. Ziphucula ukuhambelana kwemveliso, ubunjani bayo, kunye nokuvakala kolusu ngelixa ziphucula uzinzo lwemveliso.

Iipeyinti kunye neeCoatings: Ii-cellulose ethers zisebenza njengezilungisi ze-rheology, iziqinisi, kunye neziqinisi kwiipeyinti, iicoatings, kunye nee-adhesives, ziphucula iipropati zokusetyenziswa, indlela yokuhamba, kunye nokwakheka kwefilimu. Ziyandisa ulawulo lwe-viscosity, ukumelana nokuwa, kunye nokuzinza kombala kwiifomyula ezisekelwe emanzini.

Ishishini leoyile negesi: I-carboxymethyl cellulose isetyenziswa njengesiguquli se-viscosity kunye nearhente yokulawula ukulahleka kolwelo kulwelo lokugrumba ukuze kuhlolwe kwaye kuveliswe ioyile negesi. Iphucula i-rheology yolwelo, ukucocwa kwemingxunya, kunye nokuzinza kwemigodi ngelixa ithintela umonakalo wokwakheka.

Ishishini Lempahla Eyenziwe Ngelaphu: Ii-cellulose ethers zisetyenziswa ekuprinteni impahla, ekudayeni, nakwiinkqubo zokugqiba ukuze kuphuculwe inkcazo yoshicilelo, ukuveliswa kombala, kunye nokuthamba kwelaphu. Zenza kube lula ukusasazwa kwemibala, ukunamathela kwimicu, kunye nokuqina kokuhlamba xa kusetyenziswa impahla eyongiweyo.

Ii-ether ze-celluloseZimela iqela elahlukeneyo leekhemikhali ezithathwe kwi-cellulose, ezibonelela ngeempawu ezahlukeneyo kunye nemisebenzi eyahlukeneyo kwizicelo ezahlukeneyo zoshishino. Ngokusebenzisa utshintsho olulawulwayo lweekhemikhali kwi-cellulose backbone, ii-cellulose ethers zibonisa iimpawu ezinqwenelekayo ezifana nokunyibilika kwamanzi, ulawulo lwe-viscosity, kunye nozinzo, nto leyo ezenza zibe zezongezo ezixabisekileyo kumashishini aqala ekutyeni namayeza ukuya kulwakhiwo kunye namalaphu. Njengoko imfuno yezinto ezizinzileyo nezinobuhlobo nokusingqongileyo iqhubeka ikhula, ii-cellulose ethers zikulungele ukudlala indima ebalulekileyo ekuhlangabezaneni neemfuno eziguqukayo zamashishini anamhlanje ngelixa zinciphisa impembelelo yokusingqongileyo.