Isakhiwo se-cellulose ethers

Izakhiwo ezijwayelekile ezimbilii-cellulose etherszinikezwe kuMfanekiso 1.1 no-1.2. Igilebhisi ngalinye eliphelelwe amanzi ngo-β-D we-molecule ye-cellulose

Iyunithi kashukela (iyunithi ephindaphindayo ye-cellulose) ishintshwa ngeqembu elilodwa le-ether ngalinye endaweni ethi C(2), C(3) kanye no-C(6), okusho ukuthi kufika kokuthathu.

iqembu le-ether. Ngenxa yokuba khona kwamaqembu e-hydroxyl, ama-cellulose macromolecules ane-intramolecular and intermolecular hydrogen bond, okunzima ukuwancibilikisa emanzini.

Futhi kunzima ukuncibilika cishe kuzo zonke izincibilikisi eziphilayo. Kodwa-ke, ngemuva kokufakwa kwe-cellulose, amaqembu e-ether angeniswa ochungechungeni lwamangqamuzana,

Ngale ndlela, izibopho ze-hydrogen ngaphakathi naphakathi kwama-molecule e-cellulose ziyabhujiswa, futhi i-hydrophilicity yayo nayo iyathuthukiswa, ukuze ukuncibilika kwayo kuthuthukiswe.

ngcono kakhulu. Phakathi kwazo, Umfanekiso 1.1 uyisakhiwo esijwayelekile samayunithi amabili e-anhydroglucose we-cellulose ether molecular chain, R1-R6=H

noma izinto eziphilayo. I-1.2 iwucezu lwe-carboxymethyl hydroxyethyl cellulose cellulose chain, izinga lokushintshwa kwe-carboxymethyl ngu-0.5,4

I-substitution degree ye-hydroxyethyl ngu-2.0, kanti i-molar substitution degree ingu-3.0.

Engxenyeni ngayinye ye-cellulose, inani eliphelele le-etherification yayo lingavezwa njengedigri yokushintsha (DS). eyenziwe ngemicu

Kungabonakala esakhiweni se-molecule eyinhloko ukuthi izinga lokushintsha lisukela ku-0-3. Okusho ukuthi, indandatho ngayinye yeyunithi ye-anhydroglucose ye-cellulose

, isilinganiso senani lamaqembu e-hydroxyl esikhundleni samaqembu e-etherifying e-ejenti ye-etherifying. Ngenxa yeqembu le-hydroxyalkyl cellulose, esikhundleni salo

I-etherification kufanele iqalwe kabusha eqenjini elisha le-hydroxyl yamahhala. Ngakho-ke, izinga lokushintshwa kwalolu hlobo lwe-cellulose ether lingavezwa kuma-moles.

degree of substitution (MS). Okubizwa ngokuthi i-molar degree of substitution ikhombisa inani le-ejenti etherifying engezwe kuyunithi ngayinye ye-cellulose ye-anhydroglucose.

Isilinganiso sesisindo sama-reactants.

1 Isakhiwo esijwayelekile seyunithi yeglucose

2 Izingcezu zamaketanga e-cellulose ether yamangqamuzana

1.2.2 Ukuhlelwa kwama-cellulose ethers

Ukuthi ama-cellulose ether angama-ether awodwa noma ama-ether axubile, izici zawo zihlukile. I-cellulose macromolecules

Uma iqembu le-hydroxyl leringi yeyunithi lithathelwa indawo yiqembu le-hydrophilic, umkhiqizo ungaba nezinga eliphansi lokushintsha ngaphansi kwesimo sezinga eliphansi lokushintsha.

Ine-solubility ethile yamanzi; uma ithathelwa indawo yiqembu le-hydrophobic, umkhiqizo unezinga elithile lokushintshwa kuphela uma izinga lokushintsha limaphakathi.

Imikhiqizo encibilikayo emanzini, efakwe kancane esikhundleni se-cellulose etherification ingakhukhumala kuphela emanzini, noma incibilike ezixazululweni ze-alkali ezingagxili kakhulu.

phakathi.

Ngokwezinhlobo zama-substitutes, ama-cellulose ether angahlukaniswa abe yizigaba ezintathu: amaqembu e-alkyl, njenge-methyl cellulose, i-ethyl cellulose;

Ama-Hydroxyalkyls, njenge-hydroxyethyl cellulose, i-hydroxypropyl cellulose; abanye, ezifana carboxymethyl cellulose, njll Uma ionization

Ukuhlukaniswa, ama-cellulose ethers angahlukaniswa abe: ionic, njenge-carboxymethyl cellulose; okungezona i-ionic, njenge-hydroxyethyl cellulose; okuxubile

uhlobo, njenge-hydroxyethyl carboxymethyl cellulose. Ngokwesigaba sokuncibilika, i-cellulose ingahlukaniswa ibe: encibilikayo emanzini, njenge-carboxymethyl cellulose,

I-Hydroxyethyl cellulose; amanzi angancibiliki, njenge-methyl cellulose, njll.

1.2.3 Izakhiwo kanye nokusetshenziswa kwama-cellulose ether

I-cellulose ether iwuhlobo lomkhiqizo ngemva kokuguqulwa kwe-cellulose etherification, futhi i-cellulose ether inezinto eziningi ezibaluleke kakhulu. njenge

Inezici ezinhle zokwenza ifilimu; njenge-paste yokuphrinta, inokuncibilika kwamanzi okuhle, izakhiwo eziqina, ukugcinwa kwamanzi nokuzinza;

5

I-ether engenalutho ayinaphunga, ayinabuthi, futhi inokuhambisana okuhle kwe-biocompatibility. Phakathi kwazo, i-carboxymethyl cellulose (CMC) ine “industrial monosodium glutamate”

isiteketiso.

1.2.3.1 Ukwakhiwa kwefilimu

Izinga le-etherification ye-cellulose ether linethonya elikhulu ezicini zayo zokwenza ifilimu njengekhono lokwenza ifilimu namandla okubopha. I-cellulose ether

Ngenxa yamandla ayo amahle emishini kanye nokuhambisana okuhle nama-resin ahlukahlukene, ingasetshenziswa kumafilimu epulasitiki, izinto zokunamathisela nezinye izinto.

ukulungiswa kwezinto.

1.2.3.2 Ukunyibilika

Ngenxa yokuba khona kwamaqembu amaningi e-hydroxyl eringini yeyunithi ye-glucose equkethe umoya-mpilo, ama-cellulose ethers anokuncibilika okungcono kwamanzi. futhi

Ngokuya esikhundleni se-cellulose ether kanye nezinga lokushintshwa, kukhona futhi ukukhetha okuhlukile kwezinyibilikisi zemvelo.

1.2.3.3 Ukuqina

I-cellulose ether incibilika kusisombululo esinamanzi ngendlela ye-colloid, lapho izinga le-polymerization ye-cellulose ether linquma i-cellulose.

I-viscosity yesisombululo se-ether. Ngokungafani noketshezi lwe-Newtonian, i-viscosity yezixazululo ze-cellulose ether iyashintsha ngamandla e-shear, futhi

Ngenxa yalesi sakhiwo sama-macromolecules, i-viscosity yesisombululo izokhula ngokushesha ngokwanda kokuqukethwe okuqinile kwe-cellulose ether, noma kunjalo i-viscosity yesixazululo.

I-viscosity nayo yehla ngokushesha ngokukhuphuka kwezinga lokushisa [33].

1.2.3.4 Ukonakala

Isixazululo se-cellulose ether esincibilikisiwe emanzini isikhathi esithile sizokhula amagciwane, ngaleyo ndlela sikhiqize amabhaktheriya e-enzyme futhi sicekele phansi isigaba se-cellulose ether.

Amabhondi eyunithi ye-glucose engashintshiwe eseduze, ngaleyo ndlela ehlisa isisindo samangqamuzana e-macromolecule. Ngakho-ke, i-cellulose ethers

Ukulondolozwa kwezixazululo ezinamanzi kudinga ukungezwa kwenani elithile lezivimbelakuvunda.

Ngaphezu kwalokho, ama-cellulose ether anezinye izinto eziningi eziyingqayizivele ezifana nomsebenzi ongaphezulu, umsebenzi we-ionic, ukuqina kwegwebu kanye nesengezo.

isenzo sejeli. Ngenxa yalezi zakhiwo, ama-cellulose ethers asetshenziselwa izindwangu, ukwenza amaphepha, okokuhlanza okokwenziwa, izimonyo, ukudla, imithi,

Isetshenziswa kabanzi emikhakheni eminingi.

1.3 Isingeniso sokutshala izinto ezingavuthiwe

Kusukela ekuhlaziyeni kwe-ether ye-cellulose engu-1.2, kubonakala ukuthi impahla eluhlaza yokulungiswa kwe-cellulose ether ikakhulukazi i-cotton cellulose, futhi okunye okuqukethwe kwalesi sihloko.

Iwukusebenzisa i-cellulose ekhishwe ezintweni zokusetshenziswa zezitshalo esikhundleni se-cotton cellulose ukulungisa i-cellulose ether. Okulandelayo isingeniso esifushane sesitshalo

impahla.

Njengoba izinsiza ezivamile ezifana nowoyela, amalahle negesi yemvelo zincipha, ukuthuthukiswa kwemikhiqizo ehlukahlukene esekelwe kuzo, njengemicu yokwenziwa namafilimu e-fiber, nakho kuzobe kuvinjelwe ngokwandayo. Ngokuthuthuka okuqhubekayo komphakathi kanye namazwe emhlabeni jikelele (ikakhulukazi

Yizwe elithuthukile) elibhekisisa kakhulu inkinga yokungcoliswa kwemvelo. I-cellulose yemvelo ine-biodegradability kanye nokuxhumana kwemvelo.

Kancane kancane izoba umthombo oyinhloko wezinto ze-fiber.