Ulwakhiwo lwee-ether ze-cellulose

Izakhiwo eziqhelekileyo ezimbiniii-ether ze-cellulosezinikwe kwiMifanekiso 1.1 kunye no-1.2. Idiliya nganye eyomileyo ye-β-D yemolekyuli yeselilulose

Iyunithi yeswekile (iyunithi ephinda-phindayo yeselilulose) ithathelwa indawo liqela elinye le-ether ngalinye kwiindawo ze-C(2), C(3) kunye ne-C(6), oko kukuthi ukuya kuthi ga kwisithathu.

iqela le-ether. Ngenxa yokubakho kwamaqela e-hydroxyl, ii-macromolecules ze-cellulose zinezibopho ze-hydrogen zangaphakathi kwee-molekyuli kunye nezangaphakathi kwee-molekyuli, ekunzima ukuzinyibilikisa emanzini.

Kwaye kunzima ukunyibilika phantse kuzo zonke izinyibilikisi ze-organic. Nangona kunjalo, emva kokufakelwa kwe-cellulose ether, amaqela e-ether afakwa kwi-molecular chain,

Ngale ndlela, iibhondi zehydrogen ngaphakathi naphakathi kweemolekyuli ze-cellulose ziyatshatyalaliswa, kwaye i-hydrophilicity yayo nayo iyaphucuka, ukuze ukunyibilika kwayo kuphuculwe.

iphuculwe kakhulu. Phakathi kwazo, uMfanekiso 1.1 lulwakhiwo oluqhelekileyo lweeyunithi ezimbini ze-anhydroglucose ze-cellulose ether molecular chain, R1-R6=H

okanye izinto ezithatha indawo yezinto eziphilayo. I-1.2 sisiqwenga se-carboxymethyl hydroxyethyl cellulose molecular chain, inqanaba lokutshintshwa kwe-carboxymethyl yi-0.5,4

Iqondo lokutshintshwa kwe-hydroxyethyl yi-2.0, kwaye iqondo lokutshintshwa kwe-molar yi-3.0.

Kwinto nganye ethatha indawo ye-cellulose, isixa siphela se-etherification yayo sinokubonakaliswa njenge-degree of substitution (DS). eyenziwe ngeefayibha.

Kuyabonakala kwisakhiwo se-prime molecule ukuba inqanaba lokutshintshwa liqala kwi-0-3. Oko kukuthi, iyunithi nganye ye-anhydroglucose ring ye-cellulose

, inani eliqhelekileyo lamaqela e-hydroxyl athathelwe indawo ngamaqela e-etherifying e-etherifying agent. Ngenxa yeqela le-hydroxyalkyl le-cellulose, i-substitutional yayo

Ukufakelwa kwe-ether kufuneka kuqalwe kwakhona kwiqela elitsha le-free hydroxyl. Ke ngoko, inqanaba lokutshintshwa kolu hlobo lwe-cellulose ether linokubonakaliswa kwiimole.

inqanaba lokutshintshwa (MS). Iqondo elibizwa ngokuba yi-molar degree of substitution libonisa ubungakanani be-etherifying agent eyongeziweyo kwiyunithi nganye ye-anhydroglucose ye-cellulose

Ubunzima obuqhelekileyo bee-reactants.

1 Ulwakhiwo ngokubanzi lweyunithi yeglucose

Iziqwenga ezi-2 zeetsheyini ze-molecular ze-cellulose ether

1.2.2 Ukuhlelwa kwee-ether ze-cellulose

Nokuba ii-cellulose ethers zii-single ethers okanye ii-mixed ethers, iimpawu zazo zahlukile kancinci.

Ukuba iqela le-hydroxyl leringi yeyunithi lithathelwa indawo liqela elithanda amanzi, imveliso inokuba nenqanaba eliphantsi lokutshintshwa phantsi kwemeko yenqanaba eliphantsi lokutshintshwa.

Inomlinganiselo othile wokunyibilika kwamanzi; ukuba itshintshwe liqela elingathandi manzi, imveliso inomlinganiselo othile wokutshintshwa kuphela xa umgangatho wokutshintshwa uphakathi.

Iimveliso ze-cellulose etherification ezinyibilikayo emanzini, ezingatshintshwanga kakhulu zinokudumba emanzini kuphela, okanye zinyibilike kwizisombululo ze-alkali ezingaxinenanga kangako.

embindini.

Ngokweentlobo zezinto ezithatha indawo, ii-cellulose ethers zinokwahlulwa zibe ziindidi ezintathu: amaqela e-alkyl, afana ne-methyl cellulose, i-ethyl cellulose;

Iihydroxyalkyls, ezifana ne-hydroxyethyl cellulose, i-hydroxypropyl cellulose; ezinye, ezifana ne-carboxymethyl cellulose, njl. Ukuba i-ionization

Udidi, ii-ether ze-cellulose zinokwahlulwa zibe: i-ionic, njenge-carboxymethyl cellulose; i-non-ionic, njenge-hydroxyethyl cellulose; ixutyiwe

uhlobo, njenge-hydroxyethyl carboxymethyl cellulose. Ngokwendlela yokunyibilika, i-cellulose inokwahlulwa ibe: inyibilika emanzini, njenge-carboxymethyl cellulose,

I-Hydroxyethyl cellulose; ayinyibiliki emanzini, njenge-methyl cellulose, njl.

1.2.3 Iimpawu kunye nokusetyenziswa kwee-ether ze-cellulose

I-Cellulose ether luhlobo lwemveliso emva kokuguqulwa kwe-cellulose etherification, kwaye i-cellulose ether ineempawu ezininzi ezibalulekileyo.

Ineempawu ezintle zokwenza ifilimu; njengentlama yokuprinta, inokunyibilika kakuhle kwamanzi, iyenza ibe nkulu, igcina amanzi kwaye izinzile;

5

I-ether engenanto ayinavumba, ayinatyhefu, kwaye ihambelana kakuhle ne-biocompatibility. Phakathi kwazo, i-carboxymethyl cellulose (CMC) ine-"industrial monosodium glutamate"

isiteketiso.

1.2.3.1 Ukwenziwa kwefilimu

Iqondo lokuguquguquka kwe-cellulose ether linempembelelo enkulu kwiimpawu zayo zokwenza ifilimu ezifana nokukwazi ukwenza ifilimu kunye namandla okubopha.

Ngenxa yokuba inamandla oomatshini kwaye ihambelana kakuhle neeresini ezahlukeneyo, ingasetyenziswa kwiifilimu zeplastiki, izincamathelisi kunye nezinye izinto.

ukulungiswa kwezinto eziphathekayo.

1.2.3.2 Ukunyibilika

Ngenxa yokuba kukho amaqela amaninzi e-hydroxyl kwiringi yeyunithi yeglucose equlethe ioksijini, ii-ether ze-cellulose zinyibilika ngcono emanzini.

Ngokuxhomekeke kwi-ether substituent ye-cellulose kunye nobungakanani bokutshintshwa kwayo, kukwakho nokukhetha okwahlukileyo kwezinyibilikisi ze-organic.

1.2.3.3 Ukutyeba

I-cellulose ether inyibilika kwisisombululo samanzi ngendlela ye-colloid, apho inqanaba le-polymerization ye-cellulose ether limisela i-cellulose.

Ukuqina kwesisombululo se-ether. Ngokungafaniyo nolwelo lwe-Newtonian, ukuqina kwezisombululo ze-ether ze-cellulose kuyatshintsha ngamandla okucheba, kwaye

Ngenxa yesi sakhiwo see-macromolecules, i-viscosity yesisombululo iya kwanda ngokukhawuleza ngokwanda komxholo oqinileyo we-cellulose ether, nangona kunjalo i-viscosity yesisombululo.

Ukuqina kwesikhumba kuncipha ngokukhawuleza xa ubushushu bunyuka [33].

1.2.3.4 Ukonakala

Isisombululo se-cellulose ether esinyibilikiswe emanzini kangangexesha elithile siya kukhulisa iintsholongwane, ngaloo ndlela sivelise iintsholongwane ze-enzyme kwaye sitshabalalise isigaba se-cellulose ether.

Iibhondi zeyunithi yeglucose engatshintshiyo ecaleni, ngaloo ndlela zinciphisa ubunzima beemolekyuli ze-macromolecule. Ke ngoko, ii-ether ze-cellulose

Ukugcinwa kwezisombululo zamanzi kufuna ukongezwa komlinganiselo othile wezinto zokugcina.

Ukongeza, ii-cellulose ethers zinezinye iimpawu ezininzi ezikhethekileyo ezifana nomsebenzi womphezulu, umsebenzi we-ionic, uzinzo lwe-foam kunye nokongeza.

Isenzo sejeli. Ngenxa yezi mpawu, ii-cellulose ethers zisetyenziswa kwimpahla, ekwenzeni amaphepha, kwiisepha zokwenziwa, kwizinto zokuthambisa, ekutyeni, kumayeza,

Isetyenziswa kakhulu kwiindawo ezininzi.

1.3 Intshayelelo kwizinto eziluhlaza zezityalo

Ngokwesishwankathelo se-1.2 cellulose ether, kubonakala ukuba izinto ezisetyenziswa ekulungiseleleni i-cellulose ether yi-cotton cellulose, kwaye yenye yezinto ezikule sihloko.

Kukusebenzisa i-cellulose ekhutshwe kwizityalo eziluhlaza ukuze kuthathelwe indawo i-cotton cellulose ukulungiselela i-cellulose ether. Oku kulandelayo yintshayelelo emfutshane ngesityalo.

izinto eziphathekayo.

Njengoko izixhobo eziqhelekileyo ezifana neoyile, amalahle kunye negesi yendalo zincipha, uphuhliso lweemveliso ezahlukeneyo ezisekelwe kuzo, ezifana neefayibha zokwenziwa kunye neefilimu zefayibha, nazo ziya kuncitshiswa ngakumbi. Ngokuqhubeka kophuhliso loluntu kunye namazwe kwihlabathi liphela (ingakumbi

Lilizwe eliphuhlileyo elinika ingqalelo enkulu kwingxaki yongcoliseko lokusingqongileyo. I-cellulose yendalo inokubola kwezinto eziphilayo kunye nokulungelelaniswa kokusingqongileyo.

Iya kuba ngumthombo ophambili wezinto zefayibha kancinci kancinci.