Ubume be-cellulose ethers

Ulwakhiwo oluqhelekileyo lwesibinii-cellulose etherszinikwe kwiMifanekiso 1.1 kunye ne-1.2. Umdiliya ngamnye one-β-D-dehydrated ye-cellulose molekyuli

Iyunithi yeswekile (iyunithi ephindayo yeselulosi) ifakwa endaweni yeqela elinye leether kwindawo nganye kwi C(2), C(3) kunye ne C(6) izithuba, okt ukuya kuthi ga kwisithathu.

Iqela le-ether. Ngenxa yobukho bamaqela e-hydroxyl, i-cellulose macromolecules ine-intramolecular kunye ne-intermolecular hydrogen bond, ekunzima ukuyinyibilika emanzini.

Kwaye kunzima ukunyibilika phantse kuzo zonke izinyibilikisi eziphilayo. Nangona kunjalo, emva kwe-etherification ye-cellulose, amaqela e-ether angeniswa kwikhonkco le-molecular,

Ngaloo ndlela, iibhondi ze-hydrogen ngaphakathi naphakathi kwee-molecule ze-cellulose zitshatyalaliswa, kwaye i-hydrophilicity yayo nayo iphuculwe, ukwenzela ukuba ukunyibilika kwayo kuphuculwe.

iphuculwe kakhulu. Phakathi kwazo, i-Figure 1.1 yisakhiwo esiqhelekileyo seeyunithi ezimbini ze-anhydroglucose ze-cellulose ether molecular chain, i-R1-R6 = H.

okanye izinto eziphilayo. I-1.2 yiqhekeza le-carboxymethyl hydroxyethyl cellulose i-molecular chain, iqondo lokutshintshwa kwe-carboxymethyl yi-0.5,4

Iqondo lokuthatha indawo ye-hydroxyethyl yi-2.0, kunye ne-molar substitution degree yi-3.0.

Kwi-substitute nganye ye-cellulose, isixa sisonke se-etherification yayo inokubonakaliswa njengeqondo lokuthatha indawo (DS). yenziwe ngemicu

Inokubonwa kwisakhiwo semolekyuli ephambili ukuba iqondo lokutshintshwa livela kwi-0-3. Oko kukuthi, iyunithi nganye ye-anhydroglucose iringi yeselulosi

, umyinge wenani lamaqela e-hydroxyl athatyathelw' indawo ngamaqela e-etherifying e-ejenti e-etherifying. Ngenxa yeqela le-hydroxyalkyl ye-cellulose, i-substitution yayo

I-etherification kufuneka iqalwe kwakhona kwiqela elitsha le-hydroxyl yasimahla. Ngoko ke, iqondo lokutshintshwa kolu hlobo lwe-cellulose ether lunokubonakaliswa kwii-moles.

iqondo lokuthatha indawo (MS). Into ebizwa ngokuba yi-molar degree of substitution ibonisa ubungakanani be-agent etherifying eyongeziweyo kwiyunithi nganye ye-anhydroglucose yeseli.

Ubunzima obuphakathi kwee-reactants.

1 Isakhiwo ngokubanzi seyunithi ye-glucose

Amaqhekeza ama-2 ee-cellulose ether chain chain

1.2.2 Ukuhlelwa kwee-ether ze-cellulose

Nokuba ii-ethers ze-cellulose zi-ethers enye okanye ii-ethers ezixubeneyo, iimpawu zazo zahlukile. I-cellulose macromolecules

Ukuba iqela le-hydroxyl leyunithi yeyunithi lithatyathelwa indawo liqela le-hydrophilic, imveliso ingaba nenqanaba eliphantsi lokutshintshwa phantsi kwemeko yeqondo eliphantsi lokutshintshwa.

Inonyibiliko oluthile lwamanzi; ukuba ifakwe endaweni yeqela le-hydrophobic, imveliso inomlinganiselo othile wokutshintshwa kuphela xa iqondo lokutshintshwa liphakathi.

Ukunyibilika kwamanzi, iimveliso ze-cellulose etherification ezingafakwanga endaweni zinokudumba kuphela emanzini, okanye zinyibilike kwizisombululo ezixineneyo zealkali.

phakathi.

Ngokweentlobo ze-substituents, i-cellulose ethers inokwahlulwa ibe ngamacandelo amathathu: amaqela e-alkyl, njenge-methyl cellulose, i-ethyl cellulose;

I-Hydroxyalkyls, njenge-hydroxyethyl cellulose, i-hydroxypropyl cellulose; abanye, ezifana carboxymethyl cellulose, njl Ukuba ionization

Ukwahlula, i-cellulose ethers inokwahlulwa ibe: ionic, njenge-carboxymethyl cellulose; i-non-ionic, efana ne-hydroxyethyl cellulose; ixutyiwe

uhlobo, olufana ne-hydroxyethyl carboxymethyl cellulose. Ngokohlelo lwe-solubility, i-cellulose inokwahlulwa ibe: i-soluble yamanzi, njenge-carboxymethyl cellulose,

Iselulosi yeHydroxyethyl; Amanzi anganyibilikiyo, njenge-methyl cellulose, njl.

1.2.3 Iipropati kunye nokusetyenziswa kwe-cellulose ethers

I-ether ye-cellulose luhlobo lwemveliso emva kokuguqulwa kwe-cellulose etherification, kunye ne-cellulose ether ineempawu ezininzi ezibaluleke kakhulu. njengaye

Ineempawu ezilungileyo zokwenza ifilimu; njenge-paste yokuprinta, ine-solubility efanelekileyo yamanzi, iipropati zokuqina, ukugcinwa kwamanzi kunye nokuzinza;

5

I-ether engenanto ayinavumba, ayinayo ityhefu, kwaye ine-biocompatibility elungileyo. Phakathi kwazo, i-carboxymethyl cellulose (CMC) ine "industrial monosodium glutamate"

isiteketiso.

1.2.3.1 Ukwenziwa kwefilimu

Iqondo le-etherification ye-cellulose ether inempembelelo enkulu kwiimpawu zayo zokwenza ifilimu ezifana nesakhono sokwenza ifilimu kunye namandla okudibanisa. Iselulosi ether

Ngenxa yamandla ayo omatshini kunye nokuhambelana kakuhle kunye neerasi ezahlukeneyo, ingasetyenziselwa kwiifilimu zeplastiki, i-adhesives kunye nezinye izinto.

ukulungiswa kwezinto.

1.2.3.2 Ukunyibilika

Ngenxa yobukho bamaqela amaninzi e-hydroxyl kwiringi yeyunithi ye-glucose eneoksijini, ii-ether ze-cellulose zinokunyibilika okungcono kwamanzi. kwaye

Ngokuxhomekeke kwi-cellulose ether substituent kunye neqondo lokutshintshela, kukho kwakhona ukhetho olwahlukileyo lwezinyibilikisi zezinto eziphilayo.

1.2.3.3 Ukujiya

I-ether ye-cellulose inyibilikiswa kwisisombululo samanzi ngendlela ye-colloid, apho iqondo le-polymerization ye-cellulose ether imisela i-cellulose.

I-Viscosity yesisombululo se-ether. Ngokungafaniyo ne-Newtonian fluids, i-viscosity yezisombululo ze-ether ye-cellulose iyatshintsha ngamandla okucheba, kunye

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

I-Viscosity iyancipha ngokukhawuleza ngokunyuka kweqondo lokushisa [33].

1.2.3.4 Ukuthotywa

Isisombululo se-cellulose ether esichithwe emanzini ixesha elithile siya kukhula ibhaktheriya, ngaloo ndlela ivelise ibhaktheriya ye-enzyme kunye nokutshabalalisa isigaba se-cellulose ether.

Izibophelelo zeyunithi ye-glucose ekufuphi engatshintshiyo, ngaloo ndlela inciphisa ubunzima be-molecular mass ye-macromolecule. Ngoko ke, i-cellulose ethers

Ukugcinwa kwezisombululo zamanzi kufuna ukongezwa kwenani elithile lokulondolozwa.

Ukongeza, ii-cellulose ethers zinezinye iipropathi ezininzi ezizodwa ezifana nomsebenzi womphezulu, umsebenzi we-ionic, ukuzinza kwegwebu kunye nokongeza.

isenzo sejeli. Ngenxa yezi zakhiwo, i-cellulose ethers isetyenziselwa iingubo, ukwenza iphepha, i-synthetic detergents, izimonyo, ukutya, amayeza,

Isetyenziswa ngokubanzi kwiinkalo ezininzi.

1.3 Intshayelelo yokutyala imathiriyeli ekrwada

Ukususela kumbono we-1.2 cellulose ether, kunokubonwa ukuba i-ether ekrwada yokulungiswa kwe-cellulose ether ikakhulu i-cotton cellulose, kwaye enye yezinto eziqulethwe kwesi sihloko.

Kukusebenzisa i-cellulose ekhutshwe kwizixhobo ezikrwada zezityalo ukuze kuthathelwe indawo icotton cellulose ukulungisa i-cellulose ether. Oku kulandelayo yintshayelelo emfutshane malunga nesityalo

impahla.

Njengoko izibonelelo eziqhelekileyo ezifana ne-oyile, amalahle kunye negesi yendalo ziyancipha, ukuphuhliswa kweemveliso ezahlukeneyo ezisekelwe kuzo, ezifana ne-synthetic fibers kunye neefilimu zefiber, nazo ziya kuthintelwa ngakumbi. Ngophuhliso oluqhubekayo loluntu kunye namazwe kwihlabathi liphela (ingakumbi

Lilizwe eliphuhlileyo) elinika ingqwalasela enkulu kwingxaki yokungcoliseka kwendalo. I-cellulose yendalo inokonakala kwezinto eziphilayo kunye nokulungelelaniswa kokusingqongileyo.

Iya kuba ngowona mthombo uphambili wezinto zefiber.