Super Absorbent Material e tsoang ho Cellulose Ether

Ts'ebetso le ts'ebetso ea lihlahisoa tsa carboxymethyl cellulose cross-linked by N, N-methylenebisacrylamide ho lokisa superabsorbent resin li ile tsa ithutoa, 'me ho ile ha buisanoa ka mahloriso a alkali, palo ea li-cross-linking agent, alkali etherification, le solvent. Phello ea litekanyetso ho ts'ebetso ea ho monya ha metsi ea sehlahisoa. Mokhoa oa adsorption oa resin e monyang metsi metsing oa hlalosoa. Liphuputso li bontšitse hore boleng ba ho boloka metsi (WRV) ba sehlahisoa sena bo fihla ho 114ml/g.

Mantsoe a bohlokoa:cellulose ether; methylenebisacrylamide; tokisetso

1,Selelekela

Superabsorbent resin ke thepa ea polymer e nang le lihlopha tse matla tsa hydrophilic le tekanyo e itseng ea ho kopanya. Lisebelisoa tse tloaelehileng tse monyang metsi joalo ka pampiri, k'hothone le hemp li na le sekhahla se tlase sa ho monya metsi le bokhoni bo fokolang ba ho boloka metsi, athe li-resin tse monyang haholo li ka monya metsi ka makhetlo a mangata boima ba tsona, 'me gel e entsoeng kamora ho monya metsi e ke ke ea felloa ke metsi. ka kgatello e nyane. Bokhoni bo botle ba ho boloka metsi. Ha e qhibilihe metsing kapa ka har'a lihlapolli tsa lintho tse phelang.

Ho na le palo e kholo ea lihlopha tsa hydroxyl, lihlopha tsa carboxyl le li-ion tsa sodium hydrate ka har'a ketane ea limolek'hule tsa thepa e monyang haholo e entsoeng ka selulose. Ka mor'a ho monya metsi, metsi a pota-potiloe ke marang-rang a hydrophilic macromolecular 'me a ka bolokoa tlas'a khatello ea ka ntle. Ha metsi a kolobisa resin ea adsorption, ho thehoa lera la semi-permeable pakeng tsa resin le metsi. Ka lebaka la khatello e phahameng ea li-ion tsa mobile (Na+) ka har'a resin e monyang metsi, ho latela Donnan.'s equilibrium molao-motheo, phapang ena ea mahloriso ea ion e ka baka khatello ea osmotic. Ho futsanehile, ho theha matla a fokolang a kolobisang le ho ruruha, metsi a feta lera lena la semi-permeable lera 'me a kopana le lihlopha tsa hydrophilic le li-ion ho macromolecules ea superabsorbent resin, ho fokotsa bongata ba li-ion tse tsamaeang, ka tsela eo ho bontša ho monya metsi a mangata le ho ruruha. Ts'ebetso ena ea adsorption e ntse e tsoela pele ho fihlela phapang ea khatello ea osmotic e bakoang ke phapang pakeng tsa mahloriso a li-ion tsa mehala e lekana le ho hanyetsa ho atolosoa ho eketsehileng ho bakoang ke matla a kopanetsoeng a marang-rang a limolek'hule tsa resin ea polymer. Melemo ea superabsorbent resin e lokiselitsoeng ho tloha selulose ke: lebelo le leka-lekaneng la ho monya metsi, lebelo la ho monya metsi ka potlako, ho hanyetsa metsi a letsoai a matle, ho se chefo, ho bonolo ho fetola boleng ba pH, e ka senyeha ka tlhaho, le theko e tlase, ka hona e na le bophara bo bongata. mefuta e mengata ea lisebelisoa. E ka sebelisoa e le sesebelisoa sa ho thibela metsi, se hloekisang mobu, le se bolokang metsi indastering le temong. Ntle le moo, e na le litebello tse ntle tsa nts'etsopele le ts'ebeliso ea bophelo bo botle, lijo, microbiology le meriana.

2. Karolo ea teko

2.1 Molao-motheo oa teko

Ho lokisoa ha k'hothone fiber superabsorbent resin ke haholo-holo ho theha sebopeho se amanang le sefapano se nang le boemo bo tlase ba ho nkela sebaka letlalong la fiber. Ho hokahanya le metsoako eo ka kakaretso e nang le lihlopha tse peli kapa ho feta tse sebetsang hantle. Lihlopha tse sebetsang tse khonang ho kopanya li-cross li kenyelletsa vinyl, hydroxyl, carboxyl, amide, acid chloride, oxirane, nitrile, joalo-joalo Karo-karolelano ea metsi a li-resin tse nang le superabsorbent e lokiselitsoeng ka mahlahana a fapaneng a ho kopanya li fapane. Tekong ena, N, N-methylenebisacrylamide e sebelisoa e le sesebelisoa se kopanyang, ho kenyelletsa le mehato e latelang:

(1) Cellulose (Rcell) e arabela ka tharollo ea alkaline ho hlahisa selulose ea alkali, 'me karabelo ea alkalization ea cellulose ke karabelo e potlakileng ea exothermic. Ho theola mocheso ho thusa ho thehoeng ha likhoele tsa alkali mme ho ka thibela hydrolysis ea bona. Ho eketsa joala ho ka eketsa bothata ba cellulose, e leng molemo ho alkalization le etherification e latelang.

RcellOH+NaOH→RcellONA+H2O

(2) Alkali cellulose le monochloroacetic acid li hlahisa sodium carboxymethyl cellulose, 'me karabelo ea etherification ke ea nucleophilic substitution reaction:

RcellONA+ClCH2COONA→RcellOCH2COONA+NaCl

(3) N, N-methylenebisacrylamide e hokahane le sefapano ho fumana resin e monyang haholo. Hobane ho ntse ho e-na le lihlopha tse ngata tsa hydroxyl holim'a ketane ea molek'hule ea carboxymethyl fiber, ionization ea sehlopha sa hydroxyl ea selulose le ionization ea acryloyl bond habeli ka ketane ea molek'hule ea N, N-methylenebisacrylamide e ka hlahisoa tlas'a ketso. ea alkali catalysis, 'me joale Cross-linking pakeng tsa selulose molek'hule liketane etsahala ka Michael condensation,' me hang-hang undergoes proton phapanyetsano le metsi ho fetoha metsi-insoluble selulose superabsorbent resin.

2.2 Lisebelisoa le lisebelisoa

Lisebelisoa tse tala: k'hothone e monyang (e khaola li-linters), sodium hydroxide, monochloroacetic acid, N, N-methylenebisacrylamide, ethanol e feletseng, acetone.

Lisebelisoa: botlolo ea melala e meraro, e susumetsang motlakase, condenser ea reflux, botlolo ea sefa se monyang, Buchner funnel, vacuum drying ontong, pompo e potolohang ea vacuum ea metsi.

2.3 Mokhoa oa ho itokisa

2.3.1 Alkaline

Eketsa 1 g ea k'hothone e monyang botlolong e nang le melamo e meraro, ebe u eketsa tekanyo e itseng ea sodium hydroxide solution le absolute ethanol, boloka mocheso o ka tlas'a mocheso oa kamore, 'me u hlohlelletse nakoana.

2.3.2 Etherification

Kenya palo e itseng ea chloroacetic acid 'me u hlohlelletse 1h.

2.3.2 Crosslinking

Nakong ea morao-rao ea etherification, N, N-methylenebisacrylamide e ile ea eketsoa ka tekanyo ea ho etsa li-cross-link, 'me e tsosoa ka mocheso oa kamore bakeng sa lihora tse peli.

2.3.4 Ka mor'a ts'ebetso

Sebelisa glacial acetic acid ho fetola pH ea boleng ho 7, hlatsoa letsoai ka ethanol, hlatsoa metsi ka acetone, sefa ka ho monya, 'me u omelle lihora tse 4 (hoo e ka bang 60).°C, vacuum degree 8.8kPa) ho fumana sehlahisoa se tšoeu sa k'hothone.

2.4 Tlhahlobo ea tlhahlobo

Sekhahla sa ho monya metsi (WRV) se khethoa ka ho sieving, ke hore, 1g ea sehlahisoa (G) e kenyelletsoa beaker e nang le 100ml ea metsi a hloekisitsoeng (V1), e kolobisitsoeng ka lihora tse 24, e tlhotliloeng ka skrineng ea tšepe ea 200-mesh. , 'me metsi a ka tlaase ho skrine a bokelloa (V2). Foromo ea lipalo ke e latelang: WRV=(V1-V2)/G.

3. Liphetho le lipuisano

3.1 Khetho ea maemo a karabelo ea alkalization

Ts'ebetsong ea ho hlahisa selulose ea alkali ka ketso ea fiber ea k'hothone le tharollo ea alkaline, maemo a ts'ebetso a na le tšusumetso e kholo mosebetsing oa sehlahisoa. Ho na le lintlha tse ngata karabelong ea alkalization. Bakeng sa boiketlo ba ho shebella, ho sebelisoa mokhoa oa ho etsa liteko tsa orthogonal.

Maemo a mang: The solvent ke 20ml ea absolute ethanol, karo-karolelano ea alkali ho etherifying agent (mol/md) ke 3:1, le crosslinking agent ke 0.05g.

Liphetho tsa liteko li bontša hore: kamano ea mantlha le ea bobeli: C>A>B, karolelano e ntle ka ho fetisisa: A3B3C3. Motsoako oa lye ke ntlha ea bohlokoa ka ho fetesisa karabelong ea alkalization. Motsoako o phahameng oa lye o thusa ho thehoa ha selulose ea alkali. Leha ho le joalo, hoa lokela ho hlokomeloa hore ha li-lye li le ngata haholo, ho na le letsoai le leholo la resin e lokiselitsoeng ea superabsorbent. Ka hona, ha u hlatsoa letsoai ka ethanol, e hlatsoe ka makhetlo a 'maloa ho netefatsa hore letsoai le sehlahisoa le tlosoa, e le hore le se ke la ama matla a ho monya metsi a sehlahisoa.

3.2 Phello ea litekanyetso tsa "crosslinking agent" sehlahisoa sa WRV

Maemo a liteko ke: 20ml ea absolute ethanol, 2.3:1 karolelano ea alkali ho etherification agent, 20ml ea lye, le 90min ea alkalization.

Liphetho li bonts'itse hore palo ea li-cross-linking agent e amme tekanyo ea khokahanyo ea CMC-Na. Ho kopanya ho feteletseng ho lebisa mohahong o thata oa marang-rang sebakeng sa sehlahisoa, se khetholloang ke tekanyo e tlaase ea ho kenngoa ha metsi le elasticity e fokolang ka mor'a ho kenngoa ha metsi; ha palo ea li-cross-linking agent e le nyenyane, ho kopanya lifapano ha hoa phethoa, 'me ho na le lihlahisoa tse qhibilihisang metsi, tse amang le tekanyo ea ho kenngoa ha metsi. Ha palo ea li-cross-linking e le ka tlase ho 0.06g, lebelo la ho monya metsi le eketseha ka keketseho ea palo ea li-cross-linking agent, ha palo ea li-cross-linking e feta 0.06g, tekanyo ea ho monya metsi e fokotseha. ka bongata ba ntho e kopanyang. Ka hona, tekanyo ea "crosslinking agent" ke hoo e ka bang 6% ea boima ba fiber ea k'hothone.

3.3 Phello ea maemo a etherification ho sehlahisoa sa WRV

Maemo a liteko ke: mahloriso a alkali 40%; tekanyo ea alkali 20ml; ethanol e feletseng 20ml; cross-linking moemeli litekanyetso li behoa 0.06g; alkalization 90min.

Ho tsoa ho motsoako oa lik'hemik'hale, alkali-ether ratio (NaOH:CICH2-COOH) e lokela ho ba 2: 1, empa palo ea sebele ea alkali e sebelisitsoeng e kholo ho feta karo-karolelano ena, hobane motsoako o itseng oa mahala oa alkali o tlameha ho tiisetsoa tsamaisong ea karabelo. , hobane: tse itseng Boemo bo phahameng ba motheo oa mahala bo loketse ho phethoa ha alkalization reaction; karabelo ea li-cross-link e tlameha ho etsoa tlas'a maemo a alkaline; liketso tse ling tsa lehlakore li ja alkaline. Leha ho le joalo, haeba palo ea alkali e eketsoa haholo, fiber ea alkali e tla senyeha haholo, 'me ka nako e ts'oanang, katleho ea moemeli oa etherification e tla fokotseha. Liteko li bontša hore karo-karolelano ea alkali ho ether e ka bang 2.5:1.

3.4 Tšusumetso ea chelete ea solvent

Maemo a liteko ke: mahloriso a alkali 40%; tekanyo ea alkali 20ml; karo-karolelano ea alkali-ether 2.5: 1; cross-linking agent dose 0.06g, alkalization 90min.

The solvent anhydrous ethanol e phetha karolo ea ho qhalakanya, homogenizing le ho boloka boemo ba slurry ea tsamaiso, e leng molemo oa ho hasanya le ho fetisa mocheso o lokollotsoeng nakong ea ho thehoa ha selulose ea alkali, 'me e ka fokotsa karabelo ea hydrolysis ea cellulose ea alkali, kahoo e fumana junifomo. cellulose. Leha ho le joalo, haeba tekanyo ea joala e ekelitsoeng e le ngata haholo, alkali le sodium monochloroacetate li tla qhibiliha ho eona, mahloriso a li-reactants a tla fokotseha, lebelo la ho itšoara le tla fokotseha, hape le tla ba le phello e mpe ho crosslinking e latelang. Ha palo ea ethanol e felletseng e le 20ml, boleng ba WRV bo boholo.

Ka kakaretso, maemo a loketseng ka ho fetisisa bakeng sa ho lokisetsa resin ea superabsorbent ho tloha k'hothone e monyang alkalized le etherified carboxymethyl cellulose cross-linked by N, N-methylenebisacrylamide ke: mahloriso a alkali 40%, 20ml ea metsi a se nang solvent le ethanol, karo-karolelano ea alkali ho ether. ke 2.5:1, 'me tekanyo ea crosslinking agent ke 0.06g (6% ea palo ea lithara tsa k'hothone).