I-Super Absorbent Material evela ku-Cellulose Ether

Inqubo nokusebenza komkhiqizo we-carboxymethyl cellulose exhunywe ngokuphambana yi-N, N-methylenebisacrylamide ukuze kulungiswe inhlaka ye-superabsorbent kwahlolisiswa, futhi ukugcwala kwe-alkali, inani le-agent exhumanisa, i-alkali etherification, ne-solvent kwaxoxwa ngayo. Umthelela womthamo ekusebenzeni kokumuncwa kwamanzi komkhiqizo. Indlela yokukhanga ye-resin emunca amanzi emanzini iyachazwa. Ucwaningo lubonise ukuthi inani lokugcinwa kwamanzi (WRV) lalo mkhiqizo lifinyelela ku-114ml/g.

Amagama angukhiye:i-cellulose ether; i-methylenebisacrylamide; ukulungiselela

1,Isingeniso

I-Superabsorbent resin iyi-polymer enamaqembu aqinile we-hydrophilic kanye nezinga elithile lokuxhumanisa. Izinto ezivamile ezimunca amanzi njengephepha, ukotini, ne-hemp zinezinga eliphansi lokumunca amanzi kanye namandla angenamandla okugcina amanzi, kuyilapho ama-resin amunca kakhulu angamunca amanzi izikhathi eziningi zesisindo sawo, futhi ijeli elakhiwe ngemva kokumunca amanzi ngeke liwothe ngisho namanzi. ngomfutho omncane. Umthamo omuhle kakhulu wokugcina amanzi. Ayincibiliki emanzini noma kuzincibilikisi zemvelo.

Kunenqwaba yamaqembu e-hydroxyl, amaqembu e-carboxyl nama-ion hydrate e-sodium ochungechungeni lwamangqamuzana ezinto ezimunca kakhulu ezenziwe nge-cellulose. Ngemva kokumunca amanzi, amanzi azungezwe inethiwekhi ye-hydrophilic macromolecular futhi ingagcinwa ngaphansi kwengcindezi yangaphandle. Lapho amanzi emanzisa i-adsorption resin, kwakheka ungqimba lwe-semi-permeable membrane phakathi kwe-resin namanzi. Ngenxa yokugcwala okuphezulu kwama-ion eselula (Na+) ku-resin emunca amanzi, ngokusho kukaDonnan.'s isimiso sokulingana, lo mehluko wokuhlushwa kwe-ion ungabangela ingcindezi ye-osmotic. Empofu, enza amandla abuthakathaka anyakazayo futhi avuvukalayo, amanzi adlula kulolu ungqimba lwe-semi-permeable membrane futhi ahlanganiswe namaqembu e-hydrophilic nama-ion kuma-macromolecule e-superabsorbent resin, ehlisa ukugcwala kwama-ion ahambayo, ngaleyo ndlela abonise ukumuncwa kwamanzi amaningi nokuvuvukala. Le nqubo ye-adsorption iyaqhubeka kuze kube yilapho umehluko we-osmotic pressure obangelwa umehluko ekugxilweni kwama-ion eselula ulingana nokumelana nokwanda okuqhubekayo okubangelwa amandla ahlangene wenethiwekhi yamangqamuzana e-polymer resin. Izinzuzo ze-superabsorbent resin elungiselelwe kusuka ku-cellulose yilezi: izinga lokumunca amanzi elimaphakathi, isivinini sokumunca amanzi ngokushesha, ukumelana kahle namanzi anosawoti, okungewona ubuthi, kulula ukulungisa inani le-pH, lingonakaliswa ngokwemvelo, kanye nezindleko eziphansi, ngakho-ke inobubanzi obubanzi. ububanzi bokusetshenziswa. Ingasetshenziswa njenge-ejenti yokuvimbela amanzi, i-conditioner yenhlabathi, kanye ne-ejenti yokugcina amanzi embonini nasezolimo. Ngaphezu kwalokho, inokuthuthuka okuhle kanye namathemba okusebenza kwezempilo, ukudla, i-microbiology, kanye nemithi.

2. Ingxenye yokuhlola

2.1 Umgomo wokuhlola

Ukulungiswa kwe-cotton fiber superabsorbent resin ngokuyinhloko ukwakha isakhiwo esixhumene nesiphambano esinezinga eliphansi lokushintsha esikhumbeni se-fiber. Ukuxhumanisa izinhlanganisela ngokuvamile ezinamaqembu amabili noma ngaphezulu asebenzayo asebenzayo. Amaqembu asebenzayo akwazi ukuxhumanisa ahlanganisa i-vinyl, i-hydroxyl, i-carboxyl, i-amide, i-acid chloride, i-oxirane, i-nitrile, njll. Isilinganiso sokumuncwa kwamanzi kwama-resins anamandla alungiselelwe ngama-agent ahlukene axhumanisa ahlukile. Kulesi sivivinyo, i-N, N-methylenebisacrylamide isetshenziswa njenge-ejenti yokuxhumanisa, okuhlanganisa nezinyathelo ezilandelayo:

(1) I-Cellulose (i-Rcell) isabela nesisombululo se-alkali ukuze ikhiqize i-alkali cellulose, futhi ukusabela kwe-alkalization kwe-cellulose kuwukusabela kwe-exothermic okusheshayo. Ukwehlisa izinga lokushisa kuyasiza ekwakhekeni kwemicu ye-alkali futhi kungavimbela i-hydrolysis yabo. Ukwengeza uphuzo oludakayo kungakhuphula ukuphazamiseka kwe-cellulose, okuzuzisa ukwakheka kwe-alkalization kanye nokufakwa kwe-etherification okulandelayo.

RcellOH+NaOH→I-RcellONA+H2O

(2) I-alkali cellulose kanye ne-monochloroacetic acid kukhiqiza i-sodium carboxymethyl cellulose, futhi ukusabela kwe-etherification kungokusabela kokushintshwa kwe-nucleophilic:

I-RcellONA+ClCH2COONA→I-RcellOCH2COONA+NaCl

(3) N, N-methylenebisacrylamide exhunywe ngokuphambanayo ukuze kutholwe inhlaka emunca kakhulu. Ngenxa yokuthi kusenenani elikhulu lamaqembu e-hydroxyl ochungechungeni lwamangqamuzana e-carboxymethyl fiber, i-ionization yeqembu le-hydroxyl ye-cellulose kanye ne-ionization ye-acryloyl bond ephindwe kabili ochungechungeni lwamangqamuzana e-N, i-N-methylenebisacrylamide ingaqalwa ngaphansi kwesenzo. ye-alkali catalysis, bese kuba Ukuxhumanisa phakathi kwamaketanga engqamuzana ye-cellulose kwenzeka nge-Michael condensation, futhi ngokushesha kungena ukushintshaniswa kwe-proton namanzi ukuze kube i-cellulose engancibiliki i-superabsorbent resin.

2.2 Impahla kanye namathuluzi

Izinto zokusetshenziswa: ukotini omuncayo (unqunywe ube ngamalitha), i-sodium hydroxide, i-monochloroacetic acid, i-N, i-N-methylenebisacrylamide, i-ethanol ephelele, i-acetone.

Izinsimbi: iflaski enentamo emithathu, ukunyakazisa kukagesi, i-reflux condenser, iflaski yesihlungi esimuncayo, ifaneli ye-Buchner, i-vacuum drying oven, iphampu yokufunxa amanzi ejikelezayo.

2.3 Indlela yokulungiselela

2.3.1 Ukwenziwa kwe-alkaline

Faka u-1 g kakotini omuncayo ebhodleleni elinezintamo ezintathu, bese wengeza inani elithile lesisombululo se-sodium hydroxide kanye ne-ethanol ephelele, gcina izinga lokushisa lingaphansi kwegumbi lokushisa, bese ugoqoza isikhashana.

2.3.2 I-Etherification

Engeza inani elithile le-chloroacetic acid bese ugoqa ihora elingu-1.

2.3.2 Ukuxhumanisa

Esigabeni sakamuva se-etherification, i-N,N-methylenebisacrylamide yengezwe ngokulingana ukuze kwenziwe ukuxhumanisa, futhi yanyakaziswa ekamelweni lokushisa amahora angu-2.

2.3.4 Ngemuva kokucubungula

Sebenzisa i-glacial acetic acid ukuze ulungise inani le-pH libe ngu-7, ugeze usawoti nge-ethanol, ugeze amanzi nge-acetone, hlunga ngokumunca, futhi uvale ukoma amahora angu-4 (cishe 60).°C, i-vacuum degree 8.8kPa) ukuze uthole umkhiqizo we-cotton filament emhlophe.

2.4 Ukuhlolwa kokuhlaziya

Izinga lokumuncwa kwamanzi (i-WRV) linqunywa ngokusefa, okungukuthi, i-1g yomkhiqizo (G) yengezwa kubhekha eliqukethe u-100ml wamanzi acwecwe (V1), acwiliswe amahora angama-24, ahlungwe ngesikrini sensimbi engagqwali engama-200-mesh. , futhi amanzi angaphansi kwesikrini aqoqwe (V2). Ifomula yokubala imi kanje: WRV=(V1-V2)/G.

3. Imiphumela kanye nengxoxo

3.1 Ukukhethwa kwezimo zokusabela kwe-alkalization

Enqubweni yokukhiqiza i-alkali cellulose ngesenzo se-cotton fiber nesisombululo se-alkaline, izimo zenqubo zinomthelela omkhulu ekusebenzeni komkhiqizo. Kunezici eziningi ekuphenduleni kwe-alkalization. Ukuze kube lula ukubuka, kwamukelwa indlela yokuklama yokuhlola ye-orthogonal.

Ezinye izimo: I-solvent ingu-20ml we-ethanol ephelele, isilinganiso se-alkali ne-etherifying agent (i-mol/md) ngu-3:1, futhi i-ejenti exhumanisayo ingu-0.05g.

Imiphumela yokuhlola ibonisa ukuthi: ubudlelwano obuyisisekelo nobesibili: C>A>B, isilinganiso esihle kakhulu: A3B3C3. Ukugxila kwe-lye kuyisici esibaluleke kakhulu ekuphenduleni kwe-alkalization. Ukugcwala okuphezulu kwe-lye kukhuthaza ukwakheka kwe-alkali cellulose. Kodwa-ke, kufanele kuqashelwe ukuthi lapho inani elikhulu le-lye liphezulu, kulapho kunosawoti omningi we-resin superabsorbent elungiselelwe. Ngakho-ke, lapho ugeza usawoti nge-ethanol, geza izikhathi eziningana ukuze uqiniseke ukuthi usawoti osemkhiqizweni uyasuswa, ukuze ungaphazamisi umthamo wokumunca amanzi womkhiqizo.

3.2 Umthelela womthamo we-ejenti ye-crosslinking kumkhiqizo we-WRV

Izimo zokuhlola yilezi: 20ml we-ethanol ephelele, 2.3:1 isilinganiso se-alkali kumenzeli we-etherification, 20ml we-lye, kanye ne-90min ye-alkalization.

Imiphumela ibonise ukuthi inani le-ejenti exhumanisayo lithinte idigri yokuxhumanisa kwe-CMC-Na. Ukuxhumanisa okweqile kuholela ekwakhiweni kwenethiwekhi okuqinile endaweni yomkhiqizo, ebonakala ngezinga eliphansi lokumuncwa kwamanzi kanye nokunwebeka okungekuhle ngemva kokumuncwa kwamanzi; lapho inani le-ejenti yokuxhumanisa lincane, ukuxhumanisa akuphelele, futhi kunemikhiqizo encibilikayo emanzini, ephinde ithinte izinga lokumuncwa kwamanzi. Uma inani le-ejenti yokuxhumanisa lingaphansi kuka-0.06g, izinga lokumunca amanzi liyakhuphuka ngokunyuka kwenani le-ejenti exhumanisayo, lapho inani le-ejenti yokuxhumanisa lingaphezu kuka-0.06g, izinga lokumuncwa kwamanzi liyehla. ngenani le-ejenti yokuxhumanisa. Ngakho-ke, umthamo we-agent ye-crosslinking cishe u-6% we-cotton fiber mass.

3.3 Umthelela wezimo ze-etherification kumkhiqizo we-WRV

Izimo zokuhlola yilezi: ukuhlushwa kwe-alkali 40%; ivolumu ye-alkali 20ml; i-ethanol ngokuphelele 20ml; Isilinganiso se-ejenti exhumanisa 0.06g; i-alkalization 90min.

Kusuka kufomula yokusabela kwamakhemikhali, isilinganiso se-alkali-ether (NaOH:CICH2-COOH) kufanele sibe ngu-2:1, kodwa inani langempela le-alkali elisetshenzisiwe likhulu kunalesi silinganiso, ngoba ukugxiliswa kwe-alkali okuthile kwamahhala kufanele kuqinisekiswe ohlelweni lokusabela. , ngoba: okuthile Ukugxila okuphezulu kwesisekelo samahhala kulungele ukuqedwa kokusabela kwe-alkalization; ukusabela kwe-cross-linking kumele kwenziwe ngaphansi kwezimo ze-alkaline; okunye ukusabela okuseceleni kudla i-alkali. Kodwa-ke, uma inani le-alkali lengezwa kakhulu, i-alkali fiber izokwehliswa kakhulu, futhi ngesikhathi esifanayo, ukusebenza kahle kwe-ejenti ye-etherification kuzoncishiswa. Ukuhlola kubonisa ukuthi isilinganiso se-alkali ne-ether cishe singu-2.5:1.

3.4 Umthelela wenani le-solvent

Izimo zokuhlola yilezi: ukuhlushwa kwe-alkali 40%; umthamo we-alkali 20ml; isilinganiso se-alkali-ether 2.5:1; Isilinganiso se-ejenti exhumanisa i-0.06g, i-alkalization 90min.

I-solvent anhydrous ethanol idlala indima yokuhlakaza, i-homogenizing nokugcina isimo se-slurry sesistimu, okuzuzisa ukuhlakaza nokudlulisa ukushisa okukhishwe ngesikhathi sokwakhiwa kwe-alkali cellulose, futhi inganciphisa ukusabela kwe-hydrolysis ye-alkali cellulose, ngaleyo ndlela ithole umfaniswano. i-cellulose. Kodwa-ke, uma inani lotshwala elingeziwe liningi kakhulu, i-alkali ne-sodium monochloroacetate izoncibilika kuyo, ukugxila kwama-reactants kuzokwehla, izinga lokuphendula lizokwehla, futhi kuzoba nomthelela omubi ekuxhumaneni okulandelayo. Uma inani le-ethanol eliphelele lingu-20ml, inani le-WRV likhulu.

Kafushane, izimo ezifanele kakhulu zokulungiselela i-superabsorbent resin evela kukotini omuncayo, i-alkalized ne-etherified carboxymethyl cellulose exhunywe yi-N, N-methylenebisacrylamide yilezi: ukuhlushwa kwe-alkali okungama-40%, okungancibiliki ku-20ml wamanzi ne-ethanol, isilinganiso se-alkali ne-ether. ngu-2.5:1, futhi umthamo we-agent exhumanisayo ngu-0.06g (6% yenani lama-linter kakotini).