Walxaha nuugista sare ee Cellulose Ether

Habka iyo waxqabadka wax soo saarka ee carboxymethyl cellulose cross-linked by N, N-methylenebisacrylamide si ay u diyaariyaan resin superabsorbent ayaa la bartay, iyo fiirsashada ee alkali, qadarka wakiilka cross-linking, alkali etherification, iyo dareeraha ayaa laga wada hadlay. Saamaynta qiyaasta ee waxqabadka nuugista biyaha ee alaabta. Habka adsorption ee xuubka biyaha nuugaya biyaha ayaa la sharaxay. Daraasaduhu waxay muujiyeen in qiimaha haynta biyaha (WRV) ee alaabtani ay gaadho 114ml/g.

Erayada muhiimka ah:ether cellulose; methylenebisacrylamide; diyaarinta

1,Hordhac

Xabagta superabsorbent waa walxo polymer ah oo leh kooxo biyo-mareeno xoog leh iyo heer go'an oo isgoysyada ah. Alaabta caadiga ah ee biyaha nuugta sida waraaqaha, suufka, iyo hemp waxay leeyihiin heerka nuugista biyaha hooseeya iyo awoodda haynta biyaha oo liidata, halka resins-nuugista badan ay nuugi karaan biyaha daraasiin jeer miisaankooda, iyo jelka la sameeyay ka dib marka la nuugo biyaha xitaa ma fuuqbaxo. cadaadis yar leh. Awood biyo hayn heer sare ah. Kuma milmo biyaha ama dareerayaasha organic.

Waxaa jira tiro badan oo ah kooxaha hydroxyl, kooxaha karboxyl iyo ion sodium hydrate on silsiladda kelli ee walxaha super nuugista ka samaysan cellulose. Ka dib marka la nuugo biyaha, biyaha waxaa ku wareegsan shabakad macromolecular hydrophilic waxaana lagu hayn karaa cadaadis dibadda ah. Marka ay biyuhu qoyaan resinka adsorption, lakabka xuubka nuska ah ayaa ka dhex abuurma xabagta iyo biyaha. Sababtoo ah fiirsashada sare ee ions mobile (Na+) ee xuubka biyaha nuugaya, sida uu qabo Donnan'Mabda'a dheellitirka, farqiga u-fiirsashada ion-kan wuxuu sababi karaa cadaadiska osmotic. Miskiin, samaynta qoyaan iyo barar awood daciif ah, biyuhu dhex maraan lakabka this of xuubka semi-permeable iyo isku daraa kooxaha hydrophilic iyo ions on macromolecules of resin superabsorbent, hoos u fiirsashada of ions mobile, markaas muujinaysaa nuugista biyaha sare iyo barar. Nidaamka xayeysiintani wuxuu sii socdaa ilaa farqiga cadaadiska osmotic ee uu keeno farqiga u dhexeeya fiirsashada ions mobile waxay la mid tahay caabbinta ballaarinta dheeraadka ah ee ay keento xoogga isku xiran ee shabakada molecular ee resin polymer. Faa'iidooyinka suufka superabsorbent ee laga diyaariyey cellulose waa: heerka nuugista dhexdhexaadka ah ee biyaha, xawaaraha nuugista biyaha degdega ah, caabbinta biyaha cusbada wanaagsan, aan sunta ahayn, si sahlan loo hagaajiyo qiimaha pH, waa la dhimi karaa dabeecadda, iyo qiimo jaban, sidaas darteed waxay leedahay ballaaran. kala duwan ee isticmaalka. Waxaa loo isticmaali karaa sidii wakiilka biyaha celinaya, qaboojiyaha carrada, iyo wakiilka biyaha ee warshadaha iyo beeraha. Intaa waxaa dheer, waxay leedahay horumar wanaagsan iyo rajada codsiga caafimaadka, cuntada, microbiology, iyo daawada.

2. Qaybta tijaabada ah

2.1 Mabda'a tijaabada ah

Diyaarinta suufka suufka ah ee loo yaqaan 'superabsorbent resin' ayaa inta badan ah in la sameeyo qaab-dhismeed isku-dhafan oo heer hoose ah oo lagu beddelayo maqaarka fiber-ka. Isku-xidhka isku-xidhka isku-xidhka guud ahaan waxay leeyihiin laba ama in ka badan oo kooxeed falcelineed. Kooxaha shaqeeya ee awood u leh inay isku xiraan waxaa ka mid ah vinyl, hydroxyl, carboxyl, amide, chloride acid, oxirane, nitrile, iwm. Tijaabadaan, N, N-methylenebisacrylamide waxaa loo istcimaalaa wakiilka iskutallaabta, oo ay ku jiraan talaabooyinka soo socda:

(1) Cellulose (Rcell) waxay la falgashaa xalalka alkaline si ay u dhaliso alkali cellulose, iyo falcelinta alkalization ee cellulose waa falcelin degdeg ah. Hoos u dhigista heerkulku waxay ku haboon tahay samaynta fiilooyinka alkali waxayna joojin kartaa hydrolysiskooda. Ku darida khamriga waxay kordhin kartaa khalkhalka cellulose, taas oo faa'iido u leh alkalization iyo etherification ku xiga.

RcellOH+NaOH→RcellONa+H2O

(2) Alkali cellulose iyo monochloroacetic acid waxay dhaliyaan sodium carboxymethyl cellulose, falcelinta etherification-ka waxaa iska leh falcelinta beddelka nucleophilic:

RcellONa+ClCH2COONa→RcellOCH2COONa+NaCl

(3) N, N-methylenebisacrylamide iskutallaabta lagu xidhay si loo helo xabagta nuugista leh. Sababtoo ah weli waxaa jira tiro badan oo kooxo hydroxyl ah oo ku saabsan silsiladda kelli ee fiber carboxymethyl, ionization ee kooxda hydroxyl ee cellulose iyo ionization of acryloyl bond double on silsilad molecular ee N, N-methylenebisacrylamide waxaa lagu kicin karaa hoos ficil. of catalysis alkali, ka dibna Cross-isku xidhka u dhexeeya silsiladaha molecular ee cellulose dhacdaa iyada oo uumi Michael, oo isla markiiba maraa proton beddelashada biyaha si ay u noqdaan xuubka cellulose biyaha-ma-milmi kara superabsorbent.

2.2 Qalab cayriin iyo qalab

Qalabka ceeriin: suufka nuugaya (la gooyay linters), sodium hydroxide, monochloroacetic acid, N, N-methylenebisacrylamide, ethanol absolute, acetone.

Qalabka: weel saddex luqun leh, walaaqaya koronto, kondenser reflux, galaaska shaandhada nuugista, Funnel Buchner, foornada faakuumka qalajinta, bamka faakuumka biyaha wareega.

2.3 Habka diyaarinta

2.3.1 Alkalinization

Ku dar 1 g oo suuf ah oo nuugaya dhalada saddexda qoor leh, ka dibna ku dar qaddar go'an oo ah xal sodium hydroxide ah iyo ethanol dhammaystiran, heerkulka ka dhig heerkulka qolka, oo walaaq in muddo ah.

2.3.2 Etherification

Ku dar qadar go'an oo ah chloroacetic acid oo walaaq ilaa 1 saac.

2.3.2 Crosslinking

Marxaladda dambe ee etherification, N, N-methylenebisacrylamide ayaa lagu daray qiyaasta si loo fuliyo isku-xirnaanta, oo lagu walaaqay heerkulka qolka 2 saacadood.

2.3.4 Processing ka dib

Isticmaal acetic acid glacial si aad u hagaajisid qiimaha pH ilaa 7, ku maydh milixda ethanol, ku maydh biyaha acetone, sifee nuugista, oo faakium qallaji ilaa 4 saacadood (qiyaastii 60).°C, vacuum degree 8.8kPa) si loo helo badeeco suuf cad ah.

2.4 Imtixaanka falanqaynta

Heerka nuugista biyaha (WRV) waxaa lagu go'aamiyaa shaandheynta, taas oo ah, 1g ee alaabta (G) waxaa lagu daraa digsi ka kooban 100ml oo biyo diirran (V1), oo la qooyay 24 saacadood, lagu sifeeyay 200-mesh shaashad bir ah oo aan lahayn , iyo biyaha hoose ee shaashadda waa la ururiyaa (V2). Habka xisaabinta waa sida soo socota: WRV=(V1-V2)/G.

3. Natiijooyinka iyo doodaha

3.1 Xulashada xaaladaha falcelinta alkalization

Habka soo saarista cellulose alkali by ficilka suufka suufka iyo xalalka alkaline, shuruudaha geedi socodka ayaa saameyn weyn ku leh waxqabadka alaabta. Waxaa jira arrimo badan oo falcelinta alkalization. Si ay ugu habboonaato indho-indheynta, habka naqshadaynta tijaabada orthogonal ayaa la qaatay.

Xaalado kale: dareeruhu waa 20ml ee ethanol dhammaystiran, saamiga alkali iyo wakiilka etherifying (mol/md) waa 3: 1, wakiilka iskutallaabtu waa 0.05g.

Natiijooyinka tijaabada ahi waxay muujinayaan in: xidhiidhka aasaasiga ah iyo kan sare: C> A> B, saamiga ugu fiican: A3B3C3. Xoojinta lye ayaa ah qodobka ugu muhiimsan ee falcelinta alkalization. Isku-darka sare ee lye wuxuu ku habboon yahay samaynta cellulose alkali. Si kastaba ha ahaatee, waa in la ogaadaa in xoojinta sare ee lye, ay ka weyn tahay maadada milixda ee resin superabsorbent ee la diyaariyey. Sidaa darteed, markaad milix ku dhaqayso ethanol, ku dhaq dhowr jeer si aad u hubiso in milixda alaabta laga saaray, si aysan u saameynin awoodda nuugista biyaha ee alaabta.

3.2 Saamaynta qiyaasta wakiilka isku xidhka ee alaabta WRV

Xaaladaha tijaabada ah waa: 20ml of ethanol buuxda, 2.3: 1 saamiga alkali ilaa wakiilka etherification, 20ml of lye, iyo 90min of alkalization.

Natiijooyinka waxay muujiyeen in qadarka wakiilka isku-xidhka ahi uu saameeyay heerka isku-xidhka ee CMC-Na. Isku-xirnaanta xad-dhaafka ah waxay keenaysaa qaab-dhismeedka shabakad adag oo ku yaala booska alaabta, taas oo lagu garto heerka nuugista biyaha hooseeya iyo barti liidata ka dib nuugista biyaha; marka qadarka wakiilka iskutallaabtu uu yar yahay, iskutallaabtu waa mid aan dhamaystirnayn, waxaana jira alaabada biyaha lagu milmo, kuwaas oo sidoo kale saameeya heerka nuugista biyaha. Marka qadarka wakiilka iskutallaabtu uu ka yar yahay 0.06g, heerka nuugista biyuhu wuxuu kordhiyaa kororka tirada wakiilka iskutallaabta, marka qadarka wakiilka iskutallaabtu uu ka badan yahay 0.06g, heerka nuugista biyaha ayaa hoos u dhacaya. oo leh qadarka wakiilka isku-xiran. Sidaa darteed, qiyaasta wakiilka iskutallaabtu waa qiyaastii 6% tirada fiber-ka suufka ah.

3.3 Saamaynta xaaladaha etherification ee alaabta WRV

Xaaladaha tijaabada ah waa: xoojinta alkali 40%; alkali mugga 20ml; ethanol dhamaystiran 20 ml; qiyaasta wakiilka iskutallaabta 0.06g; alkalization 90min.

Laga soo bilaabo qaacidada fal-celinta kiimikada, saamiga alkali-ether (NaOH: CICH2-COOH) waa inuu ahaadaa 2: 1, laakiin qadarka dhabta ah ee alkali ee la isticmaalo ayaa ka weyn saamigan, sababtoo ah fiirsashada alkali ee bilaashka ah waa in lagu dammaanad qaado nidaamka falcelinta. , sababtoo ah: qaar ka mid ah fiirsashada sare ee saldhiga xorta ah ayaa ku haboon dhamaystirka falcelinta alkalization; falcelinta isku-xiran waa in lagu fuliyaa xaaladaha alkaline; Dareen-celinta qaarkood waxay cunaan alkali. Si kastaba ha noqotee, haddii qadarka alkali lagu daro si aad ah, fiber alkali ayaa si dhab ah u dhimi doonta, isla markaana, waxtarka wakiilka etherification ayaa hoos u dhacaya. Tijaabooyinku waxay muujinayaan in saamiga alkali iyo ether uu yahay qiyaastii 2.5: 1.

3.4 Saamaynta qaddarka dareeraha

Xaaladaha tijaabada ah waa: xoojinta alkali 40%; qiyaasta alkali 20ml; saamiga alkali-ether 2.5: 1; qiyaasta wakiilka iskutallaabta 0.06g, alkalization 90min.

Ethanol-ka dareeraha ah ee anhydrous wuxuu ka ciyaaraa doorka kala firdhinta, isku-dhafka iyo ilaalinta nidaamka nidaamka, taas oo faa'iido u leh in la kala diro oo lagu wareejiyo kulaylka la sii daayo inta lagu jiro samaynta cellulose alkali, waxayna hoos u dhigi kartaa falcelinta hydrolysis ee cellulose alkali, sidaas darteed helitaanka dharka cellulose . Si kastaba ha noqotee, haddii qadarka khamriga lagu daro uu aad u badan yahay, alkali iyo sodium monochloroacetate ayaa ku milmi doona, xoojinta falcelinta ayaa hoos u dhici doonta, heerka falcelinta ayaa hoos u dhici doonta, sidoo kale waxay saameyn xun ku yeelan doontaa isku-xidhka xiga. Marka qadarka ethanol ee saxda ah uu yahay 20ml, qiimaha WRV waa weyn yahay.

Marka la soo koobo, shuruudaha ugu habboon ee loogu talagalay diyaarinta resin superabsorbent oo ka soo baxa suufka nuugaya iyo etherified karboxymethyl cellulose cross-linked by N, N-methylenebisacrylamide waa: fiirsashada alkali 40%, 20ml dareere ah oo biyo ah iyo ethanol, saamiga alkali ilaa ether waa 2.5:1, iyo qiyaasta wakiilka iskutallaabtu waa 0.06g (6% qadarka suufka suufka ah).