Dareen-celinta etherification ee ether cellulose

Dhaqdhaqaaqa etherification ee cellulose ayaa lagu daraaseeyay mashiinka cajiinka iyo kicinta kicinta siday u kala horreeyaan, iyo hydroxyethyl cellulose iyo carboxymethyl cellulose waxaa loo diyaariyey chloroethanol iyo monochloroacetic acid siday u kala horreeyaan. Natiijooyinka waxay muujiyeen in falcelinta etherification ee cellulose lagu sameeyay kicinta kicinta iyada oo la raacayo xaaladda kacsanaanta sare. Cellulose waxay leedahay falcelinta etherification wanaagsan, taas oo ka fiican habka cajiinka ee hagaajinta waxtarka etherification iyo kor u qaadista iftiinka sheyga ee xalka aqueous. alaabta.

Erayada muhiimka ah:falcelinta etherification; Cellulose;Hydroxyethyl cellulose; Carboxymethyl cellulose

Horumarinta alaabta ether cellulose suufka la safeeyey, habka dareeraha ayaa si ballaaran loo isticmaalaa iyo mashiinka cajiinka waxaa loo isticmaalaa qalab falcelin ah. Si kastaba ha ahaatee, cellulose suufku wuxuu inta badan ka kooban yahay gobollada crystals halkaas oo molecules loo habeeyey si hagaagsan oo dhow. Marka mashiinka cajiinka loo isticmaalo sida qalabka falcelinta, cududda cajiinka ee mashiinka cajiinka ayaa gaabis ah inta lagu jiro falcelinta, iyo iska caabinta wakiilka etherifying si ay u galaan lakabyada kala duwan ee cellulose waa weyn yahay xawaaruhuna waa gaabis, taasoo keentay waqti dheer oo falcelin ah, saamiga sare ee dhinaca falcelinta iyo qaybinta aan sinnayn ee kooxaha beddelka ah ee silsiladaha molecular cellulose.

Caadiyan falcelinta etherification ee cellulose waa falcelin kala duwan oo dibadda iyo gudaha ah. Haddii aysan jirin ficil firfircoon oo dibadeed, wakiilka etherifying way adagtahay in la galo aagga crystallization of cellulose. Iyo iyada oo loo marayo daweynta suufka la safeeyey (sida isticmaalka hababka jireed si loo kordhiyo dusha sare ee suufka la safeeyey), isla markaana leh kicinta kicinta qalabka falcelinta, iyadoo la adeegsanayo falcelinta etherification ee degdega ah, marka loo eego sababaha, cellulose si xoog leh ayey u barari kartaa, bararka aagga cellulose amorphous iyo aagga crystallization waxay u egtahay inay joogto, wanaajiso dhaqdhaqaaqa falcelinta. Qaybinta isku midka ah ee beddelka ether-ka cellulose ee nidaamka falcelinta etherogeneous waxaa lagu gaari karaa iyadoo la kordhinayo awoodda kicinta dibadda. Markaa waxay noqon doontaa jihada horumarineed ee mustaqbalka ee dalkeena si loo horumariyo alaabada etherification cellulose tayo sare leh oo leh kiliyaha falcelinta nooca walaaqaya sida qalabka falcelinta.

1. Qaybta tijaabada ah

1.1 Walax cayriin oo suuf ah oo la safeeyey si loo tijaabiyo

Marka loo eego qalabka falcelinta ee kala duwan ee loo isticmaalo tijaabada, hababka ka-hortagga ee cellulose suufku way kala duwan yihiin. Marka cajiinka loo isticmaalo sida qalabka falcelinta, hababka daaweynta ka hor ayaa sidoo kale ka duwan. Marka cajiinka loo isticmaalo sida qalabka falcelinta, crystallinity of cellulose suuf la safeeyey la isticmaalo waa 43.9%, iyo celceliska dhererka cellulose suuf la safeeyey waa 15 ~ 20mm. crystallinity of cellulose cudbi la safeeyey waa 32.3% iyo celceliska dhererka cellulose suuf la safeeyey ka yar yahay 1mm marka reactor walaaqaya loo isticmaalo sida qalab falcelin.

1.2 Horumarinta carboxymethyl cellulose iyo hydroxyethyl cellulose

Diyaarinta karboxymethyl cellulose iyo hydroxyethyl cellulose waxaa lagu fulin karaa iyadoo la isticmaalayo 2L kneader sida qalabka falcelinta (celceliska xawaaraha inta lagu jiro falcelinta waa 50r / min) iyo 2L reactor walaaqaya sida qalabka falcelinta (celceliska xawaaraha inta lagu jiro falcelinta waa 500r / min).

Inta lagu jiro falcelinta, dhammaan alaabta ceeriin waxaa laga soo qaatay falcelinta adag ee tirada. Alaabta laga helay falcelinta waxaa lagu dhaqaa w=95% ethanol, ka dibna lagu qalajiyo faakuumka 24h iyadoo cadaadiska taban ee 60℃ iyo 0.005mpa. Maaddada qoyaanka ee muunadda la helay waa w=2.7%±0.3%, muunadda badeecada ee falanqaynta waa la dhaqaa ilaa ay ka kooban tahay dambaska w <0.2%.

Tallaabooyinka diyaarinta mashiinka cajiinka sida qalabka falcelinta waa sida soo socota:

Falcelinta Etherification → alaabta lagu dhaqo → qalajinta → granulation daadi → baakadaha waxaa lagu sameeyaa cajiin.

Tallaabooyinka diyaarinta kicinta reactor sida qalabka falcelinta waa sida soo socota:

Dareen-celinta Etherification → dhaqidda alaabta → qalajinta iyo granulation → baakadaha waxaa lagu sameeyaa reactor-kicin.

Waxaa la arki karaa in cajiinka loo isticmaalo qalab falcelin ah oo loogu talagalay diyaarinta sifooyinka waxtarka falcelinta hooseeya, qalajinta iyo xoqidda granulation tallaabo tallaabo, iyo tayada alaabta ayaa si weyn hoos loogu dhigi doonaa habka wax lagu shiidayo.

Astaamaha habka diyaarinta leh reactor-kicin sida qalabka falcelinta waa sida soo socota: waxtarka falcelinta sare, granulation wax soo saarka ma qaataan habka granulation dhaqameed ee habka qalajinta iyo shiidi, iyo habka qalajinta iyo granulation waxaa lagu fuliyaa waqti isku mid ah. badeecooyinka aan la qalajin ka dib markii la dhaqo, iyo tayada alaabta ayaa weli ah mid aan isbeddelin habka qalajinta iyo granulation.

1.3 Falanqaynta kala-duwanaanta raajada

Falanqaynta kala-duwanaanta raajada waxaa sameeyay Rigaku D / max-3A Diffractometer X-ray, monochromator graphite, Θ xagal wuxuu ahaa 8 ° ~ 30 °, CuKα ray, cadaadiska tuubada iyo qulqulka tuubada waxay ahaayeen 30kV iyo 30mA.

1.4 Falanqaynta infrared spectrum

Spectrum-2000PE FTIR spectrometer infrared ayaa loo isticmaalay falanqaynta spectrum infrared. Dhammaan muunadaha falanqaynta infrared spectrum waxay lahaayeen miisaan dhan 0.0020g. Muunadahan waxaa lagu qasi jiray 0.1600g KBr, siday u kala horreeyaan, ka dibna la riixay (oo leh dhumucdii <0.8mm) oo la falanqeeyay.

1.5 Ogaanshaha gudbinta

Gudbinta waxaa lagu ogaaday 721 spectrophotometer. Xalka CMC w=w1% waxa lagu riday saxan midabaysan 1cm oo dhererkiisu yahay 590nm

1.6 heerka ogaanshaha beddelka

Darajada beddelka HEC ee cellulose hydroxyethyl waxaa lagu cabbiray habka falanqaynta kiimikaad ee caadiga ah. Mabda'a ayaa ah in HEC ay burburin karto HI hydroiodate at 123 ℃, iyo heerka beddelka HEC waxaa lagu ogaan karaa iyada oo la cabbirayo walxaha jajaban ee ethylene iyo ethylene iodide ee la soo saaro. Heerka beddelka hydroxymethyl cellulose sidoo kale waxaa lagu tijaabin karaa hababka falanqaynta kiimikada caadiga ah.

2. Natiijooyinka iyo doodaha

Laba nooc oo kiishka falcelinta ah ayaa halkan loo isticmaalaa: mid waa mashiinka cajiinka sida qalabka falcelinta, kan kalena waa kicinaya nooca falcelinta sida qalabka falcelinta, nidaamka falcelinta heterogeneous, xaalada alkaline iyo nidaamka dareeraha biyaha khamriga, falcelinta etherification ee cellulose suuf la safeeyey ayaa la bartay. Waxaa ka mid ah, sifooyinka teknoolajiyada ee mashiinka cajiinka sida qalabka falcelinta waa: Fal-celinta, xawaaraha cududda cududda waa mid gaabis ah, waqtiga falcelinta waa dheer yahay, saamiga fal-celinta dhinacyadu waa sarreeyaa, heerka isticmaalka ee wakiilka etherifying waa hooseeyaa, iyo Midnimada beddelka qaybinta kooxda ee falcelinta etherizing ayaa liidata. Habka cilmi-baadhistu waxa uu ku koobnaan karaa oo keliya xaaladaha falcelinta oo cidhiidhi ah. Intaa waxaa dheer, hagaajinta iyo xakamaynta xaaladaha falcelinta muhiimka ah (sida saamiga qubeyska, fiirsashada alkali, cududda cududda xawaaraha mashiinka wax lagu cajiiyo) aad bay u liidataa. Way adag tahay in la gaaro isku midnimada qiyaas ahaan falcelinta etherification iyo in si qoto dheer loo barto wareejinta tirada badan iyo dhexgalka habka falcelinta etherification si qoto dheer. Astaamaha geeddi-socodyada kicinta kicinta sida qalabka falcelinta waa: xawaaraha kicinta degdegga ah ee falcelinta, xawaaraha falcelinta degdegga ah, heerka isticmaalka sare ee wakiilka etherizing, qaybinta isku midka ah ee beddelka etherizing, la hagaajin karo oo la xakamayn karo xaaladaha falcelinta muhiimka ah.

Carboxymethyl cellulose CMC waxaa loo diyaariyey qalabka falcelinta cajiimi iyo walaaqaya qalabka falcelinta reactor siday u kala horreeyaan. Marka cajiinka loo isticmaalo sida qalabka falcelinta, xoojinta kicinta ayaa hooseysa celceliska xawaaraha wareegga wuxuu ahaa 50r / min. Marka reactor-ka kicinta loo isticmaalo sidii qalabka falcelinta, xoojinta kicinta ayaa sarraysay celceliska xawaaraha wareeggu wuxuu ahaa 500r/min. Marka saamiga molarka ee monochloroacetic acid iyo cellulose monosaccharide uu ahaa 1:5:1, wakhtiga falcelinta waxay ahayd 1.5h at 68℃. Gudbinta iftiinka ee CMC ee lagu helay mashiinka cajiintu waxay ahayd 98.02% iyo waxtarka etherification waxay ahayd 72% sababtoo ah wanaajinta wanaagsan ee CM ee wakiilka chloroacetic acid. Marka reactor-ka-kicinta loo isticmaalo sida qalabka fal-celinta, qulqulka wakiilka etherifying ayaa ka fiicnaaday, gudbinta CMC waxay ahayd 99.56%, iyo waxtarka falcelinta etherizing ayaa la kordhiyay ilaa 81%.

Hydroxyethyl cellulose HEC waxaa lagu diyaariyey cajiin iyo kicinta kicinta sida qalabka falcelinta. Marka cajiinka loo isticmaalo qalabka falcelinta, waxtarka falcelinta ee wakiilka etherizing wuxuu ahaa 47% iyo milanka biyuhu wuu liitay markii awoodda chloroethyl aalkolada etherizing wakiilka ay liidatay iyo saamiga molar ee chloroethanol iyo monosaccharide cellulose wuxuu ahaa 3: 1 at 60 ℃ 4h. . Kaliya marka saamiga molar ee chloroethanol iyo monosaccharides cellulose uu yahay 6: 1, alaabooyinka leh milanka biyaha wanaagsan ayaa la samayn karaa. Marka reactor-ka-kicinta loo isticmaalo sidii qalabka fal-celinta, awood-u-yeelashada wakiilka aalkolada chloroethyl waxay noqotay mid ka wanaagsan 68 ℃ 4 saac. Marka saamiga molar ee chloroethanol iyo cellulose monosaccharide uu ahaa 3: 1, natiijada HEC waxay lahayd biyo nadiif ah oo wanaagsan, iyo waxtarka falcelinta etherification ayaa la kordhiyay ilaa 66%.

Waxtarka falcelinta iyo xawaaraha falcelinta ee wakiilka etherizing chloroacetic acid ayaa aad uga sarreeya kan chloroethanol, iyo reactor-ka kicinta sida qalabka falcelinta etherizing-ka ayaa faa'iidooyin muuqda ka leh cajiinka, kaas oo si weyn u wanaajinaya waxtarka falcelinta etherizing. Gudbinta sare ee CMC waxay sidoo kale si dadban u muujineysaa in reactor-ka kicinta sida qalabka falcelinta etherizing uu hagaajin karo isku midka ah ee falcelinta etherizing. Tani waa sababta oo ah silsiladda cellulose waxay leedahay saddex kooxood oo hydroxyl ah giraan kasta oo gulukoos-koox ah, oo kaliya marka si xoog leh u bararaan ama la milmay ayaa ah dhammaan lammaanaha cellulose hydroxyl ee molecules etherifying oo la heli karo. Dareen-celinta etherification ee cellulose caadi ahaan waa fal-celin kala duwan oo ka yimaada dibadda ilaa gudaha, gaar ahaan gobolka crystalline ee cellulose. Marka qaab-dhismeedka crystal ee cellulose uu weli dhawrsan yahay iyada oo aan saamaynta xoog dibadda, wakiilka etherifying waa ay adag tahay in ay galaan qaab-dhismeedka crystalline, saameeya isku midka ah ee falcelinta heterogeneous. Sidaa darteed, iyada oo la sii daweynayo suufka la safeeyey (sida kordhinta dusha gaarka ah ee suufka la safeeyey), falcelinta suufka la safeeyey waa la hagaajin karaa. Saamiga weyn ee qubeyska (ethanol / cellulose ama isopropyl khamriga / cellulose iyo falcelinta kicinta xawaaraha sare leh, sida ku cad sababta, nidaamka aagga crystallization cellulose waa la dhimi doonaa, wakhtigan cellulose si xoog leh u barari karo, si bararka bararka. ee amorphous iyo crystalline cellulose aagga u janjeera in ay si joogto ah, Sidaa darteed, falcelinta gobolka amorphous iyo gobolka crystalline la mid ah.

Iyada oo la adeegsanayo falanqaynta spectrum infrared iyo falanqaynta kala-baxa raajada, habka falcelinta etherification ee cellulose ayaa si cad loo fahmi karaa marka kicinta reactor loo isticmaalo sida qalabka falcelinta etherification.

Halkan, spectra infrared iyo raajada kala qaybsanaanta ayaa lagu falanqeeyay. Dareen-celinta etherification ee CMC iyo HEC waxaa lagu sameeyay reactor-kicin ee xaaladaha falcelinta ee kor lagu sharaxay.

Falanqaynta spectrum infrared waxay muujinaysaa in falcelinta etheration ee CMC iyo HEC ay si joogto ah u beddesho kordhinta wakhtiga falcelinta, heerka beddelka ayaa ka duwan.

Iyada oo loo marayo falanqaynta qaabka kala-duwanaanta raajada, crystallinity ee CMC iyo HEC waxay u janjeertaa eber iyadoo la kordhinayo waqtiga falcelinta, taasoo muujineysa in geeddi-socodka decrystallisation asal ahaan lagu ogaaday marxaladda alkalization iyo heerka kuleylka ka hor falcelinta etherification ee suufka la safeeyey. . Sidaa darteed, falcelinta karboxymethyl iyo hydroxyethyl etherification ee suufka la safeeyey hadda kama xaddidna crystallinity-ka suufka la safeeyey. Waxay la xiriirtaa qulqulka wakiilka etherifying. Waxaa la tusi karaa in falcelinta etherification ee CMC iyo HEC lagu sameeyo fal-celinta kicinta sida qalabka falcelinta. Under walaaqaya xawaaraha sare, waxay faa'iido u tahay habka decrystallisation ee suufka la safeeyey ee marxaladda alkalization iyo marxaladda kulaylka ka hor falcelinta etherification, oo ka caawisaa wakiilka etherification si ay u dhex gal cellulose ah, si loo hagaajiyo hufnaan falcelinta etherification iyo beddelka uniformity. .

Gebogebadii, daraasaddan ayaa xoogga saaraysa saameynta awoodda kicinta iyo arrimo kale oo ku saabsan waxtarka falcelinta inta lagu jiro habka falcelinta. Sidaa darteed, soo jeedinta daraasaddan waxay ku salaysan tahay sababahan soo socda: Nidaamka falcelinta etherogeneous, isticmaalka saamiga qubeyska weyn iyo xoojinta kicinta sare, iwm. qaybinta; Nidaamka falcelinta etherogeneous heterogeneous gaar ah, ether waxqabadka sare leh ether cellulose ah oo ku dhawaad ​​qaybinta lebis ee beddelka waxaa lagu diyaarin karaa iyadoo la isticmaalayo reactor walaaqaya sida qalab falcelin, taas oo muujinaysa in cellulose ether xal aqueous uu leeyahay gudbin sare, taas oo muhiimad weyn u leh in la ballaariyo guryaha. iyo hawlaha ether cellulose. Mashiinka cajiinka waxaa loo isticmaalaa sidii qalab falcelin ah si loo barto falcelinta etherification ee suufka la safeeyey. Sababtoo ah xoojinta kicinta hoose, uma fiicna gelitaanka wakiilka etherification, waxayna leedahay qaar ka mid ah faa'iido darrada sida saamiga sare ee falcelinta dhinaca iyo isku midka ah qaybinta liidata ee beddelka etherification.