Focus on Cellulose ethers

Etherification reaction kuri selile ether

Etherification reaction kuri selile ether

Igikorwa cya etherification ya selile cyakozweho imashini yo gukata no gukurura reaction, hanyuma hydroxyethyl selulose na carboxymethyl selulose byateguwe na chloroethanol na acide monochloroacetic. Ibisubizo byerekanaga ko reaction ya etherification ya selile yakozwe no gukurura reakteri bitewe nubushyuhe bukabije. Cellulose ifite reaction nziza ya etherification, ikaba iruta uburyo bwa knader mugutezimbere imikorere ya etherification no kuzamura urumuri rwibicuruzwa mubisubizo byamazi.) Kubwibyo rero, kunoza ubukana bwibikorwa bya reaction nuburyo bwiza bwo guteza imbere insimburangingo ya selulose ya selile. ibicuruzwa.

Amagambo y'ingenzi:reaction ya etherification; Cellulose;Hydroxyethyl selile; Carboxymethyl selulose

 

Mugutezimbere ibicuruzwa bitunganijwe neza bya selulose ether, uburyo bwa solvent burakoreshwa cyane naho imashini yo gukata ikoreshwa nkibikoresho bya reaction. Nyamara, ipamba selulose igizwe ahanini nuturere twa kirisiti aho molekile zitunganijwe neza kandi hafi. Iyo imashini yo gukata ikoreshwa nkibikoresho byo kubyitwaramo, ukuboko gukata imashini yo guteka biratinda mugihe cyo kubyitwaramo, kandi kurwanya imiti ya etherifying yinjira mubice bitandukanye bya selile nini kandi umuvuduko uratinda, bikavamo igihe kirekire cyo kubyitwaramo, igice kinini cyuruhande reaction no gukwirakwiza kutaringaniza amatsinda asimbuye kumurongo wa selile.

Mubisanzwe etherification reaction ya selile ni reaction itandukanye kandi imbere. Niba nta gikorwa cyo hanze cyigikorwa, etherifying agent biragoye kwinjira muri kristu ya selile. Kandi binyuze mukwiyitirira ipamba inoze (nko gukoresha uburyo bwumubiri kugirango wongere ubuso bwa pamba itunganijwe), icyarimwe hamwe na reaction ya reaction ya ibikoresho bya reaction, ukoresheje reaction yihuta ya etherification, ukurikije ibitekerezo, selile irashobora kubyimba cyane, kubyimba agace ka selulose amorphous hamwe na kristu ya kristalisiti ikunda kuba ihamye, kunoza ibikorwa bya reaction. Ikwirakwizwa ryogukwirakwiza insimburangingo ya selulose ether muri sisitemu ya reaction ya heterogeneous etherification reaction irashobora kugerwaho hongerwa imbaraga zo gukurura hanze. Bizaba rero icyerekezo cyiterambere cyigihugu cyacu kugirango dutezimbere ibicuruzwa byiza bya selile nziza ya etherification hamwe nubwoko bwa reaction ya kettle nkibikoresho bya reaction.

 

1. Igice cyubushakashatsi

1.1 Ipamba nziza ya selulose ibikoresho fatizo byo kwipimisha

Ukurikije ibikoresho bitandukanye bya reaction byakoreshejwe mubushakashatsi, uburyo bwo kwitegura ipamba selile iratandukanye. Iyo ikariso ikoreshwa nkibikoresho bya reaction, uburyo bwo kwitegura nabwo buratandukanye. Iyo ikariso ikoreshwa nkibikoresho byo kubyitwaramo, kristu ya selile yamashanyarazi yatunganijwe ikoreshwa ni 43.9%, naho impuzandengo yuburebure bwa selile nziza yatunganijwe ni 15 ~ 20mm. Ikirahure cya selile nziza itunganijwe ni 32.3% naho impuzandengo yuburebure bwa pamba selile itunganijwe ntiri munsi ya 1mm mugihe reaction ya reaction ikoreshwa nkibikoresho bya reaction.

1.2 Iterambere rya carboxymethyl selulose na hydroxyethyl selile

Gutegura carboxymethyl selulose na hydroxyethyl selulose birashobora gukorwa hakoreshejwe ikariso ya 2L nkibikoresho byo kubyitwaramo (umuvuduko ugereranije mugihe cya reaction ni 50r / min) na 2L ikurura reaction nkibikoresho byo kubyitwaramo (umuvuduko ugereranije mugihe cya reaction ni 500r / min).

Mugihe cyo kubyitwaramo, ibikoresho byose bibisi biva muburyo bukomeye bwo kubara. Ibicuruzwa byakuwe muri reaction byogejwe na w = 95% Ethanol, hanyuma ukumishwa na vacuum kuri 24h munsi yumuvuduko mubi wa 60 ℃ na 0.005mpa. Ibirungo by'icyitegererezo cyabonetse ni w = 2,7% ± 0.3%, naho icyitegererezo cyibicuruzwa byo gusesengura cyogejwe kugeza ivu w <0.2%.

Intambwe zo gutegura imashini yo guteka nkibikoresho bya reaction nibi bikurikira:

Etherification reaction → gukaraba ibicuruzwa → gukama → granulation granated → gupakira bikorerwa muri knader.

Intambwe zo kwitegura gukurura reaction nkibikoresho bya reaction nibi bikurikira:

Etherification reaction → gukaraba ibicuruzwa → gukama no guhunika → gupakira bikorerwa mumashanyarazi.

Birashobora kugaragara ko ikariso ikoreshwa nkibikoresho byogukora kugirango hategurwe ibiranga imikorere idahwitse, kumisha no gusya granulation intambwe ku yindi, kandi ubwiza bwibicuruzwa buzagabanuka cyane mugusya.

Ibiranga gahunda yo kwitegura hamwe na reakteri yashizwemo nkibikoresho byo kubyitwaramo nibi bikurikira: uburyo bwiza bwo kubyitwaramo neza, guhunika ibicuruzwa ntabwo bifata uburyo bwa gakondo bwo guhunika no gusya, kandi uburyo bwo kumisha no guhunika bukorwa icyarimwe hamwe ibicuruzwa bidakaranze nyuma yo gukaraba, kandi ubuziranenge bwibicuruzwa ntibuhinduka mugihe cyo kumisha no guhunika.

1.3 Isesengura rya X-ray

Isesengura rya X-ray ryakozwe na Rigaku D / max-3A X-ray diffractometer, grafite monochromator, le Inguni yari 8 ° ~ 30 °, CuKα ray, igitutu cyumuvuduko numuyoboro wa 30kV na 30mA.

1.4 Isesengura ridafite ishingiro

Spectrum-2000PE FTIR infrarafurike ya sprometrike yakoreshejwe mugusesengura infragre. Ibyitegererezo byose byo gusesengura ibintu bitagira ingano byari bifite uburemere bwa 0.0020g. Izi ngero zavanze na 0.1600g KBr, hanyuma, hanyuma zikanda (hamwe nubunini bwa <0.8mm) zirasesengurwa.

1.5 Kumenyekanisha kohereza

Ihererekanyabubasha ryagaragaye na 721 spectropotometometero. Umuti wa CMC w = w1% washyizwe mubisahani bya 1cm kuri 590nm yumuraba.

1.6 Impamyabumenyi yo gutahura

Impamyabumenyi ya HEC ya hydroxyethyl selulose yapimwe nuburyo busanzwe bwo gusesengura imiti. Ihame ni uko HEC ishobora kubora na HI hydroiodate kuri 123 ℃, kandi urugero rwo gusimbuza HEC rushobora kumenyekana mugupima ibintu byangirika Ethylene na iode ya etilene yakozwe. Urwego rwo gusimbuza hydroxymethyl selulose rushobora kandi kugeragezwa nuburyo busanzwe bwo gusesengura imiti.

 

2. Ibisubizo n'ibiganiro

Ubwoko bubiri bwa reaction ya keteti ikoreshwa hano: imwe ni imashini ikata nkibikoresho bya reaction, ubundi ikurura ubwoko bwa reaction kettle nkibikoresho bya reaction, muri sisitemu ya reaction itandukanye, imiterere ya alkaline na sisitemu yo gukemura amazi ya alcool, ubushakashatsi bwakozwe na etherification ya selile nziza. Muri byo, tekinoloji iranga imashini yo gukata nkibikoresho byo kubyitwaramo ni: Mubisubizo, umuvuduko wamaboko yo guteka uratinda, igihe cyo kubyitwaramo ni kirekire, igipimo cyibisubizo byuruhande ni kinini, igipimo cyo gukoresha imiti ya etherifingi ni gito, kandi uburinganire bwo gusimbuza amatsinda kugabana muri etherizing reaction ni mibi. Inzira yubushakashatsi irashobora kugarukira gusa kubintu bigereranijwe. Byongeye kandi, guhinduka no kugenzurwa nuburyo bukuru bwibikorwa (nko kugereranya kwiyuhagira, kwibumbira kwa alkali, umuvuduko wamaboko yihuta yimashini). Biragoye kugera kuburinganire bwa reaction ya etherification no kwiga kwimurwa ryinshi no kwinjira mubikorwa bya etherification byimbitse. Ibikorwa biranga reaction ya reaction nkibikoresho byo kubyitwaramo ni: umuvuduko ukabije wihuta mubisubizo, umuvuduko wihuse, umuvuduko mwinshi wo gukoresha ibikoresho bya etherizing, gukwirakwiza kimwe kubintu bisimburana, guhinduka kandi kugenzurwa nuburyo bukuru bwibisubizo.

Carboxymethyl selulose CMC yateguwe nibikoresho bya reaction hamwe nibikoresho bikurura reaction. Iyo ikariso yakoreshwaga nkibikoresho byo kubyitwaramo, ubukana bwikaraga bwari buke kandi impuzandengo yo kuzunguruka yari 50r / min. Iyo reaction ya moteri yakoreshwaga nkibikoresho bya reaction, ubukana bwikaraga bwari hejuru kandi impuzandengo yo kuzunguruka yari 500r / min. Iyo igipimo cya molari ya acide monochloroacetic na selulose monosaccharide yari 1: 5: 1, igihe cyo kubyitwaramo cyari 1.5h kuri 68 ℃. Ihererekanyabubasha rya CMC ryabonetse hakoreshejwe imashini yo guteka ryari 98.02% naho etherification ikora yari 72% kubera uburyo bwiza bwa CM muri chloroacetic acide etherifying agent. Iyo reakteri ikangura yakoreshejwe nk'ibikoresho bya reaction, ubwikorezi bwa agent ya etherifying bwari bwiza, kohereza CMC byari 99.56%, naho reaction ya etherizing yongerewe kugera kuri 81%.

Hydroxyethyl selulose HEC yateguwe hamwe na knader hamwe na reaction ya reaction nkibikoresho bya reaction. Iyo knader yakoreshwaga nk'ibikoresho bya reaction, reaction ya agent ya etherizing yari 47% kandi ubushobozi bwo gukemura amazi bwari bubi mugihe ubwikorezi bwa chloroethyl alcool ya eterizing yari ikennye kandi igipimo cya molari ya chloroethanol na selile monosaccharide cyari 3: 1 kuri 60 ℃ kuri 4h . Gusa mugihe igipimo cya molari ya chloroethanol na selile monosaccharide ari 6: 1, hashobora kuboneka ibicuruzwa bifite amazi meza. Iyo reakteri ikangura yakoreshejwe nk'ibikoresho bya reaction, ubwikorezi bwa chloroethyl alcool etherification bwabaye bwiza kuri 68 ℃ kuri 4h. Iyo igipimo cya molari ya chloroethanol na selile monosaccharide yari 3: 1, HEC yavuyemo yari ifite amazi meza, kandi reaction ya etherification yongerewe kugera kuri 66%.

Imikorere ya reaction hamwe nihuta ryibintu bya etherizing agent chloroacetic aside irarenze cyane irya chloroethanol, kandi reaction ya reaction nka etherizing reaction reaction ifite ibyiza bigaragara kuri knader, ibyo bikaba bitezimbere cyane etherizing reaction. Ikwirakwizwa ryinshi rya CMC naryo ryerekana mu buryo butaziguye ko reakteri ikurura nkibikoresho bya reaction ya etherizing bishobora guteza imbere ubutinganyi bwa etherizing reaction. Ni ukubera ko urunigi rwa selile rufite amatsinda atatu ya hydroxyl kuri buri mpeta ya glucose-groupe, kandi gusa muburyo bwabyimbye cyane cyangwa bwashonze byose ni selile hydroxyl ya selile ya selile ya molekile ya etherifingi igerwaho. Imyitwarire ya etherification ya selile mubisanzwe ni reaction itandukanye kuva hanze kugeza imbere, cyane cyane mukarere ka kristalline ya selile. Iyo imiterere ya kristu ya selile ikomeje kuba ntangaruka zingufu ziva hanze, agent ya etherifying biragoye kwinjira mumiterere ya kristaline, bigira ingaruka kuburinganire bwa reaction ya heterogeneous reaction. Kubwibyo, muguhitamo ipamba inoze (nko kongera ubuso bwihariye bwipamba itunganijwe), reaction yipamba yatunganijwe irashobora kunozwa. Mu kigero kinini cyo kwiyuhagiriramo (Ethanol / selulose cyangwa inzoga ya isopropyl / selile na reaction yihuta cyane, ukurikije impamvu, gahunda ya zone ya kristu ya selile izagabanuka, muriki gihe selile irashobora kubyimba cyane, kugirango kubyimba y'akarere ka amorphous na kristalline selile ikunda guhora, Rero, reaction yakarere ka amorphous nakarere ka kristalline irasa.

Hifashishijwe isesengura rya infragre ya sprifike hamwe nisesengura rya X-ray, inzira ya etherification reaction ya selile irashobora kumvikana neza mugihe reaction ya reaction ikoreshwa nkibikoresho bya reaction ya etherification.

Hano, isesengura rya infragre na X-ray itandukanya. Imyitwarire ya etherification ya CMC na HEC yakorewe mumashanyarazi yashizwemo mubihe byasobanuwe haruguru.

Isesengura rya infragre sprifike yerekana ko reaction ya etheration ya CMC na HEC ihinduka buri gihe hamwe no kongera igihe cyo kubyitwaramo, urwego rwo gusimbuza rutandukanye.

Binyuze mu isesengura ryerekana imiterere ya X-ray, kristu ya CMC na HEC ikunda kuba zeru hamwe no kongera igihe cyo kubyitwaramo, byerekana ko inzira ya decrystallisation yagaragaye ahanini mubyiciro bya alkalisation ndetse nicyiciro cyo gushyushya mbere ya etherification ya pamba itunganijwe . Kubwibyo, carboxymethyl na hydroxyethyl etherification reaction ya pamba itunganijwe ntikibujijwe cyane cyane na kristu ya pamba itunganijwe. Bifitanye isano na permeability ya agent ya etherifying. Birashobora kwerekanwa ko reaction ya etherification ya CMC na HEC ikorwa hamwe na reaction ya reaction nkibikoresho bya reaction. Mugihe cyihuta cyihuta, ni ingirakamaro kubikorwa byo gutobora ipamba itunganijwe murwego rwa alkalisation hamwe nicyiciro cyo gushyushya mbere ya reaction ya etherification, kandi ifasha umukozi wa etherification kwinjira muri selile, kugirango arusheho kunoza imikorere ya etherification hamwe no gusimbuza uburinganire. .

Mu gusoza, ubu bushakashatsi bushimangira ingaruka zo gukurura imbaraga nizindi mpamvu ku mikorere yimikorere mugihe cyibikorwa. Kubwibyo, icyifuzo cyubu bushakashatsi gishingiye kumpamvu zikurikira: Muri sisitemu ya reaction ya heterogeneous etheration reaction, gukoresha igipimo kinini cyo kwiyuhagiriramo hamwe nimbaraga nyinshi zikurura, nibindi, nibisabwa shingiro ryogutegura hafi ya selile ya selireose hamwe na matsinda asimbuye gukwirakwiza; Muri sisitemu yihariye ya etheration reaction, sisitemu yo hejuru ya selulose ether hamwe nogukwirakwiza hafi gusimbuza insimburangingo irashobora gutegurwa ukoresheje reakteri ikurura nkibikoresho bya reaction, byerekana ko igisubizo cyamazi ya selile ya selile gifite transmitance nyinshi, gifite akamaro kanini kwagura imitungo n'imikorere ya selile ether. Imashini yo guteka ikoreshwa nkibikoresho bya reaction yo kwiga etherification reaction yipamba inoze. Bitewe nubushyuhe buke butera imbaraga, ntabwo aribyiza byinjira mubikoresho bya etherification, kandi bifite ibibi bimwe nkigice kinini cyibisubizo byuruhande hamwe no gukwirakwiza nabi kubisimbuza etherification.


Igihe cyo kohereza: Mutarama-23-2023
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