1. Intshayelelo
Okwangoku, izinto ezisetyenziswa kakhulu ekulungiselelenii-cellulose etheryikotoni, kwaye imveliso yayo iyehla, kwaye nexabiso liyanyuka;
Ngaphezu koko, izinto ezisetyenziswa rhoqo njenge-chloroacetic acid (enobungozi kakhulu) kunye ne-ethylene oxide (ebangela umhlaza) nazo ziyingozi ngakumbi emzimbeni womntu nakwindalo esingqongileyo.
Kule sahluko, i-pine cellulose enobumsulwa obungaphezulu kwe-90% ekhutshwe kwisahluko sesibini isetyenziswa njengezinto ezisetyenzisiweyo, kwaye i-sodium chloroacetate kunye ne-2-chloroethanol zisetyenziswa njengezithathi-ndawo.
Ukusebenzisa i-chloroacetic acid enetyhefu kakhulu njenge-etherifying agent, i-anionici-carboxymethyl cellulose (CMC), kwalungiswa i-non-ionic hydroxyethyl cellulose.
I-Cellulose (HEC) kunye ne-mixed hydroxyethyl carboxymethyl cellulose (HECMC) ii-ether ezintathu ze-cellulose. i-single factor
Iindlela zokulungiselela ii-ether ezintathu ze-cellulose zenziwe ngcono ngokusebenzisa iimvavanyo kunye novavanyo lwe-orthogonal, kwaye ii-ether ze-cellulose ezidityanisiweyo zaphawulwa yi-FT-IR, i-XRD, i-H-NMR, njl.
Iziseko ze-cellulose etherification
Umgaqo we-cellulose etherification unokwahlulwahlulwa ube ngamacandelo amabini. Inxalenye yokuqala yinkqubo ye-alkalization, oko kukuthi, ngexesha le-alkalization reaction ye-cellulose,
Isasazwa ngokulinganayo kwisisombululo se-NaOH, i-pine cellulose idumba ngamandla phantsi kwesenzo sokuxukuxa ngoomatshini, kunye nokwanda kwamanzi
Inani elikhulu leemolekyuli ezincinci ze-NaOH zingene ngaphakathi kwe-pine cellulose, zaza zasabela kunye namaqela e-hydroxyl kwiringi yeyunithi yesakhiwo seglucose,
Ivelisa i-alkali cellulose, iziko elisebenzayo le-etherification reaction.
Inxalenye yesibini yinkqubo ye-etherification, oko kukuthi, impendulo phakathi kweziko elisebenzayo kunye ne-sodium chloroacetate okanye i-2-chloroethanol phantsi kweemeko ze-alkaline, nto leyo ebangela ukuba
Kwangaxeshanye, i-etherifying agent i-sodium chloroacetate kunye ne-2-chloroethanol nazo ziya kuvelisa iqondo elithile lamanzi phantsi kweemeko ze-alkaline.
Iimpendulo ezingalindelekanga zisonjululwa ukuvelisa i-sodium glycolate kunye ne-ethylene glycol, ngokulandelanayo.
2 Unyango lwangaphambi kokususwa kwekristale yephayini nge-alkali exineneyo
Okokuqala, lungisa umxube othile wesisombululo se-NaOH ngamanzi anyibilikisiweyo. Emva koko, kubushushu obuthile, i-2g yefayibha yephayini
I-vitamin iyanyibilika kumthamo othile wesisombululo se-NaOH, ixutywe ixesha elithile, ize ihluzwe ukuze isetyenziswe.
Umenzi weModeli yeZixhobo
Imitha ye-pH echanekileyo
Uhlobo lomqokeleli lobushushu obuhlala buhleli bokufudumeza isivuseleli semagnethi
I-oven yokomisa nge-vacuum
Ibhalansi ye-elektroniki
Impompo yokuvaleka eneenjongo ezininzi yohlobo lwamanzi ajikelezayo
I-Fourier Transform Infrared Spectrometer
I-diffractometer ye-X-ray
I-Spectrometer yeMagnetic Resonance yeNyukliya
I-Hangzhou Aolilong Instrument Co., Ltd.
I-Hangzhou Huichuang Instrument Equipment Co., Ltd.
Izixhobo zovavanyo zeShanghai Jinghong Co., Ltd.
I-METTLER TOLEDO Instruments (Shanghai) Co., Ltd.
I-Hangzhou David Science and Education Instrument Co., Ltd.
I-American Thermo Fisher Co., Ltd.
Inkampani ye-American Thermoelectric Switzerland ARL
Inkampani yaseSwitzerland iBRUKER
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Ukulungiswa kwee-CMCs
Ukusebenzisa i-alkali cellulose yomthi wepayini ephathwe kwangaphambili nge-concentrated alkali decrystallization njengezinto eziluhlaza, kusetyenziswa i-ethanol njenge-solvent kunye nokusebenzisa i-sodium chloroacetate njenge-etherification
I-CMC ene-DS ephezulu ilungiselelwe ngokongeza i-alkali kabini kunye ne-etherifying agent kabini. Yongeza i-2g ye-alkali cellulose yomthi wepayini kwiflaski enentamo ezine, uze wongeze umthamo othile we-ethanol solvent, uze uxube kakuhle imizuzu engama-30.
malunga, ukuze i-alkali cellulose isasazeke ngokupheleleyo. Emva koko yongeza inani elithile le-alkali agent kunye ne-sodium chloroacetate ukuze isebenze ixesha elithile kubushushu obuthile be-etherification.
Emva kwexesha, kongezwa okwesibini i-alkaline agent kunye ne-sodium chloroacetate kulandele i-etherification kangangexesha elithile. Emva kokuba impendulo iphelile, phola uze uphole, emva koko
Hluza nge-glacial acetic acid efanelekileyo, uze uyihluze, uyihlambe uze uyomise.
Ukulungiswa kwee-HEC
Ukusebenzisa i-alkali cellulose yomthi wepayini ephathwe kwangaphambili nge-concentrated alkali decrystallization njengezinto eziluhlaza, i-ethanol njenge-solvent kunye ne-2-chloroethanol njenge-etherification
I-HEC ene-MS ephezulu ilungiselelwe ngokongeza i-alkali kabini kunye ne-etherifying agent kabini. Yongeza i-2g ye-alkali cellulose yomthi wepayini kwiflaski enentamo ezine, kwaye wongeze umthamo othile we-90% (inxalenye yomthamo) ye-ethanol, uvuselele.
Xuba ixesha elithile ukuze usasazeke ngokupheleleyo, uze wongeze ubungakanani obuthile be-alkali, uze uyifudumale kancinci, wongeze ubungakanani obuthile be-2-
I-Chloroethanol, inyibilikiswe kubushushu obungaguqukiyo kangangexesha elithile, yaze yongeza i-sodium hydroxide eseleyo kunye ne-2-chloroethanol ukuze kuqhutyekwe ne-etherification kangangexesha elithile.
Emva kokuba ukusabela kugqityiwe, susa ulwelo ngomlinganiselo othile we-glacial acetic acid, uze ekugqibeleni uhluze ngesihluzo seglasi (G3), uhlambe, uze womise.
Ukulungiswa kwe-HEMCC
Ukusebenzisa i-HEC elungiselelwe kwi-3.2.3.4 njengezinto eziluhlaza, i-ethanol njengesixhobo sokusabela, kunye ne-sodium chloroacetate njenge-etherifying agent ukulungiselela
I-HECMC. Inkqubo ethile yile: thatha isixa esithile se-HEC, usifake kwi-flask ene-100 mL enentamo ezine, uze wongeze isixa esithile somthamo.
I-ethanol engama-90%, yixube ngoomatshini kangangexesha elithile ukuze isasazeke ngokupheleleyo, yongeza inani elithile le-alkali emva kokufudumeza, uze uyixube kancinci kancinci
I-Sodium chloroacetate, i-etherification kubushushu obungaguqukiyo iphela emva kwexesha elithile. Emva kokuba impendulo igqityiwe, yilungise nge-glacial acetic acid ukuze uyilungise, uze usebenzise isihluzi seglasi (G3)
Emva kokufunxa, ukuhlamba nokomisa.
Ukucocwa kwee-ether ze-cellulose
Kwinkqubo yokulungiselela i-cellulose ether, ezinye iimveliso eziphumayo zihlala ziveliswa, ikakhulu ityuwa engaphelelanga i-sodium chloride kunye nezinye izinto.
ukungcola. Ukuze kuphuculwe umgangatho we-cellulose ether, kwenziwe ukucoca okulula kwi-cellulose ether efunyenweyo. kuba isemanzini.
Kukho ukunyibilika okwahlukeneyo, ngoko ke olu vavanyo lusebenzisa iqhekeza elithile le-ethanol emanzi ukucoca ii-ether ezintathu ze-cellulose ezilungisiweyo.
utshintsho.
Beka isampuli ye-cellulose ether elungiselelwe ngomgangatho othile kwi-beaker, yongeza inani elithile le-80% ye-ethanol esele ishushu ukuya kuma-60 ℃ ~ 65 ℃, kwaye ugcine ukuxuba ngoomatshini kwi-60 ℃ ~ 65 ℃ kwi-stirrer yemagnethi yokufudumeza eshushu engaguqukiyo kangange-10 ℃. imizuzu. Thatha i-supernatant ukuze yome.
Kwibhotile ecocekileyo, sebenzisa i-silver nitrate ukujonga ii-ion ze-chloride. Ukuba kukho i-precipitate emhlophe, yihluze nge-glass filter uze uthathe i-solid
Phinda amanyathelo angaphambili kwilungu lomzimba, de i-filtrate emva kokongeza ithontsi eli-1 lesisombululo se-AgNO3 ingabi namanzi amhlophe, oko kukuthi, ukucoca nokuhlamba kugqityiwe.
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faka (ngokuyintloko ukususa i-reaction by-product NaCl). Emva kokufunxa, ukomisa, ukupholisa ukuya kubushushu begumbi kunye nokulinganisa.
ubunzima, g.
Iindlela zoVavanyo kunye noBume beCellulose Ethers
Ukumiselwa kweDigri yoTshintsho (DS) kunye neDigri yoTshintsho lweMolar (MS)
Ukuqinisekiswa kwe-DS: Okokuqala, linganisa i-0.2 g (echanekileyo ukuya kwi-0.1 mg) yesampuli ye-cellulose ether ecociweyo neyomileyo, uyinyibilikise kwi
I-80mL yamanzi acociweyo, axutywe kubushushu obungaguqukiyo bamanzi kwi-30℃ ~ 40℃ imizuzu eli-10. Emva koko lungisa ngesisombululo se-sulfuric acid okanye isisombululo se-NaOH
i-pH yesisombululo ide i-pH yesisombululo ibe yi-8. Emva koko kwibheki exhotyiswe nge-electrode yemitha ye-pH, sebenzisa isisombululo esiqhelekileyo se-sulfuric acid
Ukuze ulinganisele, phantsi kweemeko ezixutyiweyo, jonga ukufundwa kwemitha ye-pH ngelixa ulinganisa, xa ixabiso le-pH yesisombululo lilungiswa ukuya kwi-3.74,
Isiphelo se-titration. Qaphela umthamo wesisombululo esiqhelekileyo se-sulfuric acid esisetyenzisiweyo ngeli xesha.
Isizukulwana:
Isimbuku samanani eeproton eziphezulu kunye neqela le-hydroxyethyl
Umlinganiselo wenani leeprotoni eziphezulu; I7 bubunzima beqela le-methylene kwiqela le-hydroxyethyl
Ubunzulu bencochoyi ye-proton resonance; bubunzulu bencochoyi ye-proton resonance yamaqela ama-5 e-methine kunye neqela elinye le-methylene kwiyunithi ye-cellulose glucose
Isixa.
Iindlela zovavanyo ezichazwe kuvavanyo lwe-infrared characterization lwe-cellulose ethers ezintathu i-CMC, i-HEC kunye ne-HEECMC
Umthetho
3.2.4.3 Uvavanyo lwe-XRD
Uvavanyo lweempawu zohlalutyo lwe-X-ray Diffraction lwe-Ethers ezintathu zeCellulose CMC, HEC kunye ne-HEECMC
indlela yovavanyo echaziweyo.
3.2.4.4 Uvavanyo lwe-H-NMR
I-H NMR spectrometer ye-HEC ilinganiswe nge-Avance400 H NMR spectrometer eyenziwe yiBRUKER.
Kusetyenziswa i-deuterated dimethyl sulfoxide njengesinyibilikisi, isisombululo savavanywa nge-liquid hydrogen NMR spectroscopy. Uvavanyo lwaluyi-75.5MHz.
Kushushu, isisombululo yi-0.5mL.
3.3 Iziphumo kunye noHlahlelo
3.3.1 Ukuphucula inkqubo yokulungiselela i-CMC
Kusetyenziswa i-pine cellulose ekhutshwe kwisahluko sesibini njengezinto eziluhlaza, kunye nokusebenzisa i-sodium chloroacetate njenge-etherifying agent, indlela yovavanyo lwe-single factor yamkelwe,
Inkqubo yokulungiselela i-CMC yenziwe ngcono, kwaye iinguqu zokuqala zovavanyo zamiselwa njengoko kubonisiwe kwiTheyibhile 3.3. Oku kulandelayo yinkqubo yokulungiselela i-HEC
Kwizobugcisa, uhlalutyo lwezinto ezahlukeneyo.
Itheyibhile 3.3 Amaxabiso okuqala
Ixabiso lokuqala leFactor
Ubushushu bokunyibilikisa i-alkalizing ngaphambi konyango/℃ 40
Ixesha lokulungisa i-alkalizing ngaphambi konyango/h 1
Umlinganiselo wangaphambi konyango oluqinileyo nolwelo/(g/mL) 1:25
Uxinzelelo lwe-lye ngaphambi konyango/% 40
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Inqanaba lokuqala lobushushu be-etherification/℃ 45
Ixesha lokufakelwa kwe-ether kwinqanaba lokuqala/h 1
Inqanaba lesibini lobushushu be-etherification/℃ 70
Ixesha lesibini le-etherification yesigaba/h 1
Idosi esisiseko kwisigaba se-etherification/g 2
Ubungakanani bearhente yokuthambisa kwisigaba sokuthambisa/g 4.3
Umlinganiselo we-etherified solid-liquid ratio/(g/mL) 1:15
3.3.1.1 Impembelelo yezinto ezahlukeneyo kwizinga lokutshintshwa kwe-CMC kwinqanaba le-alkaliization yangaphambi konyango
1. Isiphumo sobushushu be-alkaliization yangaphambi konyango kwizinga lokutshintshwa kwe-CMC
Ukuze kuqwalaselwe impembelelo yobushushu be-alkaliization ngaphambi konyango kwinqanaba lokutshintshwa kwi-CMC efunyenweyo, kwimeko yokulungisa ezinye izinto njengexabiso lokuqala,
Phantsi kweemeko, isiphumo sobushushu be-alkaliization ngaphambi konyango kwizinga lokutshintshwa kwe-CMC siyaxoxwa, kwaye iziphumo ziboniswe kwiFig.
Ubushushu bokunyibilikisa i-alkalizing ngaphambi konyango/℃
Isiphumo sobushushu bokunyibilikisa i-alkalizing ngaphambi konyango kwi-CMC substitution degree
Kuyabonakala ukuba inqanaba lokutshintshwa kwe-CMC liyanda ngokunyuka kobushushu be-alkalization ngaphambi konyango, kwaye ubushushu be-alkalization buyi-30 °C.
Amanqanaba angentla okutshintshwa ayancipha xa ubushushu bunyuka. Oku kungenxa yokuba ubushushu be-alkalizing buphantsi kakhulu, kwaye iimolekyuli azisebenzi kangako kwaye azikwazi ukwenza njalo.
Yitshabalalise ngempumelelo indawo yekristale ye-cellulose, nto leyo eyenza kube nzima ukuba i-etherifying agent ingene ngaphakathi kwe-cellulose kwinqanaba le-etherification, kwaye inqanaba lokuphendula liphezulu.
iphantsi, nto leyo ebangela ukuba imveliso itshintshelwe kwenye indawo ngeqondo eliphantsi. Nangona kunjalo, iqondo lobushushu be-alkali akufanele libe phezulu kakhulu. Njengoko iqondo lobushushu lisanda, phantsi kwefuthe lobushushu obuphezulu kunye ne-alkali enamandla,
I-Cellulose ithambekele ekuwohlokeni kwe-oxidative, kwaye izinga lokutshintshwa kwemveliso ye-CMC liyancipha.
2. Impembelelo yexesha lokwenziwa kwe-alkaline ngaphambi konyango kwi-CMC substitution degree
Phantsi kwemeko yokuba iqondo lobushushu be-alkalization yangaphambi konyango liyi-30 °C kwaye ezinye izinto ziyimilinganiselo yokuqala, isiphumo sexesha le-alkalization yangaphambi konyango kwi-CMC siyaxoxwa ngaso.
Isiphumo sokutshintsha. Ubungakanani bokutshintsha
Ixesha lokulungisa i-alkalizing ngaphambi konyango/h
Isiphumo sexesha lokwenziwa kwe-alkaline ngaphambi konyangoI-CMCisidanga sokutshintsha
Inkqubo yokuqokelelana ngokwayo ikhawuleza kakhulu, kodwa isisombululo se-alkali sidinga ixesha elithile lokusasazwa kwi-fiber.
Kuyabonakala ukuba xa ixesha le-alkalizing liyi-0.5-1.5h, inqanaba lokutshintshwa kwemveliso liyanda ngokunyuka kwexesha le-alkalizing.
Umlinganiselo wokutshintshwa kwemveliso ofunyenweyo wawuphezulu xa ixesha laliyi-1.5h, kwaye umgangatho wokutshintshwa wehla ngokwanda kwexesha emva kwe-1.5h. Oku kungenza
Kusenokwenzeka ukuba ekuqaleni kwe-alkalization, kunye nokwandiswa kwexesha le-alkalization, ukungena kwe-alkali kwi-cellulose kwanele ngakumbi, ngoko ke i-fiber
Ulwakhiwo oluphambili lukhululekile ngakumbi, nto leyo enyusa i-etherifying agent kunye ne-active medium
Ixesha leposi: Epreli-26-2024