1 Isingeniso
Njengamanje, izinto ezisetshenziswa kakhulu ekulungiselelenii-cellulose etherikotini, futhi umkhiqizo wayo uyehla, futhi intengo nayo iyakhuphuka;
Ngaphezu kwalokho, izinto ezivame ukusetshenziswa njenge-chloroacetic acid (enobuthi obukhulu) kanye ne-ethylene oxide (ebangela umdlavuza) nazo ziyingozi kakhulu emzimbeni womuntu kanye nasemvelweni.
Kulesi sahluko, i-pine cellulose enokuhlanzeka okungaphezu kuka-90% okukhishwe esahlukweni sesibili isetshenziswa njengezinto zokusetshenziswa, kanti i-sodium chloroacetate kanye ne-2-chloroethanol kusetshenziswa njengezithasiselo.
Ukusebenzisa i-chloroacetic acid enobuthi kakhulu njenge-etherifying agent, i-anionici-carboxymethyl cellulose (CMC), kwalungiswa i-non-ionic hydroxyethyl cellulose.
I-Cellulose (HEC) kanye ne-mixed hydroxyethyl carboxymethyl cellulose (HECMC) ama-ether amathathu e-cellulose. i-single factor
Amasu okulungiselela ama-ether amathathu e-cellulose alungiselelwe ngokusebenzisa izivivinyo kanye nokuhlolwa kwe-orthogonal, kanti ama-ether e-cellulose ahlanganisiwe abonakala nge-FT-IR, XRD, H-NMR, njll.
Izisekelo ze-cellulose etherification
Umgomo we-cellulose etherification ungahlukaniswa izingxenye ezimbili. Ingxenye yokuqala inqubo ye-alkalizing, okungukuthi, ngesikhathi sokusabela kwe-alkalizing kwe-cellulose,
Uma ihlakazeka ngokulinganayo kusisombululo se-NaOH, i-pine cellulose ivuvukala ngamandla ngaphansi kwesenzo sokuxubha ngomshini, kanye nokwanda kwamanzi.
Inani elikhulu lama-molecule amancane e-NaOH langena ngaphakathi kwe-pine cellulose, futhi lasabela namaqembu e-hydroxyl endandatho yeyunithi yesakhiwo se-glucose,
Ikhiqiza i-alkali cellulose, isikhungo esisebenzayo se-etherification reaction.
Ingxenye yesibili inqubo yokufakelwa kwe-ether, okungukuthi, ukusabela phakathi kwesikhungo esisebenzayo kanye ne-sodium chloroacetate noma i-2-chloroethanol ngaphansi kwezimo ze-alkaline, okuholela ku-
Ngesikhathi esifanayo, i-etherifying agent i-sodium chloroacetate kanye ne-2-chloroethanol nazo zizokhiqiza izinga elithile lamanzi ngaphansi kwezimo ze-alkaline.
Ukusabela okungekuhle kuxazululwa ngokukhiqiza i-sodium glycolate kanye ne-ethylene glycol, ngokulandelana.
2 Ukwelashwa kwangaphambilini kwe-pine cellulose okugxilile kwe-alkali decrystallization
Okokuqala, lungisa ukuhlushwa okuthile kwesisombululo se-NaOH ngamanzi ahlanzekile. Bese, ekushiseni okuthile, 2g we-pine fiber
I-vithamini incibilikiswa kumthamo othile wesisombululo se-NaOH, ivuselelwe isikhathi esithile, bese ihlungwa ukuze isetshenziswe.
Umkhiqizi Wemodeli Yezinsimbi Zomculo
Imitha ye-pH enembile
Isivuseleli sikagesi esihlala sikhona sokushisa okushisayo kohlobo lomqoqi
Ihhavini yokomisa nge-vacuum
Ibhalansi ye-elekthronikhi
Iphampu yokuvaleka yemishini yohlobo lwamanzi amaningi ejikelezayo
I-Fourier Transform Infrared Spectrometer
I-diffractometer ye-X-ray
I-Spectrometer ye-Magnetic Resonance ye-Nuclear
I-Hangzhou Aolilong Instrument Co., Ltd.
I-Hangzhou Huichuang Instrument Equipment Co., Ltd.
I-Shanghai Jinghong Experimental Equipment 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 i-BRUKER
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Ukulungiswa kwama-CMC
Ukusebenzisa i-alkali cellulose yokhuni lwephayini ephathwe kusengaphambili nge-decrystallization egxilile ye-alkali njengezinto zokusetshenziswa, kusetshenziswa i-ethanol njenge-solvent kanye nokusebenzisa i-sodium chloroacetate njenge-etherification
I-CMC ene-DS ephezulu yalungiswa ngokufaka i-alkali kabili kanye ne-etherifying agent kabili. Faka u-2g we-alkali cellulose ye-pine wood ebhodleleni elinezintamo ezine, bese ufaka umthamo othile we-ethanol solvent, bese uvuselela kahle imizuzu engama-30.
cishe, ukuze i-alkali cellulose ihlakazeke ngokuphelele. Bese ufaka inani elithile le-alkali agent kanye ne-sodium chloroacetate ukuze isabele isikhathi esithile ekushiseni okuthile kwe-etherification.
Ngemva kwesikhathi, kwengezwa okwesibili kwe-alkaline agent kanye ne-sodium chloroacetate kulandelwe yi-etherification isikhathi esithile. Ngemva kokuthi ukusabela sekuphelile, phola bese uphola, bese
Hlukanisa ngenani elifanele le-glacial acetic acid, bese uhlanza, ugeze bese womisa.
Ukulungiswa kwama-HEC
Ukusebenzisa i-alkali cellulose yokhuni lwephayini kuphathwe nge-decrystallization egxilile ye-alkali njengezinto zokusetshenziswa, i-ethanol njenge-solvent kanye ne-2-chloroethanol njenge-etherification
I-HEC ene-MS ephezulu yalungiswa ngokufaka i-alkali kabili kanye ne-etherifying agent kabili. Faka u-2g we-alkali cellulose ye-pine wood ebhodleleni elinezintamo ezine, bese ufaka ivolumu ethile ye-90% (ingxenye yevolumu) ye-ethanol, uvuselele.
Hlanganisa isikhathi esithile ukuze uhlakazeke ngokuphelele, bese ufaka inani elithile le-alkali, bese ushisa kancane kancane, engeza ivolumu ethile engu-2-
I-Chloroethanol, iqiniswe ekushiseni okungaguquki isikhathi esithile, bese yengeza i-sodium hydroxide esele kanye ne-2-chloroethanol ukuze kuqhutshekwe nokuqina kwayo isikhathi esithile.
Ngemva kokuthi ukusabela sekuqediwe, susa i-glacial acetic acid ngenani elithile, bese ekugcineni uhlunga ngesihlungi sengilazi (G3), ugeze, bese womisa.
Ukulungiswa kwe-HEMCC
Ukusebenzisa i-HEC elungiselelwe ku-3.2.3.4 njengezinto zokusetshenziswa, i-ethanol njenge-reaction medium, kanye ne-sodium chloroacetate njenge-etherifying agent ukulungiselela
I-HECMC. Inqubo ethile yile: thatha inani elithile le-HEC, ulifake ebhodleleni elinezintamo ezine elingu-100 mL, bese ufaka inani elithile levolumu.
I-ethanol engu-90%, uvuselele ngomshini isikhathi esithile ukuze ihlakazeke ngokuphelele, engeza inani elithile le-alkali ngemva kokushisa, bese ufaka kancane kancane
I-Sodium chloroacetate, i-etherification ekushiseni okulinganayo iphela ngemva kwesikhathi esithile. Ngemva kokuba ukusabela sekuqediwe, yilungise nge-glacial acetic acid ukuze uyilungise, bese usebenzisa isihlungi sengilazi (G3)
Ngemva kokuhlunga, ukuwasha nokomisa.
Ukuhlanzwa kwama-ether e-cellulose
Enqubweni yokulungiselela i-cellulose ether, eminye imikhiqizo engaphansi kwe-extract ivame ukukhiqizwa, ikakhulukazi usawoti ongaxubile i-sodium chloride kanye neminye
ukungcola. Ukuze kuthuthukiswe ikhwalithi ye-cellulose ether, kwenziwa ukuhlanzwa okulula ku-cellulose ether etholiwe. ngoba kusemanzini.
Kunezinhlobo ezahlukene zokuncibilika, ngakho-ke ukuhlolwa kusebenzisa ingxenye ethile yevolumu ye-ethanol enamanzi ukuhlanza ama-ether amathathu e-cellulose alungisiwe.
ushintsho.
Beka isampula ye-cellulose ether elungiselelwe ngekhwalithi ethile ebhekheni, engeza inani elithile le-ethanol engu-80% elishiswe ku-60 ℃ ~ 65 ℃, bese ugcina ukuxuba ngomshini ku-60 ℃ ~ 65 ℃ ku-stirrer yamagnetic yokushisa engaguquki isikhathi esingama-10 ℃. Imizuzu. Thatha i-supernatant ukuze yome.
Ebhekheni elihlanzekile, sebenzisa i-silver nitrate ukuhlola ama-ion e-chloride. Uma kukhona i-precipitate emhlophe, yihlunge ngesihlungi sengilazi bese uthatha okuqinile
Phinda izinyathelo zangaphambilini zengxenye yomzimba, kuze kube yilapho i-filtrate ngemuva kokufaka ithonsi eli-1 lesisombululo se-AgNO3 ingenawo umhlophe, okungukuthi, ukuhlanzwa nokugezwa sekuqediwe.
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ku (ikakhulukazi ukususa ukusabela komkhiqizo olandelanayo i-NaCl). Ngemva kokumunca ukuhlunga, ukomisa, ukupholisa kufike ekushiseni kwegumbi kanye nokulinganisa.
isisindo, g.
Izindlela Zokuhlola Nokuchaza Izinhlamvu ze-Cellulose Ethers
Ukunqunywa Kwezinga Lokufaka Esimweni (DS) kanye Nezinga Lokufaka Esimweni (MS)
Ukunqunywa kwe-DS: Okokuqala, sikala u-0.2 g (onembile kuya ku-0.1 mg) wesampula ye-cellulose ether ehlanziwe neyomisiwe, uyincibilikise ku-
Ama-80mL amanzi acwecwe, axutshwe emanzini afudumele angaguquki ku-30℃ ~ 40℃ imizuzu eyi-10. Bese ulungisa ngesisombululo se-sulfuric acid noma isixazululo se-NaOH
i-pH yesisombululo kuze kube yilapho i-pH yesisombululo ingu-8. Bese usebenzisa ikhava efakwe i-electrode yemitha ye-pH ejwayelekile yesisombululo se-sulfuric acid.
Ukuze ulinganise, ngaphansi kwezimo ezivuselelayo, qaphela ukufundwa kwemitha ye-pH ngenkathi ulinganisa, lapho inani le-pH lesisombululo lilungiswa libe ngu-3.74,
I-titration iyaphela. Qaphela umthamo wesisombululo esijwayelekile se-sulfuric acid esisetshenziswa ngalesi sikhathi.
Isizukulwane:
Isamba sezinombolo zeprotoni ephezulu kanye neqembu le-hydroxyethyl
Isilinganiso senani lama-proton aphezulu; I7 isisindo seqembu le-methylene eqenjini le-hydroxyethyl
Ukuqina kwe-proton resonance peak; ukuqina kwe-proton resonance peak yamaqembu ama-methine ama-5 kanye neqembu elilodwa le-methylene kuyunithi ye-cellulose glucose
Isamba.
Izindlela zokuhlola ezichazwe ekuhlolweni kwezimpawu ze-infrared zama-ether amathathu e-cellulose CMC, HEC kanye ne-HEECMC
Umthetho
3.2.4.3 Ukuhlolwa kwe-XRD
Ukuhlolwa Kokuhlukaniswa Kwe-X-ray Ukuhlaziywa Kwezimpawu Ze-Ether Ezintathu Ze-Cellulose CMC, HEC kanye ne-HEECMC
indlela yokuhlola echazwe.
3.2.4.4 Ukuhlolwa kwe-H-NMR
I-H NMR spectrometer ye-HEC ilinganiswe nge-Avance400 H NMR spectrometer ekhiqizwe yi-BRUKER.
Kusetshenziswa i-deuterated dimethyl sulfoxide njenge-solvent, isixazululo sahlolwa nge-liquid hydrogen NMR spectroscopy. Imvamisa yokuhlola yayingu-75.5MHz.
Kufudumele, ikhambi lingu-0.5mL.
3.3 Imiphumela Nokuhlaziywa
3.3.1 Ukuthuthukisa inqubo yokulungiselela i-CMC
Kusetshenziswa i-pine cellulose ekhishwe esahlukweni sesibili njengezinto zokusetshenziswa, kanye nokusebenzisa i-sodium chloroacetate njenge-etherifying agent, kwasetshenziswa indlela yokuhlola i-single factor,
Inqubo yokulungiselela i-CMC yenziwe ngcono, futhi iziguquguquko zokuqala zokuhlola zabekwa njengoba kuboniswe kuThebula 3.3. Okulandelayo inqubo yokulungiselela i-HEC
Kubuciko, ukuhlaziywa kwezici ezahlukahlukene.
Ithebula 3.3 Amanani Ezinto Zokuqala
Inani lokuqala le-Factor
Izinga lokushisa lokuhlanzeka ngaphambi kokwelashwa/℃ 40
Isikhathi sokulungisa i-alkali ngaphambi kokwelashwa/h 1
Isilinganiso soketshezi oluqinile ngaphambi kokwelashwa/(g/mL) 1:25
Ukuhlushwa kwe-lye ngaphambi kokwelashwa/% 40
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Izinga lokushisa lesigaba sokuqala le-etherification/℃ 45
Isikhathi sokufakelwa kwe-ether sesigaba sokuqala/h 1
Izinga lokushisa lesigaba sesibili le-etherification/℃ 70
Isikhathi sesibili sokufakelwa kwe-ether/h 1
Isilinganiso esiyisisekelo esigabeni sokufakelwa kwe-ether/g 2
Inani le-ejenti yokushisa esigabeni sokushisa/g 4.3
Isilinganiso se-etherified solid-liquid/(g/mL) 1:15
3.3.1.1 Ithonya lezici ezahlukahlukene ezingeni lokufakwa esikhundleni se-CMC esigabeni sokwakheka kwe-alkali ngaphambi kokwelashwa
1. Umphumela wokushisa kwe-alkalization ngaphambi kokwelashwa ngezinga lokufaka esikhundleni se-CMC
Ukuze kucatshangelwe umphumela wokushisa kwe-alkalization ngaphambi kokwelashwa ngezinga lokushintsha ku-CMC etholakele, uma kulungiswa ezinye izici njengezindinganiso zokuqala,
Ngaphansi kwezimo, kuxoxwa ngomphumela wokushisa kwe-alkalization ngaphambi kokwelashwa ngezinga lokushintshana kwe-CMC, futhi imiphumela iboniswe ku-Fig.
Ukushisa kwe-alkalizing kwangaphambi kokwelashwa/℃
Umphumela wokushisa kwe-alkalizing ngaphambi kokwelashwa kuzinga lokufakwa esikhundleni se-CMC
Kungabonakala ukuthi izinga lokufakwa esikhundleni kwe-CMC liyakhula ngokukhuphuka kwezinga lokushisa lokufakwa kwe-alkali ngaphambi kokwelashwa, kanti izinga lokushisa lokufakwa kwe-alkali lingu-30 °C.
Amazinga angenhla okushintshana ayancipha ngokushisa okwandayo. Lokhu kungenxa yokuthi izinga lokushisa le-alkalizing liphansi kakhulu, futhi ama-molecule awasebenzi kahle futhi awakwazi ukwenza kanjalo.
Bonakalisa ngempumelelo indawo yekristalu ye-cellulose, okwenza kube nzima nge-etherifying agent ukungena ngaphakathi kwe-cellulose esigabeni se-etherification, futhi izinga lokusabela liphezulu kakhulu.
okuphansi, okuholela ezingeni eliphansi lokushintshaniswa komkhiqizo. Kodwa-ke, izinga lokushisa le-alkali akufanele libe phezulu kakhulu. Njengoba izinga lokushisa likhuphuka, ngaphansi kwesenzo sokushisa okuphezulu kanye ne-alkali enamandla,
I-Cellulose ithambekele ekuwohlokeni kwe-oxidative, futhi izinga lokufakwa esikhundleni komkhiqizo i-CMC liyancipha.
2. Ithonya lesikhathi sokwenziwa kwe-alkaline ngaphambi kokwelashwa ngezinga lokufakwa esikhundleni kwe-CMC
Ngaphansi kwesimo sokuthi izinga lokushisa lokulungisa ngaphambi kokwelashwa lingu-30 °C kanye nezinye izici kuyizindinganiso zokuqala, umphumela wesikhathi sokulungisa ngaphambi kokwelashwa ku-CMC uyaxoxwa.
Umphumela wokushintshana. Izinga lokushintshana
Isikhathi sokulungisa i-alkalizing ngaphambi kokwelashwa/h
Umphumela wesikhathi sokwenziwa kwe-alkaline ngaphambi kokwelashwa kuI-CMCizinga lokushintshana
Inqubo yokuhlanganisa ngokwayo ishesha kakhulu, kodwa ikhambi le-alkali lidinga isikhathi esithile sokusabalalisa ku-fiber.
Kungabonakala ukuthi uma isikhathi se-alkalizing singu-0.5-1.5h, izinga lokushintsha lomkhiqizo liyakhula ngokwanda kwesikhathi se-alkalizing.
Izinga lokushintsha umkhiqizo elitholiwe laliphezulu kakhulu lapho isikhathi singu-1.5h, futhi izinga lokushintsha lehla ngokwanda kwesikhathi ngemva kwe-1.5h. Lokhu kungenza
Kungase kube ngoba ekuqaleni kokwakheka kwe-alkali, ngesikhathi sokwandiswa kwesikhathi sokwakheka kwe-alkali, ukungena kwe-alkali ku-cellulose kwanele, ngakho-ke i-fiber
Isakhiwo esiyinhloko sikhululekile kakhulu, sandisa i-etherifying agent kanye ne-medium esebenzayo
Isikhathi sokuthunyelwe: Ephreli-26-2024