1 Selelekela
Hona joale, ka sehloohong e tala sebelisoa ha ho lokisetsa eacellulose etherke k’hothone, ’me tlhahiso ea eona ea theoha, ’me theko le eona ea phahama;
Ho feta moo, li-etherifying agents tse sebelisoang ka tloaelo tse kang chloroacetic acid (chefo e ngata) le ethylene oxide (carcinogenic) le tsona li kotsi ho feta 'meleng oa motho le tikolohong. Buka
Khaolong ena, selulose ea phaene e nang le bohloeki bo lekanyelitsoeng ho feta 90% e ntšitsoeng khaolong ea bobeli e sebelisoa e le lisebelisoa tse tala, 'me sodium chloroacetate le 2-chloroethanol li sebelisoa e le sebaka.
Ho sebelisa chloroacetic acid e chefo haholo joalo ka etherifying anioniccarboxymethyl cellulose (CMC), cellulose e seng ionic hydroxyethyl e ile ea lokisoa.
Cellulose (HEC) le motsoako oa hydroxyethyl carboxymethyl cellulose (HECMC) li-ether tse tharo tsa cellulose. ntlha e le nngwe
Mekhoa ea ho lokisa ea li-ether tse tharo tsa cellulose e ile ea ntlafatsoa ka liteko le liteko tsa orthogonal, 'me li-ethers tse entsoeng ka cellulose li ne li khetholloa ke FT-IR, XRD, H-NMR, joalo-joalo.
Lintho tsa motheo tsa cellulose etherification
Molao-motheo oa cellulose etherification o ka aroloa likarolo tse peli. Karolo ea pele ke ts'ebetso ea alkalization, ke hore, nakong ea karabelo ea alkalization ea cellulose,
Ka mokhoa o ts'oanang o qhalakantsoeng ka tharollo ea NaOH, pine cellulose e ruruha ka matla tlas'a ts'ebetso ea mochine, le ka ho atolosoa ha metsi.
Palo e kholo ea limolek'hule tse nyane tsa NaOH li kenelletse kahare ho selulose ea phaene, 'me li sebetsana le lihlopha tsa hydroxyl lesale la yuniti ea sebopeho sa tsoekere,
E hlahisa alkali cellulose, setsi se sebetsang sa karabelo ea etherification.
Karolo ea bobeli ke ts'ebetso ea etherification, ke hore, karabelo lipakeng tsa setsi se sebetsang le sodium chloroacetate kapa 2-chloroethanol tlasa maemo a alkaline, e bakang
Ka nako e ts'oanang, moemeli oa etherifying sodium chloroacetate le 2-chloroethanol le tsona li tla hlahisa tekanyo e itseng ea metsi tlas'a maemo a alkaline.
Karabelo ea lehlakore e rarolloa ho hlahisa sodium glycolate le ethylene glycol, ka ho latellana.
2 Keletso e matla ea alkali decrystallization pretreatment ea pine cellulose
Ntlha ea pele, lokisetsa motsoako o itseng oa tharollo ea NaOH ka metsi a deionized. Joale, ka mocheso o itseng, 2g ea fiber ea phaene
Vithamine e qhibiliha ka bongata bo itseng ba tharollo ea NaOH, e tsosoa ka nako e itseng, ebe e sefshoa hore e sebelisoe.
Moetsi oa Mohlala oa Lisebelisoa
Precision pH Meter
Mokelli oa mofuta o sa khaotseng oa mocheso o futhumatsang magnetic stirrer
Setofo sa ho omisa ka vacuum
Tekanyo ea elektronike
Pompo ea vacuum ea mefuta e mengata e potolohang ea metsi
Fourier Transform Infrared Spectrometer
X-ray diffractometer
Nuclear Magnetic Resonance Spectrometer
Hangzhou Aolilong Instrument Co., Ltd.
Hangzhou Huichuang Instrument Equipment Co., Ltd.
Shanghai Jinghong Experimental Equipment Co., Ltd.
METTLER TOLEDO Instruments (Shanghai) Co., Ltd.
Hangzhou David Science and Education Instrument Co., Ltd.
Thermo Fisher Co., Ltd.
Khampani ea ARL ea Amerika ea Thermoelectric Switzerland
Khamphani ea Switzerland BRUKER
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Tokisetso ea li-CMCs
Ho sebelisa pine wood alkali cellulose pretreated by concentrated alkali decrystallization e le thepa e tala, sebelisa ethanol e le solvent le ho sebelisa sodium chloroacetate e le etherification.
CMC e nang le DS e phahameng e lokiselitsoe ka ho eketsa alkali habeli le moemeli oa etherifying habeli. Kenya 2g ea lehong la alkali cellulose ka har'a botlolo ea melamo e mene, ebe u eketsa mokelikeli o itseng oa ethanol, 'me u hlohlelletse hantle bakeng sa 30min.
hoo e ka bang, e le hore selulose ea alkali e qhalane ka ho feletseng. Ebe u eketsa tekanyo e itseng ea alkali agent le sodium chloroacetate ho itšoara ka nako e itseng mochesong o itseng oa etherification.
Kamora nako, tlatsetso ea bobeli ea moemeli oa alkaline le sodium chloroacetate e lateloang ke etherification ka nako e itseng. Ka mor'a hore karabelo e felile, pholisa fatše 'me u phomole, joale
Neutralize ka bongata bo loketseng ba glacial acetic acid, ebe sefata, hlatsoa le ho omisa.
Tokisetso ea HECs
Ho sebelisa pine wood alkali cellulose pretreated ka concentrated alkali decrystallization e le thepa e tala, ethanol e le solvent le 2-chloroethanol e le etherification.
HEC e nang le MS e phahameng e lokiselitsoe ka ho eketsa alkali habeli le moemeli oa etherifying habeli. Kenya 2g ea pine wood alkali cellulose ka har'a botlolo ea melamo e mene, 'me u kenyelletse molumo o itseng oa 90% (karolo ea molumo) ethanol, hlohlelletsa.
Hlohlelletsa nako e itseng ho qhala ka botlalo, ebe u eketsa palo e itseng ea alkali, 'me butle-butle u futhumetse, eketsa molumo o itseng oa 2-
Chloroethanol, e etherified ka mocheso kamehla ka nako e itseng, 'me joale phaella ka ho re setseng sodium hydroxide le 2-chloroethanol ho tsoela pele etherification ka nako e itseng. tšoara
Ka mor'a hore karabelo e phethoe, fokotsa ka tekanyo e itseng ea glacial acetic acid, 'me qetellong u sefe ka sefe ea khalase (G3), hlatsoa, 'me u omelle.
Tokisetso ea HEMCC
Ho sebelisa HEC e lokiselitsoeng ho 3.2.3.4 e le thepa e tala, ethanol e le mokhoa oa ho arabela, le sodium chloroacetate e le etherifying agent ho lokisetsa.
HECMC. Mokhoa o ikhethileng ke: nka tekanyo e itseng ea HEC, e kenye ka har'a 100 mL e nang le melamo e mene, ebe o eketsa palo e itseng ea molumo.
90% ea ethanol, e tsosoa ka mochine ka nako e itseng ho etsa hore e qhalakane ka botlalo, eketsa palo e itseng ea alkali ka mor'a ho futhumatsa, 'me butle-butle eketsa
Sodium chloroacetate, etherification ka mocheso oa kamehla e fela ka mor'a nako e itseng. Ka mor'a hore karabelo e phethe, e fokotse ka glacial acetic acid ho e fokotsa, ebe u sebelisa sefe ea khalase (G3)
Ka mor'a ho suction filtration, ho hlatsoa le ho omisa.
Ho hloekisoa ha cellulose ethers
Ha ho etsoa tlhahiso ea cellulose ether, hangata lihlahisoa tse ling li hlahisoa, haholo-holo letsoai la sodium chloride le tse ling.
litšila. E le ho ntlafatsa boleng ba cellulose ether, tlhoekiso e bonolo e ile ea etsoa ho ether ea cellulose e fumanoeng. hobane di ka metsing
Ho na le ho qhibiliha ho fapaneng, kahoo teko e sebelisa karoloana e itseng ea molumo oa hydrated ethanol ho hloekisa li-ether tse tharo tse lokiselitsoeng tsa cellulose.
phetoho.
Beha sampole ea cellulose ether e lokisitsoeng ka boleng bo itseng ka beaker, eketsa palo e itseng ea 80% ea ethanol e seng e futhumetse ho 60 ℃ ~ 65 ℃, 'me u boloke ho sisinyeha ha mochine ho 60 ℃ ~ 65 ℃ ka mocheso o sa khaotseng oa mocheso oa magnetic stirrer. bakeng sa 10 ℃. min. Nka supernatant ho omisa
Ka beaker e hloekileng, sebelisa nitrate ea silevera ho hlahloba li-ion tsa chloride. Haeba ho na le pula e tšoeu, e sefa ka sefe ea khalase 'me u nke e tiileng
Pheta mehato e fetileng bakeng sa karolo ea 'mele, ho fihlela filtrate ka mor'a ho eketsa lerotholi la 1 la tharollo ea AgNO3 e se na precipitate e tšoeu, ke hore, tlhoekiso le ho hlatsoa li phethiloe.
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ho kena (haholo-holo ho tlosa karabelo ka sehlahisoa sa NaCl). Ka mor'a ho suction filtration, ho omisa, ho pholisa mocheso oa kamore le boima ba 'mele.
boima, g.
Mekhoa ea Teko le Litšobotsi tsa Cellulose Ethers
Determination of Degree of Substitution (DS) le Molar Degree of Substitution (MS)
Boikemisetso ba DS: Ntlha ea pele, bekha 0.2 g (e nepahetseng ho isa ho 0.1 mg) ea sampole e hloekisitsoeng le e omisitsoeng ea cellulose ether, e qhale ka har'a
80mL ea metsi a hloekisitsoeng, a tsosoa ka ho hlapa metsi ka mocheso o sa feleng ho 30 ℃ ~ 40 ℃ bakeng sa 10min. Ebe u lokisa ka tharollo ea sulfuric acid kapa tharollo ea NaOH
pH ea tharollo ho fihlela pH ea tharollo e le 8. Ebe ka bekeng e nang le electrode ea pH meter, sebelisa tharollo e tloaelehileng ea sulfuric acid.
Ho titrate, tlas'a maemo a susumetsang, sheba pH meter e baloa ha u ntse u reketla, ha pH ea tharollo e fetoloa ho 3.74,
Titration e fela. Ela hloko boholo ba tharollo e tloaelehileng ea sulfuric acid e sebelisoang nakong ena.
Moloko:
Kakaretso ea linomoro tse ka holimo tsa proton le sehlopha sa hydroxyethyl
Karolelano ea palo ea liprothone tse holimo; I7 ke boima ba sehlopha sa methylene sehlopheng sa hydroxyethyl
Matla a tlhōrō ea proton resonance; ke matla a tlhoro ea proton resonance ea lihlopha tse 5 tsa methine le sehlopha se le seng sa methylene ho unit ea glucose ea cellulose.
Kakaretso.
Mekhoa ea liteko e hlalositsoeng bakeng sa tlhahlobo ea infrared characterization ea li-cellulose ethers tse tharo tsa CMC, HEC le HEECMC.
Molao
3.2.4.3 tlhahlobo ea XRD
X-ray Diffraction Analysis Test Characterization Test of Three Cellulose Ethers CMC, HEC le HEECMC
mokhoa oa teko o hlalositsoeng.
3.2.4.4 Teko ea H-NMR
Sehlahlo sa H NMR sa HEC se lekantsoe ka Avance400 H NMR spectrometer e hlahisoang ke BRUKER.
Ho sebelisoa deuterated dimethyl sulfoxide e le solvent, tharollo e ile ea lekoa ke spectroscopy ea hydrogen NMR ea metsi. Nako ea teko e ne e le 75.5MHz.
Mofuthu, tharollo ke 0.5mL.
3.3 Liphetho le Tlhahlobo
3.3.1 Ntlafatso ea tšebetso ea boitokiso ea CMC
Ho sebelisa pine cellulose e ntšitsoeng khaolong ea bobeli e le lisebelisoa tse tala, le ho sebelisa sodium chloroacetate e le moemeli oa etherifying, mokhoa oa teko ea ntlha e le 'ngoe o ile oa amoheloa,
Mokhoa oa ho itokisa oa CMC o ile oa ntlafatsoa, 'me mefuta ea pele ea teko e ile ea behoa joalokaha ho bontšitsoe ho Lethathamo la 3.3. Se latelang ke mokhoa oa ho lokisetsa HEC
Ho bonono, tlhahlobo ea lintlha tse fapaneng.
Lethathamo la 3.3 Maemo a Ntlha a Pele
Factor Boleng ba pele
Phekolo ea mocheso oa alkalizing/℃ 40
Teko pele ho nako ea alkalizing/h 1
Pretreatment solid-liquid ratio/(g/mL) 1:25
Khatiso ea lye pele ho kalafo/% 40
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Mohato oa pele etherification mocheso/℃ 45
Mohato oa pele oa nako ea etherification/h 1
Mohato oa bobeli etherification mocheso/℃ 70
Mokhahlelo oa bobeli etherification nako/h 1
Base dosage sethaleng sa etherification/g 2
Palo ea etherifying agent sethaleng sa etherification/g 4.3
Etherified solid-liquid ratio/(g/mL) 1:15
3.3.1.1 Tšusumetso ea lintlha tse fapaneng mabapi le lengolo la sebaka sa CMC molemong oa kalafo ea alkalization.
1. Phello ea pretreatment alkalization mocheso ka boemo ba sebaka sa CMC
Bakeng sa ho nahana ka phello ea mocheso oa alkalization oa pretreatment ka tekanyo ea ho kenya sebaka sa CMC e fumanoeng, tabeng ea ho lokisa lintlha tse ling e le litekanyetso tsa pele,
Tlas'a maemo, phello ea mocheso oa pretreatment alkalization ho CMC substitution degree e tšohloa, 'me liphetho li bontšoa ho Feiga.
Phekolo ea mocheso oa alkalizing/℃
Phello ea pretreatment alkalizing mocheso ka CMC substitution degree
Hoa hlokomeleha hore tekanyo ea ho nkela sebaka sa CMC e eketseha ka ho eketseha ha mocheso oa alkalization pele ho phekoloa, 'me mocheso oa alkalization ke 30 °C.
Likhato tse ka holimo tsa ho fetola li fokotseha ka mocheso o ntseng o eketseha. Sena se bakoa ke hore mocheso oa alkalizing o tlase haholo, 'me limolek'hule ha li sebetse ebile ha li khone
Senya hantle sebaka sa crystalline sa cellulose, se etsang hore ho be thata hore moemeli oa etherifying a kene ka hare ho selulose sethaleng sa etherification, 'me tekanyo ea karabelo e batla e phahame.
tlase, e bakang boemo bo tlase ba phano ya sehlahiswa. Leha ho le joalo, mocheso oa alkalization ha oa lokela ho ba holimo haholo. Ha mocheso o ntse o eketseha, tlas'a ketso ea mocheso o phahameng le alkali e matla,
Cellulose e na le tšekamelo ea ho senyeha ha oxidative, 'me tekanyo ea ho fetola sehlahisoa sa CMC ea fokotseha.
2. Tšusumetso ea nako ea pele ea kalafo ea alkalinization ho lengolo la sebaka sa CMC
Tlas'a boemo ba hore pretreatment alkalization mocheso ke 30 °C le lintlha tse ling ke boleng ba pele, phello ea nako ea pele ea phekolo ea alkalization ho CMC e tšohloa.
Phello ya ho nkela sebaka. Boemo ba ho nka sebaka
Teko pele ho nako ea alkalizing/h
Phello ea pretreatment alkalinization nako kaCMClengolo la phetoho
The bulking process ka boeona e batla e potlakile, empa tharollo ea alkali e hloka nako e itseng ea phallo ea fiber.
Ho ka bonoa hore ha nako ea alkalization e le 0.5-1.5h, tekanyo ea ho fetola sehlahisoa e eketseha ka ho eketseha ha nako ea alkalization.
Tekanyo ea ho kenya sebaka sa sehlahisoa se fumanoeng e ne e le e phahameng ka ho fetisisa ha nako e ne e le 1.5h, 'me tekanyo ea ho fetola e fokotsehile ka ho eketseha ha nako ka mor'a 1.5h. Sena se ka
E ka 'na ea e-ba hobane qalong ea alkalization, ka ho lelefatsa nako ea alkalization, ho kenngoa ha alkali ho selulose ho lekaneng, e le hore fiber.
Sebopeho se ka sehloohong se phutholohile haholoanyane, se eketsa moemeli oa etherifying le seaplane se sebetsang
Nako ea poso: Apr-26-2024