1 Nhanganyaya
Parizvino, iyo huru mbishi zvinhu inoshandiswa mukugadzirira kwecellulose etheridonje, uye kubuda kwaro kuri kuderera, uye mutengo uri kukwirawo;
Uyezve, zvinowanzoshandiswa etherifying agents senge chloroacetic acid (yakanyanya muchetura) uye ethylene oxide (carcinogenic) zvakare zvinokuvadza zvakanyanya kumuviri wemunhu uye nharaunda. Book
Muchitsauko chino, pine cellulose ine hutsanana hunopfuura 90% yakatorwa muchitsauko chechipiri inoshandiswa seyakagadzirwa, uye sodium chloroacetate uye 2-chloroethanol inoshandiswa sechinzvimbo.
Kushandisa yakanyanya chepfu chloroacetic asidhi se etherifying agent, anionicCarboxymethyl cellulose (CMC), isiri-ionic hydroxyethyl cellulose yakagadzirwa.
Cellulose (HEC) uye yakasanganiswa hydroxyethyl carboxymethyl cellulose (HECMC) matatu cellulose ethers. chinhu chimwe chete
Maitiro ekugadzirira ematatu cellulose ether akagadziridzwa nenzira yekuyedza uye orthogonal kuyedza, uye synthesized cellulose ethers yairatidzwa neFT-IR, XRD, H-NMR, nezvimwe.
Zvinokosha zve cellulose etherification
Nheyo ye cellulose etherification inogona kukamurwa kuita zvikamu zviviri. Chikamu chekutanga ndeye alkalization process, ndiko kuti, panguva ye alkalization reaction ye cellulose,
Yakaenzana yakaparadzirwa muNaOH mhinduro, pine cellulose inoputika nechisimba pasi pechiito chemagetsi chinomutsa, uye nekuwedzera kwemvura.
Huwandu hukuru hweNaOH mamorekuru madiki akapinda mukati mepine cellulose, uye akabatana nemapoka ehydroxyl parin'i yeglucose structural unit.
Inogadzira alkali cellulose, iyo inoshanda pakati peiyo etherification reaction.
Chikamu chechipiri ndechekuita etherification, ndiko kuti, kuita pakati penzvimbo inoshanda uye sodium chloroacetate kana 2-chloroethanol pasi pemamiriro ealkaline, zvichikonzera
Panguva imwecheteyo, iyo etherifying agent sodium chloroacetate uye 2-chloroethanol inoburitsawo imwe dhigirii remvura pasi pemamiriro ealkaline.
Maitiro eparutivi anogadziriswa kugadzira sodium glycolate uye ethylene glycol, zvichiteerana.
2 Yakadzika alkali decrystallization pretreatment yepine cellulose
Kutanga, gadzirira imwe yekusangana kweNaOH mhinduro nemvura yakasvibiswa. Zvadaro, pane imwe tembiricha, 2g yepine fiber
Iyo vhitamini inonyungudutswa mune imwe vhoriyamu yeNaOH mhinduro, yakasimudzwa kwenguva yakati, uye yozosefa kuti ishandiswe.
Instrument Model Mugadziri
Precision pH Meter
Collector mhando inogara tembiricha inodziya magineti stirrer
Vacuum drying oven
Electronic balance
Kutenderera mvura mhando multi-chinangwa vacuum pombi
Fourier Shandura Infrared Spectrometer
X-ray diffractometer
Nuclear Magnetic Resonance Spectrometer
Iyo kambani 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 Sainzi uye Dzidzo Instrument Co., Ltd.
Nhoroondo yeAmerican Thermo Fisher Co., Ltd.
American Thermoelectric Switzerland ARL Company
Kambani yeSwitzerland BRUKER
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Kugadzirira kweCMCs
Kushandisa pine wood alkali cellulose pretreated neyakaomeswa alkali decrystallization seyakabikwa, uchishandisa ethanol se solvent uye kushandisa sodium chloroacetate seetherification.
CMC ine yepamusoro DS yakagadzirwa nekuwedzera alkali kaviri uye etherifying mumiririri kaviri. Wedzera 2g yepine wood alkali cellulose muflask ine mitsipa ina, wobva wawedzera imwe volume ye ethanol solvent, uye fambisa zvakanaka kwemaminitsi makumi matatu.
pamusoro, kuitira kuti alkali cellulose iparadzwe zvizere. Wobva wawedzera imwe chiyero che alkali agent uye sodium chloroacetate kuita kwenguva yakati pane etherification tembiricha.
Mushure menguva, kuwedzera kwechipiri kwe alkaline agent uye sodium chloroacetate inoteverwa ne etherification kwenguva yakati. Mushure mokunge mhinduro yapera, tonhorera pasi uye utonhorere pasi, ipapo
Neutralize nehuwandu hwakakodzera hweglacial acetic acid, wobva watora sefa, geza uye woomesa.
Kugadzirira kweHECs
Kushandisa pine huni alkali cellulose pretreated neyakaomeswa alkali decrystallization seyakabikwa, ethanol se solvent uye 2-chloroethanol se etherification.
Iyo HEC ine yakakwira MS yakagadzirwa nekuwedzera alkali kaviri uye etherifying mumiririri kaviri. Wedzera 2g yepine wood alkali cellulose muflask ine mitsipa ina, uye wedzera imwe vhoriyamu ye90% (vhoriyamu chikamu) ethanol, kurunga.
Kurudzira kwekanguva kuti upararire zvizere, wobva wawedzera imwe alkali, uye zvishoma nezvishoma kupisa, wedzera imwe vhoriyamu ye2-
Chloroethanol, etherified pakugara tembiricha kwenguva yakati, uyezve yakasara sodium hydroxide uye 2-chloroethanol kuenderera etherification kwenguva yakati. kubata
Mushure mekuita kwapera, gadzirisa neimwe huwandu hweglacial acetic acid, uye pakupedzisira sefa negirazi sefa (G3), geza, uye woomesa.
Kugadzirira kweHEMCC
Kushandisa HEC yakagadzirwa mu 3.2.3.4 seyakagadzirwa, ethanol seyekuita svikiro, uye sodium chloroacetate seyo etherifying agent yekugadzirira.
HECMC. Iyo chaiyo maitiro ndeiyi: tora imwe chiyero cheHEC, isa mu 100 mL ine mitsipa ina flask, uye wobva wawedzera humwe huwandu hwevhoriyamu.
90% ethanol, michina inomutsa kwechinguva kuti inyatsopararira, wedzera imwe alkali mushure mekupisa, uye zvishoma nezvishoma wedzera.
Sodium chloroacetate, iyo etherification pane inogara tembiricha inopera mushure menguva yenguva. Mushure mekuita kwapera, ita kuti isaite neglacial acetic acid kuti isaite, wobva washandisa girazi sefa (G3)
Mushure mekusveta filtration, kugeza nekuomesa.
Kucheneswa kwe cellulose ethers
Mukugadzirira kwe cellulose ether, zvimwe zvinobva-zvigadzirwa zvinowanzogadzirwa, kunyanya inorganic munyu sodium chloride uye zvimwewo.
tsvina. Kuti uvandudze kunaka kwe cellulose ether, kucheneswa kuri nyore kwakaitwa pane yakawanikwa cellulose ether. nokuti vari mumvura
Kune kunyungudika kwakasiyana, saka kuyedza kunoshandisa imwe vhoriyamu chikamu chehydrated ethanol kuchenesa matatu akagadzirwa cellulose ethers.
shanduko.
Isa iyo cellulose ether sampu yakagadzirwa nehumwe hunhu mubeaker, wedzera imwe huwandu hwe80% ethanol yakafanopiswa kusvika 60 ℃ ~ 65 ℃, uye chengetedza mechanical ichikurudzira pa60 ℃ ~ 65 ℃ pane inogara tembiricha inopisa magineti inosimudzira. kwe10 ℃. min. Tora mashura kuti aome
Mubeaker yakachena, shandisa sirivheri nitrate kutarisa chloride ions. Kana paine mvura yakachena, isefa nesefa yegirazi wotora yakasimba
Dzokorora nhanho dzakapfuura dzechikamu chemuviri, kusvika iyo filtrate mushure mekuwedzera 1 donhwe reAgNO3 mhinduro isina chena precipitate, ndiko kuti, kucheneswa uye kugeza kwapera.
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kupinda (kunyanya kubvisa maitiro ne-chigadzirwa NaCl). Mushure mekusveta filtration, kuomesa, kutonhora kusvika kukamuri tembiricha uye kuyera.
misa, g.
Kuedza uye Hunhu Nzira dzeCellulose Ethers
Kutsunga kweDhigirii reKutsiva (DS) uye Molar Dhigirii reKutsiva (MS)
Kutsunga kweDS: Chekutanga, kuyera 0.2 g (chaiyo kusvika 0.1 mg) yeyakacheneswa uye yakaomeswa cellulose ether sampu, inyungudise mukati.
80mL yemvura yakanyungudutswa, yakasimudzwa mune inogara tembiricha yekugezera mvura pa30 ℃ ~ 40 ℃ ye10min. Zvadaro gadzirisa ne sulfuric acid solution kana NaOH solution
pH yemushonga kusvika pH yemushonga yave 8. Zvino mubeaker ine pH meter electrode, shandisa yakajairwa solution ye sulfuric acid.
Kuti tite, pasi pemamiriro ezvinhu anomutsa, tarisa pH mita kuverenga uchitarisa, apo iyo pH kukosha kwemhinduro yakagadziridzwa kusvika 3.74,
Titration inopera. Cherechedza huwandu hwesulfuric acid standard solution inoshandiswa panguva ino.
Chizvarwa:
Huwandu hwenhamba dzeproton dzepamusoro neboka rehydroxyethyl
Chiyero chehuwandu hwemapurotoni epamusoro; I7 ndiyo uwandu hweboka remethylene pane hydroxyethyl boka
Kusimba kweiyo proton resonance peak; ndiko kusimba kweproton resonance peak ye5 methine mapoka uye rimwe boka remethylene pane cellulose glucose unit.
Sum.
Nzira dzekuyedza dzakatsanangurwa dzekuyedzwa kwe infrared characterization yeatatu cellulose ethers CMC, HEC uye HEECMC.
Mutemo
3.2.4.3 XRD bvunzo
X-ray Diffraction Analysis Hunhu Kuedzwa kweMatatu Cellulose Ethers CMC, HEC uye HEECMC
nzira yekuedza inotsanangurwa.
3.2.4.4 Kuedzwa kweH-NMR
Iyo H NMR spectrometer yeHEC yakayerwa neAvance400 H NMR spectrometer yakagadzirwa naBRUKER.
Kushandisa deuterated dimethyl sulfoxide se solvent, mhinduro yakaedzwa nemvura yehydrogen NMR spectroscopy. Iyo yekuyedza frequency yaive 75.5MHz.
Inodziya, mhinduro ndeye 0.5mL.
3.3 Migumisiro uye Ongororo
3.3.1 Optimization yeCMC gadziriro yekugadzirira
Uchishandisa pine cellulose yakabviswa muchitsauko chechipiri seyakagadzirwa, uye nekushandisa sodium chloroacetate seye etherifying agent, nzira yekuedzwa kwechinhu chimwe chete yakagamuchirwa,
Nzira yekugadzirira yeCMC yakagadziridzwa, uye maitiro ekutanga ekuedza akaiswa sezvinoratidzwa muTebhu 3.3. Izvi zvinotevera maitiro ekugadzirisa HEC
Mune unyanzvi, kuongororwa kwezvinhu zvakasiyana-siyana.
Tafura 3.3 Yekutanga Factor Values
Factor Initial kukosha
Pretreatment alkalizing tembiricha/℃ 40
Pretreatment alkalizing time/h 1
Pretreatment solid-liquid ratio/(g/mL) 1:25
Pretreatment lye concentration/% 40
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Yekutanga nhanho etherification tembiricha/℃ 45
Yekutanga-danho etherification nguva/h 1
Chechipiri nhanho etherification tembiricha/℃ 70
Chikamu chechipiri etherification nguva/h 1
Base dosage mu etherification nhanho/g 2
Huwandu hwe etherifying agent mu etherification stage/g 4.3
Etherified solid-liquid ratio/(g/mL) 1:15
3.3.1.1 Kupesvedzera kwezvinhu zvakasiyana-siyana paCMC substitution degree in pretreatment alkalization stage.
1. Mhedzisiro ye pretreatment alkalization tembiricha pane inotsiva dhigirii yeCMC
Kuti titarise mhedzisiro ye pretreatment alkalization tembiricha pane dhigirii rekutsiva muCMC yakawanikwa, kana iri nyaya yekugadzirisa zvimwe zvinhu sekutanga kukosha,
Pasi pemamiriro ezvinhu, mhedzisiro ye pretreatment alkalization tembiricha paCMC substitution degree inokurukurwa, uye mhedzisiro inoratidzwa muFig.
Pretreatment alkalizing tembiricha/℃
Mhedzisiro yepretreatment alkalizing tembiricha paCMC substitution degree
Zvinogona kuonekwa kuti dhigirii rekutsiva CMC rinowedzera nekuwedzera kweiyo pretreatment alkalization tembiricha, uye tembiricha yealkalization i30 °C.
Iwo madhigirii ari pamusoro ekutsiva anoderera nekuwedzera tembiricha. Izvi zvinodaro nekuti tembiricha yealkalizing yakadzikira, uye mamorekuru haashande uye haakwanise
Nyatsoparadza iyo crystalline nzvimbo ye cellulose, izvo zvinoita kuti zviome kune etherifying agent kupinda mukati me cellulose mu etherification nhanho, uye dhigirii rekuita rakanyanya kukwirira.
yakaderera, zvichikonzera dhigirii yakaderera yekutsiviwa kwechigadzirwa. Nekudaro, tembiricha ye alkalization haifanire kunge yakakwira zvakanyanya. Sezvo tembiricha inowedzera, pasi pekuita kwekushisa kwakanyanya uye alkali yakasimba,
Cellulose inowanzoita oxidative degradation, uye dhigirii rekutsiva chigadzirwa CMC inodzikira.
2. Pesvedzero yepretreatment alkalinization nguva paCMC substitution degree
Pasi pemamiriro ekuti pretreatment alkalization tembiricha iri 30 °C uye zvimwe zvinhu ndizvo zvekutanga kukosha, mhedzisiro ye pretreatment alkalization nguva paCMC inokurukurwa.
Mhedzisiro yekutsiva. Degree rekutsiva
Pretreatment alkalizing nguva/h
Mhedzisiro ye pretreatment alkalinization nguva paCMCsubstitution degree
Iyo bulking process pachayo inokurumidza, asi alkali mhinduro inoda imwe nguva yekupararira mufiber.
Zvinogona kuonekwa kuti kana nguva ye alkalization iri 0.5-1.5h, dhigirii yekutsinhanisa yechigadzirwa inowedzera nekuwedzera kwenguva ye alkalization.
Chiyero chekutsiviwa kwechigadzirwa chakawanikwa chaive chepamusoro apo nguva yaive 1.5h, uye dhigirii yekutsinhanisa yakaderera nekuwedzera kwenguva mushure me1.5h. Izvi zvinogona
Zvingave nekuti pakutanga kwe alkalization, nekuwedzera kwenguva ye alkalization, kupinza kwe alkali kune cellulose kwakanyanya kukwana, kuitira kuti fiber.
Iyo yekutanga chimiro yakasununguka, ichiwedzera iyo etherifying agent uye inoshanda yepakati
Nguva yekutumira: Kubvumbi-26-2024