1 Gabatarwa
A halin yanzu, babban albarkatun kasa da ake amfani da su a cikin shirye-shiryencellulose etherauduga ne, kuma abin da ake fitar da shi yana raguwa, kuma farashin ma yana tashi;
Bugu da ƙari, abubuwan da aka saba amfani da su kamar chloroacetic acid (mai guba sosai) da ethylene oxide (carcinogenic) suma sun fi cutar da jikin ɗan adam da muhalli. Littafi
A cikin wannan babi, pine cellulose tare da tsaftar dangi fiye da 90% da aka fitar a babi na biyu ana amfani da shi azaman albarkatun ƙasa, kuma ana amfani da sodium chloroacetate da 2-chloroethanol a madadin.
Yin amfani da chloroacetic acid mai guba mai guba a matsayin wakili na etherifying, anionicCarboxymethyl cellulose (CMC), wadanda ba ionic hydroxyethyl cellulose aka shirya.
Cellulose (HEC) da kuma gauraye hydroxyethyl carboxymethyl cellulose (HECMC) uku cellulose ethers. factor guda ɗaya
Hanyoyin shirye-shiryen na ethers na cellulose guda uku an inganta su ta hanyar gwaje-gwajen gwaje-gwaje da gwaje-gwaje na orthogonal, kuma ethers cellulose da aka haɗa sun kasance suna da FT-IR, XRD, H-NMR, da dai sauransu.
Muhimman abubuwan etherification na cellulose
Ka'idar etherification cellulose za a iya raba kashi biyu. Kashi na farko shine tsarin alkalization, wato lokacin alkalization na cellulose.
Ko da yaushe ya watse a cikin maganin NaOH, pine cellulose yana kumbura da ƙarfi a ƙarƙashin aikin motsa jiki, kuma tare da faɗaɗa ruwa.
Yawancin ƙananan ƙwayoyin NaOH sun shiga cikin ciki na pine cellulose, kuma sun amsa tare da ƙungiyoyin hydroxyl akan zobe na rukunin tsarin glucose,
Yana haifar da alkali cellulose, cibiyar aiki na etherification dauki.
Sashe na biyu shine tsarin etherification, wato, amsawa tsakanin cibiyar aiki da sodium chloroacetate ko 2-chloroethanol a ƙarƙashin yanayin alkaline, wanda ya haifar da
A lokaci guda, wakilin etherifying sodium chloroacetate da 2-chloroethanol kuma za su samar da wani matakin ruwa a ƙarƙashin yanayin alkaline.
An warware halayen gefe don samar da sodium glycolate da ethylene glycol, bi da bi.
2 Mai da hankali alkali decrystallisation pretreatment na Pine cellulose
Na farko, shirya wani taro na maganin NaOH tare da ruwan da aka lalatar. Sa'an nan, a wani zazzabi, 2g na Pine fiber
Ana narkar da bitamin a cikin wani takamaiman ƙarar maganin NaOH, yana motsawa na ɗan lokaci, sannan tace don amfani.
Maƙerin Samfurin Kaya
Daidaitaccen pH Mita
Mai tarawa irin akai zazzabi dumama Magnetic stirrer
Tanda bushewa
Ma'aunin lantarki
Nau'in ruwa mai kewayawa famfo famfo mai manufa da yawa
Fourier Canza Infrared Spectrometer
X-ray diffractometer
Nukiliya Magnetic Resonance Spectrometer
Hangzhou Aolilong Instrument Co., Ltd.
Hangzhou Huichuang Instrument Equipment Co., Ltd.
Kudin hannun jari Shanghai Jinghong Experimental Equipment Co., Ltd.
METTLER TOLEDO Instruments (Shanghai) Co., Ltd.
Hangzhou David Science and Education Instrument Co., Ltd.
Kudin hannun jari American Thermo Fisher Co., Ltd.
American Thermoelectric Switzerland ARL Company
Kamfanin BRUKER na Switzerland
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Shirye-shiryen CMCs
Amfani da Pine itace alkali cellulose pretreated ta mayar da hankali alkali decrystallization a matsayin albarkatun kasa, ta yin amfani da ethanol a matsayin sauran ƙarfi da kuma amfani da sodium chloroacetate a matsayin etherification.
An shirya CMC tare da DS mafi girma ta ƙara alkali sau biyu da etherifying wakili sau biyu. Sai ki zuba 2g na alkali cellulose na bishiyar bishiya a cikin kwanon wuyansa hudu, sannan a zuba wani adadin sinadarin ethanol, sannan a juye sosai na tsawon mintuna 30.
game da, don haka alkali cellulose ya tarwatse sosai. Sa'an nan kuma ƙara wani adadin adadin alkali da sodium chloroacetate don amsawa na wani lokaci a wani zafin jiki na etherification.
Bayan lokaci, ƙari na biyu na wakilin alkaline da sodium chloroacetate tare da etherification na wani lokaci. Bayan maganin ya ƙare, kwantar da hankali kuma yayi sanyi, sannan
Tsabtace tare da daidai adadin glacial acetic acid, sannan tace tsotsa, wanke kuma bushe.
Shiri na HECs
Amfani da Pine itace alkali cellulose pretreated tare da mayar da hankali alkali decrystallization a matsayin albarkatun kasa, ethanol a matsayin sauran ƙarfi da 2-chloroethanol a matsayin etherification.
An shirya HEC tare da MS mafi girma ta ƙara alkali sau biyu da etherifying wakili sau biyu. Ƙara 2g na itacen pine alkali cellulose a cikin flask mai wuya huɗu, sa'annan a ƙara wani ɗan ƙarar 90% (ƙarashin juzu'i) ethanol, motsawa.
Ki dakashi na tsawon wani lokaci don watsewa sosai, sannan a zuba alkali kadan kadan, sai a rika dumama a hankali, sai a kara 2-
Chloroethanol, wanda ke daɗaɗawa a yawan zafin jiki na ɗan lokaci, sannan ya ƙara sauran sodium hydroxide da 2-chloroethanol don ci gaba da etherification na ɗan lokaci. bi da
Bayan an gama amsawa, cire shi da wani adadin glacial acetic acid, sannan a tace tare da tace gilashi (G3), wanke, kuma bushe.
Shirye-shiryen HEMCC
Yin amfani da HEC da aka shirya a cikin 3.2.3.4 a matsayin albarkatun kasa, ethanol a matsayin matsakaiciyar amsawa, da sodium chloroacetate a matsayin wakili na etherifying don shirya.
HECMC. Takamammen tsari shine: Ɗauki wani adadin HEC, saka shi a cikin kwalban wuyansa 100 ml 100, sa'an nan kuma ƙara wani adadin ƙarar.
90% ethanol, ta hanyar injina na ɗan lokaci don sanya shi gabaɗaya, ƙara ɗan adadin alkali bayan dumama, sannan a hankali ƙara.
Sodium chloroacetate, da etherification a akai-akai zazzabi ya ƙare bayan wani lokaci. Bayan an gama amsawa, cire shi da glacial acetic acid don kawar da shi, sannan yi amfani da tace gilashin (G3)
Bayan tsotsa tacewa, wankewa da bushewa.
Tsarkakewar ethers cellulose
A cikin tsarin shirye-shiryen cellulose ether, ana samar da wasu samfurori sau da yawa, yawanci gishirin inorganic sodium chloride da wasu sauran.
kazanta. Don inganta ingancin ether cellulose, an gudanar da tsarkakewa mai sauƙi akan ether cellulose da aka samu. saboda suna cikin ruwa
Akwai solubility daban-daban, don haka gwajin yana amfani da ɗan ƙaramin juzu'i na hydrated ethanol don tsarkake ethers cellulose da aka shirya.
canji.
Sanya samfurin ether na cellulose wanda aka shirya tare da wani inganci a cikin beaker, ƙara wani adadin 80% ethanol wanda aka riga aka rigaya zuwa 60 ℃ ~ 65 ℃, da kuma kula da motsawar injiniya a 60 ℃ ~ 65 ℃ a kan madaidaicin zafin jiki na dumama Magnetic stirrer. za 10 ℃. min. Ɗauki supernatant don bushewa
A cikin tukwane mai tsabta, yi amfani da nitrate na azurfa don bincika ions chloride. Idan akwai farin hazo sai a tace ta cikin tace gilashin sannan a dauki daskararrun
Maimaita matakan da suka gabata don sashin jiki, har sai tacewa bayan ƙara 1 digo na maganin AgNO3 ba shi da farin farin ciki, wato, an gama tsarkakewa da wankewa.
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cikin (yafi don cire amsawar samfurin NaCl). Bayan tsotsa tacewa, bushewa, sanyaya zuwa dakin zafin jiki da yin awo.
taro, g.
Gwaji da Hanyoyin Halaye don Ethers Cellulose
Ƙayyade Degree na Sauya (DS) da Molar Degree of Substitution (MS)
Ƙaddamar da DS: Na farko, auna 0.2 g (daidai zuwa 0.1 MG) na samfurin ether mai tsabta da busassun cellulose, narkar da shi a ciki.
80ml na distilled ruwa, zuga a cikin wani m zazzabi ruwa wanka a 30 ℃ ~ 40 ℃ na 10min. Sannan daidaita tare da maganin sulfuric acid ko maganin NaOH
pH na maganin har sai pH na maganin shine 8. Sa'an nan kuma a cikin beaker sanye take da electrode pH mita, yi amfani da daidaitaccen bayani na sulfuric acid.
Don titrate, ƙarƙashin yanayin motsawa, kula da karatun pH yayin titrating, lokacin da aka daidaita ƙimar pH na maganin zuwa 3.74,
Titration ya ƙare. Kula da ƙarar daidaitaccen maganin sulfuric acid da aka yi amfani da shi a wannan lokacin.
Tsari:
Jimlar lambobin proton na sama da ƙungiyar hydroxyethyl
Matsakaicin adadin protons na sama; I7 shine yawan ƙungiyar methylene akan ƙungiyar hydroxyethyl
Ƙarfin ƙwayar proton resonance kololuwa; shine tsananin girman resonance proton na ƙungiyoyin methine 5 da ƙungiyar methylene ɗaya akan rukunin glucose na cellulose.
Sum
Hanyoyin gwajin da aka bayyana don gwajin halayen infrared na uku cellulose ethers CMC, HEC da HEECMC
Doka
3.2.4.3 gwajin XRD
X-ray Diffraction Analysis Halayen Gwajin Gwajin Ethers Cellulose Uku CMC, HEC da HEECMC
hanyar gwajin da aka bayyana.
3.2.4.4 Gwajin H-NMR
An auna sikirin H NMR na HEC ta Avance400 H NMR spectrometer da BRUKER ya samar.
Yin amfani da deuterated dimethyl sulfoxide a matsayin kaushi, an gwada maganin ta ruwa hydrogen NMR spectroscopy. Mitar gwajin ya kasance 75.5MHz.
Dumi, maganin shine 0.5mL.
3.3 Sakamako da Nazari
3.3.1 Inganta tsarin shirye-shiryen CMC
Yin amfani da pine cellulose cirewa a cikin babi na biyu a matsayin albarkatun kasa, da kuma yin amfani da sodium chloroacetate a matsayin etherifying wakili, Hanyar gwajin factor guda daya da aka dauka,
An inganta tsarin shirye-shiryen CMC, kuma an saita masu canji na farko na gwaji kamar yadda aka nuna a cikin Table 3.3. Mai zuwa shine tsarin shirye-shiryen HEC
A cikin fasaha, nazarin dalilai daban-daban.
Tebur 3.3 Mahimman Factor Na Farko
Factor Farkon ƙimar
Pretreatment alkalizing zafin jiki / ℃ 40
Pretreatment alkalizing time/h 1
Pretreatment m-ruwa rabo/(g/ml) 1:25
Pretreatment lye maida hankali/% 40
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Matakin farko etherification zafin jiki/℃ 45
Lokacin etherification na matakin farko/h 1
Zazzabi etherification mataki na biyu/℃ 70
Lokacin etherification mataki na biyu 1
Matsakaicin tushe a matakin etherification/g 2
Adadin wakilin etherifying a matakin etherification/g 4.3
Rawanin ruwa mai kauri/(g/ml) 1:15
3.3.1.1 Tasirin dalilai daban-daban akan digirin maye gurbin CMC a matakin alkalization na pretreatment
1. Sakamakon pretreatment alkalization zafin jiki a kan maye gurbin digiri na CMC
Don yin la'akari da tasirin zafin jiki na pretreatment alkalisation akan matakin maye gurbin da aka samu a cikin CMC da aka samu, a cikin yanayin daidaita wasu dalilai azaman ƙimar farko,
A ƙarƙashin yanayin, ana tattauna tasirin zafin jiki na pretreatment alkalisation akan digiri na CMC, kuma an nuna sakamakon a cikin siffa.
Pretreatment alkalizing zafin jiki/℃
Tasirin pretreatment alkalizing zafin jiki akan CMC maye gurbin digiri
Ana iya ganin cewa matakin maye gurbin CMC yana ƙaruwa tare da haɓakar zafin jiki na pretreatment alkalization, kuma yawan zafin jiki shine 30 ° C.
Matsayin da ke sama na maye yana raguwa tare da ƙara yawan zafin jiki. Wannan shi ne saboda zafin jiki na alkalizing ya yi ƙasa da ƙasa, kuma kwayoyin ba su da aiki kuma ba za su iya ba
Yadda ya kamata halakar da crystalline yanki na cellulose, wanda ya sa shi da wuya ga etherifying wakili shiga ciki na cellulose a cikin etherification mataki, da kuma mataki na dauki ne in mun gwada da high.
ƙananan, yana haifar da ƙananan digiri na maye gurbin samfur. Koyaya, zafin alkalization bai kamata ya yi girma ba. Yayin da zafin jiki ya karu, a ƙarƙashin aikin babban zafin jiki da alkali mai ƙarfi,
Cellulose yana da haɗari ga lalatawar iskar oxygen, kuma matakin maye gurbin samfurin CMC yana raguwa.
2. Tasirin pretreatment alkalinization lokaci a kan CMC maye gurbin digiri
A ƙarƙashin yanayin cewa zafin jiki na pretreatment alkalization shine 30 ° C kuma wasu dalilai sune ƙimar farko, ana tattauna tasirin lokacin alkalization na pretreatment akan CMC.
Tasirin canji. Digiri na canji
Pretreatment alkalizing lokaci/h
Sakamakon pretreatment alkalinization lokaci a kanCMCcancantar digiri
Tsarin bulking kanta yana da saurin sauri, amma maganin alkali yana buƙatar wani lokaci yadawa a cikin fiber.
Ana iya ganin cewa lokacin da lokacin alkalization ya kasance 0.5-1.5h, matakin maye gurbin samfurin yana ƙaruwa tare da karuwar lokacin alkalization.
Matsayin maye gurbin samfurin da aka samu shine mafi girma lokacin da lokacin ya kasance 1.5h, kuma matakin maye gurbin ya ragu tare da karuwar lokaci bayan 1.5h. Wannan zai iya
Yana iya zama saboda a farkon alkalization, tare da tsawaita lokacin alkalization, shigar da alkali zuwa cellulose ya fi wadatar, ta yadda zaren fiber.
Tsarin farko ya fi annashuwa, yana ƙara yawan etherifying wakili da matsakaici mai aiki
Lokacin aikawa: Afrilu-26-2024