1 Kupu Whakataki
I tenei wa, ko te rauemi mata matua e whakamahia ana i roto i te whakarite oether cellulosehe miro, kei te heke haere tona hua, kei te piki hoki te utu;
I tua atu, he nui ake te kino ki te tinana o te tangata me te taiao ko nga mea whakaetere penei i te waikawa chloroacetic (tino paitini) me te ethylene oxide (carcinogenic). Pukapuka
I roto i tenei upoko, ka whakamahia te cellulose paina me te 90% o te purenga i tangohia i te upoko tuarua hei rauemi mata, ka whakamahia te konutai chloroacetate me te 2-chloroethanol hei whakakapi.
Ma te whakamahi i te waikawa chloroacetic tino paitini hei kaihoko whakaetere, anioniccarboxymethyl cellulose (CMC), i whakaritea te hydroxyethyl cellulose kore-ionic.
Cellulose (HEC) me te whakauru hydroxyethyl carboxymethyl cellulose (HECMC) e toru nga etera cellulose. take kotahi
Ko nga tikanga whakarite o nga etera cellulose e toru i arotauhia na roto i nga whakamatautau me nga whakamatautau orthogonal, a ko nga ether cellulose synthesized i tohuhia e FT-IR, XRD, H-NMR, etc.
Ko nga kaupapa o te whakaetere o te cellulose
Ka taea te wehea te kaupapa o te etherification cellulose ki nga wahanga e rua. Ko te waahanga tuatahi ko te tukanga whakaalkalization, ara, i te wa o te tauhohenga o te tauhohenga o te cellulose,
Ka marara noa i roto i te otinga NaOH, ka pupuhi te paina cellulose i raro i te mahi o te whakakorikori miihini, me te roha o te wai.
He nui nga ngota ngota iti NaOH ka uru ki roto o te paina cellulose, ka tauhohe ki nga roopu hydroxyl i runga i te mowhiti o te waeine hanganga huka,
Ka whakaputa i te cellulose alkali, te pokapū kaha o te tauhohenga etherification.
Ko te waahanga tuarua ko te tukanga whakaeera, ara, ko te tauhohenga i waenga i te pokapū kaha me te konutai chloroacetate, 2-chloroethanol ranei i raro i nga tikanga kawakore, ka puta
I te wa ano, ka whakaputa ano te kaihoko konutai konutai chloroacetate me te 2-chloroethanol i tetahi tohu wai i raro i nga tikanga kawakore.
Ka whakatauhia nga tauhohenga taha ki te whakaputa i te konutai glycolate me te ethylene glycol.
2 Ko te whakamaaramatanga kawakore i mua i te maimoatanga o te cellulose paina
Tuatahi, whakarite i tetahi kukū o te otinga NaOH me te wai whakaheke. Na, i tetahi pāmahana, 2g o te muka paina
Ka rewa te huaora ki tetahi rōrahi o te otinga NaOH, ka whakaohokia mo tetahi wa, ka tātarihia hei whakamahi.
Kaihanga Tauira Taputapu
Tika pH Meter
Momo kaikohi te whakamahana whakamahana i nga wa katoa
Umu whakamaroke korehau
Taurite hiko
Momo wai porohita papu maha-mahinga korehau
Fourier Panoni Pokarekare Hikoi
X-ray diffractometer
Te Irirangi Aukume Resonance Spectrometer
Hangzhou Aolilong Instrument Co., Ltd.
Hangzhou Huichuang Taputapu Taputapu Co., Ltd.
Shanghai Jinghong Experimental Equipment Co., Ltd.
METTLER TOLEDO Instruments (Shanghai) Co., Ltd.
Hangzhou David Science and Education Instrument Co., Ltd.
American Thermo Fisher Co., Ltd.
American Thermoelectric Switzerland ARL Company
Ko te kamupene Swiss BRUKER
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Te Whakaritenga o nga CMC
Ma te whakamahi i te cellulose alkaline te rakau paina i mua i te whakamaoritanga kawakore hei rauemi mata, ma te whakamahi i te waihano hei whakarewa me te whakamahi i te konutai chloroacetate hei whakaeera.
Ko te CMC me te DS teitei ake i whakaritea ma te taapiri i te kawakore kia rua me te kaihoko whakaemi kia rua. Taapirihia he 2 karamu o te rakau paina kawakore cellulose ki roto i te ipu kaki e wha, katahi ka tapirihia he riipene wairewa wairewa, ka whakaoho pai mo te 30min.
mo, kia tino marara te cellulose alkali. Kātahi ka tāpirihia he nui o te māngai kawakore me te konutai chloroacetate hei tauhohe mo tetahi wa i tetahi pāmahana whakaeterera.
I muri i te wa, he taapiri tuarua o te kaihoko kawakore me te konutai chloroacetate ka whai i te whakamaarama mo tetahi wa. Ka mutu te tauhohenga, whakamatao ka whakamatao, katahi
Whakakorehia me te nui o te waikawa acettic glacial, katahi ka tātari momi, ka horoi ka whakamaroke.
Te Whakaritenga o nga HEC
Ma te whakamahi i te rakau paina he waahua alkaline i mua i te whakamaoritanga kawakore hei rauemi mata, te waihano hei whakarewa me te 2-chloroethanol hei whakamaarama.
Ko te HEC me te MS teitei ake i whakaritea ma te taapiri i te kawakore kia rua, ka rua te waahana whakaetherifying. Taapirihia he 2 karamu o te rakau paina kawakore cellulose ki roto i te ipu kaki wha, ka tapirihia he rōrahi o te 90% (hautanga rōrahi) waihā, whakaohokia.
Oho mo tetahi wa kia tino marara, katahi ka tapirihia he nui o te kawakawa, ka ata whakamahana, ka tapirihia he rōrahi 2-
Chloroethanol, he mea whakahaehae i te paohana mo te wa roa, katahi ka tapirihia te toenga konutai waikawa me te 2-chloroethanol kia mau tonu te whakaeera mo tetahi wa. maimoatanga
I muri i te otinga o te tauhohenga, whakakorehia me etahi waikawa acettic glacial, ka mutu ka tātari ki te tātari karaihe (G3), horoi, ka whakamaroke.
Whakaritenga o HEMCC
Ma te whakamahi i te HEC kua oti te whakarite i te 3.2.3.4 hei rauemi mata, te waihano hei reo tauhohenga, me te konutai chloroacetate hei kaihoko whakaetere hei whakarite.
HECMC. Ko te tukanga motuhake ko: tangohia he nui HEC, hoatu ki roto i te 100 mL ipu kaki wha, katahi ka tapirihia he rahinga o te rōrahi.
90% te waihā, whakaohokia ma te miihini mo tetahi wa kia tino marara, taapirihia he kawakore i muri i te whakamahana, ka ata taapiri
Ko te konutai chloroacetate, ka mutu te whakamaaramatanga i te pāmahana tonu i muri i te waa. I muri i te otinga o te tauhohenga, whakakorehia ki te waikawa acettic glacial hei whakakore, katahi ka whakamahia he tātari karaihe (G3)
I muri i te tātari momi, te horoi me te whakamaroke.
Te purenga o nga ethers cellulose
I roto i te whakaritenga o te cellulose ether, he maha nga hua ka mahia, ko te tote konutai puota hauota me etahi atu.
poke. Hei whakapai ake i te kounga o te cellulose ether, i mahia he purenga ngawari ki runga i te ether cellulose kua whiwhi. no te mea kei roto ratou i te wai
He rereke te wairewa, no reira ka whakamahia e te whakamatautau tetahi hautanga rōrahi o te waihā wai wai hei pure i nga etera cellulose e toru.
huri.
Whakanohoia te tauira ether cellulose kua rite ki te ahua o te kounga ki roto i te ipurau, tāpirihia he nui o te 80% ewaro kua whakamahana ki te 60 ℃ ~ 65 ℃, ka mau tonu te whakaoho miihini ki te 60 ℃ ~ 65 ℃ i runga i te whakamahana whakamahana i te whakamahana i nga wa katoa. mo te 10 ℃. min. Tangohia te supernatant kia maroke
I roto i te ipurau pokekore, whakamahia te pakawa hiriwa hei tirotiro mo nga katote hauota. Mēnā he rerenga mā, tātarihia mā te tātari karaihe ka tango i te totoka
Whakahokia nga mahi o mua mo te wahanga o te tinana, tae noa ki te filtrate i muri i te taapiri i te 1 topata o te otinga AgNO3 kaore he rerenga ma, ara, ka oti te purenga me te horoi.
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ki roto (te nuinga ki te tango i te tauhohenga a-hua NaCl). I muri i te filtration momi, whakamaroke, whakamatao ki te pāmahana rūma me te pauna.
papatipu, g.
Nga Tikanga Whakamatau me te Whakaaturanga mo nga Etera Cellulose
Te Whakataunga o te Tohu Whakakapi (DS) me te Molar Degree of Substitution (MS)
Te Whakataunga o te DS: Tuatahi, paunatia te 0.2 g (tika ki te 0.1 mg) o te tauira cellulose ether kua purea me te whakamaroke, memeha ki roto
80mL o te wai māturu, ka oho i roto i te pati wai mahana tonu i te 30 ℃~40 ℃ mo te 10min. Na ka whakatika ki te wairewa waikawa pungatara, otinga NaOH ranei
pH o te wairewa tae noa ki te 8 te pH o te wairewa. Na i roto i te ipurau kua mau ki te hiko ira pH mita, whakamahia he otinga paerewa o te waikawa pungatara.
Ki te titrate, i raro i nga tikanga whakaohooho, tirohia te panui pH mita i te wa e titrate ana, ina whakatikahia te uara pH o te otinga ki te 3.74,
Ka mutu te titration. Tuhia te rōrahi o te wairewa paerewa waikawa pungatara e whakamahia ana i tenei wa.
Whakatupuranga:
Te tapeke o nga tau proton o runga me te roopu hydroxyethyl
Te ōwehenga o te maha o ngā protons o runga; Ko te I7 te papatipu o te roopu methylene i te roopu hydroxyethyl
Te kaha o te tihi resonance proton; Ko te kaha o te tihi resonance proton o nga roopu metini e 5 me tetahi roopu methylene ki te waeine hukahuka cellulose.
Huihuinga.
Ko nga tikanga whakamatautau i whakaahuahia mo te whakamatautau tohu infrared o nga etera cellulose e toru CMC, HEC me HEECMC
Ture
3.2.4.3 whakamātautau XRD
X-ray Diffraction Analysis Tohu Whakamātautau mo nga Etera Cellulose E toru CMC, HEC me HEECMC
te tikanga whakamatautau i whakaahuatia.
3.2.4.4 Whakamatau i te H-NMR
Ko te H NMR spectrometer o HEC i ine e Avance400 H NMR spectrometer i hangaia e BRUKER.
Ma te whakamahi i te dimethyl sulfoxide kua whakakorehia hei whakarewa, i whakamatauria te wairewa ma te hauwai hauwai NMR spectroscopy. Ko te auau whakamatautau ko 75.5MHz.
Mahana, he 0.5mL te otinga.
3.3 Ngā Hua me te Tātaritanga
3.3.1 Arotautanga o te tukanga whakarite CMC
Ma te whakamahi i te cellulose paina i tangohia i roto i te upoko tuarua hei rauemi mata, me te whakamahi i te konutai chloroacetate hei kaihoko whakamaarama, i whakamahia te tikanga o te whakamatautau take kotahi,
Ko te tukanga whakarite o te CMC i arotauhia, a ko nga taurangi tuatahi o te whakamatautau i whakatauhia penei i te Ripanga 3.3. E whai ake nei ko te tukanga whakarite HEC
I roto i nga mahi toi, ko te tātari i nga momo ahuatanga.
Ripanga 3.3 Uara Ahua Tuatahi
Tauwehe Uara tuatahi
Te whakamaamaa i mua i te whakamaarama alkalizing/℃ 40
Te wa whakamaoritanga o mua i te maimoatanga/h 1
Te maimoatanga o mua ōwehenga totoka-wai/(g/mL) 1:25
Te kukū o te reitia i mua i te maimoatanga/% 40
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Ko te waahi tuatahi o te whakamahana pāmahana/℃ 45
Wā whakawera tuatahi/h 1
Wāhanga tuarua te pāmahana whakawera/℃ 70
Te wahanga tuarua o te wa etherification/h 1
Inenga turanga i roto i te wahanga etherification/g 2
Te nui o te kaihoko whakaetere i te wahanga whakaetere/g 4.3
Te ōwehenga totoka-wai kua whakahaera/(g/mL) 1:15
3.3.1.1 Te awenga o nga momo ahuatanga ki te tohu whakakapinga CMC i roto i te waahi whakamaarama o mua i te maimoatanga.
1. Ko te paanga o te whakamahana o te whakamaarama i mua i te maimoatanga ki te tohu whakakapinga o te CMC
Ki te whakaaro ki te paanga o te whakamahana o te whakamaarama i mua i te maimoatanga i runga i te tohu o te whakakapinga o te CMC kua whiwhi, ki te whakatika i etahi atu mea hei uara tuatahi,
I raro i nga tikanga, ka korerohia te paanga o te whakamahana o te whakamaarama o mua ki te tohu whakakapinga CMC, ka whakaatuhia nga hua ki te Fig.
Te whakamaamaa i mua i te pāmahana alkalizing/℃
Te paanga o te whakamaarama kawakore o mua i te maimoatanga ki te tohu whakakapinga CMC
Ka kitea ka piki ake te tohu whakakapinga o te CMC me te pikinga o te pāmahana whakamaarama o mua i te maimoatanga, a ko te 30 °C te pāmahana whakamaarama.
Ko nga nekehanga o runga o te whakakapi ka heke ki te piki haere o te pāmahana. Ko tenei na te mea he iti rawa te pāmahana alkalizing, a he iti te kaha o nga ngota ngota me te kore e taea
He pai ki te whakangaro i te waahi tioata o te cellulose, he uaua ki te whakauru mai o te kaihoko etherifying ki roto o te cellulose i roto i te wahanga etherification, a he tino tiketike te tohu o te tauhohenga.
he iti, he iti ake te ahua o te whakakapinga hua. Heoi, kia kaua e tiketike rawa te pāmahana o te alkaliization. Ka piki ake te pāmahana, i raro i te mahi o te pāmahana teitei me te alkali kaha,
Ko te Cellulose he kaha ki te whakaheke i te waikura, ka heke te tohu o te whakakapinga o te hua CMC.
2. Te awe o te wa alkalinization pretreatment ki te tohu whakakapinga CMC
I raro i te ahuatanga ko te 30 °C te pāmahana o te whakamaaramatanga o mua, me etahi atu mea ko nga uara tuatahi, ka korerohia te paanga o te wa whakamaarama i mua i te maimoatanga i runga i te CMC.
Te painga o te whakakapi. Te tohu whakakapinga
Te wa whakamaoritanga i mua i te maimoatanga
Te paanga o te wa whakamaoritanga i mua i te maimoatangaCMCtohu whakakapinga
Ko te tukanga bulking ano he tino tere, engari ko te otinga alkali me te wa tohatoha i roto i te muka.
Ka taea te kite i te wa ko te 0.5-1.5h te wa whakamaaramatanga, ka piki ake te tohu whakakapinga o te hua me te piki o te wa whakamaarama.
Ko te tohu o te whakakapinga o te hua i whiwhi ko te teitei rawa i te wa ko te 1.5h te wa, a ka heke te tohu o te whakakapi me te piki o te wa i muri i te 1.5h. Ka taea tenei
Na te mea pea i te timatanga o te whakamaaramatanga, me te roanga o te wa whakamaaramatanga, ka nui ake te whakauru o te kawakore ki te cellulose, kia pai ai te muka.
He ngawari ake te hanganga matua, te whakanui ake i te kaihoko whakaetere me te reo kaha
Te wa tuku: Apr-26-2024