Focus on Cellulose ethers

Te tauhohenga whakaetere i runga i te cellulose ether

Te tauhohenga whakaetere i runga i te cellulose ether

I akohia te mahi whakaetherification o te cellulose e te miihini pokepoke me te reactor whakakorikori, me te hydroxyethyl cellulose me te carboxymethyl cellulose i whakaritea e te chloroethanol me te waikawa monochloroacetic. Ko nga hua i whakaatu ko te tauhohenga etherification o te cellulose i mahia ma te whakakorikori reactor i raro i te ahua o te whakaoho kaha. He pai te tauhohenga etherification o te Cellulose, he pai ake i te tikanga pokepoke i roto i te whakapai ake i te pai o te etherification me te whakarei ake i te tuku marama o te hua i roto i te wairewa wai.) Na reira, ko te whakapai ake i te kaha whakakorikori o te tukanga tauhohenga he huarahi pai ake ki te whakawhanake i te whakakapi i te whakakotahitanga cellulose homogeneous. hua.

kupu matua:tauhohenga etherification; Cellulose;Hydroxyethyl cellulose; Carboxymethyl cellulose

 

I roto i te whakawhanaketanga o nga hua miro cellulose ether parakore, ka whakamahia te tikanga whakarewa ka whakamahia te miihini miihini hei taputapu urupare. Heoi ano, ko te miro cellulose te nuinga o nga rohe karaihe kei reira te whakatakotoranga o nga ngota ngota i te pai me te tata. I te wa e whakamahia ana te miihini pokepoke hei taputapu tauhohenga, he puhoi te ringa o te miihini pokepoke i te wa o te tauhohenga, a he nui te aukati o te kaihoko etherifying ki te uru ki nga paparanga rereke o te cellulose, he puhoi te tere, na te roa o te tauhohenga, he nui te waahanga o te taha. nga tauhohenga me te tohatoha koretake o nga roopu whakakapi ki nga mekameka ngota ngota cellulose.

I te nuinga o te wa ko te tauhohenga etherification o te cellulose he tauhohenga rereke o waho me roto. Mena karekau he mahi hihiri o waho, he uaua ki te uru atu ki te rohe whakatioatanga o te cellulose. Na roto i te pretreatment o te miro para parakore (pērā i te whakamahi tikanga tinana ki te whakanui ake i te mata o te miro parakore), i te wa ano ki te whakakorikori reactor mo taputapu tauhohenga, te whakamahi i tere whakaoho etherification tauhohenga, i runga i te whakaaro, ka taea e te cellulose kaha te pupuhi, te pupuhi. o te waahi amorphous cellulose me te waahi whakatioatanga ka rite tonu, ka pai ake te mahi tauhohenga. Ko te tohatoha rite o te cellulose ether substituents i roto i te pūnaha tauhohenga etherification heterogeneous ka taea te whakatutuki ma te whakanui ake i te mana whakaoho o waho. Na ka waiho hei huarahi whanaketanga a meake nei o to tatou whenua ki te whakawhanake i nga hua whakateera cellulose o te kounga teitei me te hohenga tauhohenga momo whakaoho hei taputapu tauhohenga.

 

1. Wāhanga whakamātautau

1.1 Miro parani te miro cellulose raw rauemi hei whakamatautau

E ai ki nga taputapu tauhohenga rereke e whakamahia ana i roto i te whakamatautau, he rereke nga tikanga o mua i te rongoa o te miro cellulose. Ina whakamahia te pokepoke hei taputapu urupare, he rereke ano nga tikanga o mua. I te wa e whakamahia ana te pokepoke hei taputapu tauhohenga, ko te 43.9% te tioata o te miro miro kua oti te whakamahi, ko te roa toharite o te miro miro he 15 ~ 20mm. Ko te tioata o te miro miro cellulose he 32.3% me te roa toharite o te miro miro cellulose he iti iho i te 1mm ina whakamahia te reactor hei taputapu tauhohenga.

1.2 Te whakawhanaketanga o te carboxymethyl cellulose me te hydroxyethyl cellulose

Ko te whakarite o te carboxymethyl cellulose me te hydroxyethyl cellulose ka taea te whakahaere ma te whakamahi i te 2L kneader hei taputapu tauhohenga (ko te tere toharite i te wa o te tauhohenga ko te 50r/min) me te 2L te reactor whakaoho hei taputapu tauhohenga (ko te tere toharite i te wa o te tauhohenga he 500r/min).

I te wa o te tauhohenga, ka ahu mai nga rauemi mata katoa mai i te tauhohenga ine nui. Ko te hua ka puta mai i te tauhohenga ka horoia ki te w=95% ewaro, ka whakamaroke ma te korehau mo te 24h i raro i te pehanga kino o 60 ℃ me te 0.005mpa. Ko te makuku o te tauira i whiwhi ko w=2.7%±0.3%, ka horoia te tauira hua mo te tātari tae noa ki te ihirangi pungarehu w <0.2%.

Ko nga takahanga o te miihini pokepoke hei taputapu urupare e whai ake nei:

Tauhohenga whakaeero → te horoinga hua → whakamaroke → te whakamaroke kuoro → ka mahia te takai ki roto i te pokepoke.

Ko nga takahanga o te whakakorikori reactor hei taputapu tauhohenga e whai ake nei:

Te tauhohenga whakaeero → te horoinga hua → te whakamaroke me te whakakoi → ka mahia te kapi i roto i te reactor whakaohooho.

Ka taea te kite ka whakamahia te miihini hei taputapu tauhohenga mo te whakarite i nga ahuatanga o te iti o te tauhohenga o te tauhohenga, te whakamaroke me te hurihanga o te granulation i te taahiraa, a ka tino heke te kounga o te hua i roto i te mahi huri.

Ko nga ahuatanga o te tukanga whakarite me te reactor whakaoho hei taputapu tauhohenga ko enei e whai ake nei: te pai o te tauhohenga teitei, kaore te whakamaaramatanga o te hua e tango i te tikanga o te whakamaroke me te huri huri, ka mahia te whakamaroke me te whakamaroke i te wa ano me te nga hua kaore i whakamarokehia i muri i te horoinga, ka noho tonu te kounga o te hua i roto i te whakamaroke me te whakamaroke.

1.3 Te wetewete o te hihihihiri X

I mahia e te Rigaku D/max-3A X-ray diffraction tātaritanga, graphite monochromator, Θ Koki ko 8°~30°, CuKα hihi, pehanga ngongo me te rere ngongo he 30kV me te 30mA.

1.4 Te tātari tūāwhiorangi pōkākā

Spectrum-2000PE FTIR tūāwhiorangi pōkākā i whakamahia mō te tātari tūāwhiorangi pōkākā. He 0.0020g te taumaha o nga tauira katoa mo te tātari hihinga infrared. I konatunatuahia enei tauira ki te 0.1600g KBr, ka pehia (he <0.8mm te matotoru) ka tātarihia.

1.5 Te kitenga tuku

I kitea te whakawhiti e te 721 spectrophotometer. Ko te otinga CMC w=w1% i kuhua ki roto i te rihi tae 1cm i te 590nm roangaru.

1.6 Tohu o te rapunga whakakapinga

Ko te tohu whakakapi HEC o te hydroxyethyl cellulose i inehia e te tikanga tātari matū paerewa. Ko te kaupapa ko te HEC ka taea te whakakorehia e te HI hydroiodate i te 123 ℃, me te tohu o te whakakapinga o te HEC ka taea te mohio ma te ine i nga matū pirau ethylene me te ethylene iodide i hangaia. Ko te tohu o te whakakapi o te hydroxymethyl cellulose ka taea hoki te whakamatautau ma nga tikanga tātari matū paerewa.

 

2. Nga hua me te matapaki

E rua nga momo hohenga tauhohenga e whakamahia ana i konei: ko tetahi he miihini miihini hei taputapu tauhohenga, ko tetahi ko te whakakorikori momo hohenga hohenga hei taputapu tauhohenga, i roto i te punaha tauhohe rerekee, te ahua kawakore me te punaha whakarewa wai waipiro, ka akohia te tauhohenga etherification o te miro cellulose parakore. I roto i a raatau, ko nga ahuatanga hangarau o te miihini miihini hei taputapu tauhohenga ko: I roto i te tauhohenga, he puhoi te tere o te ringaringa o te ringaringa, he roa te wa tauhohenga, he nui te waahanga o nga tauhohenga taha, he iti te tere o te whakamahi o te kaihoko etherifying, me te Ko te riterite o te whakakapi i te tohatoha roopu i roto i te tauhohenga etherizing he kino. Ka taea anake te mahi rangahau ki nga tikanga tauhohenga whaiti. I tua atu, ko te whakatikatika me te mana whakahaere o nga tikanga tauhohenga matua (pēnei i te ōwehenga pati, te kukū alkali, te tere o te ringa o te pokepoke i te miihini) he tino rawakore. He uaua ki te whakatutuki i te riterite tata o te tauhohenga etherification me te ako i te whakawhitinga papatipu me te urunga o te tukanga tauhohenga etherification i roto i te hohonu. Ko nga ahuatanga o te tukanga o te whakakorikori reactor hei taputapu tauhohenga ko: tere whakaohooho tere i roto i te tauhohenga, tere tere tauhohenga, tere whakamahi tiketike o te kaihoko whakaetere, tohatoha rite o nga whakakapi whakaetere, te whakarite me te whakahaere tikanga tauhohenga matua.

Ko te Carboxymethyl cellulose CMC i whakaritea e nga taputapu tauhohenga pokepoke me te whakakorikori i nga taputapu tauhohenga reactor. I te wa i whakamahia ai te pokepoke hei taputapu tauhohenga, he iti te kaha o te whakaoho me te tere hurihanga toharite ko 50r / min. I te wa i whakamahia ai te reactor whakaoho hei taputapu tauhohenga, he nui te kaha o te whakaoho me te tere hurihanga toharite ko 500r / min. I te 1:5:1 te ōwehenga molar o te waikawa monochloroacetic ki te cellulose monosaccharide, he 1.5h te wa tauhohenga i te 68 ℃. Ko te whakawhiti marama o te CMC i whiwhihia e te miihini pokepoke ko te 98.02% me te pai o te etherification he 72% na te pai o te uruhanga o CM i roto i te waikawa chloroacetic etherifying agent. I te wa i whakamahia ai te reactor whakakorikori hei taputapu tauhohenga, he pai ake te uruhanga o te kaihoko etherifying, ko te whakawhitinga o te CMC ko 99.56%, a ko te kaha o te tauhohenga etherizing kua piki ake ki te 81%.

I whakaritea te Hydroxyethyl cellulose HEC ki te pokepoke me te whakakorikori reactor hei taputapu tauhohenga. I te wa i whakamahia te pokepoke hei taputapu tauhohenga, he 47% te pai o te tauhohenga o te kaihoko whakaetere me te ngoikore o te wairewa i te wa he ngoikore te uruhanga o te kaihoko whakaetere waipiro chloroethyl me te tauwehenga molar o te chloroethanol ki te cellulose monosaccharide he 3:1 i te 60 ℃ mo te 4h. . Anake ina he 6:1 te ōwehenga molar o te chloroethanol ki te cellulose monosaccharides, ka taea te hanga i nga hua me te wairewa pai. I te wa i whakamahia ai te reactor whakakorikori hei taputapu tauhohenga, ka pai ake te uruhanga o te kaihoko waipiro chloroethyl etherification i te 68 ℃ mo te 4h. I te 3:1 te ōwehenga molar o te chloroethanol ki te cellulose monosaccharide, he pai ake te wairewa o te HEC, a, ka piki ake te pai o te tauhohenga etherification ki te 66%.

Ko te pai o te tauhohenga me te tere o te hohenga o te waikawa chloroacetic kaihoko etherizing he nui ake i tera o te chloroethanol, a ko te reactor whakakorikori hei taputapu tauhohe etherizing he tino painga ki runga i te kneader, e tino pai ake ai te pai o te tauhohenga whakaetere. Ko te whakawhitinga teitei o te CMC e tohu ana ko te reactor whakaoho hei taputapu tauhohe etherizing ka taea te whakapai ake i te riterite o te tauhohenga etherizing. Na te mea ko te mekameka cellulose e toru nga roopu hydroxyl i runga i ia mowhiti roopu-kuhukohu, a, i roto i te ahua tino tetere, te memeha noa ranei, ka taea te uru atu ki nga takirua cellulose hydroxyl o nga ngota ngota kaihoko whakaetere. Ko te tauhohenga etherification o te cellulose ko te tikanga he tauhohenga rereke mai i waho ki roto, ina koa i roto i te rohe tioata o te cellulose. I te wa e mau tonu ana te hanganga karaihe o te cellulose me te kore e pa ki te kaha o waho, he uaua ki te whakauru atu ki te hanganga tioata, ka pa te rite o te tauhohenga rereke. Na reira, ma te rongoa i mua i te miro para (penei i te whakanui ake i te mata motuhake o te miro para parakore), ka taea te whakapai ake te tauhohenga o te miro parakore. I roto i te nui o te pati pati (ethanol / cellulose or isopropyl alcohol / cellulose me te tere tere o te whakaohooho, i runga i te whakaaro, ka whakaitihia te raupapa o te rohe o te cellulose crystallization, i tenei wa ka kaha te pupuhi o te cellulose, na te mea ka pupuhi te pupuhi. o te amorphous and crystalline cellulose zone tely to be consistent, Na, he rite te tauhohenga o te rohe amorphous me te rohe tioata.

Ma te tātari hihinga infrared me te wetewete o te hihi X-ray, ka tino marama ake te tukanga hohenga etherification o te cellulose ina whakamahia te reactor whakaoho hei taputapu tauhohenga etherification.

I konei, i tātarihia te tuāwhiorangi pōkākā me te tūāwhiorangi hōrapa X-ray. Ko te tauhohenga etherification o CMC me HEC i mahia i roto i te reactor whakakorikori i raro i nga tikanga tauhohenga i whakaahuatia i runga ake nei.

Ko te tātari hihinga infrared e whakaatu ana ka huri te tauhohenga etheration o CMC me HEC i nga wa katoa me te roanga o te wa tauhohenga, he rereke te tohu o te whakakapi.

Na roto i te tātaritanga o X-ray tauira pahekeheke, te crystallinity o CMC me HEC ahu ki te kore ki te toronga o te wa tauhohenga, tohu e kua fele te tukanga decrystallization i roto i te wāhanga alkaliization me te atamira whakawera i mua i te tauhohenga etherification o te miro para . No reira, ko te tauhohenga o te carboxymethyl me te hydroxyethyl etherification o te miro parakore kua kore e aukatihia e te tioata o te miro parakore. E pa ana ki te uruhanga o te kaihoko etherifying. Ka taea te whakaatu ko te tauhohenga etherification o CMC me HEC e mahia ana me te reactor whakaoho hei taputapu tauhohenga. I raro i te tere tere o te whakaoho, he painga ki te tukanga whakahekenga o te miro parakore i roto i te waahanga whakamahana me te waahi whakamahana i mua i te tauhohenga etherification, me te awhina i te kaihoko etherification ki te uru ki roto i te cellulose, kia pai ake ai te pai o te tauhohenga etherification me te whakakotahitanga whakakapi. .

Hei mutunga, ka whakanuia e tenei rangahau te awe o te mana whakakorikori me etahi atu mea i runga i te pai o te tauhohenga i te wa o te mahi tauhohenga. Na reira, ko te tono o tenei rangahau e pa ana ki nga take e whai ake nei: I roto i te punaha tauhohenga heterogeneous etheration, ko te whakamahi i te tauwehenga pati nui me te kaha whakaohooho teitei, me etahi atu, ko nga tikanga taketake mo te whakarite i te etera cellulose riterite me te roopu whakakapi. tohatoha; I roto i tetahi punaha tauhohenga rerekee rerekee, ka taea te whakarite i te reactor whakakorikori hei taputapu tauhohenga, e whakaatu ana ko te wairewa cellulose ether he nui te whakawhiti, he mea nui ki te whakawhānui ake i nga taonga. me nga mahi o te cellulose ether. Ka whakamahia te miihini pokepoke hei taputapu tauhohenga ki te ako i te tauhohenga etherification o te miro parakore. Na te iti o te whakakorikori, kaore i te pai mo te kuhu o te kaihoko whakaeera, a he ngoikoretanga penei i te nui o nga tauhohenga taha me te ngoikore o te tohatoha o nga kaiwhakakapi etherification.


Te wa tuku: Hanuere-23-2023
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