Yenziwa njani ihydroxyethyl cellulose?

I-Hydroxyethyl Cellulose (HEC) yipolymer eqhelekileyo e-soluble yamanzi esetyenziswa ngokubanzi kwiikhemikhali zemihla ngemihla, ukwakhiwa, iingubo, amayeza, ukutya kunye namanye amashishini. Yi-ether ye-cellulose engeyo-ionic eyenziwe ngokuguqula i-cellulose yendalo ngokwemichiza. Inkqubo yokwenziwa kwe-hydroxyethyl cellulose ibandakanya ukuphendulwa kweekhemikhali ezintsonkothileyo, kubandakanywa i-cellulose extraction, unyango lwe-alkalization, i-etherification reaction, njl. Oku kulandelayo kukwaziswa okucacileyo kwinkqubo yokuvelisa.

1. Ukukhethwa kwezinto eziluhlaza kunye nokukhutshwa kwe-cellulose
Isiseko semathiriyeli ekrwada ye-hydroxyethyl cellulose yiselulosi yendalo, ephuma ikakhulu kumaplanga, umqhaphu okanye ezinye iintsinga zezityalo. Umxholo we-cellulose kwiindonga zeeseli zezityalo ziphezulu, kwaye i-cellulose ecocekileyo inokukhutshwa kwezi zinto zendalo ngeendlela zoomatshini okanye zeekhemikhali. Inkqubo yokukhutshwa ibandakanya ukutyumza, ukususwa kwezinto ezingcolileyo (ezifana ne-lignin, i-hemicellulose), i-bleaching kunye namanye amanyathelo.

I-cellulose extraction: Iselulosi yendalo idla ngokuphathwa ngoomatshini okanye ngokwekhemikhali ukuze kususwe izinto ezingezizo i-cellulose ukufumana i-high-purity cellulose. Ifayibha yomqhaphu, i-pulp yeplanga, njl. Ngethuba lenkqubo yokonyango, i-alkali (efana ne-sodium hydroxide) isetyenziselwa ukunyibilikisa i-non-cellulose components, kwaye intsalela ininzi i-cellulose.
2. Unyango lwe-alkalization
I-cellulose ecocekileyo kufuneka iqale i-alkaliized. Eli nyathelo lelokwenza amaqela e-hydroxyl kwitsheyina le-cellulose yemolekyuli asebenze ngakumbi ukuze abe nokusabela ngokulula ngakumbi nge-ejenti e-etherifying. Amanyathelo aphambili onyango lwe-alkalization ngala alandelayo:

Ukusabela kwe-cellulose nge-alkali: i-cellulose ixutywe ne-alkali eyomeleleyo (ngokuqhelekileyo i-sodium hydroxide) ukuvelisa i-alkali cellulose (i-Alkali Cellulose). Le nkqubo idla ngokuqhutyelwa kwindawo enamanzi. I-alkali cellulose yimveliso yokusabela ye-cellulose kunye ne-sodium hydroxide. Le nto inesakhiwo esikhululekileyo kunye ne-reactivity ephezulu, ekhuthaza ukusabela kwe-etherification elandelayo.
Inkqubo ye-alkalization yenzeka ikakhulu kubushushu obufanelekileyo kunye nokufuma, ngokuqhelekileyo kuluhlu lwe-20℃~30℃ iiyure ezininzi ukuqinisekisa ukuba amaqela e-hydroxyl kwiimolekyuli ze-cellulose ayasebenza ngokupheleleyo.

3. Ukusabela kwe-Etherification
I-Etherification linyathelo eliphambili kwimveliso ye-hydroxyethyl cellulose. I-Hydroxyethyl cellulose iveliswa ngokusabela i-alkali cellulose kunye ne-ethylene oxide ukwazisa amaqela e-hydroxyethyl. Amanyathelo athile ngala alandelayo:

Ukusabela nge-ethylene oxide: I-alkali cellulose iphendula ngomlinganiselo othile we-ethylene oxide phantsi kweemeko ezithile zobushushu kunye noxinzelelo. Isakhiwo sendandatho kwi-ethylene oxide sivula ukwenza ibhondi ye-ether, isabela kunye namaqela e-hydroxyl kwii-molecule ze-cellulose, kwaye yazisa amaqela e-hydroxyethyl (-CH2CH2OH). Le nkqubo inokulungelelanisa iqondo le-etherification ngokulawula iimeko zokusabela (ezifana nobushushu, uxinzelelo, kunye nexesha).
Ukusabela ngokuqhelekileyo kuqhutyelwa kwindawo ye-alkaline ukuqinisekisa ukusebenza kakuhle kwe-etherification. Ubushushu bokusabela ngokuqhelekileyo yi-50 ℃ ~ 100 ℃, kwaye ixesha lokuphendula ziiyure ezininzi. Ngokulungelelanisa ubungakanani be-ethylene oxide, iqondo lokutshintshwa kwemveliso yokugqibela inokulawulwa, oko kukuthi, mangaphi amaqela e-hydroxyl kwii-molecule ze-cellulose athatyathwa ngamaqela e-hydroxyethyl.

4. Ukungathathi hlangothi kunye nokuhlamba
Emva kokuba i-etherification reaction igqityiwe, izinto ze-alkaline kwinkqubo yokusabela kufuneka zithintelwe. Ngokuqhelekileyo ukusetyenziswa kwe-neutralizers zizinto ezinobumuncu, ezifana ne-acetic acid okanye i-hydrochloric acid. Inkqubo ye-neutralization iya kunciphisa i-alkali engaphezulu kwi-salts, engayi kuchaphazela ukusebenza kwemveliso.

I-neutralization reaction: Thatha imveliso kwi-reactor kwaye wongeze isixa esifanelekileyo se-asidi yokungathathi hlangothi de ixabiso le-pH kwisixokelelwano lifikelele ekungathathi hlangothi. Le nkqubo ayisusi kuphela i-alkali eshiyekileyo, kodwa inciphisa impembelelo yokusabela ngeemveliso ekusebenzeni kwe-hydroxyethyl cellulose.

Ukuhlanjwa kunye nokuphelelwa ngamanzi emzimbeni: Imveliso engathathi hlangothi kufuneka ihlanjwe amaxesha amaninzi, ngokuqhelekileyo ngamanzi okanye i-ethanol kunye nezinye izinyibilikisi zokuhlamba ukungcola okushiyekileyo kunye neemveliso. Imveliso ehlanjiweyo ihlanjwe yi-centrifugation, i-filter pressing kunye nezinye iindlela zokunciphisa umxholo wokufuma.

5. Ukomisa kunye nokutyumza
Emva kokuhlamba kunye nokuphelelwa ngamanzi emzimbeni, i-cellulose ye-hydroxyethyl isenomlinganiselo othile wokufuma kwaye kufuneka yomiswe ngakumbi. Inkqubo yokumisa inokwenziwa ngokumisa komoya okanye i-vacuum drying ukuqinisekisa ukuba imveliso inozinzo oluhle ngexesha lokugcinwa kunye nokusetyenziswa.

Ukomisa: Yomisa imveliso kwiqondo lobushushu elithile (lidla ngokuba ngaphantsi kwe 60°C) ukususa ukufuma okushiyekileyo. Ukushisa kokumisa akufanele kube phezulu kakhulu, ngaphandle koko kunokubangela ukuthotywa kwemveliso kwaye kuchaphazele ukusebenza kwayo.

Ukutyumza kunye nokuhlolwa: Iselulosi eyomileyo ye-hydroxyethyl idla ngokubakho kwiibhloko okanye amagaqa, kwaye kufuneka icolwe ukufumana umgubo ocolekileyo. Imveliso etyumkileyo iphinda ihlolwe ukuze ifumane ukusabalalisa ubungakanani beengqungquthela ezihlangabezana neemfuno zokuqinisekisa ukunyibilika kwayo kunye nokusabalalisa kwizicelo eziphathekayo.

6. Uvavanyo kunye nokupakishwa kweemveliso zokugqibela
Emva kokuveliswa, i-hydroxyethyl cellulose kufuneka ivavanyelwe umgangatho wokuqinisekisa ukuba izikhombisi zokusebenza zihlangabezana neemfuno eziqhelekileyo. Izinto zovavanyo zihlala ziquka:

Umlinganiselo we-Viscosity: I-viscosity ye-hydroxyethyl cellulose emva kokuchithwa emanzini isibonakaliso esibalulekileyo somgangatho, esichaphazela ukusetyenziswa kwayo kwiingubo, ukwakhiwa, iikhemikhali zemihla ngemihla kunye nezinye iindawo.
Isiqulatho sokufuma: Vavanya isiqulatho sokufuma kwimveliso ukuqinisekisa ukuzinza kwayo ekugcinweni kwayo.
I-Degree of substitution (DS) kunye ne-molar substitution (MS): Qinisekisa iqondo lokutshintshwa kunye ne-molar substitution kwimveliso ngohlalutyo lweekhemikhali ukuqinisekisa umphumo we-etherification reaction.
Emva kokuphumelela uvavanyo, i-hydroxyethyl cellulose iya kupakishwa ibe ngumgubo okanye imveliso yegranular, ihlala kwiingxowa zeplastiki ezinobungqina bokufuma okanye iingxowa zephepha ukuyikhusela ekubeni ifume okanye ingcoliseke.

Inkqubo yokwenziwa kwe-hydroxyethyl cellulose ikakhulu ibandakanya amanyathelo e-cellulose extraction, unyango lwe-alkalization, i-etherification reaction, i-neutralization kunye nokuhlamba, ukumisa kunye nokutyumza. Yonke le nkqubo ixhomekeke kwi-alkalization kunye ne-etherification kwi-chemical reaction, kwaye i-cellulose inikwa ukunyibilika kwamanzi okulungileyo kunye neempawu ezikhulayo ngokuzisa amaqela e-hydroxyethyl. I-cellulose ye-Hydroxyethyl isetyenziswa ngokubanzi kumashishini amaninzi, njenge-thickener yokwambathisa, i-arhente yokugcina amanzi kwizinto zokwakha, ukuzinzisa kwiimveliso zemichiza yemihla ngemihla, njl njl. yemveliso.