Yenziwa kanjani i-hydroxyethyl cellulose?

I-Hydroxyethyl Cellulose (HEC) iyi-polymer evamile encibilika emanzini esetshenziswa kabanzi kumakhemikhali ansuku zonke, ukwakhiwa, okokugqoka, imithi, ukudla nezinye izimboni. I-ether engeyona i-ionic cellulose eyenziwe ngokushintsha amakhemikhali i-cellulose yemvelo. Inqubo yokukhiqiza i-hydroxyethyl cellulose ihlanganisa ukusabela kwamakhemikhali okuyinkimbinkimbi, okuhlanganisa ukukhishwa kwe-cellulose, ukwelashwa kwe-alkalization, ukusabela kwe-etherification, njll. Okulandelayo isingeniso esinemininingwane yenqubo yokukhiqiza.

1. Ukukhethwa kwezinto zokusetshenziswa kanye nokukhishwa kwe-cellulose
Impahla eyisisekelo ye-hydroxyethyl cellulose i-cellulose yemvelo, ephuma ikakhulukazi okhunini, ukotini noma eminye imicu yezitshalo. Okuqukethwe kwe-cellulose ezindongeni zamaseli ezitshalo kuphezulu, futhi i-cellulose ehlanzekile ingakhishwa kulezi zinto zemvelo ngezindlela zemishini noma zamakhemikhali. Inqubo yokukhipha ihlanganisa ukuchotshozwa, ukususwa kokungcola (okufana ne-lignin, i-hemicellulose), i-bleaching nezinye izinyathelo.

Ukukhishwa kwe-cellulose: I-cellulose yemvelo ngokuvamile iphathwa ngomshini noma ngamakhemikhali ukuze kukhishwe izinto ezingezona i-cellulose ukuze kutholakale i-high-purity cellulose. Ifayibha kakotini, i-pulp yokhuni, njll. konke kungaba imithombo evamile yezinto ezingavuthiwe. Phakathi nenqubo yokwelapha, i-alkali (njenge-sodium hydroxide) isetshenziselwa ukusiza ukuncibilikisa izingxenye ezingezona i-cellulose, futhi okusele ikakhulukazi i-cellulose.
2. Ukwelashwa kwe-alkalization
I-cellulose ehlanzekile kufanele iqale i-alkali. Lesi sinyathelo esokwenza amaqembu e-hydroxyl kuchungechunge lwengqamuzana ye-cellulose asebenze kakhulu ukuze akwazi ukusabela kalula nge-ejenti efaka i-etherifying. Izinyathelo eziyinhloko zokwelashwa kwe-alkalization zimi kanje:

Ukusabela kwe-cellulose ne-alkali: i-cellulose ixutshwe ne-alkali eqinile (imvamisa i-sodium hydroxide) ukukhiqiza i-alkali cellulose (i-Alkali Cellulose). Le nqubo ngokuvamile yenziwa endaweni enamanzi. I-alkali cellulose ingumkhiqizo wokusabela we-cellulose ne-sodium hydroxide. Le nto inesakhiwo esixegayo kanye nokusebenza kabusha okuphezulu, okuhambisana nokusabela kwe-etherification okulandelayo.
Inqubo ye-alkalization yenzeka ikakhulukazi ezingeni lokushisa elifanele kanye nomswakama, ngokuvamile ebangeni lika-20℃~30℃ amahora ambalwa ukuze kuqinisekiswe ukuthi amaqembu e-hydroxyl kuma-molecule e-cellulose enziwa asebenze ngokugcwele.

3. Ukusabela kwe-Etherification
I-Etherification iyisinyathelo esibalulekile ekukhiqizeni i-hydroxyethyl cellulose. I-Hydroxyethyl cellulose ikhiqizwa ngokusabela i-alkali cellulose ne-ethylene oxide ukwethula amaqembu e-hydroxyethyl. Izinyathelo eziqondile zimi kanje:

Ukusabela nge-ethylene oxide: I-alkali cellulose isabela ngenani elithile le-ethylene oxide ngaphansi kwezimo ezithile zokushisa nezingcindezi. Isakhiwo sendandatho ku-ethylene oxide sivuleka ukuze sakhe ibhondi ye-ether, isabelana namaqembu e-hydroxyl kuma-molecule e-cellulose, futhi yethula amaqembu e-hydroxyethyl (–CH2CH2OH). Le nqubo ingalungisa izinga le-etherification ngokulawula izimo zokusabela (ezifana nezinga lokushisa, ingcindezi, nesikhathi).
Ukusabela ngokuvamile kwenziwa endaweni ene-alkali ukuze kuqinisekiswe ukusebenza kahle kwe-etherification. Izinga lokushisa lokusabela ngokuvamile lingu-50℃~100℃, futhi isikhathi sokusabela singamahora ambalwa. Ngokulungisa inani le-ethylene oxide, izinga lokushintshwa komkhiqizo wokugcina lingalawulwa, okungukuthi, mangaki amaqembu e-hydroxyl kuma-molecule e-cellulose athathelwa indawo ngamaqembu e-hydroxyethyl.

4. Ukungathathi hlangothi nokugeza
Ngemva kokuqedwa kokusabela kwe-etherification, izinto ezine-alkali ohlelweni lokusabela zidinga ukuncishiswa. Ama-neutralizer asetshenziswa kakhulu yizinto ezine-acidic, njenge-acetic acid noma i-hydrochloric acid. Inqubo yokwenza i-neutralization izonciphisa i-alkali eyeqile ibe usawoti, okungeke kuphazamise ukusebenza komkhiqizo.

Ukusabela kokungathathi hlangothi: Khipha umkhiqizo ku-reactor bese wengeza inani elifanele le-asidi ukuze lincishiswe kuze kube yilapho inani le-pH kusistimu lifinyelela kokumaphakathi. Le nqubo ayisusi kuphela i-alkali esele, kodwa futhi yehlisa umthelela wokusabela ngemikhiqizo ekusebenzeni kwe-hydroxyethyl cellulose.

Ukuwashwa kanye nokuphelelwa amandla kwamanzi: Umkhiqizo ongashintshiwe udinga ukugezwa izikhathi ezimbalwa, ngokuvamile ngamanzi noma i-ethanol nezinye izincibilikisi ukuze kugezwe ukungcola okusele kanye nemikhiqizo engase ivele. Umkhiqizo ogeziwe uphelelwa amanzi ngenxa ye-centrifugation, ukucindezela isihlungi nezinye izindlela zokunciphisa umswakama.

5. Ukomisa nokuchoboza
Ngemuva kokugeza nokuphelelwa amanzi emzimbeni, i-hydroxyethyl cellulose isaqukethe inani elithile lomswakama futhi idinga ukuphinda yomiswe. Inqubo yokomisa ingenziwa ngokumiswa komoya noma ukomisa nge-vacuum ukuze kuqinisekiswe ukuthi umkhiqizo unokusimama okuhle ngesikhathi sokugcinwa nokusetshenziswa.

Ukomisa: Yomisa umkhiqizo ezingeni lokushisa elithile (imvamisa libe ngaphansi kuka-60°C) ukuze ususe umswakama osele. Izinga lokushisa lokumisa akufanele libe phezulu kakhulu, ngaphandle kwalokho lingabangela ukuwohloka komkhiqizo futhi kuthinte ukusebenza kwawo.

Ukuchotshozwa nokuhlolwa: I-hydroxyethyl cellulose eyomisiwe ngokuvamile iba khona emabhuloki noma izigaxa, futhi kufanele ichotshozwe ukuze kutholakale impushana ecolekile. Umkhiqizo ochotshoziwe futhi udinga ukubhekwa ukuze uthole ukusabalalisa usayizi wezinhlayiyana ezihlangabezana nezidingo zokuqinisekisa ukuncibilika nokuhlakazeka kwawo ekusebenzeni okungokoqobo.

6. Ukuhlolwa nokupakishwa kwemikhiqizo yokugcina
Ngemuva kokukhiqiza, i-hydroxyethyl cellulose idinga ukuhlolwa ikhwalithi ukuze kuqinisekiswe ukuthi izinkomba zokusebenza kwayo zihlangabezana nezidingo ezijwayelekile. Izinto zokuhlola ngokuvamile zihlanganisa:

Ukulinganisa kwe-viscosity: I-viscosity ye-hydroxyethyl cellulose ngemva kokuqedwa emanzini iyinkomba yekhwalithi ebalulekile, ethinta ukusetshenziswa kwayo ekugqokeni, ekwakhiweni, kumakhemikhali nsuku zonke nakwezinye izinkambu.
Okuqukethwe umswakama: Hlola okuqukethwe komswakamo womkhiqizo ukuze uqinisekise ukuzinza kwawo.
I-Degree of substitution (DS) kanye ne-molar substitution (MS): Thola izinga lokushintshwa kanye nokushintshwa kwe-molar emkhiqizweni ngokuhlaziywa kwamakhemikhali ukuze uqinisekise umthelela wokusabela kwe-etherification.
Ngemuva kokuphumelela ukuhlolwa, i-hydroxyethyl cellulose izopakishwa ibe yimpushana noma imikhiqizo eyimbudumbudu, imvamisa ezikhwameni zepulasitiki ezivikela umswakama noma ezikhwameni zephepha ukuze inqande ukuthi ingabi manzi noma ingcoliswe.

Inqubo yokukhiqiza i-hydroxyethyl cellulose ikakhulukazi ihlanganisa izinyathelo zokukhishwa kwe-cellulose, ukwelashwa kwe-alkalization, ukusabela kwe-etherification, ukungathathi hlangothi nokuwashwa, ukomiswa nokuchotshozwa. Yonke le nqubo incike ekuhlanganiseni kwe-alkalization kanye ne-etherification ekuphenduleni kwamakhemikhali, futhi i-cellulose inikezwa ukuncibilika okuhle kwamanzi kanye nezakhiwo zokujiya ngokwethula amaqembu e-hydroxyethyl. I-Hydroxyethyl cellulose isetshenziswa kabanzi ezimbonini eziningi, njenge-thickener yokumboza, i-ejenti egcina amanzi yezinto zokwakha, i-stabilizer emikhiqizweni yamakhemikhali yansuku zonke, njll. Isixhumanisi ngasinye senqubo yokukhiqiza sidinga ukulawulwa ngokuqinile ukuze kuqinisekiswe izinga eliphezulu nokusebenza okuzinzile. yomkhiqizo.