Ukuguqulwa kwe-cellulose etherification

01. Ukwethulwa kwe-cellulose

I-Cellulose iyi-polysaccharide enkulu eyakhiwe yi-glucose. Ayincibiliki emanzini nasezithambisweni eziphilayo ezijwayelekile. Iyingxenye eyinhloko yodonga lwamaseli esitshalo, futhi futhi iyi-polysaccharide esakazeke kakhulu futhi eningi kakhulu ngokwemvelo.

I-cellulose iyisisetshenziswa esivuselelekayo esitholakala kakhulu emhlabeni, futhi iyi-polymer yemvelo enokuqongelela okukhulu kakhulu. Inezinzuzo zokuba ivuseleleke, ibole ngokuphelele, futhi ihambisana kahle nezinto eziphilayo.

02. Izizathu zokushintsha i-cellulose

Ama-macromolecule e-cellulose aqukethe inani elikhulu lamaqembu e--OH. Ngenxa yomphumela wezibopho ze-hydrogen, amandla phakathi kwama-macromolecule makhulu kakhulu, okuzoholela ku-enthalpy enkulu yokuncibilika △H; ngakolunye uhlangothi, kunezindandatho kuma-macromolecule e-cellulose. Njengesakhiwo, ukuqina kweketanga lama-molecule kukhulu, okuzoholela ekushintsheni okuncane kwe-entropy yokuncibilika ΔS. Lezi zizathu ezimbili zenza izinga lokushisa le-cellulose encibilikisiwe (= △H / △S ) lizophakama, futhi izinga lokushisa lokubola kwe-cellulose liphansi kakhulu. Ngakho-ke, lapho i-cellulose ishiswa ezingeni lokushisa elithile, kuzovela imicu. Isenzakalo sokuthi i-cellulose ibolile ngaphambi kokuba iqale ukuncibilika, ngakho-ke, ukucutshungulwa kwezinto ze-cellulose akukwazi ukusebenzisa indlela yokuncibilika kokuqala bese kuba ukubumba.

03. Ukubaluleka kokuguqulwa kwe-cellulose

Njengoba izinsizakusebenza zasendulo zincipha kancane kancane kanye nezinkinga ezinkulu zemvelo ezibangelwa yizindwangu zefayibha yamakhemikhali angcolile, ukuthuthukiswa nokusetshenziswa kwezinto zemvelo zefayibha evuselelekayo sekungenye yezindawo ezishisayo abantu abazinakayo. I-Cellulose iyinsiza yemvelo evuselelekayo etholakala kakhulu emvelweni. Inezakhiwo ezinhle kakhulu njenge-hygroscopicity enhle, i-antistatic, i-air permeability enamandla, i-dyeability enhle, ukugqokwa okukhululekile, ukucutshungulwa kwendwangu okulula, kanye nokubola kwayo. Inezici ezingenakuqhathaniswa nefayibha yamakhemikhali.

Ama-molecule e-cellulose aqukethe inani elikhulu lamaqembu e-hydroxyl, okulula ukwakha izibopho ze-hydrogen zangaphakathi kwama-molecule kanye naphakathi kwama-molecule, futhi aqhekeke emazingeni okushisa aphezulu ngaphandle kokuncibilika. Kodwa-ke, i-cellulose inokusabela okuhle, futhi isibopho sayo se-hydrogen singabhujiswa ngokuguqulwa kwamakhemikhali noma ukusabela kokuxhunyelelwa, okunganciphisa ngempumelelo iphuzu lokuncibilika. Njengemikhiqizo eyahlukahlukene yezimboni, isetshenziswa kabanzi ezindwangu, ekuhlukaniseni i-membrane, epulasitikini, kugwayi nasezimbozweni.

04. Ukuguqulwa kwe-cellulose etherification

I-Cellulose ether uhlobo lwe-cellulose derivative olutholakala ngokuguqulwa kwe-etherification ye-cellulose. Isetshenziswa kabanzi ngenxa yokuqina kwayo okuhle kakhulu, i-emulsification, i-suspension, ukwakheka kwefilimu, i-colloid evikelayo, ukugcinwa komswakama, kanye nezakhiwo zokunamathela. Isetshenziswa ekudleni, emithini, ekwenzeni amaphepha, ekupendeni, ezintweni zokwakha, njll.

Ukufakwa kwe-cellulose etherification kuwuchungechunge lwezinto ezikhiqizwa ukusabela kwamaqembu e-hydroxyl ku-cellulose molecular chain nama-alkylating agents ngaphansi kwezimo ze-alkaline. Ukusetshenziswa kwamaqembu e-hydroxyl kunciphisa inani lezibopho ze-hydrogen eziphakathi kwama-molecule ukuze kuncishiswe amandla aphakathi kwama-molecule, ngaleyo ndlela kuthuthukiswe ukuzinza kokushisa kwe-cellulose, kuthuthukiswe ukusebenza kokucubungula kwezinto, futhi ngesikhathi esifanayo kuncishiswe iphuzu lokuncibilika kwe-cellulose.

Izibonelo zemiphumela yokuguqulwa kwe-etherification kweminye imisebenzi ye-cellulose:

Besebenzisa ukotini ocoliwe njengezinto eziyisisekelo zokusetshenziswa, abacwaningi basebenzise inqubo ye-etherification yesinyathelo esisodwa ukulungiselela i-ether ye-carboxymethyl hydroxypropyl cellulose complex ene-reaction efanayo, i-viscosity ephezulu, ukumelana okuhle kwe-asidi kanye nokumelana nosawoti ngokusebenzisa i-alkalization kanye ne-etherification reactions. Besebenzisa inqubo ye-etherification yesinyathelo esisodwa, i-carboxymethyl hydroxypropyl cellulose ekhiqizwayo inokumelana okuhle nosawoti, ukumelana ne-asidi kanye nokuncibilika. Ngokushintsha inani elilinganiselwe le-propylene oxide kanye ne-chloroacetic acid, imikhiqizo enokuqukethwe okuhlukile kwe-carboxymethyl kanye ne-hydroxypropyl ingalungiswa. Imiphumela yokuhlolwa ikhombisa ukuthi i-carboxymethyl hydroxypropyl cellulose ekhiqizwa ngendlela yesinyathelo esisodwa inomjikelezo omfushane wokukhiqiza, ukusetshenziswa okuphansi kwe-solvent, futhi umkhiqizo unokumelana okuhle kakhulu nosawoti we-monovalent kanye ne-divalent kanye nokumelana okuhle kwe-asidi.

05. Ithemba lokuguqulwa kwe-cellulose etherification

I-Cellulose iyinto ebalulekile yokusetshenziswa kwamakhemikhali namakhemikhali ecebile ngezinsizakusebenza, eluhlaza futhi enobungani nemvelo, futhi evuselelekayo. Izakhi zokuguqulwa kwe-cellulose etherification zisebenza kahle kakhulu, ububanzi bokusetshenziswa kanye nemiphumela emihle yokusetshenziswa, futhi zihlangabezana nezidingo zomnotho wezwe ngezinga elikhulu. Futhi izidingo zentuthuko yezenhlalo, ngentuthuko yezobuchwepheshe eqhubekayo kanye nokufezwa kokuhweba esikhathini esizayo, uma izinto zokusetshenziswa zokwenziwa kanye nezindlela zokwenziwa zezakhi zokwenziwa ze-cellulose zingathuthukiswa kakhulu, zizosetshenziswa ngokugcwele futhi zifeze ububanzi bezicelo. Inani