Ukuguqulwa kwe-cellulose etherification

01. Ukwethulwa kwe-cellulose

I-Cellulose iyi-macromolecular polysaccharide eyakhiwe nge-glucose. Ayincibiliki emanzini nasezincibilikisini ezivamile. Iyingxenye eyinhloko yodonga lwamaseli ezitshalo, futhi iyi-polysaccharide esatshalaliswa kakhulu futhi eningi kakhulu ngokwemvelo.

I-Cellulose iyinsiza evuselelekayo eningi kakhulu emhlabeni, futhi iyi-polymer yemvelo enqwabelene kakhulu. Inezinzuzo zokuvuselelwa, ukubola ngokuphelele, kanye nokuhambisana okuhle kwe-biocompatibility.

02. Izizathu zokushintsha i-cellulose

Ama-cellulose macromolecules aqukethe inani elikhulu lamaqembu -OH. Ngenxa yomphumela wamabhondi e-hydrogen, amandla phakathi kwama-macromolecules makhulu uma kuqhathaniswa, okuzoholela ekuncibilikeni okukhulu kwe-enthalpy △H; ngakolunye uhlangothi, kukhona izindandatho kuma-cellulose macromolecules. Njengesakhiwo, ukuqina kweketango lamangqamuzana kukhulu, okuzoholela ekushintsheni okuncane kokuncibilika kwe-entropy ΔS. Lezi zizathu ezimbili zenza izinga lokushisa le-cellulose elincibilikisiwe (= △H / △S ) libe phezulu, futhi izinga lokushisa lokubola le-cellulose libe liphansi kakhulu. Ngakho-ke, lapho i-cellulose ishisa ukushisa okuthile, izintambo zizovela Isenzakalo sokuthi i-cellulose iye yachithwa ngaphambi kokuba iqale ukuncibilika, ngakho-ke, ukucutshungulwa kwezinto ze-cellulose akukwazi ukwamukela indlela yokuqala yokuncibilika bese ibumba.

03. Ukubaluleka kokuguqulwa kwe-cellulose

Ngokuwohloka kancane kancane kwemithombo yezinto ezimbiwa phansi kanye nezinkinga ezikhulayo zemvelo ezibangelwa udoti wezindwangu ze-fiber fiber, ukuthuthukiswa kanye nokusetshenziswa kwezinto zomcu wemvelo ovuselelekayo sekungenye yezindawo ezishisayo abantu abazinaka. I-Cellulose iwumthombo wemvelo ovuselelekayo omningi kakhulu emvelweni. Inezici ezinhle kakhulu ezifana ne-hygroscopicity enhle, i-antistatic, ukungena komoya okuqinile, ukudaya okuhle, ukugqoka okunethezekile, ukucutshungulwa kwezindwangu okulula, kanye nokubola kwe-biodegradability. Inezici ezingenakuqhathaniswa nemicu yamakhemikhali. .

Ama-molecule e-cellulose aqukethe inani elikhulu lamaqembu e-hydroxyl, okulula ukwenza i-intramolecular and intermolecular hydrogen bond, futhi abola emazingeni okushisa aphezulu ngaphandle kokuncibilika. Kodwa-ke, i-cellulose inokuphinda isebenze kahle, futhi ibhondi yayo ye-hydrogen ingacekelwa phansi ukuguqulwa kwamakhemikhali noma ukusabela kokuxhunyelelwa, okunganciphisa ngempumelelo indawo yokuncibilika. Njengemikhiqizo ehlukahlukene yezimboni, isetshenziswa kakhulu ezindwangu, ukuhlukaniswa kwe-membrane, amapulasitiki, ugwayi kanye nezingubo.

04. Ukuguqulwa kwe-cellulose etherification

I-Cellulose ether iwuhlobo lokuphuma kokuphuma ku-cellulose okutholwe ngokuguqulwa kwe-etherification ye-cellulose. Isetshenziswa kabanzi ngenxa yokuqina kwayo okuhle kakhulu, i-emulsification, ukumiswa, ukwakheka kwefilimu, i-colloid evikelayo, ukugcinwa komswakama, kanye nezakhiwo zokunamathela. Isetshenziselwa ukudla, imithi, ukwenza amaphepha, upende, izinto zokwakha, njll.

I-Etherification ye-cellulose uchungechunge lokuphuma kokunye okukhiqizwa ukusabela kwamaqembu e-hydroxyl ochungechungeni lwamangqamuzana e-cellulose nama-alkylating agents ngaphansi kwezimo ze-alkali. Ukusetshenziswa kwamaqembu e-hydroxyl kunciphisa inani lamabhondi e-hydrogen e-intermolecular ukunciphisa amandla e-intermolecular, ngaleyo ndlela Kuthuthukiswe ukuzinza okushisayo kwe-cellulose, kuthuthukise ukusebenza kokucubungula kwezinto, futhi ngesikhathi esifanayo kunciphise indawo yokuncibilika kwe-cellulose.

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

Besebenzisa ukotini ocwengekile njengezinto eziyisisekelo zokusetshenziswa, abacwaningi basebenzisa inqubo ye-etherification yesinyathelo esisodwa ukuze balungiselele i-ether eyinkimbinkimbi ye-carboxymethyl hydroxypropyl cellulose ene-reactivity efanayo, i-viscosity ephezulu, ukumelana ne-asidi enhle kanye nokumelana nosawoti ngokusebenzisa ukusabela kwe-alkalization kanye ne-etherification. Isebenzisa inqubo ye-etherification enesinyathelo esisodwa, i-carboxymethyl hydroxypropyl cellulose inokumelana nosawoti okuhle, ukumelana ne-asidi kanye nokuncibilika. Ngokushintsha amanani ahlobene e-propylene oxide ne-chloroacetic acid, imikhiqizo enokuqukethwe okuhlukile kwe-carboxymethyl kanye ne-hydroxypropyl ingalungiswa. Imiphumela yokuhlolwa ibonisa ukuthi i-carboxymethyl hydroxypropyl cellulose ekhiqizwa indlela yesinyathelo esisodwa inomjikelezo omfushane wokukhiqiza, ukusetshenziswa kwe-solvent ephansi, futhi umkhiqizo unokumelana okuhle kakhulu nosawoti we-monovalent kanye ne-divalent kanye nokuphikiswa okuhle kwe-asidi.

05. Ithemba lokuguqulwa kwe-cellulose etherification

I-Cellulose iyinto ebalulekile yamakhemikhali namakhemikhali eluhlaza ecebile ngezinsiza, eluhlaza futhi ehambisana nemvelo, futhi evuselelekayo. Okuphuma kokunye kokuguqulwa kwe-cellulose etherification kusebenza kahle kakhulu, ukusetshenziswa okubanzi nemiphumela emihle kakhulu yokusetshenziswa, futhi kuhlangabezana nezidingo zomnotho kazwelonke ngezinga elikhulu. Futhi izidingo zokuthuthukiswa komphakathi, ngenqubekelaphambili yezobuchwepheshe eqhubekayo kanye nokufezekiswa kokuhweba esikhathini esizayo, uma izinto zokwenziwa zokwenziwa nezindlela zokwenziwa zokuphuma kwe-cellulose zingathuthukiswa kakhulu, zizosetshenziswa ngokugcwele futhi zibone uhla olubanzi lwezinhlelo zokusebenza. . Inani