Ukulungiswa kwe-hydroxyethyl cellulose

I-Hydroxyethyl cellulose (HEC) iyi-polymer engeyona i-ionic, encibilika emanzini etholakala ku-cellulose, i-polymer yemvelo etholakala ezindongeni zamaseli ezitshalo. Isetshenziswa kabanzi ezimbonini ezahlukahlukene, kufaka phakathi imithi, izimonyo, upende, kanye nezinamathiselo, ngenxa yezakhiwo zayo ezinhle kakhulu zokuqina, ukwakha ifilimu, kanye nezakhiwo ze-rheological. Ukulungiswa kwe-hydroxyethyl cellulose kuhilela ukwenziwa kwe-cellulose nge-ethylene oxide ngaphansi kwezimo ze-alkaline. Le nqubo ingahlukaniswa ngezinyathelo eziningana ezibalulekile: ukuhlanzwa kwe-cellulose, ukwenziwa kwe-alkalization, ukwenziwa kwe-etherification, ukwenziwa kwe-neutralization, ukugeza, nokomisa.

1. Ukuhlanzwa kwe-Cellulose
Isinyathelo sokuqala ekulungiseleleni i-hydroxyethyl cellulose ukuhlanzwa kwe-cellulose, evame ukutholakala ku-pulp yokhuni noma kuma-linter kakotini. I-cellulose eluhlaza iqukethe ukungcola okufana ne-lignin, i-hemicellulose, nezinye izinto ezikhiphayo okumele zisuswe ukuze kutholakale i-cellulose ehlanzekile kakhulu efanelekile ukuguqulwa kwamakhemikhali.

Izinyathelo ezihilelekile:

Ukucubungula Ngomshini: I-cellulose eluhlaza icutshungulwa ngomshini ukuze inciphise usayizi wayo futhi yandise indawo yayo engaphezulu, okwenza kube lula ukwelashwa ngamakhemikhali okulandelayo.
Ukwelashwa Kwamakhemikhali: I-cellulose iphathwa ngamakhemikhali anjenge-sodium hydroxide (NaOH) kanye ne-sodium sulfite (Na2SO3) ukuze kuqhekeke i-lignin ne-hemicellulose, kulandelwe ukugeza nokumhlopheza ukuze kususwe ukungcola okusele futhi kutholakale i-cellulose emhlophe, ene-fibrous.

2. Ukwenziwa kwe-Alkalization
I-cellulose ehlanziwe ibe isifakwa i-alkali ukuze isebenze ukuze i-etherification iphendule. Lokhu kuhilela ukwelapha i-cellulose ngesisombululo samanzi se-sodium hydroxide.

Ukusabela:
I-Cellulose+NaOH→I-Alkali cellulose

Inqubo:

I-cellulose ilenga emanzini, bese kufakwa isixazululo se-sodium hydroxide. Ukuhlushwa kwe-NaOH kuvame ukuba phakathi kuka-10-30%, futhi ukusabela kwenzeka emazingeni okushisa aphakathi kuka-20-40°C.
Ingxube iyavuselelwa ukuqinisekisa ukumuncwa okufanayo kwe-alkali, okuholela ekwakhekeni kwe-alkali cellulose. Lokhu okuphakathi kusabela kakhulu ku-ethylene oxide, okwenza kube lula inqubo ye-etherification.

3. Ukushintshashintsha kwe-Ether
Isinyathelo esibalulekile ekulungiseleleni i-hydroxyethyl cellulose ukwenziwa kwe-alkali cellulose etherification nge-ethylene oxide. Lokhu kusabela kwethula amaqembu e-hydroxyethyl (-CH2CH2OH) emgogodleni we-cellulose, okwenza incibilike emanzini.

Ukusabela:
I-alkali cellulose+i-ethylene oxide→i-Hydroxyethyl cellulose+i-NaOH

Inqubo:

I-ethylene oxide ifakwa ku-alkali cellulose, kungaba ngeqoqo noma inqubo eqhubekayo. Ukusabela kuvame ukwenziwa ku-autoclave noma ku-pressure reactor.
Izimo zokusabela, okuhlanganisa izinga lokushisa (50-100°C) kanye nokucindezela (1-5 atm), zilawulwa ngokucophelela ukuqinisekisa ukuthi amaqembu e-hydroxyethyl afakwa esikhundleni esifanele. Izinga lokufakwa esikhundleni (DS) kanye nokufakwa esikhundleni kwe-molar (MS) kuyimingcele ebalulekile ethonya izakhiwo zomkhiqizo wokugcina.

4. Ukungathathi hlangothi
Ngemva kokusabela kwe-etherification, ingxube iqukethe i-hydroxyethyl cellulose kanye ne-residual sodium hydroxide. Isinyathelo esilandelayo ukuncishiswa kwe-alkali, lapho i-alkali eningi incishiswa khona kusetshenziswa i-asidi, ngokuvamile i-acetic acid (CH3COOH) noma i-hydrochloric acid (HCl).

Impendulo:NaOH+HCl→NaCl+H2O

Inqubo:

I-asidi ifakwa kancane kancane engxubeni yokusabela ngaphansi kwezimo ezilawulwayo ukuze kugwenywe ukushisa ngokweqile futhi kuvinjelwe ukuwohloka kwe-hydroxyethyl cellulose.
Ingxube engasebenzi kahle ibe isilungiswa ukuze kuqinisekiswe ukuthi ingaphakathi kobubanzi obufunwayo, ngokuvamile izungeze i-pH engasebenzi kahle (6-8).
5. Ukugeza
Ngemva kokungaguquguquki, umkhiqizo kumele ugezwe ukuze kususwe usawoti kanye neminye imikhiqizo engaphansi kwawo. Lesi sinyathelo sibalulekile ekutholeni i-hydroxyethyl cellulose emsulwa.

Inqubo:

Ingxube yokusabela ixutshwa ngamanzi, bese i-hydroxyethyl cellulose ihlukaniswa ngokuhlunga noma nge-centrifugation.
I-hydroxyethyl cellulose ehlukanisiwe igezwa ngokuphindaphindiwe ngamanzi acwengekile ukuze kususwe usawoti osele kanye nokungcola. Inqubo yokuwasha iyaqhubeka kuze kube yilapho amanzi okuwasha efika endaweni ethile yokuhambisa amanzi, okubonisa ukususwa kokungcola okuncibilikayo.
6. Ukomisa
Isinyathelo sokugcina ekulungiseleleni i-hydroxyethyl cellulose ukomisa. Lesi sinyathelo sisusa amanzi angaphezulu, sikhiphe umkhiqizo owomile, onophuphu ofanele ukusetshenziswa okuhlukahlukene.

Inqubo:

I-hydroxyethyl cellulose ehlanziwe isakazwa emathileyi okomisa noma idluliselwe ngomhubhe wokomisa. Izinga lokushisa lokomisa lilawulwa ngokucophelela ukuze kugwenywe ukuwohloka kokushisa, ngokuvamile kusukela ku-50-80°C.
Ngaphandle kwalokho, ukomisa ngesifutho kungasetshenziswa ukomisa ngokushesha nangokuphumelelayo. Ekomiseni ngesifutho, isixazululo se-hydroxyethyl cellulose esimanzi sihlukaniswa sibe amaconsi amancane bese somiswa emoyeni oshisayo, okuholela ku-powder ecolekile.
Umkhiqizo owomisiwe ube usugaywa ufike kusayizi wezinhlayiya ozifunayo bese upakishwa ukuze ugcinwe futhi usatshalaliswe.
Ukulawulwa Kwekhwalithi kanye Nezicelo
Kuyo yonke inqubo yokulungiselela, kusetshenziswa izinyathelo zokulawula ikhwalithi eqinile ukuqinisekisa ukuhambisana kanye nekhwalithi ye-hydroxyethyl cellulose. Amapharamitha abalulekile njenge-viscosity, izinga lokufakwa esikhundleni, okuqukethwe komswakama, kanye nosayizi wezinhlayiya aqashelwa njalo.

Izicelo:

Imithi: Isetshenziswa njenge-ejenti yokujiya, i-binder, kanye ne-stabilizer ekwakhiweni okufana namathebulethi, ama-suspension, kanye namafutha okugcoba.
Izimonyo: Inikeza ukujiya kanye nokuthungwa kwemikhiqizo efana nokhilimu, ama-lotion, kanye nama-shampoo.
Upende Nokumboza: Kusebenza njengesithako sokujiya kanye nokuguqula i-rheology, kuthuthukisa izakhiwo zokusetshenziswa kanye nokuqina kopende.
Imboni Yokudla: Isebenza njengesithambisi, isiqinisi, kanye nesihlanganisi emikhiqizweni yokudla ehlukahlukene.

Ukulungiswa kwe-hydroxyethyl cellulose kuhilela uchungechunge lwezinqubo zamakhemikhali nezemishini ezichazwe kahle ezihlose ukuguqula i-cellulose ukuze kwethulwe amaqembu e-hydroxyethyl. Isinyathelo ngasinye, kusukela ekuhlanzweni kwe-cellulose kuya ekomiseni, sibalulekile ekunqumeni ikhwalithi nokusebenza komkhiqizo wokugcina. Izakhiwo ze-hydroxyethyl cellulose eziguquguqukayo ziyenza ibe yisithako esibaluleke kakhulu ezimbonini eziningi, okugqamisa ukubaluleka kwemikhuba yokukhiqiza enembile ukuze kuhlangatshezwane nezidingo ezithile zezicelo ezahlukahlukene.