| Texto completo | |
| Autor(es): |
Ferreira, Daniela C.
[1, 2]
;
Oliveira, Mayara L.
[1]
;
Bioni, Thais A.
[1]
;
Nawaz, Haq
[1]
;
King, Alistair W. T.
[3]
;
Kilpelainen, Ilkka
[3]
;
Hummel, Michael
[4]
;
Sixta, Herbert
[4]
;
El Seoud, Omar A.
[1]
Número total de Autores: 9
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Inst Chem, Prof Lineu Prestos Av 748, BR-05508000 Sao Paulo, SP - Brazil
[2] Inst Technol Res State Sao Paulo, Prof Almeida Prado Av 532, BR-05508901 Sao Paulo, SP - Brazil
[3] Univ Helsinki AI Virtasen Aukio 1, Dept Chem, POB 55, Helsinki 00014 - Finland
[4] Aalto Univ, Sch Chem Engn, Dept Bioprod & Biosyst, POB 16300, FI-00076 Aalto - Finland
Número total de Afiliações: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Carbohydrate Polymers; v. 212, p. 206-214, MAY 15 2019. |
| Citações Web of Science: | 4 |
| Resumo | |
The efficiency of mixtures of ionic liquids (ILs) and molecular solvents in cellulose dissolution and derivatization depends on the structures of both components. We investigated the ILs 1-(1-butyl)-3-methylimidazolium acetate (C(4)MeImAc) and 1-(2-methoxyethyl)-3-methylimidazolium acetate (C(3)OMeImAc) and their solutions in dimethyl sulfoxide, DMSO, to assess the effect of presence of an ether linkage in the IL side-chain. Surprisingly, C(4)MeImAc-DMSO was more efficient than C(3)OMeImAc-DMSO for the dissolution and acylation of cellulose. We investigated both solvents using rheology, NMR spectroscopy, and solvatochromism. Mixtures of C(3)OMeImAc-DMSO are more viscous, less basic, and form weaker hydrogen bonds with cellobiose than C(4)MeImAc-DMSO. We attribute the lower efficiency of C(3)OMeImAc to ``deactivation{''} of the ether oxygen and C2-(H) under bar of the imidazolium ring due to intramolecular hydrogen bonding. Using the corresponding ILs with C2-(CH3) under bar instead of C2-(H) under bar, namely, 1-butyl-2,3-dimethylimidazolium acetate (C(4)Me(2)ImAc) and 1-(2-methoxyethyl)-2,3-dimethylimidazolium acetate (C(3)OMe(2)ImAc) increased the concentration of dissolved cellulose; without noticeable effect on biopolymer reactivity. (AU) | |
| Processo FAPESP: | 14/22136-4 - Uso de solventes verdes e suas misturas na otimização de processos químicos |
| Beneficiário: | Omar Abou El Seoud |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |