Binary mixtures of ionic liquids-DMSO as solvents for the dissolution and derivatization of cellulose: Effects of alkyl and alkoxy side chains

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Daniela C. Ferreira
  • Mayara L. Oliveira
  • Thais A. Bioni
  • Haq Nawaz
  • Alistair W.T. King
  • Ilkka Kilpeläinen
  • Michael Hummel

  • Herbert Sixta

  • Omar A. El Seoud

Research units

  • Universidade de São Paulo
  • University of Helsinki

Abstract

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 of the imidazolium ring due to intramolecular hydrogen bonding. Using the corresponding ILs with C2–CH 3 instead of C2–H, 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.

Details

Original languageEnglish
Pages (from-to)206-214
Number of pages9
JournalCarbohydrate Polymers
Volume212
Publication statusPublished - 15 May 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Biopolymer derivatization, Cellulose dissolution, Cellulose esters, Ionic liquid-DMSO, Solvatochromism, OXIDATION, AQUEOUS-SOLUTIONS, ACETYLATION, ACYLATION, SOLVATOCHROMISM, ACID ANHYDRIDE MIXTURES, MICROWAVE-ASSISTED DERIVATIZATION, DEPENDENCE, DIMETHYL-SULFOXIDE, CELLOBIOSE

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