Surprising Insensitivity of Homogeneous Acetylation of Cellulose Dissolved in Triethyl(n-octyl)ammonium Chloride/Molecular Solvent on the Solvent Polarity

Author(s)

Achtel, Christian ^[1] ; Jedvert, Kerstin ^[1] ; Kostag, Marc ^[2] ; El Seoud, Omar A. ^[2] ; Heinze, Thomas ^[1]

Affiliation

^[1] Friedrich Schiller Univ Jena, Inst Organ Chem & Macromol Chem, Ctr Excellence Polysaccharide Res, Humboldtstr 10, D-07743 Jena - Germany

^[2] Univ Sao Paulo, Inst Chem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: MACROMOLECULAR MATERIALS AND ENGINEERING; v. 303, n. 5 MAY 2018.
• Web of Science Citations: 4

Abstract

The homogeneous acetylation of microcrystalline cellulose (MCC) by acetyl chloride and acetic anhydride in triethyl(n-octyl)ammonium chloride (N2228Cl)/molecular solvents (MSs) is investigated. The reaction with both acylating agents shows the expected increase of the degree of substitution (DS) on reaction temperature and time. Under comparable reaction conditions, however, DS is surprisingly little dependent on the MS employed, although the MSs differ in empirical polarity by 7 kcal mol(-1) as calculated by use of solvatochromic probes. The empirical polarities of (MCC + N2228Cl + MS) differ only by 0.8 kcal mol(-1). The formation a polar electrolyte sheath around cellulose chains presumably contributes to this leveling-off of the dependence DS on the polarity of the parent MS employed. N2228Cl recovery and recycling is feasible. (AU)

• FAPESP's process: 14/22136-4 - Use of green solvents and their mixtures for optimizing chemical processes
• Grantee: Omar Abou El Seoud
• Support Opportunities: Research Projects - Thematic Grants