Directed discovery of greener cosolvents

Ella Gale, Remigius H. Wirawan, Rodrigo L. Silveira, Caroline S. Pereira, Marcus A. Johns, Munir S. Skaf, Janet L. Scott

OAI: oai:purehost.bath.ac.uk:openaire_cris_publications/99476171-17c5-4519-ac85-3e680ffc0181 • DOI: https://doi.org/10.1021/acssuschemeng.6b02020

Cellulose is an abundant, cheap, renewable, yet recalcitrant, material, which, if dissolved, may be formed into a wide range of materials, composites and mixtures. Much attention has recently been focused on the use of mixtures of ionic liquids and some solvents (so-called organic electrolyte solutions, OESs) as efficient cellulose dissolution solvents, but many of the cosolvents used lack green credentials – a perennial problem where dipolar aprotic solvents are the solvents of choice. We present a rational approach, based on definition of ranges of solvent parameters gathered together in recently published databases, to find ‘greener’ cosolvents for OES formation. Thus, γ-butyrolactone is identified as a suitable OES former for dissolution of microcrystalline cellulose and biobased γ-valerolactone as a marginally less efficient, but significantly safer, alternative. Comparison of cosolvent efficiency reveals that previous use of measures of mass, or concentration, of cellulose dissolved may have masked the similarities between 1-methylimidazole, dimethylsulfoxide (DMSO), N,N-dimethylformamide, N-N’-dimethylimidazolidinone, N,N-dimethylacetamide, N-methylpyrrolidinone and sulfolane (seldom considered), while comparison on a molar basis reveals that the molar volume of the solvent is an important factor. Reference-interaction site model (RISM) calculations for the DMSO/1-ethyl-3-methylimidazolium acetate OES suggest competition between DMSO and the acetate anion and preferential solvation of cellulose by the ionic liquid.

/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energy name=SDG 7 - Affordable and Clean Energy