Fully Biosourced Materials from Combination of Choline Chloride Based Deep Eutectic Solvents and Guar Gum

This study describes biosourced binary materials which synergize the attributes of guar gum, a vegetal galactomannan, with the ones of deep eutectic solvents (DES). The preparation of a library of DES, stemming from the H-bonding complexation of renewable molecules such as choline chloride (ChCl) with urea, di or triacids, polyols, or carbohydrates was confirmed by thermal analysis, WAXS morphology, and viscosity study. Interestingly, guar gum develops favorable polar interactions (mainly H-bonds) with most of these DES, leading to macroscopically homogeneous mixtures. The integrity of guar chains, recovered from DES, is preserved and the features of Guar/DES biohybrids, in terms of internal (nano)structure and viscoelasticity properties, are closely governed by the H-bond donor species engaged in the DES. Guar/ChCl-Urea appears as the most promising mixture and exhibits enhanced cohesion with striking ionic transport properties. DES can be regarded as a relevant alternative to conventional imidazolium-ionic liquids toward multicomponent biosourced systems for the design of advanced materials with lower environmental footprint.