Greener, Faster, Stronger: The Benefits of Deep Eutectic Solvents in Polymer and Materials Science

Abstract

Deep eutectic solvents (DESs) represent an emergent class of green designer solvents that find numerous applications in different aspects of chemical synthesis. A particularly appealing aspect of DES systems is their simplicity of preparation, combined with inexpensive, readily available starting materials to yield solvents with appealing properties (negligible volatility, non-flammability and high solvation capacity). In the context of polymer science, DES systems not only offer an appealing route towards replacing hazardous volatile organic solvents (VOCs), but can serve multiple roles including those of solvent, monomer and templating agent—so called “polymerizable eutectics.” In this review, we look at DES systems and polymerizable eutectics and their application in polymer materials synthesis, including various mechanisms of polymer formation, hydrogel design, porous monoliths, and molecularly imprinted polymers. We provide a comparative study of these systems alongside traditional synthetic approaches, highlighting not only the benefit of replacing VOCs from the perspective of environmental sustainability, but also the materials advantage with respect to mechanical and thermal properties of the polymers formed.

Deep Eutectic Solvents and Multicomponent Reactions: Two Convergent Items to Green Chemistry Strategies

“…There is, opportunity to explore polymer synthesis and recycling in environmentally friendly, renewable solvents as DES. [82] …”

“…There is, opportunity to explore polymer synthesis and recycling in environmentally friendly, renewable solvents as DES. [82] Polyethylene terephthalate (PET) is of the most commonly used thermoplastic polymer used to prepare fibers, packaging, bottles for water and carbonated soft drinks etc. [83] Recycling process has taken on great importance, to obtain again high value products from waste matter by depolymerization of polymer into its monomers, in order to obtain the former polymer (Scheme 1).…”

Promising Technological and Industrial Applications of Deep Eutectic Systems

“…Acid-based DESs have significantly been employed as media and reagents in different transformations, such as esterification [152], polymerization reactions [153] and for biomass valorization through the cleavage of chalcogenide moieties present in lignin feedstocks [154]. An interesting overview on the chemical and technological applications of Brønsted and Lewis acid based DESs, together with a discussion of their structural and acidity characteristics is offered by the recent survey of Qin et al [155].…”

Applications of Deep Eutectic Solvents Related to Health, Synthesis, and Extraction of Natural Based Chemicals

“…Due to the nature and versatility of DESs, these mixtures are attracting attention from the academic and industry sectors. It has been demonstrated that DESs can be used for many applications such as synthesis [18][19][20], separation processes [21,22], extraction [23][24][25][26][27][28], biocatalysis [29], nanomaterials, biotechnology [12,13], electrochemistry [30,31], food [32], cosmetics, pharmaceuticals [33][34][35][36][37][38], or as a biofuel [12,14,16,25,39]. DESs are also useful in the pharmaceutical industry as excipients for the delivery of hydrophobic drugs or as a vehicle [40].…”