Ionic liquids assisted processing of animal resources for fabrication of sustainable composite materials

It is a global ambition to realize sustainable development goals (SDGs) by 2030 following the aspiring climate change and pollution alleviation, and thus, the notion of sustainable biorefinery has emerged as an indispensable asset for worldwide sustenance and economy. Animal derived materials are biopolymers that are produced in nature during the life cycles of animals and usually considered as versatile, biocompatible, non-toxic, stable, and cheap feedstock with a promising closed-loop life cycles in the industrial ecology of future materials. Such materials could produce a severe hazard to the environment and its occupants if not ditched appropriately. Conversely, animal derived wastes are complex molecules in which manifold structure and heterogeneous networks of inter- and intra-molecular clutches endure unresolved challenges to sustainable processing and purification of these valuable waste matrices into biomaterials with numerous applications. Utilizing ionic liquids (ILs), which are environmentally safe and recyclable alternatives to organic solvents, greatly facilitates the handling and processing of biopolymers obtained from animals. ILs have been used progressively for the use of biopolymers. Compared to customary techniques, ILs assisted processing of animal-based biopolymers is superior as ILs are noncorrosive, possess extremely low vapor pressure, exhibit high thermal solidity and superb dissolution capabilities under relatively moderate conditions. Currently, a broad spectrum of various techniques has been studied to further tune up the proficiency of ILs processing of animal derived biopolymers for sustainable product development. The primary aim of this review is to illustrate the latest advancements in technology wherein the ILs leverages as processing media for animal-based biopolymers for the manufacturing of a plethora of sustainable materials have been progressively recognized. In addition to examining how various ILs serve as solvents, reagents and/or (co)solvents, we also look at the larger process and system context in which the ILs are used. It is anticipated that the current review will infuse new thoughts and reconciliation in ILs-mediated processing of animal waste resources for a promising paradigm of sustainable biorefinery.