Are lignin-derived monomers and polymers truly sustainable?
A new review, aiming at scientists, industries and investors, strives to provide a critical outlook for the existing synthetic methods of lignin-derived monomers and polymers and motivates researchers to call for the integration of sustainability factors.
The usage of renewable resources has become a hot topic upon the rising global awareness against fossil feedstock consumption. Lignin, the 2nd most abundant natural polymer on Earth, is an aromatic biomacromolecule that holds a tremendous potential for the synthesis of biobased materials. The production of monomers and polymers from lignin has been investigated for years and keeps on expanding.
However, the sustainability of the synthetic reactions has not been systematically analysed. In the new paper green chemistry plays a vital role in this area and provides several tools to design eco-friendly production methods. This critical review first describes the preeminent approaches for the synthesis of biobased monomers and polymers from lignin-derived compounds. In the second part, the “greenness” aspects of the 175 key monomer synthetic methods and 32 polymerisation methods are evaluated based on selected criteria, including waste generation, atom efficiency, energy efficiency, usage of safer solvents, and biocatalytic methodology.
Improvement opportunities
The accessible green metrics, such as environmental factor and atom economy are calculated to measure the greenness and to provide a quantitative base for strategic decisions. Furthermore, the study provides insights for the improvement opportunities and lights up the room for further developments.
The review article has been published in Green Chemistry, Issue 4, 2021.
