Lignin Upconversion by Functionalization and Network Formation

Abstract

Lignin, a complex and abundant biopolymer derived from plant cell walls, has emerged as a promising feedstock for sustainable material development. Due to the high abundance of phenylpropanoid units, aromatic rings, and hydroxyl groups, lignin is an ideal candidate for being explored in various material applications. Therefore, the demand on lignin valorization for development of value‐added products is significantly increasing. This mini‐review provides an overview of lignin upconversion, focusing on its functionalization through chemical and enzymatic routes, and its application in lignin‐based polymer resins, hydrogels, and nanomaterials. The functionalization of lignin molecules with various chemical groups offers tailored properties and increased compatibility with other materials, expanding its potential applications. Additionally, the formation of lignin‐based networks, either through cross‐linking or blending with polymers, generates novel materials with improved mechanical, thermal, and barrier properties. However, challenges remain in optimizing functionalization techniques, preserving the innate complexity of lignin, and achieving scalability for industrial implementation. As lignin's potential continues to be unlocked, it is poised to contribute significantly to the shift towards more eco‐friendly and resource‐efficient industries

Organic Chemicals from Wood: Selective Depolymerization and Dearomatization of Lignin via Aqueous Electrocatalysis

“…Lignin, a wood‐related and one of the most abundant biomacromolecules on Earth, has garnered substantial attention in recent years as a sustainable and renewable resource in the production of high‐value chemicals and materials [1–4] . Successful valorization of this polyphenol has the potential to revolutionize the Green Chemistry landscape by reducing the reliance on fossil fuels and minimizing environmental impacts [2,5] .…”

“…The key advantage of this method is the absence of additional solvents, as the sodium carbonate solution creates an alkaline environment where lignin can be successfully dissolved, thus circumventing the need for other potentially environmentally impactful solvents. Although sodium hydroxide has been often chosen for oxidative depolymerization of lignin, [4] this base presents many disadvantages compared to sodium carbonate, including significant environmental repercussions associated with its production. Significant environmental impacts arise from the production of one kilogram of sodium hydroxide.…”