Recent developments towards performance-enhancing lignin-based polymers

Fossil fuels are a cheap and abundant feedstock for polymeric materials that have enabled innumerable quality-of-life improvements. Yet, their declining supply and non-renewable nature have driven the pursuit of bio-based alternatives. Lignin represents the largest natural source of aromatic carbon on the planet, and thus, lignin-derived products have emerged as critical elements in the next generation of polymers. The relative abundance, large concentration of functional handles, and thermal stability of lignin make it an attractive target for bio-based polymers. However, the valorization of lignin to high-performance and cost-competitive materials remains a challenge. In this review, developments in the translation of lignin into value-added macromolecular components are discussed. Strategies to incorporate bulk lignin in polymer blends and composites are introduced with a focus on applications. Furthermore, recent advances in the preparation of higher-value thermoplastics, thermosets, and vitrimers from deconstructed lignin products are highlighted from a synthetic perspective. Finally, key hurdles and future opportunities in lignin valorization are explored.

Automated summary

Fossil fuels, while important for polymeric materials, are being replaced by bio-based alternatives due to their limited supply and non-renewable nature. Lignin, as the largest natural source of aromatic carbon on earth, with its abundance, functional handles, and thermal stability, has become an attractive target for bio-based polymers. However, the challenge lies in valorizing lignin into high-performance and cost-competitive materials.