Recent developments in polymers derived from industrial lignin

Lignin is an aromatic polymer that makes up 15-30% of the cell walls of terrestrial plants. While lignin's role in facilitating water transport through the vasculature, providing rigidity and acting as a defense against pests and pathogens is important for the plant's survival, industries that process plant biomass for the production of biofuels and bio-based chemicals have historically primarily been interested in the cell wall polysaccharides, especially cellulose. Consequently, lignin is generated in large quantities as a by-product that is often burned to generate heat and electricity, or that is used in low-value applications. It is becoming clear that, rather than treating it as waste, lignin is very suitable for the production of enhanced composites, carbon fibers, and nanomaterials, which offers both economic and environmental benefits. This review highlights recent uses of these polymers as adsorbents, flocculants, adhesives, anti-oxidants, energy storing films, and vehicles for drug delivery and gene therapy. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42069.