Lignin-based UV-protective Materials

Abstract

Protecting living organisms and organic compounds from ultraviolet (UV) radiation is important due to its harmfulness to them. In this chapter, we describe the usefulness of lignin, a plant aromatic polymer, as a UV absorber (UVA). Here, different procedures like simple mixing, chemical reaction with organic/inorganic molecules, and nanoparticulation of lignin derivatives are introduced for its utilization as a UV-absorber. Especially, the nanoparticulated lignin extracted by simultaneous enzymatic saccharification and comminution of plants gives an excellent UV-protective material by combination with a poly(vinyl alcohol) or clay mineral matrix without dramatically affecting the transparency of the matrix. Lignin-based UV-absorbers never need toxic reagents; i.e., lignin is ideal for application as a UVA of packaging films for organic materials. The UV-absorption nature of lignin not only encourages us to treat plant biomass as a high-value organic material, but also decreases the environmental impact because many current UV-absorbers are obtained from toxic petroleum-based reagents.