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Resumo(s)
The objective of this chapter is to provide a concise overview of lignin composition and
structure in different species and materials (wood, barks and nonwood plants). It includes
a brief review on the lignin precursors and their polymerization as well as of the analytical
tools used for lignin characterization from wet chemical to spectroscopic methods. Wood
of gymnosperms is characterized by high lignin content (25–35%) and a HG-type of lignin
with more guaiacyl (G) units and a small portion of p-hydroxyphenyl (H) units. Wood of
angiosperms has a lignin content of 15–28%, with a GS-lignin having different proportions
of syringyl (S) units. Nonwoody monocotyledon species have different lignin content
(9–20%) and a HGS type of lignin, characterized by a high proportion of H units. Bark
lignin content ranges from 13 to 43% and is of HGS-type with species-specific composition
and different in the bark components, phloem and cork. Lignin composition and macromolecular
structure are key issues to understand the properties of lignocellulosic materials
and to design a lignin-based pathway within biomass biorefineries. The available information
on lignin composition is still limited to a few species and plant components. This is
certainly an area where more research is needed.
Descrição
Palavras-chave
analytical tools biomass lignin composition monolignols S/G ratio
Contexto Educativo
Citação
Lourenço, A., & Pereira, H. (2018). Compositional variability of lignin in biomass. InTech. doi: 10.5772/intechopen.71208
Editora
IntechOpen
