Fabrication and Application of Lignin-Lignin Composites

Abstract

Lignin, the second most abundant native polymer on Earth, can be a major source of renewable materials. This low cost material has potential in composites as a matrix and/or reinforcement in resin, filler, fibre, and aerogel forms. In the resin form, lignin and its derivatives can be used to make coatings, coupling agents, and composites, and can form stable mixtures. Some of the applications, for instance, can be in the wood industry, civil and electrical engineering. In the fibre form, lignin, a promising precursor candidate for manufacturing carbon fibre, can replace petroleum based precursors, such as polyacrylonitrile and pitch (petroleum or coal). The lignin-based composite nanofibres reinforced by carbon nanotube/nanocrystalline cellulose can be used for automobile and structural applications. In addition, the fibre can be functionalized by embedded nanoparticles and/or surface modification. The concept of multifunctional carbon nanofibre can be extended to a wide range of advanced applications in the energy, electronic, and environmental sectors. In the aerogel form, lignin-based carbon composites, due to their unique network structure, low density and high surface area, are promising materials as electrodes for hydrogen and electrical storage, supercapacitors, thermal and acoustic insulators, adsorbents, catalyst supports and sensors.