An Overview on the Use of Lignin and Its Derivatives in Fire Retardant Polymer Systems

Lignin is a highly abundant bio-polymeric material that constitutes cellulose one of major component in cell wall of woody plants. Alternatively, large quantity of lignin is yearly available from numerous pulping and paper industries; this is the key point that justifies its large use for industrial applications. Lignin could be one of the most essential and sustainable bio-resources as raw material for the development of environmentally friendly polymer composite. Owing to its huge chemical structure, lignin can provide additional functionality such as filler, reinforcing agent, compatibilizer, stabilizer, etc. In this study, the fire retardant functionality of lignin has been imployed in polymeric materials. Due to high charring capability, lignin is effectively used as carbon source in combination with other flame retardants for designing the intumescent system for polymeric materials. Further in this, several articles related to lignin-based intumescent are reviewed and interesting work formulation as well as meaningful results achieved in the flame retardancy are discussed. More attention is given to the studies concerning the use of current intumescent systems for textile applications by means of coating on fabric/nonwoven and melt blending in bulk polymers.