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 employed 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.
Part of the book: Lignin
Nowadays, textiles functionalization is developing increasingly, fabrics are not only defined by the intrinsic properties of the fiber but some properties are also brought to provide them added value. Among the desired properties, antibacterial activity is targeted to improve the comfort and durability of textiles but many commercial products use chemical substances which are harmful for the environment (regulation 528/2012). The goal of this study was to use bio-based biocide which can be incorporated in the polyethylene terephthalate (PET) by melt spinning for the development of functional PET. This biocide had to resist to the PET processing temperature up to 264°C which was the maximum temperature of implementation. Two kinds of Kraft lignin and titanium dioxide as reference were added by melting way. The antimicrobial activity was characterized at low concentration (1 and 2 wt.%), to avoid a significant decrease in mechanical strength for the multifilaments and to maintain optimal rheological properties of the polymer for the melt spinning process. Filled PET pellets were obtained by twin screw extrusion step and the multifilaments by melt spinning step. Finally, knitting structures were developed for the evaluation of the antibacterial activity. The mechanical (tensile test) and thermal (DSC and TGA) properties of the filaments were characterized.
Part of the book: Organic Polymers