Use of modified chicken feather to enhance flame retardancy and mechanical properties of polymeric composites

Abstract

In spite of composite materials having lots of advantages from the mechanical performance point of view, these days due to stringent fire regulations, flammability has often become an important issue of consideration. A number of chemical additives are used for preparing polymer composites requiring improved flammability performance, but in most cases, the addition of such a flame retardant adversely affects the mechanical properties. Furthermore, it has been shown that the chemical toxicity not only has a lasting effect on human life, but may cause fatal damages during a fire situation. As a consequence, the recent developments of flame retardant (FR) materials have focused on finding natural materials that can replace the chemical compounds. Among these materials for FR synthesis, protein-based fibres have attracted great attention due to their abundance, self-extinguishing properties and good compatibility with polymer matrices. Yet, their insufficient flame retardancy in raw form and poor processability still pose challenges. In this context, we have used chemically treated chicken feather fiber as an FR additive for polypropylene (PP). Owing to considerably changed physical properties after the treatment the FR additive not only overcame the inherent limitations of the protein but also achieved uniform dispersion during melt compounding with PP. It has also been shown that its size and distribution can be significantly affected by the chemical treatment used in this process. The modified composites achieved ∼75% reduced peak heat release rate in cone calorimeter tests along with significantly improved mechanical properties compared to those of neat PP.