Fire and mechanical properties of polymeric composites with keratin-based flame retardants

Due to the high flammability of polymeric materials, the development of a flame retardant with high-performance, low-toxicity and cost-effectiveness has been one of the most important issues in the polymer industry. To address these requirements, keratinous fibres have been employed for a novel intumescent flame-retardant fabrication. Phosphate loaded keratinous fibres through the sequential infiltration of phosphoric acid and reactive amines have shown a successful demonstration of the self-extinguishment (VO grade) and similar to 80% reduced peak heat release rate in the vertical burn test (UL94) and cone calorimeter test, respectively. Owing to the unique char formation behaviour of the fibres with the combined effects of phosphorus compounds, the composites have achieved the improvement of flame retardancy compared to the commercial ammonium polyphosphate/polypropylene composite. Furthermore, the fibre addition has contributed to enhance the mechanical properties of the composites. For the practical application of the new FR, cost reduction capability depending on the type of reactive amine used for the phosphate production in the fibre, has also been investigated.