Effect of intumescent flame retardants on the properties of poly(ethylene‐co‐vinyl acetate)/high‐density polyethylene blends

Abstract

This study investigates the innovative use of intumescent flame retardants (IFRs), specifically ammonium polyphosphate (APP), dipentaerythritol (DPER), and melamine cyanurate (MC), to enhance the flame retardancy and thermal stability of poly(ethylene‐co‐vinyl acetate)/high‐density polyethylene (EVA/HDPE) blends. The blends were prepared through a melt mixing process, followed by compression molding, allowing for a thorough integration of the IFRs into the polymer matrix. Comprehensive characterization techniques, including limiting oxygen index (LOI) measurements, UL‐94 vertical combustion tests, and cone calorimeter tests, were employed to evaluate the flame retardant performance of the blends. The findings reveal that the incorporation of IFRs significantly improves the flame retardant properties of the EVA/HDPE blends, achieving LOI values of 30.0% and UL‐94 ratings of V‐0 at higher IFR concentrations. This work contributes to the field by demonstrating the effectiveness of IFRs in forming a protective char layer that enhances thermal stability and reduces heat release during combustion. The study not only provides insights into the optimal formulation of EVA/HDPE blends for improved fire safety but also paves the way for the development of advanced materials suitable for applications in wire and cable insulation, where enhanced flame resistance is paramount.Highlights Intumescent flame retardants (IFRs) were incorporated to improve flame retardancy. The effect of IFRs content was investigated. EVA/HDPE/IFRs blends exhibited high thermal stability and flame retardancy.