Fire retardancy in nanocomposites by using nanomaterial additives

The use of flame retardant (FR) additives is the most common strategy to impart fire retardant properties to polymer-based materials. However, most commercially available FRs are hazardous to human health and the environment and/or affect mechanical properties and industrial processing, as they are usually employed at high loads. Synergism between conventional FRs and additives allow reducing the overall amount of FR loading while maintaining mechanical performance and processability. Nano-sized additives can provide excellent FR performance at very low loadings due to their very large specific surface area, resulting in improved interfacial interactions and dispersion in polymer matrices. This article highlights the most important aspects of the most commonly used and promising nanoscale FRs and briefly reviews the literature published in the last decade on FR synergies in nanocomposites. Finally, a simple analytical framework for comparing the fire behaviour and mechanical properties of flame retardant nanocomposites from the literature is proposed.