Flame-Retardant Polymer Nanocomposites and Their Heat-Release Rates

Abstract

Flame-retardant polymer nanocomposites exhibiting remarkably improved flame-retardant and environmentally friendly properties have been widely utilized to replace traditional halogenated fire retardants. In this review, flame retardant mechanisms of polymer nanocomposites such as barrier effect, char formation, three-dimensional nanostructure, and radical trapping, are discussed to explain how nanomaterials can be incorporated in a polymer to reduce the polymer’s flammability. Properties that are critical in governing the flame-retardant mechanisms of polymer nanocomposites are discussed in this review. Specifically, category, surface property, and concentration of nanomaterials are critical in affecting flame-retardant properties of polymer nanocomposites and are reviewed in detail. Nanocomposite categories, especially, silicates (clays), inorganic hydroxides, carbonaceous materials, metal oxides, polysilsequioxanes, and their combinations are well described. The use of synergism and surface modification of nanomaterials are important strategies for optimizing flame retardancy of polymer nanocomposites. The peak heat-release rate (HRR), the most important parameter for predicting fire hazard, is widely involved in this review.