Chapter 18 - Fire Retardancy of Elastomers and Elastomer Nanocomposites

Abstract

Elastomers show a major potential for replacing conventional materials such as wood, metal, and ceramics in automotive, aerospace, construction, and electronic applications, on account of their unique combination of mechanical strength and flexibility. However, the low resistance of these elastomeric products to fire poses a threat to their usage in such critical applications. Therefore, elastomeric blends and composites with flame-retardant (FR) additives such as alumina trihydrate and zinc hydroxyl stannate are conventionally used. Nanofillers such as montmorillonite, layered double hydroxides, and carbon nanotubes known for tremendous improvement in mechanical and thermal properties of elastomers have also been found to improve fire resistance of elastomers, prompting research in this field. The present chapter summarizes recent advances on the fire retardancy of industrially important elastomers, their blends and nanocomposites based on cone calorimetric studies, limiting oxygen index, oxygen index, and the UL-94 test. The elastomers addressed are ethylene vinyl acetate copolymer, ethylene–propylene diene rubber , polyurethane, silicone rubber, styrene–butadiene rubber, acrylonitrile–butadiene rubber, natural rubber, and polychloroprene rubber. The effect of a variety of nanofillers on the fire retardancy of these elastomers both with and without conventional FR additives is also extensively discussed, highlighting their synergistic effects. This chapter is planned to comprise a guiding tool for the design and development of elastomer formulations intended for products fulfilling fire safety requirements.