9 - Flammability and fire resistance of composites

Abstract

All fiber-reinforced composites comprise matrix materials that are flammable to varying degrees and, compared with metals such as aluminum or steel, can burn vigorously, often with evolution of smoke. While organic fiber reinforcement such as polyester, aramid, and even carbon may add fuel to the burning composite, even if inorganic fibers, such as E-glass, are the reinforcing structures, the general composite fire resistance and performance (including smoke generation) will be determined by that of the organic matrix. The overall physical behavior under heat and flame conditions will be influenced by the thermal properties of the fibers present since resins are often thermoplastic or deformable except in the highest performance examples, such as phenolics and polyimides. This chapter illustrates the thermal properties of typical fiber reinforcement for composites. It provides general overviews of composite fire resistance. It presents a brief overview of composite fire behavior, focusing on the recent research that has concentrated on understanding resin thermal behavior and the resins used and means of enhancing fire and smoke performance using flame retardants that do not use the environmentally and toxicologically questioned antimony–bromine-based flame retardants.