ABSTRACT
In recent decades, synthetic polymeric materials, because of their unique physical properties, have rapidly replaced the more traditional materials such as steel and non-ferrous metals, as well as natural polymeric materials such as wood, cotton, and natural rubber. One of the limiting factors in the application of polymers at high temperatures is their tendency to not only become softer but also to thermally degrade. However, one weak aspect of synthetic polymeric materials compared with steel and other metals is that these materials are combustible under certain conditions. Most of the synthetic polymers are highly thermally sensitive due to the limited strength of the covalent bonds that make up their structures. The breaking of chemical bonds under the influence of heat is the result of overcoming bond dissociation energies. Thermal degradation can present an upper limit to the service temperature of polymers much as the possibility of mechanical property loss. Indeed unless correctly prevented, significant thermal degradation can occur at temperatures much lower than those at which mechanical failure is likely to occur.
