Effect of Fire Retardants, Melamine Derivatives, on Thermal Properties of Ethylene Vinyl Acetate

Abstract

Ethylene and vinyl acetate copolymers are widely used to produce materials for various purposes. These materials are flammable. To reduce their flammability and combustibility, fire retardants with different mechanisms of action are used. The paper presents a comparative study of the influence of various fire retardants (melamine phosphate, melamine polyphosphate, melamine borate, and melamine cyanurate) on the process of thermal-oxidative decomposition of ethylene vinyl acetate. The effect of these fire retardants on the heat resistance of the polymer material and the processes of destruction of ethylene vinyl acetate at different stages is described. It has been demonstrated that melamine-based fire retardants, as a rule, increase the heat resistance of the polymer material, shift the polymer degradation range toward higher temperatures, and reduce the weight loss. Among the fire retardants used, the best results in increasing the heat resistance of ethylene vinyl acetate have been achieved in the case of melamine polyphosphate. Melamine derivatives, when decomposed, form, together with the products of ethylene vinyl acetate destruction, refractory and highly condensed phases, which affect the process of gas evolution during the decomposition of polymeric materials, and are also responsible for the formation of foam coke with fragments of the polymer matrix, which has a barrier effect.