Термодеструкція нанокомпозитів полімер-наноглина у вогнезахисних інтумесцентних покриттях

Abstract

The aim of this work is to determine the effect of organomodified montmorillonite clay and thermally expandable graphite on the mechanism of thermodestruction and the flame retardant properties of the intumescent system of ammonium polyphosphate/melamine/pentaerythritol/polymer (nanocomposite). The structure, physico-chemical and thermal properties of polymers and nanocomposites obtained from copolymers of ethylene vinyl acetate, styrene butyl acrylate, and nanomaterials – modified benzalkonium montmorillonite (MMT) and thermally expanded graphite (EG) have been investigated. It has been proved that nanoclay and nanographite in the composition of nanocomposites enhance the thermal characteristics of the original polymers. It has been established that the thermal stability of the investigated compounds increases in a number: polymer<polymer-EG<polymer-MMT<polymer-MMT-EG. It has been shown that graphite systems are characterized by low temperature swelling (<200 °C), small length of stabilization region of swelling coefficient and significant mass loss of coke residue in the temperature range of 200–400 °C. It has been determined that the main direction of the positive effect of nanographite is the barrier effect. In turn, systems with MMT are characterized by a slowing of the onset of swelling, as well as a decrease in the swelling coefficient over the entire interval of thermal destruction of the intumescent system 200–700 °С. It has been shown that polymer-MMT nanocomposites have a positive effect on the formation of a coke layer with increasing its strength, density and adhesion to metal substrates. Based on the obtained results, an intumescent basis of fire retardant paint was developed for steel structures, which can be applied to increase the limit of metal fire resistance.