Influence of the Structure of Acrylate Groups on the Flame Retardant Behavior of Ethylene Acrylate Copolymers Modified with Chalk and Silicone Elastomer

Abstract

This study treats the flame retardant effects of different ethylene acrylate copolymers used in a chalk and silicone elastomer system, specifically the flame retardant chemistry and behavior at lower temperatures. The presence or absence of ester pyrolysis, formation of ionomers or other crosslinks, viscosity, and the effects of these factors on the formation and stability of the intumescent structure formed during heating are discussed. The effects of the acrylate content and melt flow rate in flame retardant compounds based on ethylene butyl acrylate copolymer and ethylene ethyl acrylate copolymer are examined. Results of oxygen index, cone calorimetry (including visual observations), dripping, viscosity measurement, thermogravimetric analysis, and infrared spectroscopy are reported.

Studies of the Action of Silicone at the Interphase on the Flame Retardant System of EBA Copolymer-chalk

“…In a recent paper [8] the authors further claimed the importance of the viscosity in the melt. Apart from the presence of ionomers, the viscosity of the starting polymer is probably the most important factor in several processes resulting in the improved flame retardance of materials based on chalk, silicone elastomer, and different ethylene acrylate copolymers, and it was found that viscosity affects the transportation of volatile gases, eventual dripping, and the formation of the intumescent structure.…”

Enhanced fire behavior of Casico-based foams

“…The dispersion of both silicone elastomer and CaCO 3 in the polymer matrix seems to be decisive in the improvement of flame retardancy [7], together with the material's viscosity in the melt state. Particularly, viscosity of the material affects the transportation of volatile gases, eventual dripping, and the formation of the intumescent structure [9]. Huang et al [10], have show that the viscosity of this kind of flame retardant formulations changes not only with the temperature but also with the content of Ca-ionomers, that are formed during the thermal decomposition of the ethylene acrylate copolymer-silicon-chalk, and have studied the evolution of the Si/C ratio with temperature.…”