Distribution of calcium carbonate and silicone elastomer in a flame retardant system based on ethylene-acrylate copolymer, chalk and silicone elastomer and its effect on flame retardant properties

A combination of microscopy studies (SEM, ESEM/EDX, and TEM/EDX) is proven to be useful in locating chalk particles and silicone elastomer in a flame retardant system based on ethylene–acrylate copolymer, chalk, and silicone elastomer. The dispersion of the two additives was also obtained. The chalk particles were visually observed (at a certain degree of magnification), and the silicone elastomer was detected using characteristic X‐ray mapping and line scans. The analysis provided a good contrast between chalk particles and silicone elastomer in the surrounding polymer matrix. It is shown that dispersion of the additives depends on the mixing conditions, where tougher mixing conditions improve dispersion. A discussion is given on how dispersion correlates with the flame retardant properties of this system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2085–2095, 2006