Surface migration and effect of ionomer network on ethylene-based copolymer-CaCO ₃-PDMS fire-retardant systems studied by rheological analysis and X-ray photoelectron spectrometry

The "barrier" mechanism in the condensed phase has long been accepted as the dominant mechanism for the halogen-free, flame-retardant polymeric composites. In previous work from this laboratory, surface-sensitive X-ray photoelectron spectroscopy was used on a silicone-containing system. It turns out that migration to the surface cannot be disregarded in studying the flame-retardant polymeric systems. With the help of rheological measurements, combined with the conventional flammability tests (cone calorimetry, loss on ignition, thermal gravimetric analysis, etc.), a mixed double-layered model has been tentatively identified.