Recent Advances in Flame Retardant Polymer Nanocomposites.
Recent Advances in Flame Retardant Polymer
Gilman, J. W.; Kashiwagi, T.; Morgan, A. B.; Harris, R.
H., Jr.; Brassell, L. D.; Awad, W. H.; Davis, R. D.;
Chyall, L.; Sutto, T.; Trulove, P. C.; DeLong, H.
Fire and Materials 2001. 7th International Conference
and Exhibition. Proceedings. Interscience
Communications Limited. January 22-24, 2001, San
Antonio, TX, 273-283 pp, 2001.
nanocomposites; flame retardants; cone calorimeters;
gasification; UL 94; flammability tests;
thermogravimetric analysis; char
A new approach to address the ever increasing demand for
higher performance flame retarded products has recently
focused on use of mica-type clays nano-dispersed in
commodity polymers. These "nanocomposites" exhibit the
unusual combination of reduced flammability, in the form
of lower peak heat release rates, and improved physical
properties. However, the details of the fire retardant
mechanism are not well understood. In October of 1998 a
NIST-industrial consortium was formed to study the
flammability of these unique materials. The focus of
research within this consortium was to develop a
fundamental understanding of the fire retardant (FR)
mechanism of polymer clay nanocomposites. We report here
on some of the results of the first year of this study;
we focus our discussions on the results for polystyrene
(PS) a polymer system commonly used in flame retarded
applications such as information technology (IT)
equipment. The most important aspect of the
nanocomposite approach is the combined improvement in
both flammability properties and physical properties.
However, methods for preparation, which supply fully
optimized nanocomposites, are still under development.
An important issue in this regard is processing
stability of the treated clays. We also report on our
recent efforts to address this issue through development
of new thermally stable imidazolium-treated