NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Nanocomposites: A Revolutionary New Flame Retardant Approach.


pdf icon Nanocomposites: A Revolutionary New Flame Retardant Approach. (794 K)
Gilman, J. W.; Kashiwagi, T.; Lichtenhan, J. D.

SAMPE Journal, Vol. 33, No. 4, 40-46, August 1997.

Keywords:

nanocomposites; flame retardants; clay; cone calorimeters; fire retardants; heat release rate; physical properties; char; thermal stability; carbon monoxide; smoke

Abstract:

To evaluate the feasibility of controlling polymer flammability via a nanocomposite approach, we have examined the flammability properties of nylon-6 clay-nanocomposites. The fire retardant (FR) properties of this new class of materials, organic-inorganic nanocomposites, are reported. The cone calorimeter data show that the peak heat release rate (HRR), the most important parameter for predicting fire hazard, is reduced by 63 percent in a nylon-6 clay-nanocomposite containing a clay mass fraction of only five percent. Not only is this a very efficient FR system, but, it does not have the usual drawbacks associated with other FR additives. This is, the physical properties are not degraded by the additive (clay), instead they are greatly improved. Furthermore, this system does not increase the carbon monoxide or soot produced during the combustion, as many commercial fire retardants do. The nanocomposite structure appears to enhance the performance of the char through reinforcement of the char layer. Indeed, transmission electron microscopy (TEM) of a section of the combustion char from the nylon-6 clay-nanocomposite (five percent) shows a multilayered silicate structure. This layer may act as an insulator and a mass transport barrier slowing the escape of the volatile products generated as the nylon-6 decomposes.