New Approaches to the Development of Fire-Safe Materials.
New Approaches to the Development of Fire-Safe
Morgan, A. B.; Gilman, J. W.; Nyden, M. R.; Jackson, C.
NISTIR 6465; 22 p. February 2000.
Available from: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
1-800-553-6847 or 703-605-6000;
Order number: PB2000-101949
nanocomposites; thermogravimetric analysis; clay;
Thermoplastic polyetherimide-clay nanocomposites were
synthesized from 1,3-phenylenediamine and bisphenol A
dianhydride using an in situ approach. Two types of
organically treated clays were utilized to synthesize
these nanocomposites. The two organically treated clays
were montmorillonite clays treated with the ammonium
salts of n-dodecylamine or 12-amino-1-dodecanoic acid.
The dispersion of the clay in the polyetherimide was
analyzed by wide-angle x-ray scattering and transmission
electron microscopy. The results showed that the clay
treated with the ammonium salt of 12-amino-1-dodecanoic
acid gave a well-dispersed intercalated nanocomposite
while the clay treated with the ammonium salt of
n-dodecylamine gave a well-dispersed immiscible blend.
These nanocomposites were then analyzed by thermal
gravimetric analysis for their thermal stability.
Computational and experimental approaches were developed
to explore the nature and consequences of thermally
induced changes that occur in the condensed phase of
burning polymers. A computational strategy for
evaluating molecular weight distributions (which should
enable us to calculate the melt viscosity during
burning) from molecular dynamics simulations was
developed based on a simple differential equation for
the time dependence of the number average degree of
polymerization, x, derived by Boyd. The experimental
effort, which we hope to be able to use in validating
the predictions of this model, was successful in
obtaining real-time measurements of the mid-infrared
spectra of burning polymers. The condensed phase spectra
of nylon 6 and a nylon 6/clay nanocomposite were
measured using a fiber optic reflectance probe while
they were burning on the cone calorimeter.