Real-Time Measurements of Condensed-Phase Spectra in Burning Polymers.
Real-Time Measurements of Condensed-Phase Spectra in
Nyden, M. R.
Applied Spectroscopy, Vol. 53, No. 12, 1653-1655, 1999.
cone calorimeters; fiber optics; FT-IR; nylon 6
(trademark); flammability measurements; nanocomposites
A major goal of the Building and Fire Research
Laboratory is to provide the polymer industry with the
technical understanding and measurement tools that are
needed to develop a new generation of fire resistant
materials. In the pursuit of this goal, we have examined
the feasibility of using mid-infrared transmitting
fibers connected to a Fourier Transform Infrared
spectrometer to monitor spectral changes occurring in
the condensed phase of burning polymers. The fiber optic
set-up used in these experiments consisted of a sapphire
probe connected at both ends to zirconium fluoride
cables. These cables are in turn connected to focusing
optics that launch an evanescent wave at the source and
capture it at the detector. A reflectance spectrum
results from the attenuation of the evanescent wave due
to absorption of the polymer (and its degradation
products) in the immediate vicinity of the probe. Recent
results which were obtained during cone calorimeter
flammability measurements made on nylon-6 and a
nylon-6klay nanocomposite will be presented.