Plastics. Part B. The Effects of FR Agents on Polymer Performance.
Plastics. Part B. The Effects of FR Agents on Polymer
Performance.
(889 K)
Babrauskas, V.
Chapter 12;
Heat Release in Fires, Elsevier Applied Science, NY,
Babrauskas, V.; Grayson, S. J., Editor(s)(s), 423-446
pp, 1992.
Keywords:
heat release rate; fire protection engineering;
plastics; flame retardants; fire hazard; oxygen index;
polyurethane foams; polystyrene; polypropylene; PMMA;
cone calorimeters
Abstract:
Flame-retarded or fire-retarded polymers - what are
they? The explanation seems simple: they produce
'slower' fires. But, is it simple? And what is
'slower', anyhow? Until very recently, to the polymer
development chemist in the U. S., this performance did,
indeed, seem simple. Such FR polymers were ones which
performed better on the limiting oxygen index (LOI) or
the UL 94 tests. Unfortunately, there has been no
evidence to show that the LOI test has any correlation
with actual fire performance. The UL 94 Bunsen burner
test, by contrast, does represent fairly realistically
the ignition of small plastic parts from small ignition
sources. Despite this limitation, it is most commonly
used as a general test for rating plastics, such as
large sheets, which are associated with very different
hazard issues. So, FR polymers show retarded fire
development in some limited or irrelevant bench-scale
tests. What about real fire performance? Can they show
improved ignitability, flame spread rates, heat release
rates, smoke evolution, etc.? There are no theoretical
or systematic answers to these questions. Thus, in this
section we will, instead, review some of the
experimental data useful for answering such questions.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899