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Plastics. Part B. The Effects of FR Agents on Polymer Performance.


pdf icon 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.