A method for the quantitative evaluation of flammability in polymers

Characterization of the burning behaviour of polymeric materials

“…[5][6][7][8] v a (o)p whre P is a constant.8 Practical results (Fig. 6) indicate that this is only true over the upper range of oxygen levels and that the value of P decreases below a critical oxygen concentration.…”

A Model for the Oxygen Index of Plasticized Poly(Vinyl Chloride

“…This is normally attributed to heat losses [see Tewarson [31]], but for our purposes here we just remark that the burning rate V has a finite value, call it V,&dquo;, at the measured Oxygen Index of the sample and this value is essentially constant [9,32] for a given test and sample geometry. Using this assumption and the power law for F(P, Y-), [30], we can write Equation (5) in the simplified form: and where Solving for Y 0% and dividing by the same expression for the pure plasticizer, we get the following equation where the superscript s refers to the pure plasticizer and we assume constant pressure. Setting Y~ equal to the Oxygen Index of the compound, 01, and Y~ equal to the Oxygen Index of the pure plasticizer, OIs and noting that most of the physical constants are very similar in the range of interest in this work we get: which can be simplified further by taking the log of both sides:…”

“…In effect, one assumes that the candle burning under opposed flow conditions of the sample is governed by the same physics as the horizontal burning of the same material. As described by Funt and Magill [30] this gives an equation relating the burning velocity, V, to the physical constants of the material and the external test conditions of pressure and atmospheric oxygen content:…”

Factors that influence the critical oxygen index of various solids

“…Refs 15, [41][42][43][44] and although the temperature of the sample seems to exert the main effect, most studies have concentrated on heating the gas stream. In an actual fire, radiant heat from the fire will preheat unburned fuel as well as increasing the ambient temperature, and so both effects will be important.…”