ISSN:
0308-0501
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Architecture, Civil Engineering, Surveying
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The combustion of polypropylene flame-retarded by the synergistic action between Sb2O3 and bromine-containing flame retardants has been studied. From the relationship between a number of the variables, a parameter quantatively reflecting the flame retardant effect has been found. With the addition of flame retardant, the rate of weight loss, the CO and CO2 emission rates and heat release all decrease while smoke density increases. These effects were considered to depend on the concentration of HBr gas in the pyrolysates released into the gas phase (i.e., dWHBr/dW, HBr flux ensity), and the following equations were obtained: \documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{1}{W_0}\left(\frac{\rm d{W}}{\rm d{t}}\right)_{\max} \propto\left(\frac{\rm d{W_{HBr}}}{\rm d{W}}\right)^{-0.64}\quad\quad {\rm and}\quad\quad\eta^{\rm *} =\frac{W_{\rm[C], CO + CO_2}}{W_{0[\rm C]}}\,\propto \left(\frac{\rm d{W_{HBr}}}{\rm d{W}}\right)^{-0.37} $$\end{document} η*(dW/dt)max, which approximately corresponds to the oxidation velocity of pyrolized hydrocarbon, is inversely proportional to the HBr flux density. As the conversion of CO to CO2 was almost independent of the amount of flame retardants added, the flame retardant effect of bromine-containing flame retardants was considered to be a retardant effect of the initial oxidation reaction at the gas liquid interface. Moreover, η* is almost proportional to the combustion efficiency η, which was obtained from the heat release measured in the flaming region. The heat release is therefore considered to be governed by the HBr flux density.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/fam.810060102
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