Combustible volatiles, reduction mechanism

The analysis of smoke and soot formation from polymers during combustion has been extensively studied 50,51 however, less is understood on how hydrated fillers influence this mechanism. It is likely that smoke reduction results from the deposition of carbon onto the high surface area oxide surface, produced on the decomposition of the filler.38 The volatilization of carbonaceous residue as carbon oxides then occurs, reducing obscuration effects from the smoke. 

The possibility of extinguishing a polymer flame depends on the mechanism of thermal decomposition of the polymer. Whereas ignition of a polymer correlates primarily with the initial temperatnre of decomposition, steady combustion is related to the tendency of the polymer to yield a char, which is produced at the expense of combnstible volatile fragments. Therefore, the dependence of steady combnstion on the amonnt of char seems to be simple, and in an early study it was established that the oxygen index shows a very good correlation with the char yield. In reality, char also serves as a physical barrier for heat flux from the flame to the polymer surface, as weU as a diffusion barrier for gas transport to the flame. Therefore, the contribution of the char can be more significant than is expected from a simple reduction in combustible gases. 

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