The mass burning rate of flame-retarded polypropylene in an oxygen-enriched atmosphere



Polypropylene containing a bromophosphorous flame-retardant exhibits a higher mass burning rate—in the atmosphere containing more than 30 vol % of oxygen — than nonretarded resin. These prodegradative reactions in combustion can be eliminated only by using a high concentration (ca. 40 phr) of inorganic alumina trihydrate. A method for distinguishing the physical and chemical effects of flame retardants is described.