Effect of Phosphorus and Halogen Compounds On the Quenching of Polymer Flames

The exhaustive literature on polymer combustion shows only a few references to the quenching of polymer flames. In the present work, we have tried to simulate the quenching process in a laboratory scale test method. A study of the extinguishment of flames when the oxygen supply is stopped to burning poly styrene samples containing various additives has been attempted. The parameters measured are the quenching time and the weight-loss during quenching. The quenching behaviour is found to depend on the nature of burn ing of the samples. Two types of burning, viz, "melt flames" and "flames on solid samples," are identified and their quenching behaviour has been discussed. The extinguishment times after the stopping of oxygen supply are almost indepen dent of the initial oxygen flow rates. NH ₄ Br and organic bromine compounds are found to be very effective in quenching. This is presumed to be due to the gas- phase flame inhibition effect of HBr. The influence of char formation on quench ing is investigated. A correspondence between the rate of weight-loss during quenching and mass burning rate of the samples has been observed.