Experimental Study on the Optimum Concentration of Ferrocene in Composite Ultrafine Dry Powder

The elimination of halon and frequent fire accidents have caused an urgent need for the development of high-efficient fire extinguishing agents. ABC dry powder has been paid much attention, and has become one of the most extensively used fire extinguishing agents nowadays owing to its wide applications in various fire protection fields. Therefore, to enhance the fire-extinguishing properties of ABC dry powder, ferrocene was used as the additive to develop a new composite ultrafine dry powder based on an ultrafine ABC dry powder product. Through flame inhibition tests, two performance indexes of the inhibition process, namely temperature drops and flame height variations, were adopted to measure the degree of flame suppression. The experimental results revealed that the temperature drops and flame height variations both increased and then decreased. Moreover, the composite ultrafine dry powder containing 0.7% ferrocene displayed the best inhibitory effect with the maximum temperature drop (152.9°C) and variation rate of flame height (14.01%). Thermogravimetric analysis and differential scanning calorimetry were used to analyze the thermal decomposition of the sample powders. Furthermore, based on the analysis results of the thermal decomposition temperature, weight loss, and other thermodynamic parameters of the sample powders, the reasons for performance advantages of composite ultrafine dry powder containing 0.7% ferrocene were clarified as the faster pyrolysis rate, more absorption of heat, stronger suffocation and chemical inhibition effect. Finally, possible speculations on the suppression mechanisms of composite ultrafine dry powder containing 0.7% ferrocene were proposed.