Effect of oxygen concentration and temperature on ignition time of polypropylene

The presented article deals with the assessment of combined impact of temperature and flow of oxidising atmosphere, its oxygen concentration and heat flux on the ignition time of isotactic polypropylene (PP). The ignition time was determined in a specially adapted hot air Setchkin furnace at temperatures (450 and 600?°C), density of heat flux (12.4 and?26.4?kW m^?2), flows of oxidation mixture (6 and 8?L?min^?1) and volume oxygen concentrations (3, 9, 15, 21, 27, 33, 39, 45 and 50?%). Obtained data allows us to assume that the temperature influence on PP induction period of ignition increases with decreasing flow rate of oxidising atmosphere. At the flow of oxidising mixture equal to 6?L?min^?1 and temperature of 600?°C, oxygen concentration had only a negligible impact on the the induction period of ignition in the analysed period. From the presented results, the induction period of ignition depends on the temperature and also on the flow rate of oxidising mixture and oxygen concentration in it. In addition, heat flux has a significant influence on the induction period. However, the quantification of the heat flux influence was not possible with the applied experimental device.