Thermal analysis of polymer ignition

• Published in: Fire and materials Vol. 42; no. 6; pp. 668 - 679
• Main Authors: Lyon, Richard E., Safronava, Natallia, Crowley, Sean
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.10.2018
• Subjects: Calorimetry; Combustion; Computer simulation; Critical temperature; Data processing; Decomposition reactions; Finite element method; fire calorimeter; Heating rate; Ignition; microscale combustion calorimetry; polymer; Polymers; Qualitative analysis; Temperature; Temperature effects; Thermal analysis; Thermal decomposition; Thermal properties; Thermodynamic properties; Thermogravimetric analysis
• ISSN: 0308-0501; 1099-1018
• DOI: 10.1002/fam.2521

Summary Gas phase criteria for the onset of flaming combustion of solids in fires are used to locate a critical temperature Tcr in a nonisothermal analysis (TA) experiment that corresponds to the surface temperature of the solid at ignition in a fire test, Tign. This critical TA temperature occurs at low conversion of solid to gaseous fuel so it is independent of the heating rate in the test or the thermal decomposition reaction model. However, Tcr depends on the thermal properties of the polymer and the conditions of the fire test in which the gas phase criteria were measured. Nonisothermal analysis data in nitrogen and air were obtained for 20 polymers by thermogravimetric analysis and microscale combustion calorimetry. The critical temperatures Tcrs obtained from TA experiments compared favorably with analytic results for a simple polymer ignition model and finite element simulations and were in qualitative agreement with ignition temperatures measured in standardized fire tests.