Assessment of the impact of fire retardants on the combustion of natural polymers employing DTG and LOI

Summary Thermal analysis is widely used for the investigation of the thermal decomposition of polymeric/lignocellulosic materials. Differential thermogravimetry (DTG) curves have been used for the assessment of fire retardants employing a mathematical technique, based on the observation that the DTG profile peaks become less pronounced and are shifted to lower temperatures when a fire retardant is added. The efficiency of a fire retardant is proposed to be assessed from a formula comprising of the following: (i) the depth of the main peak; (ii) the main decomposition peak temperature; (iii) the temperature range of the DTG curve; and (iv) the area above the curve. Initially, four well-known fire retardants have been assessed for their efficiency on a lignocellulosic matrix (Olea europaea). All the results deriving from the mathematical technique have been compared with the mass residue criterion and a limiting oxygen index test (Relative Limiting Oxygen Index). Both are commonly used as reliable tools for the assessment of a fire retardant. Secondly, the impact of fire retardant concentration on efficiency was investigated. In addition, using mathematical routines, an optimum concentration zone was proposed; further, an optimum concentration value (%) has been estimated. Copyright © 2014 John Wiley & Sons, Ltd.