LLDPE kinetic properties estimation combining thermogravimetry and differential scanning calorimetry as optimization targets

Abstract

Thermal analysis techniques play a crucial role to characterize solid-phase thermal decomposition, since it provides information about how mass is lost (thermal gravimetric analysis) and energy released [differential scanning calorimetry (DSC)]. However, most of the input thermal parameters and kinetic properties to be used in fire computer modelling cannot be obtained directly from those tests. Early works looked forward achieving those parameters employing indirect fitting methods, which enable the user to obtain a set of parameters capable of simulating accurately the mass loss curve (TG) or its derivative (DTG). This work aims to study the possibility of adding the energy released as a new target in the process, applying the analysis to linear low-density polyethylene. Results obtained in the present work reveal the major challenge of getting a set of parameters that can also fit DSC curve. The level of accuracy of the fitting to TG curve is higher than to DSC curve. This fact increases the value of the errors when both curves are used as targets to approach. As a result, this paper includes an alternative to consider the effects of the DSC curve.