Kinetics and volatile products of thermal degradation of building insulation materials

The thermal degradation of three typical organic insulation materials, rigid polyurethane (PU) foam, extruded polystyrene (XPS) and expanded polystyrene (EPS) were investigated using thermogravimetry (TG) and simultaneous thermal analysis (STA) coupled with mass spectrometry and Fourier transform infrared spectroscopy (TG–DSC–MS–FTIR). The Kissinger–Akahira–Sunose method was utilized for calculating the activation energy values of the materials. Volatile products obtained from the degradation were identified by MS and FTIR. The results of TG–DTG–DSC curves under 10 °C/min heating rate in a nitrogen environment revealed the differences in characteristics of the three materials during the thermal degradation. Only one obvious mass loss stage of EPS was observed, and XPS shows two degradation stages and the second one is the main stage. While PU is more complex, and the degradation process involves three steps and the whole mass loss is continuous. The largest heat absorption is in the main mass loss stage.

► We compare the activation energy of EPS, XPS and PU.
► EPS, XPS and PU show different degradation stages.
► In the first degradation stage of PU, water and some other volatile fragments release.
► Most of the volatile products of XPS and EPS are flammable.