Apart from different IR absorption or Raman scattering properties,
plastic polymers also differ in their thermal stability. In polymer science,
these features have been used by means of thermogravimetry coupled
to differential scanning calorimetry (TGA-DSC) to verify the purity of
synthetic materials, examine thermal degradation or phase transitions
(Lampman, 2003). In environmental research, use of the
thermal decomposition characteristics has been made in coupling
thermogravimetry (TGA) with GC–MS for the identification of
polyethylene in environmental samples (Dümichen et al., 2015).
During DSC analysis, a sample is heated using a controlled temperature
gradient with a defined heating rate, e.g. 10 K min−1. Thereby, the
heat flow difference is measured by comparison of the sample to a
reference. Basic principles and applications have been extensively
described elsewhere (Menczel and Prime, 2008).