Structural identification on an unknown material by Pyrolysis / GCMS

Pyrolysis coupled with gas chromatography (GC) with detection by mass spectrometry (MS) is a chemical analysis technique allowing to work on macromolecules.

The principle is based on a molecular degradation of the material by contribution of thermal energy, which causes a rupture of the polymer chains and a desorption of the volatile molecules present.
The study of tracer fragments makes it possible to go back to the structure of the polymer matrix.

For this technique, the material is directly introduced into the injection syringe. The latter is placed in a thermostatically controlled zone capable of achieving a flash temperature rise which causes the polymer chains traceable by GCMS to be broken.

The pyrolytic fragments obtained are characteristic for each identified polymer.

Thus the exploitation of triplets comprising a linear diene, a linear alkene and a linear alkane makes it possible to give with certainty the nature of this polymer: Polyethylene (PE).