Polymer Analysis by Pyrolysis GCMS with Evolved Gas Analysis (EGA) and Double-Shot Methods

Introduction

Pyrolysis analysis using the evolved gas analysis (EGA) or double-shot (multi-step pyrolysis) analysis method can be performed by combining a double-shot pyrolyzer with heating features and a gas chromatograph mass spectrometer. In this example, the PY-2020D double-shot pyrolyzer from Frontier Laboratories Ltd. and Shimadzu GCMS-QP5050A gas chromatograph mass spectrometer were used. With the EGA method, the pyrolyzer outlet is connected directly to the MS with a metal inert capillary tube and the substances evolved from the heated sample are analyzed online. This method provides EGA curve similar to thermogravimetric analysis (TG). From information on the constituent substances of the sample gained from that data, the temperature fraction corresponding to the target substance can be clearly determined. The double-shot method first analyzes volatile substances, such as additives and residual solvents, in the polymer by thermal desorption at a low temperature (100 - 300 ̊C), and then pyrolyzes the remaining polymer substrate. By this stepped heating process, polymers containing solvents and the mixed polymers with different decomposition temperatures can be separated for analyzing individual substances. In this Application News, the sample analyzed using PYR4A in Application News M174 (a vinyl acetate based adhesive) was analyzed in more detail using the EGA and double-shot methods.

August 26, 2004 GMT