TGA Analyzer

In this example, PPO polymer is heated through decomposition in an inert nitrogen atmosphere with the offgas collected by the attached MS. The TGA-MS hyphenated technique allows for the detection and identification of the resultant decomposition products. The data is displayed as an overlay of ion current and weight loss with respect to temperature. TGA shows a monotonic weight loss step; however, the mass spectroscopy data presents the detection of several decomposition entities that range in mass to charge ratios of 65 to 136 amu, which is the molecular ion of the repeating unit. Proposed possible decomposition products, based on the structure of the polyether, are also shown.

Copper oxalate (CuC2O4 ) is a salt that decomposes to elemental copper upon heating in an inert atmosphere. It is often used to measure the inertness of the TGA atmosphere, as the high surface area of copper is readily oxidized at high temperatures. In this example an oxidation-reduction (redox) reaction experiment was accomplished using the Blending GDM, Pfeiffer MS and the Discovery TGA. After decomposition of the oxalate during the initial temperature ramp, oxygen was introduced into the TGA sample chamber resulting in the formation of copper (II) oxide. Subsequent reduction of the copper oxide was achieved through the introduction of small amounts of hydrogen gas. Forming gas was safely used as the hydrogen source in the TGA.