ABSTRACT
We designed a simple evolved gas analysis (EGA) system to act as a sampler between solid samples at atmospheric pressure and the high vacuum inside a mass spectrometer. The newly designed stainless steel system is simple, small and rugged and fulfills all the basic requirements for EGA. The temperature is programmable with 60 degrees C/min as the maximum heating rate and the temperature range is up to 600 degrees C. With this system coupled with lithium ion attachment mass spectrometry (IAMS), it is possible to study the temperature-programmed decomposition of a number of solid materials by detecting any chemical species on a real-time basis. For illustrative purposes, EGA-IAMS experiments of polyethylene polymers have been conducted.
ABSTRACT
The thermal decomposition of poly(bisphenol A carbonate) (PoC) results in the formation of the endocrine disruptor bisphenol A (BPA). In the present work, we investigated the kinetics of the thermal decomposition of PoC, and the subsequent decomposition of BPA, under pyrolysis conditions and in the presence of oxygen by using infrared image furnace-ion attachment mass spectrometry. The decomposition of PoC obeyed Arrhenius kinetics, which allowed us to determine the activation energy (E(a)) for thermal decomposition to BPA from Arrhenius plots. From the selected ion monitoring curves for BPA, E(a) for thermal decomposition in a nitrogen atmosphere was calculated to be 133.2 kcal mol(-1), whereas E(a) for oxidative thermal decomposition was calculated to be approximately 35% lower (86.5 kcal mol(-1)).
