Sulphurous additives for polystyrene: Influencing decomposition behavior in the condensed phase
(2015)
The thermal decomposition behaviour of polystyrene (PS) containing sulphur and phosphorus additives was investigated, using thermogravimetry coupled with Fourier transform infrared spectroscopy (TGA-FTIR). It was found that the additives influence the decomposition process of the polymer in the condensed phase, resulting in a decrease in styrene monomer formation and an increase in styrene oligmer derivatives. Via reference measurements with binary mixtures it was found that the presence of sulphur additives influences the radicalic decomposition process of PS. In combination with quantum chemical calculations it was concluded that this is due to the formation of radicals that abstract hydrogen from the polymer matrix at lower temperatures, disfavouring the radicalic decomposition pathway leading to styrene.
Laser-induced breakdown spectroscopy (LIBS) is a fast and versatile technique for (semi) quantitative element analysis of solids, liquids, gases, and particulate matter. The LIBS method is used for optical sensing in various branches of industrial production. In the contribution we review some of our recent results on LIBS analysis of slags from secondary metallurgy in industrial steel making. Major oxides in steel slags are measured at-line and after homogenization using a calibration-free (CF) method. Two approaches for CF analysis based on the Boltzmann plot method and on the calculation of synthetic spectra are compared for the analysis of quaternary oxides. We also present the research in cooperation with our industrial partners in the process-analytical chemistry network PAC.