An evolved gas analysis method for the characterization of sulfur vapor

Abstract

In this study, thermal analysis coupled with soft ionization mass spectrometry was used for the speciation of sulfur vapor. Its investigation is still a challenge, since it exhibits a complex molecular composition. A thermal analysis-mass spectrometry system was equipped with a single photon ionization time-of-flight mass spectrometer (SPI-TOFMS). Single photon ionization is a soft ionization method which produces less or no fragments. Ionization is performed with vacuum ultraviolet (VUV) photons generated by an electron beam pumped excimer lamp (EBEL) and a deuterium lamp. The applicability of the developed system was demonstrated for the determination of sulfur vapor composition. Several allotropic modifications were detected in the gas phase depending on temperature. Since the ionization energies of the species are between 8.6 and 9.7 eV, soft ionization is crucial for this reason. Thermogravimetric and DSC data deliver additional information to the mass spectrometric data and enable the detection of allotropic transitions in solid and liquid phase.

Novel polypropyleneβ‐nucleating agent with polyhedral oligomeric silsesquioxane core: synthesis and application

“…To evaluate the relative fraction of -phase content in crystallized iPP samples, WAXS profiles were analysed in accordance with Eqn (7) and the results are shown in Fig. 9.…”

Structure and properties of aβ-nucleated polypropylene impact copolymer

“…6,8,12 However, because of the thermal sensitivity of the various polymorphs in iPP, the formation of a pure -phase material may be achieved through special thermal treatment. 13 Based on the above, it seems obvious that the use of a -NA in a propylene impact copolymer could further influence the impact resistance of this type of polymer without softening the polymer. The use of -nucleation in polypropylene random copolymers, 6 impact polypropylene 2,3 and impact polypropylene copolymer (IPC) nanocomposites 14 has been reported, and more recently we reported on the effect of using -NAs on the crystalline phase morphology of an IPC.…”

Molecular weight dependency of crystallization and melting behavior of β-nucleated isotactic polypropylene

“…[11][12][13] Many reports have illustrated the growth mechanism of the unstable crystallites in iPP. 9,[14][15][16] In these cases, the b phase was the most commonly studied due to its enhanced impact strength and toughness compared with the a phase. [17][18][19] The b phase could be achieved by methods such as shearing, 20,21 crystallization with temperature gradient 22,23 or adding b nucleating agents.…”