Iron-assisted pyrolysis (Fe-assisted pyrolysis) is a high-efficiency technique to remove sulfur from low-rank coal. However, the sulfur removal mechanism of Fe-assisted pyrolysis did not compressively address. For filling this gap, this study explored the sulfur removal mechanism of diphenyl sulfone during Fe-assisted pyrolysis based on the factor optimization of desulfurization performance. The iron powder under the optimal conditions of Fe-assisted pyrolysis was characterized with X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS), showing that FeS and some FeS2 were formed on the surface of post-pyrolysis iron powder. Gas chromatography (GC) analysis manifested that the addition of iron powder in the pyrolysis process could considerably reduce the SO2 emission. GC and Fourier transform infrared spectrometer (FTIR) analyses demonstrated that there was C–S bond broken in the diphenyl sulfone structure during Fe-assisted pyrolysis. From the results of thermogravimetry-mass spectrometry (TG-MS), the addition of iron powder in the pyrolysis process could enhance the reaction rate and reduce the temperature required for the reaction. We believe that the results of the present study provided a theoretical basis for a profound understanding of the desulfurization mechanism of Fe-assisted pyrolysis.
4,4′-Dichlorodiphenyl sulfoxide is the main raw material for the manufacture of polysulfone, polyether sulfone and other engineering plastics. It is also an intermediate for medicines, dyes and pesticides, which has been widely utilized in engineering plastics, fine chemicals and other fields. The alkylation of chlorobenzene with thionyl chloride can give 4,4′-dichlorodiphenyl sulfoxide as a product using Lewis acidic ionic liquids. In this work, metal-based methylimidazolium ionic liquids were synthesized, which were found to be efficient catalysts for alkylation reactions. The molar ratio of different metal chlorides to 1-butyl-3-methyl imidazole chloride and the influence of different metal chlorine additives on the catalytic Lewis acid center were investigated. The fissionable species of AlCl3 in ionic liquids will enhance the acidity of ionic liquids and, thus, promote the catalytic performance of ionic liquids. Under the optimized reaction conditions, the conversion rate of excess chlorobenzene was 45.3% and the selectivity of 4,4′-dichlorodiphenyl sulfoxide was 31.9%.
To investigate the influence of fabrication method on the biological properties of modified PEEK. Two materials were tested in this study: press and CAD/CAM milled ceramic-reinforced PEEK (BioHPP, Bredent, Germany). The residual diphenyl sulfone in these two materials was detected and their biological effects on human gingival fibroblasts (HGFs) were evaluated by assaying cell viability, apoptosis, and inflammation. Diphenyl sulfone was not detected in press and milled BioHPP. The cell viability of them complied with ISO standards. The mRNA expression levels of Bax and Caspase-3 were up-regulated and that of Bcl-2 was downregulated when HGFs were cultured with the eluates of these two materials. There was no difference in cell viability, apoptosis, and inflammation between them. Hence, the fabrication method did not affect the biological properties of modified PEEK, the press and CAD/CAM milled modified PEEK all presented favorable cytocompatibility despite the expression of apoptosis-associated genes at the mRNA level.
危险品化学品经营许可证（带存储）