Synthesis, characterization, and properties of a polyhedral oligomeric octadiphenylsulfonylsilsesquioxane

Abstract

A novel polyhedral oligomeric octadiphenylsulfonylsilsesquioxane (ODPSS) was synthesized from octaphenylsilsesquioxane and benzenesulfonyl chloride via a Friedel-Crafts reaction with a high yield. ODPSS was identified by Fourier transform infrared spectroscopy, 1 H-NMR, 13 C-NMR, 29 Si-NMR, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), wide-angle X-ray diffraction, and elemental analysis to be a kind of polyhedral oligomeric silsesquioxane of a T 8 R 8 structure. ODPSS exhibited superior thermal stability according to thermogravimetric analysis. Its initial thermal decomposition temperature (T onset ) was at 491 C in air and 515 C in nitrogen. Thermal and mechanical properties of epoxy resin (EP) composites with ODPSS added were studied by differential scanning calorimetry and tensile testing. The results show that the incorporation of ODPSS at a low loading content not only improved the glass-transition temperature of the EP composites but also enhanced their tensile strength.

Why do the [PhSiO1.5]8,10,12cages self-brominate primarily in the ortho position? Modeling reveals a strong cage influence on the mechanism

“…Indeed, as expected AlCl 3 catalyzed Friedel-Crafts acylation and sulfonation provide phenyl cages where meta selectivity is 480% as the SiO 1.5 corner offers electron withdrawing properties akin to -CF 3 . [15][16][17][18] In contrast to traditional aromatic bromination, we have reported that uncatalyzed bromination of [PhSiO 1.5 ] 8 in refluxing dichloromethane leads, after recrystallization to [o-BrPhSiO 1.5 ] 8 , where ortho bromination dominates, 85%. 16 This result is supported by both single crystal X-ray diffractometry and selective Si-C bond cleavage with F À /H 2 O 2 .…”

Synthesis, characterization, and properties of a novel polyhedral oligomeric octamethyldiphenylsulfonylsilsesquioxane

“…In our previous work, diphenylsulfone-containing POSS (ODPSS) was synthesized successfully and introduced into an epoxy resin [32]. It is a functionalized (PhSiO 3/2 ) 8 with high thermal stability, while the solubility of ODPSS in commonly used solvents is not desirable.…”

Synthesis of Sulfonated Phenylsilsesquioxanes Guided by Machine Learning

“…Octaphenylsilsesquioxane (OPS) is an important member of the polyhedral oligomeric phenylsilsesquioxane (POSS) family, which has attracted much attention due to its excellent thermal stability properties. − However, the chemical inertness and low solubility in most organic solvents of OPS restrict its broader application. , Over the last two decades, OPS modified by a variety of groups has been reported, such as nitrated octa­(phenyl)­silsesquioxane (NO 2 -OPS), , aminated octa­(phenyl)­silsesquioxane (NH 2 -OPS), , octadiphenylsulfonylsilsesquioxane (ODPSS), octamethyldiphenylsulfonylsilsesquioxane (OMDPSS), , and polycarboxyl octaphenylsilsesquioxanes . ODPSS and OMDPSS improved the solubility of OPS by 400 and 3000 times in dichloromethane, respectively.…”