Sulfur‐Containing Silsesquioxane Derivatives Obtained by the Thiol‐ene Reaction: Synthesis and Thermal Degradation

Abstract

This article presents the synthesis of new derivatives of octa(3thiopropyl)silsesquioxane (SSQ-8SH) via thiol-ene reaction with simple olefins bearing alkyl groups as well as methoxysilyl, substituted aryl or fluoroalkyl groups. All products were characterized by 1 H NMR, 13 C NMR, 29 Si NMR, FTIR, GPC, MALDI-TOF-MS, as well as thermal analysis (TGA) to confirm their structures, purity and thermal stability, and finally give some insight into their thermal degradation pathway. In some of the structures obtained, the T 5% values take place at high temperatures and are close to 230 °C. The thiol-ene reaction allowed to obtain 7 new compounds with high yield (> 92 %), no byproducts and in a relatively short time (24 h). All products are characterized by high conversion > 99 %. New derivatives can find potential use as modifiers of plastics to improve their certain properties for example hydrophobicity or thermooxidative stability.

New Ethynylphenylborasilsesquioxanes—Their Reactivity and Behavior during Thermal Decomposition

“…In this work, we synthesized mono- and diethynylphenylborasilsesquioxane by the condensation reaction. Furthermore, this is a continuation of our team’s previous work on thermally inducted chemical and structural transformations of silsesquioxanes and heterosilsesquioxanes [ 7 , 39 , 40 , 41 , 42 ].…”

Click Addition Reaction of Urethane–Acrylate Resin Using Octa(3-thiopropyl)silsesquioxane Derivatives as Cross-Linking Agents

“…Octa(3-thiopropyl)silsesquioxane was prepared according to the literature [37,47] and our previous article [44].…”

“…A crystalline product with a defined cage structure and an oil product, which is a mixture of condensed and incompletely condensed silanols, were used for the thiol-ene reaction. Both products of octa(3-thiopropyl)silsesquioxane crystalline and oil were obtained according to our previous work [44] (Figure 3). In accordance with the current trend focused on green chemistry, the oil product, which is a by-product of the reaction, has also been functionalized.…”

“…Both the benzoyl and methyl radicals can participate in the thiol-ene reaction [18]. In the first stage of the study, we prepared partially substituted SSQ-8SH derivatives using the AIBN-initiated reaction, following the procedure outlined in our first paper [44]. Reactions were carried out in toluene at 65 °C under an inert gas flow (Argon) for 24 h, then the products were evaporated on a vacuum line.…”

“…Other examples indicate a reaction between SSQ-8SH and 1,4-divinylbenzene, methacrylate ethyl trimethyl ammonium chloride [39], 2-(perfluorooctyl) ethyl acrylate [40], 9-vinyl carbazole [41], 1-methyl-3-butenylimidazolium bromide, 1-methyl-3-pentenylimidazolium bromide, 1-pentafluorobenzene-4-allylpyridinium bromide, 1-butyl-4-allylpyridinium bromide [42], 2-methacryloyloxyethylphosphorylcholine, or allylphosphorylcholine [43]. Our previous work presents the functionalization of octa(3-thiopropyl)silsesquioxane (SSQ-8SH) via radical reaction in the presence of azobisisobutyronitrile (AIBN) [44]. In Professor Maciejewski's group, silsesquioxanes with sulfur atoms in the structure were obtained through hydrothiolation of (ViSiMe 2 O) 8 Si 8 O 12 .…”