13176-70-0Relevant academic research and scientific papers
Monosodiumoxyorganoalkoxysilanes: Synthesis and properties
Rebrov,Muzafarov
, p. 514 - 541 (2006)
The reaction of organoalkoxysilanes with sodium hydroxide was studied in detail. Studies indicate that this reaction involves more than one stage and involves rather complex multistep process, which leads to the formation of both monosodiumoxyorganoalkoxysilanes (MSOAS) and several secondary products. Analysis of experimental evidence makes it possible to advance the mechanism behind this phenomenon and to define the optimum conditions for the preparation of pure MSOAS with high yields. Different MSOAS were synthesized and their basic physicochemical properties were studied. MSOAS are shown to constitute multifunctional reagents with chemically independent functional groups, and their reaction with trimethylchlorosilane selectively proceeds via - ONa groups, whereas their interaction with triethylesilanol and higher alcohols proceeds exclusively via - OAlk groups. Exchange interaction between MSOAS and organoalkoxysilanes via - ONa and - OAlk groups was found and studied in detail. Temperature corresponding to the onset of thermal degradation of MSOAS was estimated to be equal to ～ 180-190°C.
Interactions of hexachlorodiphosphazenium ion with an alcohol and with some silicon-oxygen reagents and their role in the catalysis of polycondensation in silanol-alkoxysilane systems
Chojnowski, Julian,Cypryk, Marek,Fortuniak, Witold,Kazmierski, Krzysztof,Taylor, Richard G.
, p. 351 - 361 (2007/10/03)
Condensation reactions of trimethylethoxysilane (MOEt) and pentamethyldisiloxanol in n-heptane catalysed by hexachloro-1λ-diphosphaza-1-enium salts were studied. Although the substrate conversion vs. time dependences point to domination by heterofunctional condensation, the process is more complex. Homofunctional condensation as well as fast consecutive hydrolysis and ethanolysis strongly contribute to the overall process. Results of kinetic studies point to inhibition of these component reactions by an excess of MOEt. Interactions of the hexachloro-1λ-diphosphaza-1-enium salts with MOEt, ethanol and silanol were studied by 31P NMR. It was demonstrated that a fast substitution reaction of chloride by ethoxy group takes place when ethanol or ethoxysilane is introduced into solutions of hexachlorodiphosphazenium salts. This process is responsible for the decrease in condensation activity of the catalyst.
