Processes in the H2PtCl6·6H2O–Solvent Systems. Part 2: Methylvinylsiloxane Solutions

• Published in: Doklady. Chemistry Vol. 506; no. 2; pp. 216 - 222
• Main Authors: Klimova, N. V., Ivanov, A. G., Lebedev, A. V., Storozhenko, P. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.10.2022; Springer Nature B.V
• Subjects: Chemical reactions; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Ethanol; High temperature; Hydrochlorination; Hydrosilylation; Industrial Chemistry/Chemical Engineering; Liquid chromatography; NMR spectroscopy; Siloxanes; vinylsiloxanes; trimethylsilylsilicate; Karstedt’s catalyst; β-elimination; colloidal platinum; siloxane complexes; high-temperature hydrosilylation; chloroplatinic acid
• ISSN: 0012-5008; 1608-3113
• DOI: 10.1134/S0012500822600377

Redox processes in the H 2 PtCl 6 ·6H 2 O–1,1,3,3-tetramethyl-1,3-divinyldisiloxane system both in the presence of ethanol and trimethylchlorosilane, and in the absence thereof were studied by 1 Н, 13 С, and  29 Si NMR spectroscopy and gas–liquid chromatography. It was found for the first time that Pt(IV) and Pt(II) chlorides catalyze the reactions of hydrochlorination of vinyl groups with their transformation into β-chloroethyl groups and the elimination of the latter to form ethylene and dimethylchlorosilanes. Based on the results obtained, it was assumed that Pt(0) is coordinated to the siloxane group. A method to produce a high-temperature hydrosilylation catalyst consisting of nanosized Pt(0) and trimethylsilylsilicate was proposed and successfully tested in practice for curing SIEL-type compounds.