Novel Synthesis of Cyclic Methylvinylsiloxanes by the Reaction of Methylvinyldiethoxysilane with Phosphorous Pentachloride

A.E. CIOLINO; B.M. VUANO; O. PIERONI; M.A. VILLAR; E.M. VALLÉS

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY

JOHN WILEY & SONS INC

Lugar: New York; Año: 2002 vol. 40 p. 3182 - 3189

0887-624X

We report a novel synthesis of the cyclic oligomers [(H2C=CH)(CH3)SiO]n obtained by the reaction between phosphorous pentachloride and methylvinyl diethoxysilane. According to gas chromatography/mass spectrometry data, the reaction product consisted of a mixture of cyclic oligomers in which the most important fractions were composed of cycles with n = 5, 6, or 7. The reaction product was also characterized by Fourier transform infrared and 1H and 13C NMR spectroscopy. Experimental results suggested a new kind of reaction between the phosphorous pentachloride and terminal olefins directly bonded to silicon, which was probably associated with sterical effects favoring C[BOND]O[BOND]Si bond cleavage of ethoxy groups instead of the conventional addition of phosphorous pentachloride to olefinic linkages.