Synthesis and Reactivity of Silyl-Ketene Acetal-Modified Polysiloxanes Preparation of Polysiloxanes with High Dielectric Constraints.

摘要

Silicones having pendant silyl ketene acetals were synthesized through hydrosilation of polymethylhydrosiloxane with a terminal olefin bearing a silyl ketene acetal or, alternatively, a terminal olefin-ester which can be subsequently converted to the silyl ketene acetal. The silicones can be reacted with the elecytrophiles such as p-nitrobenzenesulfenyl chloride, affording derivatives having highly polar pendants. These materials have dielectric constants as high as 9 and loss factors of 0.02-0.06 at 100kHz at room temperature. The temperature dependencies of the dielectric constants are a function of polar pendant group concentration and the glass transition temperature.