Icosahedral carboranes. XVI. Preparation of linear poly‐m‐carboranylenesiloxanes

Abstract

The first members of the series of poly‐m‐carboranylenesiloxanes were synthesized by the ferric chloride‐catalyzed condensation of methoxy‐ and chloro‐terminated monomers and generally obtained as insoluble crosslinked gums It has now been discovered that long‐chain, linear polymers can be prepared by simple hydrolytic condensation of m‐B10H10C2(SiMe2OSiMe2Cl)2 and m‐B10H10C2(SiMe2OSiMe2OSiMe2Cl)2 at ice bath temperature, as well as by acid‐catalyzed condensation of the corresponding silanols. In addition, phenyl‐substituted copolymers have been obtained which show outstanding thermo‐oxidative stability at elevated temperature. These linear polymers are soluble waxes and liquids with molecular weights between 16,000 and 30,000; they are potentially useful as high‐temperature liquids and coatings and can be cured at room temperature to form elastomers.

Determination of Lanthionine and Lysinoalanine as N-Trifluoroacetyl n-Butyl Esters by Gas-Liquid Chromatography

“…The stationary phase evaluated next was Dexsil 300 GC, a thermally stable carborane dimethylsiloxane polymer [18]. Table I.. was not satisfactory, therefore BS was the internal standard of choice.…”

High-temperature elastomers: A systematic series of linear poly(carborane-siloxane)s containing icosahedral (CB10H10C) cages. III. Spectroscopic identification

“…The structure was considered to be random. 6 The structure is random in the scnsc' that although there is on average one phcnylatrd siloxanc group per repeat unit, consecutive phenylated siloxane groups are expected to occur which result in incorporation of both 10-SiB-3 unitsand [-Si(CH3)(C6H5)-O-ln (n = 1,2, 3, . .…”

Boron-Containing Polymers—The Carboranesiloxanes

“…Most later investigations used thermogravimetry and the results of these studies are summarized here. 20 losses for Dexsil 300 and 500 and poly(dimethylsiloxane) when heated in argon at a rate of 2SC/minute. The greatly improved thermal stability of the poly(carborane siloxanes) compared with poly(dimethylsiloxane) is immediately evident.…”