| 摘要 |
<p>Azaboroxines of the formula:- wherein R and R', which may be the same or different, each represent an alkyl, an aryl, a cycloalkyl or heterocyclic group which may be unsubstituted or substituted with at least one halogen atom, R possibly also representing a sily group and R' a silyloxy group, and X represents an oxygen atom or a sulphur atom; and polymeric azaboroxines having a repeating unit of:- are novel compounds. The monomers are prepared by reacting a suitable boroxine with a monofunctional isocyanate or thioisocyanate and the polymers by reacting the boroxine with a polyfunctional isocyanate or thioisocyanate. The compounds are ceramic precursors.</p> |
