Metal-Catalyzed Alkynylation of (Bromophenyl)Oligophenylenes. A Rapid Route to Thermoset Precursors of High Density Monolithic Glass-Like Carbon
SOUTH CAROLINA UNIV COLUMBIA
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The functionalization of bromophenyloligophenylene with several alkynes is described. The bromide groups on the oligomer were replaced with terminal alkynes using a PdCu catalysts system. Substitution of nearly all the original bromide locations was achieved. The functionalized oligomers, freely soluble in THF, exhibited high char yields on thermolysis to 900 deg C under a nitrogen atmosphere. Several of the functionalized oligomers flowed on heating. The oligomer that was functionalized with phenylacetylene exhibited a well-defined melting point at 190 deg C and acetylenic coupling did not take place until 310 deg C. The hot oligomer flowed to form a monolith of glassy carbon. Depending on the alkyne used, a range of densities from 1.39-1.95 gcc could be obtained in the final carbon glass. The structureproperty relationships and the material applications are discussed.
- Organic Chemistry
- Physical Chemistry
- Polymer Chemistry
- Ceramics, Refractories and Glass