Thermoset Precursor to Monolithic Carbon Glass Prepared by the Pd/Cu- Catalyzed Alkynylation of Polyphenylenes
Abstract
The functionalization of (bromophenyl)oligophenylene with several alkynes is described. The bromide groups on the oligomer were replaced with terminal alkynes using a Pd/Cu 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 g/cc could be obtained in the final carbon glass. The structure/property relationships and the material applications are discussed. Thermosets, glassy carbon, high density, polyphenylene, cross coupling.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 25, 1992
- Accession Number
- ADA249920
Entities
People
- Eric B. Stephens
- James Tour
Organizations
- University of South Carolina