THERMALLY STABLE ACETYLENIC ADAMANTANE POLYMERS

1,3-Diethynyladamantane (4) was synthesized from adamantane in 67% yield and polymerized thermally at 210-degrees-C or in the presence of catalysts at 160-190-degrees-C. After postcure at 320-degrees-C, the resulting clear thermoset polymer exhibited an onset of major decomposition at 476-degrees-C in air and 475-degrees-C in helium (TGA). The polymer did not show thermal transitions in the DSC between 25 and 450-degrees-C, but exhibited a weak glass transition in DMTA at 260-degrees-C. Soluble oligomers were prepared by either thermal or bis-(benzonitrile)palladium chloride catalyzed oligomerization and characterized by thermal analysis and molecular weight determinations. The catalyzed oligomers contained cyclotrimerized acetylene groups, whereas thermal oligomers contained linear polyene structures. 1-Ethynyladamantane (6), which formed no thermal homopolymer, formed copolymers with 4.