High Carbon Yielding and Melt Processable Bis-Ortho-diynylarene (Boda)-Derived Resins for Rapid Processing of Dense Carbon/carbon Composites

Bis-ortho-diynylarene (BODA)-derived resins undergo thermal, radical-mediated Bergman cyclization to predominately naphthalene diradicals which propagate in a stepwise fashion to highly branched processable intermediates that are amenable to current composite fabrication techniques prior to network cure and subsequent carbonization. Post-carbonization analysis reveals significantly higher density and consolidation in the BODA-derived carbon/carbon (C/C) over existing phenolic-based C/Cs without the need for arduous, multiple infusion and carbonization steps. The modular BODA approach combines and controls: (1) variable melt processability dictated by terminal or spacer group substitution, (2) mild cure kinetics via a non-autocatalytic reaction, (3) high carbon yield (>80%) to provide relatively dense (similar to 1.55 g/cm(3)) C/C substrates after a single carbonization at 1000 degrees C, and (4) remarkable efficiencies that allow fast carbonization ramp rates (10 degrees C/min) while maintaining high density. Isothermal DSC kinetics, monomer melt stability in air, order/disorder characterization by Raman and WAXS, resin processing under selected air environments, and fractured cross-section analyses of C/C composites by SEM is discussed.