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 (∼1.55 g/cm3) C/C substrates after a single carbonization at 1000 °C, and (4) remarkable efficiencies that allow fast carbonization ramp rates (10 °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. Bis-ortho-diynylarene (BODA) monomers undergo thermal polymerization to branched processable reactive resins that further crosslink and carbonize to give high char yield carbon/carbon (C/C) composites with excellent consolidation. [Display omitted] •High carbon yield resins (>80%) amenable to standard composite processing techniques in air.•Synthetic handles for controlled processing, crystallinity, and density.•Fast carbonization rates (10 °C/min) without compromising final carbon density.