Structural features and physicochemical properties of promising diamond-containing modifier fillers for industrial polymers, namely, detonation nanodiamonds and nanodiamond soot, are considered. Experimental results demonstrating the possibility to create prepregs with the use of the carbon fabric 1.5 К and a detonation-diamond soot-modified binder based on the epoxy-resin mixture Epikote828/Epikote154 with an anhydride-type curing agent are presented. The rheological characteristics of the diamond-sootmodified binder remain practically the same after storage for 2 or 3 days at room temperature. The dependence of the glass-transition temperatures of the binders on the content of diamond soot in the concentration range 0.025–0.1 wt % is studied, and the correlation between these results and the mechanical characteristics (breaking strength, flexural strength, and crack resistance) of the cured binders is ascertained. Within the entire range of diamond-soot concentrations, the parameters of gelation are determined and the activation energies of this process are calculated.