Disclosed herein are compositions including (a) a first component comprising (1) an epoxy-adduct that is the reaction product of reactants comprising a first epoxy compound, a polyol, and an anhydride and/or a diacid and (2) a second epoxy compound; (b) rubber particles having a core/shell structure and/or graphenic carbon particles; and (c) a second component that chemically reacts with the first component at ambient or slightly thermal conditions. Also disclosed herein are compositions including (a) an epoxy-capped flexibilizer; (b) a heat-activated latent curing agent; and optionally (c) rubber particles having a core/shell structure and/or graphenic carbon particles; (d) an epoxy/CTBN adduct; and/or (e) an epoxy/dimer acid adduct.