Yet, small-angle X-ray scattering (SAXS) reveals pronounced primary peaks characteristic of microstructural ordering, as shown by the radially integrated one-dimensional intensity profiles in Fig. . The SAXS patterns are consistent with the classical block copolymer self-assembly that forms a sphere microstructure at 𝑓 lower than 0.18. Interestingly, as 𝜆 increases, the position of the primary scattering peak, q * , moves towards higher wavevector numbers. This indicates that the distance between two neighboring spherical domains decreases at higher concentration of reversible bonds (see Table and SAXS measurements in SI Materials and Methods). By contrast, in a sphere microstructure self-assembled by conventional triblock copolymers without reversible bonds, to balance the interfacial repulsion between incompatible blocks, the middle block is stretched to a size 𝑅 that is determined by its MW 𝑀 𝑅 and the end block volume fraction 𝑓:𝑅~𝑓 2/9 𝑀 𝑅 2/3 . 30 Such a difference is likely attributed to the inter-and intra-molecular interactions of stickers on the middle block, which help balance the interfacial repulsion between the incompatible ends and middle blocks to result in less stretched network strands. Further understanding of the effects of reversible bonds on block copolymer self-assembly is beyond the scope of this paper and will be subjected to future explorations. Nevertheless, the LAL polymers self-assemble into an elastomer consisting of a strong network crosslinked by glassy nodules and an associative polymer network crosslinked by hydrogen bonds. We use a stress-controlled rheometer to quantify the dynamic mechanical properties of the polymer networks. At room temperature, the shear storage modulus G' of polymer networks is nearly constant at low frequency, as shown by solid symbols in Fig. . Therefore, we take the value of G' at the lowest oscillatory shear frequency, 0.1 rad/sec, as the equilibrium shear modulus G. The shear modulus for the network without reversible bonds, 𝜆 = 0, 𝐺 is 2.7 kPa. As 𝜆 increases from 0 to 0.25, corresponding to on average 2.2 amide groups per Kuhn segment , G increases by nearly 4 times from 2.7 kPa to 10.8 kPa. This increase suggests that at relatively high fraction of associative groups, the contribution to the network stiffness from reversible bonds dominates that from glassy nodules.