We denote a LAL triblock copolymer as 𝐴 𝑦 (𝐵 which is weak enough to dissociate at laboratory time scales at room temperature yet strong enough for efficient energy dissipation. Such a balance between dissociation and association is critical to achieving a combination of high toughness and rapid self-healing, as both theoretically predicted and experimentally 27 demonstrated in previous studies. Furthermore, the reversible blocks explored in this study have a Tg below -40 ℃ and remain elastomeric at room temperature. We start with quantifying the reaction kinetics of the spacer and the sticky monomers using proton nuclear magnetic resonance spectroscopy ( 1 H NMR characterization in SI Materials and Methods). Because both monomers have the same acrylate functional group and similar molecular structure, they exhibit the same reaction rate, as shown by the same fraction of sticky monomers before and after polymerization (Fig. ). The conversion rate increases linearly with reaction time regardless of the fraction of reversible groups explored in this study (Fig. ). This informs the successful synthesis of a set of LAL triblock polymers with fixed 𝑓 ≈ 0.10 but various 𝜆 = 0, 0.09, and 0.25 (Fig. , and synthesis conditions in Table ), which respectively corresponds to an average of 0, 0.8, and 2.2 amide groups per Kuhn segment , as well as fixed 𝜆 =0.25 but various 𝑓 ≈ 0.10, 0.13, 0.27, and 0.32 (Fig. ). Importantly, the MW of all polymers is fixed near 40 kg/mol which is below the critical MW of poly(hexyl acrylate) (PHA) and will limit the effects of entanglements. This set of triblock polymers allows exploring the effects of reversible bonds on the properties of unentangled polymer networks. At room temperature, the LAL polymers form a colorless and optically transparent solid (Fig. ).