Self-Healing Recovery and Dynamics of Associating Polymers under Uniaxial Extension

Associating polymers are a desirable class of materials with intrinsic abilities to self-heal without the need for additional components or added stimulus. While experimental and theoretical measurements of recovery exist in the literature, quantifying recovery in terms of fundamental rheological parameters is often difficult. In this work we use filament stretching uniaxial extension to probe the recovery of unentangled and entangled hydrogen bonding polymers. Using a novel methodology, we confirm the role of process timescales such as the time before and after recovery on both the transient rheology and ultimate recovery of associating polymers. Furthermore, we show the importance of architecture and molecular timescales of the network on recovery. We find that while strongly associating groups provide improved mechanical strength, they often delay the process of recovery. Additionally, we show that the presence of entanglements has a complex role on recovery, introducing t he flow timescale as an additional parameter. With this work, we develop a framework that is both useful for evaluation of self-healing soft materials and for design of novel self-healing polymers.