Research

Intrinsically self-healing polymers are plastics that rapidly repair damage when two broken interfaces are brought into contact.  Self-healing plastics have garnered interest as sustainable alternatives to conventional plastics that can be repaired and reused, reducing plastic waste accumulation. However, designing self-healing plastics remains challenging because the molecular mechanisms governing self-healing remain poorly understood in many polymer systems. We lack this knowledge because self-healing occurs at nanoscale polymer interfaces, and experiments cannot easily access these details while systems heal. The objective of our project is to combine molecular dynamics simulations and mechanical welding experiments to identify the molecular mechanisms that mediate the self-healing process in a diverse class of self-healing polymers: precisely sequenced thermoplastic elastomers. Molecular simulations can directly resolve the molecular-scale details that are difficult to observe and directly relate them to the time-dependent recovery of mechanical strength measured in experiments. This combined approach will build fundamental relationships relating the chemical structure of polymer chains to the speed at which they recover specific mechanical properties like strength, stiffness, and yield stress during interfacial welding. Our findings will guide the molecular design and synthesis of new self-healing plastics with improved mechanical properties and repairability.