Application of an Experimental Framework for Evaluating Self-Healing in Aminated Polyolefins

Amine-containing polymers synthesized through catalytic methods have recently attracted attention for their enhanced rheo-mechanical adhesion and intrinsic self-healing capability. In amine-functionalized polyethylene (APE), pendant amine groups appear regularly along the backbone, up to one group per repeating unit. Previous work from our group showed that associative interactions in APE reform quickly, indicating that interfacial recovery occurs in a rapid bond-exchange regime. To test this prediction, we performed tensile measurements using a dynamic mechanical analyzer (DMA) to systematically probe the effects of healing time, waiting time, applied normal stress, and extension rate on mechanical recovery. By explicitly accounting for processing time scales and applied normal stress, we establish a systematic methodology for evaluating self-healing performance in APE, within the entangled molecular weight regime. Despite theoretical expectations of limited interfacial bridging at these conditions, APE samples exhibit substantial recovery of mechanical properties, underscoring the combined contributions of sticker rebonding and backbone re-entanglements. This discrepancy highlights the need to consider not only sticker dynamics but also entanglement density and interfacial processes, including sticker availability at the fractured surface and effective contact area, in describing recovery. Importantly, very few prior studies have examined the coupled influence of processing parameters on healing efficiency; our work identifies these parameters as critical descriptors of self-healing. Overall, this study establishes a systematic experimental methodology for assessing self-healing in entangled associating polymer networks, with extension to broader molecular weight and sticker density ranges identified as an important direction for future work.