Self-healing Polymers (SHPs) via Reversible Deactivation Radical Polymerization (RDRP): Synthesis, properties and applications

Self-healing polymeric materials are intelligent materials engineered to autonomously repair damages using external stimuli which are the vanguard of sustainable materials research. The ability to maintain product quality and functionality, extended lifespan of products and cost-effectiveness play a significant role for the development of self-healing polymers (SHPs) and all of which substantially reduce the environmental impact of plastic waste. Over the years, Reversible Deactivation Radical Polymerization (RDRP) techniques, such as Nitroxide-mediated radical polymerization (NMP), Atom Transfer Radical Polymerization (ATRP), Reversible AdditionFragmentation Chain Transfer (RAFT) polymerization and Ring-Opening Metathesis Polymerization (ROMP) have been widely used to synthesize SHPs with precise control over the molecular weight, distribution, architecture and functionality. Despite their potential, there is no comprehensive review that addresses the synthesis, advantages and applications of SHPs via RDRP methods. This review fills that gap by presenting detailed case studies that elucidate the unique properties and applications of SHPs synthesized through RDRP methods. The primary goal of this review is to provide a comprehensive perspective on the design of SHPs using various RDRP techniques, highlighting how these methods enable the preparation of SHPs with controlled architectures. Case studies of various RDRP techniques like ATRP, RAFT, NMP and ROMP are described, exhibiting their application in different healing mechanisms, such as reversible Diels-Alder (DA) and retro-DA (rDA) reactions, it-it interactions, hydrogen bonding and encapsulated microcapsules. By bridging the gap between fundamental RDRP techniques and practical applications of SHPs, this review aims to guide researchers and industry professionals in developing next-generation materials with enhanced self-healing capabilities.