Progress in Utilizing Dynamic Bonds to Fabricate Structurally Adaptive Self-Healing, Shape Memory, and Liquid Crystal Polymers.

Stimuli-responsive structurally dynamic polymers are capable of mimicking the biological systems to adapt themselves to the surrounding environmental changes and subsequently exhibiting a wide range of responses ranging from self-healing to complex shape-morphing. Dynamic self-healing polymers (SHPs), shape-memory polymers (SMPs), and liquid crystal elastomers (LCEs), which are three representative examples of stimuli-responsive structurally dynamic polymers, have been attracting broad and growing interest in recent years because of their potential applications in the fields of electronic skin, sensors, soft robots, artificial muscles, and so on. Recent advances and challenges in the developments toward dynamic SHPs, SMPs, and LCEs are reviewed, focusing on the chemistry strategies and the dynamic reaction mechanisms that enhance the performances of the materials including self-healing, reprocessing, and reprogramming. The different dynamic chemistries and their mechanisms on the enhanced functions of the materials are compared and discussed, where three summary tables are presented: A library of dynamic bonds and the resulting characteristics of the materials. Finally, a critical outline of the unresolved issues and future perspectives on the emerging developments is provided.