Requirements for Achieving Self-Healing at Low/Room Temperature in Polymers.

Low-temperature self-healing polymers are crucial, as many real-world damage events occur in environments where external heating is impractical or energy-inefficient. However, achieving effective self-healing at these temperatures remains a significant challenge due to the restricted polymer chain mobility. To tackle this challenge, strategies have been investigated, such as modulating the strength of reversible chemical bonds; however, these approaches alone are often inadequate. In this Perspective, we comprehensively examine the factors influencing polymer chain mobility under low and ambient temperatures. We focus on optimizing material design to balance mechanical strength and healing performance, considering factors such as polymers with low glass transition temperatures, different types of polymers, branched to hyperbranched architectures, the role of shape-memory effects, and the facilitative impact of solvents. These insights provide a foundation for designing self-healing polymers tailored to specific application demands. Furthermore, we outline key considerations in synthetic design, molecular mobility, healing time, mechanical properties, and other functional properties, such as hydrophobicity and impedance modulus, as well as perspectives for creating materials that effectively self-heal at low or room temperatures.