Flexible polyurethane-based phase change materials with excellent thermal management for human thermal therapy

Phase change materials with high energy storage density and stable phase change temperature are ideal choices for personal thermal therapy and heat management. However, leakage and poor flexibility have long been bottlenecks in their application. Excellent latent heat performance and flexibility are crucial, especially in the thermal management of flexible wearable devices. In this study, a simple strategy was adopted to prepare a flexible polyurethane-based phase change material using a prepolymer method with polyethylene glycol (PEG) as the phase change material. Attributed to the cross-linked network structure in the polymer, the prepared phase change material exhibits excellent thermal stability and shape stability without leakage. Additionally, it shows relatively high latent heat and good flexibility. Based on these significant comprehensive properties, a performance-improved thermal wrist wrap was designed to achieve thermal therapy and efficient human heat management. This work provides insights into the rational design of flexible and shape-stable high latent heat phase change materials, demonstrating tremendous potential applications in wearable thermal management.