Ultraflexible, cost-effective and scalable polymer-based phase change composites for wearable thermal management

Abstract

Phase change materials (PCMs) offer great potential for realizing zero-energy thermal management due to superior thermal storage and stable phase-change temperature. However, the liquid leakage and solid rigidity of PCMs are two long-standing challenges for PCM-based wearable thermal management applications. Herein, a facile and cost-effective strategy is reported, which utilizes the peroxide radical-initiated mechanism to develop ultraflexible polymer-based phase change composites with a dual 3D crosslinked network of olefin block copolymers (OBC) and styrene-ethylene-butylene-styrene (SEBS) inside PCMs. The synergistic effect of OBC-SEBS dual network on brittleness and elasticity enhancement enables the resultant paraffin wax (PW) composites of PW@OBC-SEBS to present outstanding flexibility (strain at break of 20-560%), high latent heat enthalpy (~ 176 J/g), superior thermal stability, and leakage-proof properties. Notably, the proposed peroxide-assisted sequential blending approach overcomes the limitations of traditional heavy processing equipment, achieving low-cost and efficient large-scale production. Furthermore, the applicability of a portable and flexible PW@OBC-SEBS module for wearable thermal management is demonstrated. The energy module can maintain a thermal comfort temperature range of 39-41°C, highlighting the realization of stable temperature control for personal thermotherapy. Our work provides a promising route to fabricate scalable and flexible polymer-based phase change composite for wearable thermal management.