Flexible Ethylene Propylene Diene Monomer/Paraffin Wax Vulcanizate with Simultaneously Increased Mechanical Strength, Thermal-Energy Storage, and Shape-Memory Behavior

Authors：Lu, Xiang^*; Yu, Hongwei; Zhang, Lihua; Zheng, Yongfeng; Xu, Linqiong; Zhao, Yongqing^*

Source：Energy and Fuels, 2020, 34(7): 9020-9029.

DOI：10.1021/acs.energyfuels.0c01800

• PHASE-CHANGE MATERIALS
• POLYETHYLENE-GLYCOL
• AEROGEL

Various flexible ethylene propylene diene monomer (EPDM)/paraffin wax (PW) vulcanizates with simultaneously increased mechanical strength, thermal energy storage (TES), and shape-memory behavior were prepared via the general meltblending method. Herein, the PW served as a phase-change working substance for TES applications and as a "hard phase" for shape fixation, and the vulcanized EPDM acted as a supporting material to avoid the leakage of PW and as a "soft phase" for shape recovery. Under the action of the vulcanizing agent, the gel loading of the EPDM component in the EPDM/PW blends increased from 42.0 to 96.0%, and the denser cross-link density provided excellent mechanical strength for the EPDM/PW vulcanizate. The melting and freezing latent heat of the EPDM/PW blend with 60.0 wt % PW (C60) were 123.5 and 121.8 J/g, respectively, and the melting and freezing relative enthalpy efficiencies of C60 were as high as 99.5 and 99.2%, respectively. In addition, C60 has good thermal reliability after 100 thermal cycles, excellent light-to-thermal energy storage, and shape-memory behavior. This study provides a strategy to prepare flexible shape-stable phase-change materials (SSPCMs) via melt-blending for large-scale preparation, and these proposed SSPCMs have a very high commercial value.

• Institution
  中国科学院; 中国科学院宁波材料技术与工程研究所