Physical Entanglements Supported Polymeric Form Stable Phase Change Materials with Ultra-high Melting Enthalpy.

With the rapid development of new energy and the upgrading of electronic devices, structurally stable phase change materials (PCMs) have attracted widespread attentions from both academia and industries. Traditional cross-linking, composites or micro-encapsulation methods for preparation of form stable PCMs usually sacrifice part of the phase change enthalpy and recyclability. Based on the basic polymer viscoelasticity and crystallization theories, in this work, a kind of novel recyclable polymeric PCM is developed by simple solution mixing ultra-high molecular weight of polyethylene oxide (UHMWPEO) with its chemical identical oligomer PEG. Rheological and leakage-proof experiments confirm that, even containing 90% of phase change fraction PEG oligomers, long-term of structure stability of PCMs could be achieved when the molecular weight of UHMWPEO is higher than 7000 kg/mol due to their ultralong terminal relaxation time and large number of entanglements per chain. Furthermore, because of the reduced overall entanglement concentration, phase change enthalpy of PCMs could be greatly promoted, even reaching to approximate 185 J/g, which is larger than any PEG based form stable PCMs in literatures. This work provides a new strategy and mechanism for designing physical entanglements supported form stable PCMs with ultrahigh phase change enthalpies. This article is protected by copyright. All rights reserved.