Abstract：
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 microencapsulation 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, here, a kind of novel recyclable polymeric PCM is developed by simple solution mixing ultrahigh molecular weight of polyethylene oxide (UHMWPEO) with its chemical identical oligomer polyethylene glycol (PEG). Rheological and leakage-proof experiments confirm that, even containing 90% of phase change fraction PEG oligomers, long-term of structure stability of PCMs can be achieved when the molecular weight of UHMWPEO is higher than 7000 kg mol-1 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 can be greatly promoted, even reaching to ≈185 J g-1, 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.
摘要：
随着新能源的快速发展和电子设备的更新换代,结构稳定的相变材料（PCM）引起了学术界和工业界的广泛关注。传统的交联,用于制备形式稳定的PCM的复合材料或微胶囊化方法通常牺牲部分相变焓和可回收性。基于基本的聚合物粘弹性和结晶理论，在这项工作中，通过简单的溶液混合超高分子量的聚环氧乙烷（UHMWPEO）和其化学相同的低聚物PEG，开发了一种新型的可回收聚合PCM。流变和防漏实验证实，甚至含有90％的相变分数PEG低聚物，当UHMWPEO的分子量高于7000kg/mol时，由于它们的超长末端弛豫时间和每条链的大量缠结，可以实现PCM的长期结构稳定性。此外，由于整体缠结浓度降低，可以大大提高PCM的相变焓，甚至达到约185J/g，其大于文献中的任何基于PEG的形式稳定的PCM。这项工作为设计具有超高相变焓的稳定PCM支持的物理缠结提供了新的策略和机制。本文受版权保护。保留所有权利。
