Zhang Chunpeng, Pang Chaoming, Mao Yunrui, Tang Zhiyuan
Jiangsu Key Laboratory of Civil Engineering Material, School of Materials Science and Engineering, Southeast University, Nanjing 211189, China.
Materials (Basel). 2022 Apr 8;15(8):2749. doi: 10.3390/ma15082749.
The use of phase change materials (PCMs) in the construction industry is one of the primary strategies for addressing the building industry's present excessive energy usage. However, since PCMs must be enclosed before being used in construction, their efficiency is limited and their compatibility with concrete is poor. Thus, polyethylene glycol (PEG), a sequence of PCMs that may be put directly into concrete, is the target of this research. The fluidity, mechanical properties, thermal properties, hydration process, and hydration products of PEG-600 cement slurry were examined by TAM, XRD, FTIR, DSC, MALDI, etc., methods in this study. Furthermore, we tested the thermal properties of PEG-800 to confirm that the same depolymerization of PEG occurred in an alkaline environment. When PEG, with a molecular weight of 600 (PEG-600), dose was increased to 10%, both compressive and flexural strength fell by 19% and 18%, respectively. The phase change points of both PEG-600 cement paste and PEG-800 cement paste decreased to 10~15 °C, and the enthalpy of the phase change was about 6 J/g. Additionally, it was discovered that PEG entered the reaction during the hydration step. PEG underwent depolymerization and subsequently formed a complex with Ca. However, due to the large dose of PEG used in this investigation, a self-curing effect of PEG in concrete was not seen. The findings of this research suggest a novel use for PCMs: PEG may be directly applied to concrete to fulfill both mechanical and thermal requirements. Additionally, the number of hydration products and phase compositions remained almost constant.
在建筑行业中使用相变材料（PCM）是解决该行业当前能源过度使用问题的主要策略之一。然而，由于PCM在用于建筑之前必须进行封装，其效率受到限制，并且与混凝土的兼容性较差。因此，本研究的目标是聚乙二醇（PEG），这是一种可直接放入混凝土中的PCM序列。本研究通过TAM、XRD、FTIR、DSC、MALDI等方法研究了PEG - 600水泥浆体的流动性、力学性能、热性能、水化过程和水化产物。此外，我们测试了PEG - 800的热性能，以确认PEG在碱性环境中发生了相同的解聚。当分子量为600的PEG（PEG - 600）用量增加到10%时，抗压强度和抗折强度分别下降了19%和18%。PEG - 600水泥浆体和PEG - 800水泥浆体的相变点均降至10~15℃，相变焓约为6 J/g。此外，还发现PEG在水化步骤中参与了反应。PEG发生解聚，随后与Ca形成络合物。然而，由于本研究中使用的PEG剂量较大，未观察到PEG在混凝土中的自养护效果。本研究结果为PCM提出了一种新的用途：PEG可直接应用于混凝土，以满足力学和热学要求。此外，水化产物的数量和相组成几乎保持不变。
