Research on the preparation and properties of high and low-temperature cement-based phase change materials

In this paper, a high and low-temperature cementitious composite incorporating phase change material (PCM) was developed by using n-tetradecane (C14) and F46 paraffin (PA) as PCMs and expanded perlite (EP) as a carrier. The thermal properties and stability of the PCM-incorporated cementitious composites were studied by high and low-temperature cyclic tests. Phase change cement-based materials (PCESMs) were characterized by thermal conductivity testing, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR). FT-IR results and SEM imaging showed that C14 and PA could effectively fill EP pores, and there was no chemical reaction between C14, PA, and EP. DSC confirmed that the composites incorporated with PCMs wrapped by the direct encapsulation method still maintained a high latent heat. The experimental results also showed decreasing mechanical properties (compressive and flexural strength) of PCESM with increased PCM dosage, whereas the corresponding thermal performance gradually increased. 20% PCM content was found optimal for the overall performance of PCESM.