Microstructure and thermal properties of cetyl alcohol/high density polyethylene composite phase change materials with carbon fiber as shape-stabilized thermal storage materials

Abstract

This work presents an experiment on thermal properties of organic cetyl alcohol phase change materials (PCMs) incorporated with high density polyethylene (HDPE). Mass proportions of PCMs ranged from 70wt% to 90 wt%. Cetyl alcohol (CtA) was chosen as the solid–liquid PCM and HDPE worked as the supporting material. While CtA performed as thermal energy storage medium, at the same time the leakage of the PCM was resolved by HDPE. The novel shape-stabilized composite phase change materials (CPCMs) were fabricated via impregnation of CtA into HDPE. In addition, the thermal conductivity of CPCMs was enhanced by carbon fiber (CF). The microstructure, crystalline phase and chemical structure were determined by scanning electronic microscope (SEM), X-ray diffractometer (XRD) and Fourier transformation infrared spectroscope (FT–IR). The results demonstrated that CtA was well impregnated into the HDPE. Differential scanning calorimeter (DSC) was utilized to analyze thermal properties of the composite phase change materials (CPCMs), the outcome indicated that the CPCMs nearly melted at around 50°C with a latent heat of 149.02–212.42kJ kg−1. Thermal gravimetric analyzer (TGA) confirmed that the CPCMs have an improved thermal reliability and the addition of CF contributed to a significant decrease in the leakage of CtA. The thermal conductivity meter (TCM) determined that the thermal conductivity of CPCM with 5wt% CF was 0.33W/(m K) and 0.47W/(m K) in liquid and solid state respectively, which was 1.25 and 1.22 times higher than that of original CPCM without CF. The experimental results indicate that the prepared CPCMs have prospects in thermal energy storage field.