Preparation, characterization and thermal properties of dodecanol, palmitic acid and hydroxylpropyl methyl cellulose as novel form-stable phase change materials

In order to adjust buildings temperature, a dodecanol (DD)-palmitic acid (PA)/hydroxylpropyl methyl cellulose (HPMC) composite phase change material was prepared by vacuum impregnation. DD-PA was absorbed into the HPMC, which was verified by specific surface area, pore size (BET) and scanning electron microscopy (SEM) analysis. The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD) indicated that the HPMC and DD-PA were only physical combination. The differential scanning calorimetry (DSC) analysis revealed that the phase change temperature and latent heat were 19.34 ºC and 113.12 J g −1 , which means good energy storage capacity. The 5% mass loss temperatures ( T -5% ) of thermo-gravimetric analysis (TG) was higher than 50 ºC, showing the good thermal stability of composite phase change materials. About 60% DD-PA was absorbed in HPMC, which detected by DSC and TG. After 100 thermal cycling, the latent heat, onset temperature ( T 0 ), peak temperature ( T peak ) and end temperature ( T end ) had changed −1.02%, −8.20%, −4.29% and −5.60%. The result showed that the composite phase change materials own good thermal reliability. In addition, the 2% multi-walled carbon nanotubes (MW CNTs) were added to improve the thermal conductivity. And the thermal conductivity was increased from 0.130 to 0.172 W (mK) −1 , the total thermal storage-release time was decreased from 3740 to 2310 s.