Preparation and Characterization of Microencapsulated Phase Change Materials for Use in Building Applications

A method for preparing and characterizing microencapsulated phase change materials (MPCM) was developed. A comparison with a commercial MPCM is also presented. Both MPCM contained paraffin wax as PCM with acrylic shell. The melting temperature of the PCM was around 21 degrees C, suitable for building applications. The M-2 (our laboratory made sample) and Micronal r DS 5008 X (BASF) samples were characterized using SEM, DSC, nano-indentation technique, and Gas Chromatography/Mass spectrometry (GC-MS). Both samples presented a 6 mu m average size and a spherical shape. Thermal energy storage (TES) capacities were 111.73 J.g(-1) and 99.3 J.g(-1) for M-2 and Micronal (R) DS 5008 X, respectively. Mechanical characterization of the samples was performed by nano-indentation technique in order to determine the elastic modulus (E), load at maximum displacement (P-m), and displacement at maximum load (h(m)), concluding that M-2 presented slightly better mechanical properties. Finally, an important parameter for considering use in buildings is the release of volatile organic compounds (VOC's). This characteristic was studied at 65 degrees C by CG-MS. Both samples showed VOC's emission after 10 min of heating, however peaks intensity of VOC's generated from M-2 microcapsules showed a lower concentration than Micronal (R) DS 5008 X.