Microencapsulated n-alkane with p(n-butyl methacrylate-co-methacrylic acid) shell as phase change materials for thermal energy storage

This study deals with fabrication and characterization of p(n-butyl methacrylate-co-methacrylic acid) shell (P(BMA-co-MAA)) microcapsules containing n-alkane as phase change materials (PCMs) for thermal energy storage. The surface morphologies, particle sizes and distributions were studied by scanning electron microscopy (SEM). The chemical characterization of P(BMA-co-MAA)/n-alkane microcapsules was determined by Fourier transformed infrared (FTIR) spectroscopy. The thermal properties, thermal reliabilities, thermal stabilities and temperature-regulated property of the microencapsulated n-alkane were investigated by differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and infrared thermography. The microcapsules containing n-octadecane or a paraffin wax show high phase change enthalpies of melting (130.3 J/g or 123.9 J/g) and freezing (125.8 J/g or 118.4 J/g). The weight loss temperatures of the P(BMA-co-MAA)/n-alkane microcapsules were significantly increased compared with the raw phase change materials (PCMs). The phase change enthalpies of the P(BMA-co-MAA)/n-alkane microcapsules varied little after thermal cycles. Thermal images showed that the gypsum board with incorporated P(BMA-co-MAA)/n-octadecane microcapsules possessed temperature-regulated property. As a result, the as-prepared microcapsules show the good potentials for thermal energy storage, such as building materials.

► n-Alkanes were encapsulated with p(n-butyl methacrylate-co-methacrylic acid).
► The microcapsules have the high latent heats.
► Weight loss temperatures of the microcapsules were increased.
► Phase change enthalpies of the microcapsules varied little after thermal cycles.
► Gypsum board with microcapsules possesses temperature-regulated property.