This study focused on the preparation, characterization, and determination of thermal properties of microencapsulated n-hexadecane with poly(butyl acrylate) (PBA) to be used in textiles with heat storage property. Microcapsules were synthesized by emulsion polymerization method, and the particle size, particle size distribution, shape, and thermal storage/release properties of the synthesized microcapsules were analyzed using Fourier-transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry techniques. Allyl methacrylate, ethylene glycol dimethacrylate, and glycidyl methacrylate were used as cross-linkers to produce unimodal particle size distribution. MicroPBA microcapsules produced using allyl methacrylate crosslinker were applied to 100% cotton and 50/50% cotton/polyester blend fabrics by pad-cure method. The mean particle size of microcapsules ranges from 0.47 to 4.25 mu m. Differential scanning calorimetry analysis indicated that hexadecane in the microcapsules melts at nearly 17 degrees C and crystallizes at around 15 degrees C. The contents of n-hexadecane of different PBA microcapsules were in the range of 27.7-50.7%, and the melting enthalpies for these ratios were between 65.67 and 120.16 J/g, respectively. The particle size and thermal properties of microcapsules changed depending on the cross-linker type. The cotton and 50/50% cotton/polyester blend fabrics stored 6.56 and 28.59 J/g thermal energy, respectively. The results indicated that PBA microcapsules have the potential to be used as a solid-state thermal energy storage material in fabrics. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: 2821-2829, 2011