Fig. 4b shows the FTIR spectra of the UF microcapsules loaded with linseed oil alone. The spectrum is dominated by a series of aliphatic vibrations around 3009 cm−1, due to the presence of large amount of CH, and CH2 groups in the fatty acids. Stretching vibration of C H, CH2 bonds lead to high absorptions at 2920 and 2860 cm−1.