Coloring study in organic hybrid of polyamide (PA6) and N'N-ethylene-bis(tetrabromophthalimide) (EPT), where the chromophore was self-assembled by hydrogen bonding formed between PA6 molecular chains and EPT compound, have been characterized by several techniques. CS930 double wavelength lamella scanner was employed to measure the change of color. The existence of hydrogen bonding in PA6/N-N'-ethylene-bis (tetrabromophthalimide) (PA6EPT) was investigated with Fourier transform infrared (FTIR), the results of which were compared with that of PA6 with the same thermal history. FTIR spectra at room temperature revealed that there is essentially hydrogen bonding between PA6 and EPT. The crystallization behavior of PA6EPT affected by hydrogen bonding was studied by using FTIR. The temperature-dependent behavior of both PA6 and PA6EPT was studied by temperature-FTIR spectroscopy and differential scanning calorimetry (DSC). With temperature increasing, changes in sensitive, high-resolution absorbance spectra are observed as dissolve-volatilizing thin film. Temperature-FTIR results showed that the hydrogen bonding in PA6EPT attenuated and dissociated considerably at a smaller rate than PA6, that is to say, hydrogen bonding in PA6EPT is more stable than that in PA6. DSC showed that the melting temperature of PA6EPT and PA6 are similar. However, the crystalline degree and crystalline temperature and melting enthalpy of PA6 and PA6EPT are different. (c) 2007 Wiley Periodicals, Inc.