This article presents the synthesis and structural, thermal and dynamic mechanical characterization of segmented polyurethane - PCLDHAB - based on poly(caprolactone)-diol (PCL-diol) as a flexible segment, and polyurethane-diol (PU-diol) as a rigid segment based on 2,2′-dihydroxyazobenzene (2,2′-DHAB). While the precursors PU-diol and PCL-diol are rigid and waxy materials, respectively, PCLDHAB is a flexible, semi-crystalline polymer, which has a heterogeneous amorphous phase. To better understand the absorption spectra of the polyurethanes, theoretical predictions by DFT and TD-DFT of a model molecule in DMF (implicitly added) were carried out. The model molecule was a fragment of the hard segment of the polyurethane’s chain, containing one 2,2′-DHAB and two 4′-isocyanate-4′-methylbenzene fragments, bonded to each other by carbamate bonds, the 4-isocyanate-4′-metylbenzene-alt-2,2′-dihydroxyazobenzene. Similar to 2,2′-DHAB, PU-diol and PCLDHAB do not show photoisomerization, however they emit fluorescence. 2,2′-DHAB segments in the polyurethane chains present different conformations with distinct spectroscopic characteristics. However, the conformer’s proportion in the polymer chains differs from the 2,2′-DHAB monomers in DMF solution. 2,2′-DHAB emits in two ranges in the UV–vis spectrum while its polyurethanes emit in three ranges, covering a broader wavelength range from ultraviolet to visible Ver menos