Quantum-chemical calculations using the Density Functional Theory (DFT) approach for structural analysis of a new azo benzene derivative: Sodium 6-amino-5-hydroxy-3-((E)-(2methoxy-4-((E)-(4-sulfonatophenyl)diazenyl)phenyl)diazenyl)naphthalene-2-sulfonate (A) (trans isomer) were designed using B3LYP method with 6-311++G** basis set. The electronic absorption spectrum of the A in water solution was calculated using TDB3LYP/6-311++G** method. The excitation energies, electronic transitions and oscillator strengths for studied structure have also been calculated. On the basis of calculations a new dichroic azo benzene dye A was synthesized. The experimental UV-Vis, FT-IR and 1 H NMR spectra of the title molecule were presented. On the basis of polyvinyl alcohol (PVA) and the dichroic synthesized azo benzene dye A thermostable polarizing film absorbing in the seen region of the spectrum (λ max = 550 nm) with Polarization Efficiency (PE) in the absorption maximum (λ max = 92 %) and Stretching Degree (R s) = 3.0 was developed. The experimental spectral-polarization parameters of stretched colored PVA-films were measured. During the work it was established that oriented PVA-films is phenomenon of anisotropy of thermal conductivity (λ || / λ ⊥). Thermal conductivity in a direction of orientation (λ ||) is higher than in a direction perpendicular orientations (λ ⊥).