Relationship Between the Structure of Organic Dyes and the Thermal Conductivity of Colored Polyvinyl Alcohol Films

For the first time in this paper, the effect of organic dyes on the thermal conductivity of polyvinyl alcohol (PVA) films was studied. This is crucial for the development of thermostable PVA films, which are utilized in various engineering and technological fields, including optoelectronics, mechanical engineering, space exploration, medicine, and others. In the course of the work, it was revealed that oriented PVA films are characterized by the phenomenon of anisotropy of thermal conduction (η_λ), which is manifested in the fact that thermal conductivity in the direction of orientation (λ_||) is higher than in the direction perpendicular to the orientation (λ_⊥). Unstretched and stretched PVA films do not have significant thermal conductivity anisotropy. Colored stretched PVA films have anisotropy of thermal conductivity. The factor that causes anisotropy of thermal conduction is an organic dye.