Effect of UV Exposure on the Mechanical Properties of Polyurethane-Coated Fabrics

Polyurethane materials can be used industrially in different ways, some of which can be used as textile materials or as auxiliary materials applied to textile materials. Polyurethane stands out as a widely used polymer for coating textile products used in outdoor applications, because of high stability at low temperature, flexibility, no or very little volatile organic component content, high water resistance, pH stability, excellent solvent resistance, weather resistance, and many other chemical and mechanical properties. In the study, cotton, polyester, and viscose fabrics were coated with polyurethane and aged under UV light to investigate the causes and behaviors of the mechanical degradation effects of UV on the coating material and fiber. The results indicate that the PU coating process improves the mechanical properties of textile materials while being exposed to UV rays deteriorates the fabric structure. The deterioration in the structure of raw and coated fabrics with the effect of UV increased the air permeability. According to the results of DSC analysis, the increase in the time of UV exposure did not create significant differences in terms of thermal degradation temperatures in both cotton and viscose fabrics. The glass transition temperatures (Tg) increase with more exposure to UV rays, and the UV exposure time had a negative effect on the melting temperature (Tm) and enthalpy (ΔH) of coated polyester fabrics.