Polymers are used in different applications that might be an issue for the environment. Thus, our strategy is to create a material that can be more sustainable and last longer in use. For this purpose, a new Schiff base was synthesized containing a triazole ring (L), which was introduced to a poly (vinyl chloride)(PVC) chain via substitution reaction. Copper chloride was then added to the previous compound to give the final product PVC-L-Cu. The films' resistivity to degradation under Ultraviolet (UV) light irradiation was investigated under accelerated conditions. Fourier-transform infrared (FTIR) spectroscopy, weight loss, and scanning electron microscopy (SEM) were used to follow the changes after exposure to UV light. The novel Schiff base enhanced the photostability of PVC polymer significantly in comparison to the pristine polymer.