This work involved the successful synthesis of three new Schiff base complexes, including Ni(II), Mn(II), and Cu(II) complexes. The Schiff base ligand was created by reacting the malonyldihydrazide molecule with naphthaldehyde, and the final step involved reacting the ligand with the corresponding metallic chloride yielding pure target complexes. FTIR, 1 H NMR, 13 C NMR, mass, and UV/Vis spectroscopies were used to comprehensively characterize the produced complexes. These substances have been employed in this study to photo-stabilize polystyrene (PS) and lessen the photo-degradation of its polymeric chains. Several methods, including FTIR, weight loss, viscosity average molecular weight, light and atomic force microscopy, and energy dispersive X-ray (EDX) mapping, were used to assess the effectiveness of produced complexes as photo-stabilizers. These experiments supported one another and showed how well novel complexes stabilize PS photos. Hence, after 300 h of exposure to UV light with a wavelength of 313 nm, they lessen the photo-degradation of PS films containing these complexes compared to blank PS. Also, it has shown that the copper(II) complex works well as a photo-stabilizer. This is due to the highly conjugated systems in these compounds. The findings of this study have significant implications for reducing PS usage globally, which poses a serious danger to the environment, particularly the marine eco-system as a result of plastic trash.
