Intercalation of anionic organic ultraviolet absorbers in bimetallic and trimetallic layered double hydroxides for low-density polyethylene protection

Bimetallic (Zn/Al) and trimetallic (Mg,Zn/Al) layered double hydroxides (LDHs) intercalated with nitrate were synthesized by the coprecipitation method and used as precursors to obtain LDHs intercalated with the organic anions 4–4′-diamino-2,2′-stilbenedisulfonate and ortho-phthalate through anion exchange reactions. The materials were used as fillers in different ratios in low-density polyethylene (LDPE) to obtain polymer nanocomposites by extrusion-injection molding. The layered materials were characterized by several instrumental techniques, and the mechanical properties of the nanocomposites were evaluated. The samples were exposed to thermo-oxidative conditions at 60 and 90 °C for 1194 h, and the degradation process of the polymer nanocomposites was studied by measurements of hardness, weight loss and oxidation index. Results showed that trimetallic and bimetallic LDH had a notable effect on the LDPE nanocomposites’ degradation, depending on the intercalated anion. Both systems showed potential use as environmentally friendly stabilizers of polymeric matrices, reducing material damage induced by heat and oxidation, increasing the lifetime of the material and lowering the environmental impact.