Zn2Al Layered Double Hydroxides Intercalated with Nitrate and p-Aminobenzoate as Ultraviolet Protective Agents in Low-Density Polyethylene Nanocomposites and Natural Insulating Oils

Zn 2 Al-Cl and Zn 2 Al-NO 3 layered double hydroxides (LDHs) were synthesized through the fixed pH co-precipitation method and used as precursor materials for the intercalation of p-aminobenzoate through anion exchange reactions.Since chloride in Zn 2 Al -Cl was only partially exchanged with p-aminobenzoate, the phases Zn 2 Al -NO 3 and Zn 2 Al-N -AB (nitrate exchanged with p-aminobenzoate) were used in different percentages as functional fillers to produce nanocomposites of low-density polyethylene doped with maleic anhydride (LDPE).Analysis of thermal properties showed that the melting and recrystallization temperatures were slightly increased in the nanocomposite containing 5 wt.%Zn 2 Al-N-AB.Weathering tests performed with neat LDPE and the nanocomposite films showed that the addition of the LDHs improved ultraviolet (UV) absorption and reduced the LDPE degradation by 25 and 76% when using Zn 2 Al-NO 3 and Zn 2 Al-N-AB, respectively, as fillers, showing a promising UV-shielding effect.Preliminary results also showed a potential application of Zn 2 Al-N-AB as antioxidant in natural insulating oils (natural ester FR3 and castor oil), opening new opportunity of applications.