This paper describes the synthesis of cobalt hydroxide nitrate (CoHN) and cobalt hydroxide p-aminobenzoate (CoHAB), which were dispersed in polyethylene with the objective of protecting the polymer from ultraviolet (UV) radiation degradation. First, CoHN was synthesized by urea hydrolysis in the presence of Co(II) nitrate and the intercalation of p-aminobenzoate into CoHAB was performed under hydrothermal alkaline conditions. The structure and thermal stability of the CoHN and CoHAB were characterized by several instrumental techniques. Results indicated that both fillers were dispersed in polyethylene and absorb radiation in the whole UV range, modifying the behavior of the polymer degradation under artificial weathering conditions. [GRAPHICS] .