The effect of nanoparticles on the loss of UV stabilizers in polyethylene films

Abstract

The adverse environmental effects (UV radiation and oxidation) on polyethylene films' durability significantly shorten their service life. This work was aimed to study the influence of incorporation of nanoparticles (hydrophobic nanosilica and Na+ nanoclays) to UV stabilized films (by hindered amine light stabilizer – HALS) on sustaining their properties by delaying the loss of the HALS from linear low-density polyethylene (LLDPE) films under photo-oxidative and humid environments. Results demonstrated that the incorporation of nanoclays to the stabilized film increased the photo-oxidative degradation of the LLDPE due to enhanced loss of the HALS from the nanocomposite film. In contrast, the addition of nano-silica delayed the loss of HALS under the same harsh conditions. The slower loss of HALS was attributed to the introduction of a longer diffusion path for the HALS molecules provided by the well-dispersed hydrophobic nanosilica particles and the immobilization effect resulting from the chemical affinity between the hydrophobic nanosilica and the hydrophobic sites on the HALS molecules. The HALS's increased retention in the LLDPE/nanosilica nanocomposite film resulted in extended retention of the film's mechanical properties.