Photodegradation of some low‐density polyethylene–montmorillonite nanocomposites containing an oligomeric compatibilizer

Abstract

The photo-oxidation behavior at the exposed surfaces of maleated low-density polyethylene [LDPE poly(ethylene-co-butylacrylate-co-maleic anhydride) (PEBAMA)] and montmorillonite (MMT) composites was studied using attenuated total reflection Fourier transform infrared spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and mechanical testing. Two different MMT clays were used with the maleated polyethylene, an unmodified clay, MMT, and an organically modified montmorillonite (OMMT) clay which was significantly exfoliated in the composite. The morphologies of sample films were examined by XRD and TEM. The results were explained in terms of the effect of the compatibilizing agent PEBAMA on the clay dispersion. It was found that the OMMT particles were exfoliated in the polymer matrix in the presence of the PEBAMA, whereas the MMT clay particles were agglomerated in this matrix. Both mechanical and spectroscopic analyses showed that the rates of photo oxidative degradation of the LDPE-PEBAMA-OMMT were higher than those for LDPE and LDPE-PEBAMA-MMT. The acceleration of the photooxidative degradation for LDPE-PEBAMA-OMMT is attributed to the effects of the compatibilizer and the organic modifier in the composite.

Theoretical and experimental assessment of UV resistance of high‐density polyethylene: Screening and optimization of hindered amine light stabilizers

“…During degradation of polyethylene, unsaturations can be formed through Norrish reactions, which predominantly leads to chain scission reactions 38,39 . The C═C bending vinyl group shows an infrared absorption at 906 cm −1 .…”