PVC-laponite nanocomposites: Enhanced resistance to UV radiation

Laponite, a clay mineral, was treated by intercalation of two different phthalocyanine amide polymers based on aliphatic amine (MF-PcAl) as well as an aromatic one (MF-PcAr). The intercalation of the amide polymers was followed by X-ray diffraction (XRD). The different forms of laponite even in its untreated form were incorporated into poly(vinyl chloride) (PVC) formulations via melt blending method to produce PVC-laponite nanocomposites of exfoliated type which was confirmed by XRD. The stabilization mode of the incorporated laponites against UV radiation is discussed based on scanning electron microscopy (SEM), XRD, UV-vis absorption and transmission spectra, electron paramagnetic resonance (EPR), differential scanning calorimetry (DSC) and mechanical properties. Improved resistance to the UV degradative effect was explained on the light of the ability of the clay to scatter the light and to trap any growing radicals as well in addition to the sacrificing role of phthalocyanines by absorbing the incident light on the expense of the PVC and transmitting the rest of the light in another non-harmful form such as heat. (C) 2008 Elsevier Ltd. All rights reserved.