Huaili Qin

Photo-oxidative degradation of polyethylene/montmorillonite nanocomposite

Abstract Photo-oxidative degradation is critical to polymer materials. It is even the case in polymer/layered silicate nanocomposites. A UV photo-oxidative degradation study on polyethylene/montmorillonite (PE/MMT) nanocomposite was carried out by FT-IR technique. It is indicated that the rate of photo-oxidative degradation of PE/MMT nanocomposite is much faster than that of pure PE. The acceleration of photo-oxidative degradation of PE/MMT nanocomposite is due to the effect of MMT and ammonium ion, in which the effect of ammonium ion is primary. It has been found that the dispersion state (either nano- or micro-) of MMT does not seem conclusive on the acceleration of degradation. Fe 3+ modified MMT can also accelerate the photo-oxidative degradation of PE matrix.

Photo-oxidation of Polyolefin/Clay Composites

The photo-oxidation behavior of the polyolefin/clay composites is characterized on the basis of the source, type and modification of clays as well as the presence of compatibilizer. It is concluded that the photo-oxidation of polyolefin matrix is mainly due to acidity of clay but less dependent on the dispersion state of the filler. The photo-stabilization of polyolefin using modified clay has discussed.

Environmental stability and flammability of polyolefin/layered silicate nanocomposites

Abstract: Photo degradation, thermal degradation and flammability of polyolefin/layered silicate nanocomposites are described in this chapter. In the presence of montmorillonite, the photo-oxidative degradation of polyethylene and polypropylene are accelerated due to the catalytic effect of the layered silicates. The order of the thermal degradation of polypropylene is lowered, even to zero in case of alkylammonium-modified or protonized montmorillonite. During combustion, the decrease of heat release rate is not only due to the barrier effect of silicate layers but mainly attributable to the protective coat-like char and physical-chemical crosslinking caused by the active sites on clay layers and acidic sites created by the decomposition of organoclay.