Studies of modification of HDPE and interfacial interaction of its composites with sericite

Ultraviolet irradiation, which is environment friendly and without any chemical pollution, was used to functionalize high-density polyethylene (HDPE) and to improve the interfacial interaction of its composites with sericite in this study. The oxygen-containing groups of C=O, C-O, and C(=O)O were quickly introduced onto molecular chains of HDPE by ultraviolet irradiation in ozone atmosphere and the contents of the introduced oxygen-containing groups increased with increasing the modification time. It is important to note that the irradiation time greatly decreased compared to that in air or oxygen atmosphere. After modification, the molecular weight of the irradiated HDPE decreased and its distribution became wider. The irradiated HDPE in ozone was not crosslinked, which is an advantage over the same reaction in air or oxygen atmosphere. With increasing the irradiation time, the melting temperature of the irradiated HDPE lightly decreased, while its crystallinity, hydrophilicity, and fluidity increased. The composites of HDPE/sericite were prepared. The results showed that the dispersion of sericite in the matrix and the interfacial interaction of sericite with the matrix were markedly improved for the irradiated HDPE/sericite composites. As a result, the irradiated HDPE/sericite composites showed significantly increased tensile yield strength and notched impact strength. Copyright (C) 2010 John Wiley & Sons, Ltd.