Interactions of montmorillonite and electron beam irradiation in enhancing the properties of alumina trihydrate–added polyethylene and ethylene vinyl acetate blends

Abstract

This study aims at investigating the effects of electron beam irradiation on the montmorillonite and alumina trihydrate–added low-density polyethylene and ethylene vinyl acetate blends. The mechanical, flammability and electrical resistivity of the montmorillonite and alumina trihydrate–added low-density polyethylene and ethylene vinyl acetate blends were investigated. The addition of montmorillonite provided the reinforcing effect to the alumina trihydrate–added low-density polyethylene and ethylene vinyl acetate, whereby the tensile strength of 150 kGy and 250 kGy irradiated samples gradually increased with increasing of montmorillonite composition (i.e. 5 phr to 20 phr). Furthermore, the addition of montmorillonite into low-density polyethylene and ethylene vinyl acetate blends increased the limiting oxygen index and thermal decomposition temperatures of samples, thus improving the flame retardancy and thermal stability. The increasing of montmorillonite and irradiation dosage promoted the char formation during combustion. Besides, the increasing of montmorillonite loading levels gradually decreased the surface and volume resistivities of the polymer blends. The high irradiation dosages (i.e. 150 kGy and 250 kGy) were found to slightly decrease the electrical resistivity of the alumina trihydrate–added low-density polyethylene and ethylene vinyl acetate blends especially at high loading of montmorillonite. The irradiation effect improved the mobility of montmorillonite ions in polymer matrix, subsequently causing the reduction of the electrical resistivity of the polymer blends. The storage capacity of electrical charges of samples was slightly declined with the increasing of montmorillonite loading levels and irradiation dosages as shown by the dielectric constant results. The dielectric loss tangent of samples slightly increased at the increasing of montmorillonite loading level. However, the dielectric loss tangent was declined with increasing of irradiation dosages.