Dielectric and mechanical properties of waste polyethylene-natural rubber blends

Waste polyethylene represents a large part of plastic environmental pollution, as such a polymer is not biodegradable. The aim of this study is to use such a polymer blended with natural rubber for electrical insulating purposes. This study is carried out to investigate the electrical as well as the mechanical properties of such a blend with different polyethylene ratios (10-50 phr). The permittivity ε\´ and the dielectric loss ε" for the investigated blends were carried out at a frequency range 1 kHz up to 50 kHz and at room temperature. By increasing the applied frequency, ε\´ shows anomalous dispersion which is followed by the appearance of more than one relaxation mechanism, especially the Maxwell Wagner effect which is detected at the lower frequency range (~500 Hz). Natural rubber possesses lower permittivity ε\´ and higher dielectric loss ε" when compared with those of waste polyethylene. The addition of such polyethylene to natural rubber is found to increase ε\´ and decrease ε" i.e. improves to some extent its insulating properties. The mechanical properties (tensile strength, elongation at break) were also investigated for such blends in which some improvement was also detected by increasing the polyethylene content up to 40 phr, after which a slight increase was detected. So from this study, it could be concluded that the addition of 40 phr waste polyethylene to natural rubber leads to an end product which possesses promising electrical and mechanical properties