Insulating performance of LLDPE/natural rubber blends by studying partial discharge characteristics and tensile properties

A series of linear low-density polyethylene (LLDPE)/natural rubber (NR) blends of composition 80/10, 70/20, 60/30, 50/40 and 40/50 containing nano-sized fillers montmorillonite (MMT) and Titanium(IV) Oxide (TiO₂) were produced by a twin-screw extruder with maleic anhydride grafted linear low-density polyethylene (LLDPE-g-MAH) of 10 wt% as a compatibilizer. An electrical performance test through partial discharge (PD) characteristics using CIGRE Method II test was conducted to study the electrical performance of the samples. Applied voltage was set on 7kVrms for 1 hour. The discharge characteristics were observed using picoscope™ and LabView™ programming. Then tensile test carried out to investigate the mechanical performance of the composites. The combine results of PD characteristics and tensile properties described the insulating performance of the composites. The results revealed that total PD numbers decreasing as increasing of weight percentages of natural rubber in the composition of the composite without any filler. In addition, it is found that total PD numbers significantly decreases on sample with MMT filler compared to TiO₂ one.