Polymer, Vol.43, No.8, 2261-2266, 2002
Space charge behaviors of low-density polyethylene blended with polypropylene copolymer
In this study, the space charge behaviors of the blend polymers of low-density polyethylene (LDPE) and polypropylene copolymer were investigated by the pulsed electro-acoustic method (PEA) with the electrode system of aluminium/specimen/semiconductive layer. The blend specimen composed by 90 wt% LDPE and 10 wt% polypropylene copolymer (B10) showed a larger amount of space charge than pure LDPE (PE) under a DC field of 50 MV m(-1) at both 30 and 60 degreesC. Positive carriers moved more slowly in B10 than in PE under a positive DC voltage applied to the semiconductive electrode at 30 degreesC. DC currents were also measured under the same experimental condition as the space charge measurement. The DC current of B10 was lower than that of PE at 30 degreesC, but higher at 60 degreesC. The experimental results were explained by the introduction of traps by blending.