The voltage and thermal aging on the electrical properties of LLDPE have been investigated. FTIR and DSC analysis have also been performed in order to evaluate the associated structural and morphological changes due to the voltage-thermal aging in LLDPE. It is observed that the electrical aging accelerated by thermal stress induces the morphological changes in the amorphous region and alters the properties of the crystalline-amorphous interface. The morphological changes may be responsible for the probable increase of hopping through the amorphous region in multistressed LLDPE. The conduction mechanism of aged LLDPE with a relatively long-period (1100 hours) may involve the injection limited effect probably due to the hetero charge formation near the electrode. The increase of the dielectric loss and decrease of the AC breakdown strength may be also due to the morphological changes.
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