Abtahi - Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran,
Zeynali - Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran,
Ehsani - Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran,
Harati - Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran,

The present paper reports about the result of testing the mechanical, thermal, morphological, dynamical mechanical and electrical properties of polymeric insulators. Low density polyethylene (LDPE), ethylene-propylene-diene monomer (EPDM) and blends of LDPE/EPDM are known polymers for use as low, medium and high voltage insulators. Studies illustrate that in LDPE/EPDM blends, tensile strength of the blends are higher than either polymer component alone. But the synergism effect in LDPE/EPDM compound is more than HDPE/EPDM. Also the blends of LDPE/EPDM show good break down voltage strength and heat resistance comparing to LDPE. The result of mechanical measurement shows that mechanical properties such as tensile strength, modulus and elongation at break of blends enhanced with increase in LDPE in formulation. Also testes were conducted to measure various properties (mechanical, surface, electrical) under accelerated ageing condition. Because the life time of these compounds are generally too long to wait for a verdict on their behavior in use. The ageing results show that mechanical properties follow same trend as before ageing.

LDPE, EPDM, blend, electrical properties, electrical insulator