A study of relationship between mechanical properties and water treeing retardation in EVA blended XLPE

The authors report the relationship between the water tree retardation phenomena and the mechanical properties in ethylene vinyl acetate (EVA) blended XLPE (cross-linked polyethylene). They also studied the electrical properties, such as the dissipation factor and the AC breakdown strength. It has been found that, by blending with EVA, growth of water trees in XLPE is retarded considerably and the toughness corresponding to the stress-crack resistance of materials increases with the VA content of blended samples. The results obtained indicate that the mechanical properties of the polymer have a strong influence on the water tree growth and that the material properties of XLPE can be improved substantially by EVA blending