Effect of additives on treeing initiation

Experimental results are presented concerning the effects of various additives (DCP, Santanox, benzophenon) on treeing initiation in low-density and cross-linked polyethylene (LDPE and XLPE) for different oxygen concentrations. The additives are shown to suppress the initiation of the deteriorated region and tree channel in LDPE. The crosslinking process combined with a degassing and heating process removes additives from the PE bulk. The effect of additives on the treeing resistance depends on O₂ concentration in the sample; the effect is most significant in the O₂ concentration range from 1 ppm to 10%, suggesting that the additive works as a radical stabilizer in PE. At the low temperature of 77 K, the additive still suppresses the deterioration region initiation