Abstract: Studies on the dynamic viscoelastic properties of high-density polyethylene(HDPE) were carried out at 200 ℃ in the atmosphere of air, nitrogen, and in the case of blending with antioxidant B215 respectively. The results revealed that there existed specific character in dynamic rheological behavior corresponding to the conditions above. Especially, in a low frequency range the dynamic storage modulus(G') increased while the dynamic loss tangent(tanδ) decreased obviously in air atmosphere. For the HDPE samples exposed to air, compared with N₂ and the condition of blending with B215, the second plateau appeared in G'~ω curves in a low frequency range and the value of peak appeared in tanδ~ω curves decreased simultaneously, together with shifting of the peak in a higher frequency range, were attributed to the change of structure in HDPE because of the oxidation-induced crosslinking of HDPE.

Key words: High density polyethylene, Oxidation-induced crosslinking, Dynamic rheological behavior, Low frequency range