Dynamic viscoelastic behavior of graphite filled high density polyethylene composites and modification of Mooney equation

A study of viscoelastic properties of graphite ( GP) filled high density polyethylene composites was carried out. The Mooney equation was modified to evaluate the formation and development of agglomerate structure for high filled suspension system. The apparent filler concentration ( phi) was substituted by the effective volume fraction, phi(eff) . It is believed that in the case of high filler concentrations the viscoelastic properties of the composites are mainly related with phi(eff), Here, we define phi(eff) = f phi, in which f (f >= 1) is the experiential factor of effective volume, corresponding to the microstructure with different relaxation time in HDPE/GP system. In the low phi region, the viscoelastic properties of the composites can be described by the original Mooney equation, while the viscoelastic properties of the high loading composites can be described by the modified Mooney equation considering the effective filler volume in the case of w = 0.1 rad/s, experientially postulate f = 1.55.