Abstract: The effect of relative molecular weight and its distribution of ethylene-α-olefin copolymers on the relationship between storage modulus (G') or loss modulus (G") and frequency (ω) and between storage modulus and loss modulus were studied by investigating the dynamic rheological behavior of the samples with various relative molecular weight and various polydispersity. The results indicated that the slopes of the G'~ω, G"~ω, G'~G" curves not only were smaller than those of the monodisperse polymers, but also decreased with relative molecular weight or its distribution increasing.

Key words: olefin copolymer, relative molecular weight, relative molecular weight distribution, dynamic rheological property