Melt rheological properties of polypropylene-maleated polypropylene blends: II. Dynamic viscoelastic properties

The dynamic viscoelastic properties of polypropylene (PP)–maleated PP blends in the molten state have been investigated with a dynamic mechanical thermal analyzer (PL‐DMTA MKII) at a frequency range (ω) of 0.6 ∗︁ 10⁻¹–3.14 ∗︁ 10² rad s⁻¹. In the study, the blends were prepared by melt‐blending in a twin‐screw extruder, using homopolypropylene and an ethylene–propylene copolymer as a matrix, respectively, and PP grafted with maleic anhydride (PP‐g‐MA) as a second component. It has been found that the data of the blends do not obey the Cox–Merz rule; the plots of log G′–log G" for the both blends show a composition dependence. It is due to the fact that the two kinds of PP are immiscible with PP‐g‐MA.