Structural and Rheological Properties of PP/EPR/PE Alloys

• Key Words:
• Abstract:Linear and non-linear rheological properties were examined for in-reactor alloy samples composed of isotactic polypropylene(i PP),ethylene-propylene rubber(EPR), and polyethylene(PE). The samples were prepared through two-or three-stage sequential polymerization,where i PP, as the majority, was synthesized in the first stage, and either EPR or PE, as the minority, was synthesized in the second or third stage.Above Tm of both PE and i PP, the linear viscoelasticity shows two relaxation processes, where the fast and slow processes are attributable to the relaxation of the i PP component and that of the EPR/PE domains, respectively. Both the damping behavior upon applying the step-strain measurements and the shear-thinning behavior under the shear-rate sweep measurements are strongly related to the different degrees of nonlinearity of the two relaxation processes.
• Volume:v.41
• Issue:02
• Translation or Not:no