Dynamic viscoelastic properties of crystalline polymer blends - Effect of the viscosity of domain phase

Abstract

We investigated the influence of viscoelasticity of the domain phase on that of the polymer blend. The polyethylene (PE, matrix phase)/polypropylene (PP, domain phase) blend was used and the viscoelastic change was measured on condition that PP alone crystallizes. The modulus of domain phase was lower than that of matrix phase at first, but was much higher when PP was completely crystalized. The average domain size was almost the same before and after the test. The storage modulus at low frequencies increased more rapidly than that at high frequencies, and then the former decreased and the latter increased continuously. These changes are almost understood by Palierne's emulsion model. Recovery from deformation of domain phase effectively makes long-time viscoelastic relaxation when the modulus of domain phase is close to or lower than that of matrix phase.