BLENDING EFFECTS ON RHEOLOGICAL PROERTIES OF MULTICOMPONENT SYSTEMS

(PART I) BLENDING LAW FOR SYSTEM OF HARD PARTICLES IN SOFT POLYMERIC MEDIA

Abstract

Interaction effects through the interface on the viscoelastic properties of the systems of hard particles suspended in soft polymeric media are approximated to the change in the effective volume fraction of the particles and the change in the free volume of both components. Since the total deformation of the mixture is a sum of those of the components, the blending law could approximately be expressed in terms of the complex compliance, J^*(ω), in the form,
J^*_bl (ω) =φ₁J^*₁ (λ₁ω) +φ₂J^*₂ (λ₂ω),
where the subscripts, bl, 1 and 2 specify the mixture, the hard and the soft components, respectively. φ and λ are the factors dependent on the interaction effects through the interface and the volume fractions of the components and others. In most cases we may expect that φ₁J^* (λ₁ω) <<φ₂J^* (λ₂ω).
The effective volume fraction of the hard particle, ν_e, could be estimated from the equation,
(φ²/λ₂)= [1-(ν_e/0.74)] ^2.5
Applications of the blending law to the experimental data on the glass beadspolyisobutylene mixture by Landel gave reasonable results on the applicability of the blending law as well as the value of the effective volume fraction of the particles.