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Effect of dispersion of particles on viscoelasticity of CaCo 3 ‐filled polypropylene melts

1990; Wiley; Volume: 30; Issue: 14 Linguagem: Inglês

10.1002/pen.760301407

1548-2634

Lin Li, Toshiro Masuda,

Polymer Nanocomposites and Properties

Abstract Viscoelastic properties of polypropylene melts filled with small (0.15 μm) and large (4.0 μm) CaCO 3 particles have been measured. The effects of particle size, loading, and rheological history on the dispersion of particles have been investigated. The dispersion of particles was found to decisively influence the viscoelastic properties of these filled polymers. The systems filled with large particles exhibit a relatively stable viscoelastic behavior. The small particle‐filled polymers with low loading are stable similarly to the large particle‐filled system. For the system filled with 30 wt% small particles, there appears a “second plateau” in the storage modulus G ′ curve in low frequency region and the height of the second plateau depends strongly on the rheological history. The results are interpreted in terms of the formation of an internal structure of particles. It was found that the internal structure of particles is broken up by a steady shear flow and the dispersion of particles is changed.