Rheological properties of system “elastomer binder–discrete carbon fiber”

Rheological properties of low-concentrated carbon-fiber suspensions of binder on the basis of poly(methylphenylsiloxane) were investigated and it was shown that those liquid systems may display dilatant, Newtonian, or pseudoplastic properties. Experiments proved that dynamic flow field is separated by the critical shear stress into two regions: a system displays dilatant properties at low stresses and pseudoplastic properties at high stresses. It was shown that transition from one state to another is due to the fact that, in the shear stress field, the colloid-dispersed particles of the binder reversibly change spherical form to asymmetrical form, resulting in thixotropic properties of the system, which are strongly pronounced at 1–3 wt % of the fiber content.