Polymeric and colloidal modes of relaxation in latex dispersions containing associative triblock copolymers

The viscoelasticity of latex dispersions containing triblock associative po lymers exhibits multiple modes of relaxation. Here we confirm that the beha vior at high frequency is imparted by the associated solution and character ized by a high frequency modulus and relaxation time comparable to the neat micellar solution at the same concentration. At low frequencies, diffusion al modes of the particles generate a power law spectrum of relaxation times . Here the time scales and the volume fraction dependence of the contributi on reflect the slower dynamics of particles incorporated into a percolating network via weak attractions between the adsorbed polymer layers. The visc oelasticity of the dispersions is correlated by superimposing the two modes . (C) 1999 The Society of rheology. [S0148-6055(99)01106-2].