Dynamics of near-critical polymer gels

We report the viscosity and the modulus of near-critical polyester gels. Previous work has shown that these gels lie in the middle of the static crossover between mean-field and critical percolation. Above the gel point, the modulus data are well described by the scaling law attributing kT of stored elastic energy per unentangled network strand. Below the gel point, the viscosity data disagree with both the de Gennes conductivity analogy and the Rouse model, possibly due to a subtle effect of chain entanglement.