Viscosity calculation of polydisperse branching polymers near gel point

The viscosity of randomly branched polymers has been calculated based on an interpolation formula by Marrinan and Hermans, which contains dependent on certain constants both the so called excluded-volume-effect and the free-draining limit. Closer inspection of the constants used shows that the first choice is better direct near the gel point and yields a logarithmic divergence of the viscosity or a finite limit depending on the gelation theory used. The theoretical calculated values for the intrinsic viscosity amount about 10 cm3/g to 20 cm3/g for typical distances from the gel point in accordance with some experimental data of Eschwey, Burchard and Whitney.