Fig. 6: Impact of backbone molecular weight and volume fraction on the extensional viscosity.

a Extensional viscosity \({\eta }_{E}\) as a function of the number of entanglements \({s}_{b}\) of the backbone for three pom-poms with varying backbone molecular weight. Selected strain rates between 3 s⁻¹ and 0.0056 s⁻¹ are shown to illustrate differences in the extensional behaviour of the three pom-poms at a reference temperature of \({T}_{{ref}}\,\)= ¹40 °C. At \(\dot{\varepsilon }\) = 3 s⁻¹ the extensional viscosity is limited by the maximum fracture stress. b Extensional viscosity normalized to the dilution modulus \({\eta }_{E}/{G}_{N,s}^{0}\) shown as a function of the volume fraction of the backbone \({\phi }_{b}\). Error bars represent typical errors in the experimental measurement of the extensional viscosity.