Rheology of Long-Chain Branched Polypropylene Copolymers

In this work, we provide more insight into the rheological properties of functionalized polypropylene copolymers with modified architectures, which originate long-chain branching. The evaluation of the average distance between branches and the fraction of long-chain branch points has been carried out quantitatively, by numerical fitting of experimental data according to a literature model, and the viscoelastic response of the samples has been analyzed in terms of a Carreau-Yasuda-like model and Cole-Cole plots. These analyses allowed us to discriminate the viscoelastic behavior of the samples on the basis of their feed composition. Moreover, we were able to highlight direct correlations between viscosity, long-chain branching level, distance between branching points and functionalization degrees of PP polymers