When Polymer Chains Are Highly Aligned: A Perspective on Extensional Rheology

We provide a Perspective on recent findings in extensional rheology for polymer melts and solutions with different macromolecular architectures. For linear polymer systems, we focus on the argument of flow-induced friction reduction and provide our comments from an experimental point of view. For branched polymers, we provide our understanding on how to control extensional viscosity for polymers with different zero-shear-rate viscosity based on recent experimental results of star and comb polymer melts. For ring polymers, we summarize the recent progress in extensional rheology and provide our view on what would be interesting for further investigation. On the basis of the above results and discussions, we show that extensional rheology is complicated for even very simple molecular architectures. More data from both experiments and simulations are important for improvement of a fundamental understanding and development of theories, which is essential for molecular design of polymer materials.

Automated summary

This article provides a perspective on recent findings in extensional rheology for polymer melts and solutions with different macromolecular architectures. It focuses on the argument of flow-induced friction reduction for linear polymer systems, understanding how to control extensional viscosity for branched polymers, and summarizes recent progress in extensional rheology for ring polymers. The article emphasizes the importance of more data from both experiments and simulations for improving the fundamental understanding and development of theories in molecular design of polymer materials.