Predicting the Rheology of Linear/Ring Polymer Blends from the Polymorphism of Ring Components

In this work, we propose a simple way to predict the diffusion and rheological properties of linear-ring polymer blends (LRB) by taking into account the polymorphic nature of the ring polymer components. In LRB, the ring components are separated by free rings and threaded rings, and their different dynamic behaviors are confirmed with the help of molecular dynamics simulation. A master curve of the LRB was established as a function of the linear chain concentration, the molar mass of linear and ring polymers, and the fraction of free ring polymers. Furthermore, the diffusion coefficient of threaded ring chains and the relaxation modulus of the blend are obtained based on the tube model framework. In our model, the relaxation of the blend is correlated with the polymorphism of the ring components, in which the threaded ring polymers relax through a constraint release hopping dynamics, while the unthreaded ring chains relax as a free ring. The threaded ring also reduces the constraint release effect for linear chains. Our theoretical prediction agrees with both simulation and experimental data with proper parametrization, which can be used to predict the dynamics of linear/ring blends for a wide range of compositions.