Influence of weak reversible cross-linkers on entangled polymer melt dynamics

TL;DR

This study models how weak reversible cross-linkers affect the dynamics of entangled polymer melts, revealing increased elastic modulus and delayed relaxation due to tethered linkers influencing chain motion.

Contribution

Introduces a slip-link model for entangled polymers with reversible cross-linkers, showing their impact on relaxation behavior and elastic properties.

Findings

Higher first plateau in elastic modulus

Delayed terminal relaxation

Reversible linkers influence chain dynamics

Abstract

In this paper we study a system of entangled chains that bear reversible cross-links in a melt state. The cross-links are tethered uniformly on the backbone of each chain. A slip-link type model for the system is presented and solved for the relaxation modulus. The effects of entanglements and reversible cross-linkers are modelled as discrete form of constraints that influence the motion of the primitive path. In contrast to a non-associating entangled system the model calculations demonstrate that the elastic modulus has a much higher first plateau and a delayed terminal relaxation. These effects are attributed to the evolution of the entangled chains as influenced by tethered reversible linkers. The model is solved for the case when linker survival time $\tau_s$ is greater than the entanglement time $\tau_e$ but less than the Rouse time $\tau_R$.