# Clustering of entanglement points in highly strained polymer melts

## TL;DR

This study uses molecular dynamics simulations to analyze how entanglement points in highly strained polymer melts cluster and relax, revealing persistent inhomogeneities and the dynamics of topological constraints during deformation.

## Contribution

It introduces a detailed analysis of entanglement point clustering and relaxation in highly deformed polymer melts using primitive path analysis.

## Key findings

- Entanglement points cluster persistently after deformation.
- Primitive path conformations follow affine deformation.
- Relaxation involves long-lived inhomogeneous distribution of constraints.

## Abstract

Polymer melts undergoing large deformation by uniaxial elongation are studied by molecular dynamics simulations of bead-spring chains in melts. Applying a primitive path analysis to strongly deformed polymer melts, the role of topological constrains in highly entangled polymer melts is investigated and quantified. We show that the over-all, large scale conformations of the primitive paths (PPs) of stretched chains follow affine deformation while the number and the distribution of entanglement points along the PPs do not. Right after deformation, PPs of chains retract in both directions parallel and perpendicular to the elongation. Upon further relaxation we observe a long-lived clustering of entanglement points. Together with the delayed relaxation time this leads to a metastable inhomogeneous distribution of topological constraints in the melts.