  We investigate the universality of entanglement kinetics in polymer melts. We
compare predictions of a recently developed constitutive equation for
disentanglement to molecular dynamics simulations of both united-atom
polyethylene and Kremer-Grest models for polymers in shear and extensional
flow. We confirm that entanglements recover on the retraction timescale, rather
than the reptation timescale. We find that the convective constraint release
parameter $\beta$ is independent of molecular weight, but that it increases
with the ratio of Kuhn length $b_K$ to packing length $p$ as $\beta\sim
(b_K/p)^\alpha$, with an exponent $\alpha=1.9$, which may suggest that
disentanglement rate correlates with an increase in the tube diameter. These
results may help shed light on which polymers are more likely to undergo shear
banding.
