Comment on "What is the entanglement length in a polymer melt?” by M. Pütz, K. Kremer and G. S. Grest
Institut für Festkörperforschung, Forschungszentrum
Jülich - D-52425 Jülich, Germany
Accepted: 17 October 2000
In a recent letter Pütz, Kremer and Grest claim that finite-chain-length effects have significant influence on the single-chain dynamic structure factor S(Q,t)/S(Q) measured by neutron-spin-echo (NSE) technique with regard to results obtained for a polyethylene (PE) melt with a molecular weight of g/mol. As a consequence of these finite-length effects, they assert the tube diameter, determined by this NSE measurement in the framework of the reptation model, to be too high by a factor of ≈ 1.5. We demonstrate that this is by no means the case.
PACS: 61.25.Hq – Macromolecular and polymer solutions; polymer melts; swelling / 83.20.Fk – Reptation theories
© EDP Sciences, 2000