It is commonly accepted that in concentrated solutions or melts high-molecular weight polymers display random-walk conformational properties without long-range correlations between subsequent bonds. This absence of memory means, for instance, that the bond-bond correlation function, P(s), of two bonds separated by s monomers along the chain should exponentially decay with s. Presenting numerical results and theoretical arguments for both monodisperse chains and self-assembled (essentially Flory size-distributed) equilibrium polymers we demonstrate that some long-range correlations remain due to self-interactions of the chains caused by the chain connectivity and the incompressibility of the melt. Suggesting a profound analogy with the well-known long-range velocity correlations in liquids we find, for instance, P(s) to decay algebraically as s−3/2. Our study suggests a precise method for obtaining the statistical segment length \bstar in a computer experiment.
@article{arxiv.cond-mat/0610359,
title = {Are polymer melts "ideal"?},
author = {J. P. Wittmer and P. Beckrich and F. Crevel and C. C. Huang and A. Cavallo and T. Kreer and H. Meyer},
journal= {arXiv preprint arXiv:cond-mat/0610359},
year = {2009}
}