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arXiv · cond-mat/0610359

Are polymer melts "ideal"?

J. P. Wittmer·P. Beckrich·F. Crevel·C. C. Huang·A. Cavallo·T. Kreer·H. Meyer
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Abstract

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.

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J. P. Wittmer, P. Beckrich, F. Crevel, C. C. Huang, A. Cavallo, T. Kreer, H. Meyer. 2006-10-13. Are polymer melts "ideal"?. https://doi.org/10.1016/j.cpc.2007.02.032

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