Are polymer melts "ideal"

It is commonly accepted that in concentrated solutions or melts high-molecular weight polymers display randomwalk 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 be in a computer experiment. Key words: Macromolecular...

• Type: Journal
• Year: 2007
• Where: CPHYSICS
• Authors: Joachim Paul Jakob Wittmer, Philippe Beckrich, F. Crevel, Chien-Cheng Huang, Anna Cavallo, T. Kreer, Hendrik Meyer
• Keywords: Chain, CPHYSICS 2007, Long-range Correlations, Polymer