Conformations of a long polymer in a melt of shorter chains: Generalizations of the Flory theorem

Large-scale simulations of the swelling of a long N-mer in a melt of chemically identical P-mers are used to investigate a discrepancy between theory and experiments. Classical theory predicts an increase of probe chain size R ∼ P-0.18 with decreasing degree of polymerization P of melt chains in the range of 1 \textless P \textless N1/2. However, both experiment and simulation data are more consistent with an apparently slower swelling R ∼ P-0.1 over a wider range of melt degrees of polymerization. This anomaly is explained by taking into account the recently discovered long-range bond correlations in polymer melts and corrections to excluded volume. We generalize the Flory theorem and demonstrate that it is in excellent agreement with experiments and simulations.

Duke Scholars

Author Michael Rubinstein Thomas Lord Department of Mechanical Engineering and Materia ...