## Abstract

Three descriptions of the rod orientation in the Flory lattice model for rods (generalized to a continuum) are compared in an athermal system with the more accurate DiMarzio model for rodlike particles in a continuum. The Flory-type rod orientation distribution functions yield distributions quite similar to the DiMarzio distribution. The Flory-type distribution function obtained from the rod orientation expression (y-1) = (x-1) sin θ can be used in the DiMarzio entropy equation at a calculational advantage to yield entropies which are virtually indistinguishable from the original. Flory-type nematic and isotropic entropies differ from the DiMarzio entropies, giving slightly different phase equilibria. A solution to the “entropy catastrophe” for rods is explained in terms of the improper use of a one-dimensional boundary condition in the third dimension.

Original language | English (US) |
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Pages (from-to) | 2243-2249 |

Number of pages | 7 |

Journal | Macromolecules |

Volume | 21 |

Issue number | 7 |

DOIs | |

State | Published - Jul 1988 |

## ASJC Scopus subject areas

- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry