### Abstract

The three-dimensional (3-D) ordered structure of semiflexible pyromellitic dianhydride oxydianiline (PMDA-ODA) is calculated using the CHARMM molecular modeling program. Polymorphism in the ordered chain conformation is calculated with chain periodicities n = 2, 3, and 4, where n is the number of monomers within the period. A planar zigzag chain cross-section is observed in the n = 2 and 4 structures while a triangular cross-section is observed in the n = 3 structure. The optimum ordered chains are packed to form a 3-D crystal by considering relative chain translations parallel and perpendicular to the chain axis by adjusting the number of basis chains, m in the unit cell. Although the n = 3 and 4 periodicities have not been reported, we calculate an approximate 3-D crystal structure factor. Corresponding structure factors along and perpendicular to the chain are calculated and compared with wide-angle X-ray scattering experiments, with good agreement. The lowest energy 3-D structure consists of an n = 2 conformation, with single chain periodicity along the interplanar packing direction and double chain periodicity along the edge-on stacking direction.

Original language | English (US) |
---|---|

Pages (from-to) | 3369-3374 |

Number of pages | 6 |

Journal | Macromolecules |

Volume | 26 |

Issue number | 13 |

DOIs | |

State | Published - Jan 1 1993 |

Externally published | Yes |

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### ASJC Scopus subject areas

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

### Cite this

*Macromolecules*,

*26*(13), 3369-3374. https://doi.org/10.1021/ma00065a021

**Structural Characterization of an Ordered Aromatic Polyimide : Pyromellitic Dianhydride-Oxydianiline.** / Poon, Tze W.; Saraf, Ravi F; Silverman, B. David.

Research output: Contribution to journal › Article

*Macromolecules*, vol. 26, no. 13, pp. 3369-3374. https://doi.org/10.1021/ma00065a021

}

TY - JOUR

T1 - Structural Characterization of an Ordered Aromatic Polyimide

T2 - Pyromellitic Dianhydride-Oxydianiline

AU - Poon, Tze W.

AU - Saraf, Ravi F

AU - Silverman, B. David

PY - 1993/1/1

Y1 - 1993/1/1

N2 - The three-dimensional (3-D) ordered structure of semiflexible pyromellitic dianhydride oxydianiline (PMDA-ODA) is calculated using the CHARMM molecular modeling program. Polymorphism in the ordered chain conformation is calculated with chain periodicities n = 2, 3, and 4, where n is the number of monomers within the period. A planar zigzag chain cross-section is observed in the n = 2 and 4 structures while a triangular cross-section is observed in the n = 3 structure. The optimum ordered chains are packed to form a 3-D crystal by considering relative chain translations parallel and perpendicular to the chain axis by adjusting the number of basis chains, m in the unit cell. Although the n = 3 and 4 periodicities have not been reported, we calculate an approximate 3-D crystal structure factor. Corresponding structure factors along and perpendicular to the chain are calculated and compared with wide-angle X-ray scattering experiments, with good agreement. The lowest energy 3-D structure consists of an n = 2 conformation, with single chain periodicity along the interplanar packing direction and double chain periodicity along the edge-on stacking direction.

AB - The three-dimensional (3-D) ordered structure of semiflexible pyromellitic dianhydride oxydianiline (PMDA-ODA) is calculated using the CHARMM molecular modeling program. Polymorphism in the ordered chain conformation is calculated with chain periodicities n = 2, 3, and 4, where n is the number of monomers within the period. A planar zigzag chain cross-section is observed in the n = 2 and 4 structures while a triangular cross-section is observed in the n = 3 structure. The optimum ordered chains are packed to form a 3-D crystal by considering relative chain translations parallel and perpendicular to the chain axis by adjusting the number of basis chains, m in the unit cell. Although the n = 3 and 4 periodicities have not been reported, we calculate an approximate 3-D crystal structure factor. Corresponding structure factors along and perpendicular to the chain are calculated and compared with wide-angle X-ray scattering experiments, with good agreement. The lowest energy 3-D structure consists of an n = 2 conformation, with single chain periodicity along the interplanar packing direction and double chain periodicity along the edge-on stacking direction.

UR - http://www.scopus.com/inward/record.url?scp=0027607616&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027607616&partnerID=8YFLogxK

U2 - 10.1021/ma00065a021

DO - 10.1021/ma00065a021

M3 - Article

VL - 26

SP - 3369

EP - 3374

JO - Macromolecules

JF - Macromolecules

SN - 0024-9297

IS - 13

ER -