Simulated crystalline structures of aromatic polyimides

Tze Wing Poon, B. David Silverman, Ravi F. Saraf, Angelo R. Rossi, Paul S. Ho

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

Semicrystalline structures involving molecular packing and optimized chain conformations of three polyimides have been obtained with the charmm molecular-dynamics program, and their densities calculated. An eclipsed conformation of face-to-face stacking of polymer chains with a relative shift is observed, and the shift is found to depend upon the molecular characteristics of the planar unit and chain linearity. Three-dimensional structures obtained by calculating the optimized edge-on confirmation of the stacked units yield the smallest calculated density for PMDA-ODA, namely 1.515 g/cm3, followed by BPDA-PDA with 1.644 g/cm3 and PMDA-PDA with 1.712 g/cm3. Both PMDA-ODA and BPDA-PDA reveal planar zigzag structure, and the former shows the largest undulation measured by the maximum difference in surface elevation on the surface cleaved along the edge-on bonds. PMDA-PDA reveals flat planar structure.

Original languageEnglish (US)
Pages (from-to)11456-11462
Number of pages7
JournalPhysical Review B
Volume46
Issue number18
DOIs
StatePublished - 1992

ASJC Scopus subject areas

  • Condensed Matter Physics

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    Poon, T. W., Silverman, B. D., Saraf, R. F., Rossi, A. R., & Ho, P. S. (1992). Simulated crystalline structures of aromatic polyimides. Physical Review B, 46(18), 11456-11462. https://doi.org/10.1103/PhysRevB.46.11456