Research Article

Synthesis, characterization and liquid crystal-aligning properties of new poly{3-[4-(n-alkyloxy)phenyloxy]pyromellitimide}s

  1. Jin Kook Lee1,
  2. Seong Jun Lee1,
  3. Jin Chul Jung1,*,
  4. Wang-Cheol Zin1,
  5. Taihyun Chang2,
  6. Moonhor Ree2

Article first published online: 23 JUN 2006

DOI: 10.1002/pat.732

Issue

Polymers for Advanced Technologies

Polymers for Advanced Technologies

Volume 17, Issue 6, pages 444–452, June 2006

Additional Information

How to Cite

Lee, J. K., Lee, S. J., Jung, J. C., Zin, W.-C., Chang, T. and Ree, M. (2006), Synthesis, characterization and liquid crystal-aligning properties of new poly{3-[4-(n-alkyloxy)phenyloxy]pyromellitimide}s. Polymers for Advanced Technologies, 17: 444–452. doi: 10.1002/pat.732

Author Information

  1. 1

    Polymer Research Institute/Center for Advanced Functional Polymers, Department of Materials Science & Engineering, Pohang University of Science & Technology (POSTECH), San 31, Hyoja-dong, Pohang, Gyeongbug 790-784, Korea

  2. 2

    BK21 Functional Polymer Thin Film Group, Department of Chemistry, Pohang University of Science & Technology (POSTECH), San 31, Hyoja-dong, Pohang, Gyeongbug 790-784, Korea

*Polymer Research Institute/Center for Advanced Functional Polymers, Department of Materials Science and Engineering, Pohang University of Science & Technology (POSTECH), San 31, Hyoja-dong, Pohang, Gyeongbug 790-784, Korea.

Publication History

  1. Issue published online: 27 JUL 2006
  2. Article first published online: 23 JUN 2006
  3. Manuscript Accepted: 10 APR 2006
  4. Manuscript Received: 30 MAR 2006

Funded by

  • Korea Research Foundation. Grant Number: KRF 2004-005-D00009

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Keywords:

  • polypyromellitimides;
  • polyimides;
  • synthesis;
  • LC alignment layers;
  • films

Abstract

Four new polypyromellitimides (MCm-PPIs and MCm-OPIs, m = 6, 8) that are singly substituted with a flexible n-alkyloxy side branch at the pyromellitimide ring were prepared by the two-step polycondensation of 3-[4-(n-alkyloxy)phenyloxy]pyromellitic dianhydrides (MCm-PMDAs, m = 6, 8) with p-phenylenediamine (PDA) and 4,4′-oxydianiline (ODA), respectively. The dianhydride monomers were synthesized from durene via several reaction steps. Inherent viscosities of the precursor poly(amic acid)s ranged from 0.57 to 1.58 dl/g. After chemical structures of the polyimides had been characterized, their thermal properties, crystalline structures, and liquid crystal (LC) aligning abilities on their rubbed thin films were determined and discussed in comparison to the polypyromellitimides that are doubly substituted at the pyromellitimide ring with the same side branches. For all polymers thermogravimetric analysis (TGA) programs showed a typical two-step degradation behavior with onset temperatures in the 430–455°C range. In X-ray scattering studies all the samples were found to be amorphous, but the presence of a loosely developed layer structure could be confirmed, in which two main chains gather together to form a double-strand backbone layer and n-alkyl branches fill the space between the layers. On the rubbed surfaces of the polyimide thin films LCs uniformly aligned parallel to the rubbing direction with the pre-tilt angles 5–7° in MCm-OPIs and 18–32° in MCm-PPIs. Copyright © 2006 John Wiley & Sons, Ltd.

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