BROWSE

Related Researcher

Author's Photo

Shin, Tae Joo
UNIST Synchrotron Radiation Research Laboratory
Research Interests
  • Synchrotron Radiation Application Researches

ITEM VIEW & DOWNLOAD

Time-resolved synchrotron X-ray diffraction and infrared spectroscopic studies of imidization and structural evolution in a microscaled film of PMDA-3,4 '-ODA poly(amic acid)

Cited 41 times inthomson ciCited 45 times inthomson ci
Title
Time-resolved synchrotron X-ray diffraction and infrared spectroscopic studies of imidization and structural evolution in a microscaled film of PMDA-3,4 '-ODA poly(amic acid)
Author
Shin, Tae JooLee, ByeongduYoun, Hwa ShikLee, Ki-BongRee, Moonhor
Issue Date
2001-12
Publisher
AMER CHEMICAL SOC
Citation
LANGMUIR, v.17, no.25, pp.7842 - 7850
Abstract
The imidization behavior and structural evolution in a microscaled film of poly(3,4'-oxydiphenylene pyromellitamic acid) precursor are studied by time-resolved synchrotron wide-angle X-ray diffraction and infrared spectroscopy to investigate the relationship between thermal imidization and structural evolution in the precursor. The precursor film displays only short-range order, but its polyimide film shows a crystalline structure based on an orthorhombic crystal lattice unit. When the precursor is heated at 2.0 degreesC/min, it undergoes imidization over the temperature range 124-310 degreesC through a two-step process: (i) decomplexation of the amide linkage from residual solvent molecules and other intra- and intermolecular amic acid groups and (ii) imide-ring closure. The maximum rate of imidization occurs at 148.4 degreesC. Anhydride rings are found to form transiently over the range 93-310 degreesC, which are attributed to the nature of the equilibrium between the precursor and its constituent anhydride- and amino-terminated species. The imidization reaction begins prior to the commencement of structural evolution. The structural evolution takes place over 132-380 degreesC as a three-step process: initiation, primary growth, and secondary growth. In particular, the initiation step requires at least 3.2% imidization. The structural evolution is further influenced by the short-range ordered structure formed in the precursor film in the process of film formation. However, the overall crystallinity in the fully imidized film is limited to only 21.4%
URI
https://scholarworks.unist.ac.kr/handle/201301/16643
URL
http://pubs.acs.org/doi/abs/10.1021/la0108656
DOI
10.1021/la0108656
ISSN
0743-7463
Appears in Collections:
UCRF_Journal Papers
Files in This Item:
There are no files associated with this item.

find_unist can give you direct access to the published full text of this article. (UNISTARs only)

Show full item record

qrcode

  • mendeley

    citeulike

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

MENU