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Effect of chemical structure and preparation process on the aggregation structure and properties of polyimide film
Author(s) -
Wang Ying,
Yang Yang,
Jia Zhenxing,
Qin Jiaqiang,
Gu Yi
Publication year - 2012
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.38068
Subject(s) - polyimide , chemical structure , condensation , polymerization , materials science , polymer chemistry , condensation polymer , thermal , degree of polymerization , chemical engineering , condensation reaction , polymer , chemistry , composite material , organic chemistry , layer (electronics) , thermodynamics , physics , catalysis , engineering
In this article, polyimide (PI) films were fabricated via the three‐step method including the reactions of condensation polymerization, chemical imidization, and thermal imidization. In comparison with the conventional two‐step method to produce PI films, there was an additional step in the present method, i.e., chemical imidization. The aim of chemical imidization was to get PI intermediates with different pre‐imidization degree (pre‐ID). And PI component in PI intermediates acted as in‐situ rigid‐rod segments and induced orientation in the films of PI intermediates. Then the orientations of molecular chains were preserved in the following thermal imidization, and caused the difference in aggregation structure and property of the final PI films. The test results indicated that the orderly degree of molecular chains and mechanical properties of PI films increased with pre‐ID increasing. Furthermore, this tendency was much more obvious for more rigid backbone structure. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013