ISSN:
0887-624X
Keywords:
polyimide
;
thermally stable polymer
;
nitrogen linked diamines
;
aromatic tetracarboxylic dianhydrides
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Two diamines, 2,5-bis (4-aminophenyl)-2,5-diazahexane and 1,4-bis (4-aminophenyl)-1,4-diazacyclohexane were chosen as components for polyimidizations because they have melting points that differ by nearly 200°C (66-67 and 229-230°C, respectively) and are relatives of p-nitro-N,N-dimethylaniline. The melting points of the model compounds (phthalic anhydride) do not differ by as much as those of the free amines [303-304 and 386°C (DSC), respectively]. Six polyimides were prepared by a two-step polycondensation of the diamines with pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, and 5,5'-[2,2,2-trifluoro-1-(trifluoromethyl) ethylidene] bis-1,3-isobenzofurandione. DSC thermograms failed to indicate any distinct transitions up to 450°C, however, the polyimide prepared from 2,5-bis (4-aminophenyl)-2,5-diazahexane and pyromellitic dianhydride shows a slight break in its DSC curve at 233°C.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pola.1992.080300616
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