ISSN:
0887-624X
Keywords:
polyimides
;
cyano-substituted polymers
;
synthesis
;
crosslinking
;
thermal stability
;
2,3-dicyanopyrazine
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
New crosslinkable aromatic polyimides were synthesized from 2,3-dicyano-5,6-di(aminophenyl)pyrazine (1b) and 2,3-dicyanopyrazino [5,6-9,10] diaminophenanthrene (2b). They were characterized by viscosimetry, IR, NMR, x-ray, DTA, TMA, TGA, and isothermal gravimetric analysis. The polyimides derived from 1b were amorphous whereas those prepared from 2b showed microcrystalline or crystalline character. The polymers were soluble in polar aprotic solvents (DMF, NMP, DMSO) at ambient temperature or upon heating. They dissolved also completely or partially in certain hot inorganic and organic acids (H2SO4, CCl3COOH). Their glass transition temperatures were in the range of 257-370°C. The crosslinked polymers obtained after an appropriate thermal treatment, were stable up to 397-426°C in N2 or air and afforded anaerobic char yields of 62-75% at 800°C. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1303-1311, 1997
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
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