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5175987 
Journal Article 
Thermal stabilities and the thermal degradation kinetics of polyimides 
Li, LQ; Guan, CX; Zhang, AQ; Chen, DH; Qing, ZB 
2004 
1 
Polymer Degradation and Stability
ISSN: 0141-3910 
84 
3 
369-373 
English 
WOS:000222122600001 
The degradation kinetics of a series of polyimides containing maleic anhydride (MA), 4,4'-oxydianiline (ODA) and hexafluoroisopropylidene 2,2-bis (phthalic anhydride) (6FDA) were measured by thermogravimetric analysis (TGA) at different heating rates in flowing nitrogen. TGA experiments were performed to elucidate the thermal behaviour and supplied the data that characterise the degradation. The apparent activation energies E-a were calculated by iterative isoconversional procedure, the mechanism and pre-exoponential factor A were determined by Coats-Redfern and Achar methods. This methodology compared four kinds of (MA + 6FDA + ODA) polyimides' excellent thermal stability: PI > PMI-1 > PMI-2 > PMI-3, it showed that E-a for thermal degradation of polyimides reduced with decrease of 6FDA content and increase of MA content. The thermal decomposition kinetics of the four polymers obeyed the Avrami-Erofeev model function. (C) 2004 Elsevier Ltd. All rights reserved. 
Polymer Science; degradation kinetics, polyimide, 6FDA, TGA, thermal stability