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Thermal behavior of PES/PEES copolymers with different sequence distribution: Comparative study of the kinetics of degradation
Author(s) -
Zhou XiaoMing
Publication year - 2008
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.28822
Subject(s) - copolymer , branching (polymer chemistry) , kinetics , thermogravimetric analysis , isothermal process , degradation (telecommunications) , materials science , activation energy , polymer chemistry , sequence (biology) , thermodynamics , chemistry , chain scission , chemical engineering , polymer , organic chemistry , composite material , physics , telecommunications , biochemistry , quantum mechanics , computer science , engineering
The degradation of three aromatic thermoplastics copolymers of polyethersulfone (PES) and polyetherethersulfone (PEES) with the same composition but different sequence distribution was performed in a thermogravimetric analyzer in both nitrogen and air environments, in isothermal and dynamic heating conditions. The obtained results suggest that the degradations started by random chain scission under all the experimental conditions. Under N 2 flow, branching and crosslinking were superimposed on the initial process, whereas complete oxidative degradation occurred in air. The apparent activation energies associated with the first degradation stage were evaluated and correlated with the sequence linkages present in the copolymer chains. The obtained values indicated that the chemical reactions occurring under nitrogen were different from those in air. In addition, a comparison of activation energies of PES/PEES copolymers with different sequence distribution was also reported. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009