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Thermal degradation of polymers. Part XIX. The thermal cyclization and characterization of quinazolone pre‐polymers
Author(s) -
Chan H. S. O.,
Still R. H.
Publication year - 1978
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.1978.070220811
Subject(s) - thermogravimetry , polymer , isothermal process , thermal stability , degradation (telecommunications) , decarboxylation , polymer chemistry , lability , materials science , infrared spectroscopy , chemistry , organic chemistry , thermodynamics , composite material , physics , catalysis , inorganic chemistry , telecommunications , computer science
A series of pre‐polymers prepared from 4,4′‐diaminodiphenyl‐3,3′dicarboxylic acid and aromatic diacetamido compounds have been thermally cyclized and their structures have been investigated using infrared spectroscopy, combustion analysis, and weight loss techniques. The structures obtained on cyclization are discussed in terms of concurrent cyclization and decarboxylation reactions resulting in incomplete cyclization. Specific structural features due to the lability of main chain bonds at the cyclization temperatures are also discussed. Dynamic thermogravimetry and isothermal weight loss studies have been used to evaluate thermal stability and kinetic parameters. The results are discussed in terms of the overall complexity of the polymer structure and the complexity of the degradation process. It is concluded that in such systems, where the structural variations are large, it is not possible to define a meaningful stability sequence because like systems are not under comparison.