Thermal Degradation of Polymers. IV. Poly-2,2′-(m-phenylene)-5,5′-bibenzimidazole
作者:
GarsonP. Shulman,
Wilson Lochte,
期刊:
Journal of Macromolecular Science: Part A - Chemistry
(Taylor Available online 1967)
卷期:
Volume 1,
issue 3
页码: 413-428
ISSN:0022-233X
年代: 1967
DOI:10.1080/10601326708053980
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
The thermal decomposition of poly-2,2′-(m-phenylene)-5,5′-bibenzimidazole has been investigated at temperatures to 916°C. Mass-spectrometric thermal analysis (MTA), supported by elemental analysis of residues at various stages of a thermogravimetric analysis, was used to determine product distribution as a function of temperature. Below 550°C, the major product is water. Above 550°C, degradation of the heterocyclic structure to hydrogen cyanide, ammonia, carbon monoxide, and water begins. Hydrogen and methane probably are formed from decomposition and condensation of the carbocyclic structure. Activation energies for the formation of each major product were derived from the MTA data. The average of these is somewhat temperature-dependent but agrees within experimental error with the value of 44 ± 11 kcal obtained from isothermal kinetics. A mechanism involving initial hydrolysis of the polymer to an amine-substituted polyamide is postulated. Subsequent homolytic reactions account for formation of the major products.
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