Thermal behavior and kinetics during the stabilization of polyacrylonitrile precursor in inert gas

The thermal behaviors of polyacrylonitrile precursor during thermal stabilization in inert gas were investigated by differential scanning calorimetry, thermomechanical analysis, and thermogravimetry. Combining these methods with the tracing of chemical changes by Fourier transform infrared spectrosc...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied polymer science 2011-10, Vol.122 (1), p.480-488
Main Authors: Xiao, Shijie, Lv, Honghong, Tong, Yuanjian, Xu, Lianghua, Chen, Biaohua
Format: Article
Language:English
Subjects:
Applied sciences
Coating
Conversion
Exact sciences and technology
Fibers and threads
Forms of application and semi-finished materials
Inert
kinetics
Materials science
Mathematical models
polyacrylonitrile
Polyacrylonitriles
Polymer industry, paints, wood
Polymers
Precursors
Reaction kinetics
Stabilization
Technology of polymers
thermal behavior
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The thermal behaviors of polyacrylonitrile precursor during thermal stabilization in inert gas were investigated by differential scanning calorimetry, thermomechanical analysis, and thermogravimetry. Combining these methods with the tracing of chemical changes by Fourier transform infrared spectroscopy indicated that complex reactions, including cyclization and pyrolytic reactions occurred sequentially. An imine‐enamine tautomeric structure was formed at around 240°C and was converted to a conjugated structure when the temperature was increased to 400°C. A thermal stabilization mechanism was proposed and confirmed experimentally by using a two‐step heating process. The apparent activation energies and the pre‐exponential factors for these stabilization reactions were also estimated by the Kissinger, Ozawa, and “Improved Coats‐Redfern” methods. To obtain a fit to the experiment data, a new kinetic model, named the “Three Regions Kinetic Model,” was proposed using the Improved Coats‐Redfern method. The applicability of this model and the prediction of the stabilization profile at a given heating rate were verified by plotting conversion rate against conversion profiles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
ISSN:0021-8995
1097-4628
1097-4628
DOI:10.1002/app.33656