Journal of thermal analysis

, Volume 47, Issue 4, pp 1081–1091 | Cite as

Kinetic compensation effect in the thermal degradation of polymers

  • M. C. Gupta
  • S. G Viswanath
Article

Abstract

The kinetic study of thermal degradation takes into account the validity of the Arrhenius equation. From TG data, the activation energy,E a and pre-exponential factor,A, are evaluated. These results are interpreted by using the ‘kinetic compensation effect’ as basis. A linear correlation between In(A) andE a is obtained in all cases studied. However, in a plot of the logarithm of the rate constant as a function of reciprocal temperature for the same series of reactions, the thermal oxidative degradations of Nylon-6 and PVC display a point of concurrence and one isokinetic temperature, whereas those of HIPS and PC do not. Therefore, in the thermal oxidative degradations of Nylon-6 and PVC a ‘true’ compensation effect occurs, which could be related to the bulk properties of metal oxides, such as different valence states, whereas for other polymers it displays only an ‘apparent’ compensation effect. This means that degradation is largely independent of the bulk properties of oxides, but may be related to the distribution of different kinds of active links in the polymer surface having different activation energies.

Keywords

kinetics thermal degradation 

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Copyright information

© Wiley Heyden Ltd., Chichester and Akadémiai Kiadó, Budapest 1996

Authors and Affiliations

  • M. C. Gupta
    • 1
  • S. G Viswanath
    • 2
  1. 1.Department of Chemistry and Regional Sophisticated Instrumentation CenterNagpur UniversityNagpur
  2. 2.Laxminarayan Institute of TechnologyNagpur UniversityNagpurIndia

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