Table of Contents
Journal of Thermodynamics
Volume 2011, Article ID 605712, 10 pages
http://dx.doi.org/10.1155/2011/605712
Research Article

Kinetics of Nonisothermal Degradation of Some Polymer Composites: Change of Entropy at the Formation of the Activated Complex from the Reagents

1Department of Material Science, Assen Zlatarov University, 8010 Burgas, Bulgaria
2Departments of Inorganic and Analytical Chemistry, Assen Zlatarov University, 8010 Burgas, Bulgaria
3Department of Physical Chemistry, Assen Zlatarov University, 8010 Burgas, Bulgaria

Received 21 November 2010; Revised 24 January 2011; Accepted 21 March 2011

Academic Editor: Krzysztof J. Ptasinski

Copyright © 2011 Sevdalina Turmanova et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Studying the nonisothermal kinetics of degradation of rice husks in air or nitrogen atmosphere, polypropylene and tetrafluoroethylene-ethylene copolymer filled with different quantities of rice husks flour or the products of its thermal degradation, namely “white” or “black” rice husks ash, a linear dependence was observed between the l n 𝐴 and 𝐸 𝐴 , known as the kinetic compensation effect or theta rule. A linear relationship was also established between 𝐸 𝐴 and the change of the entropy Ξ” 𝑆 β‰  for the formation of the activated complex from the reagents. These dependences are related to the assumption of identical kinetic mechanisms of thermal degradation of the composites studied. The negative values of Ξ” 𝑆 β‰  obtained show that the activated complex is a “more organized” structure than the initial reactants and that these reactions may be classified as “slow” ones. It may be concluded that the products of the thermal degradation of rice husks in a fluidized bed reactor can successfully replace the more expensive synthetic fillers to obtain different polymer composites. These polymer composites can lead to the futuristic “organic-inorganic hybrid materials” with specific properties.