Chapter 24. Modeling, Analysis and Kinetics of Transformations in Blackglas™ Preceramic Polymer Pyrolysis

  1. John B. Wachtman Jr
  1. J. Annamalai1,
  2. W. N. Gill1 and
  3. A. Tobin2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470314715.ch24

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4

How to Cite

Annamalai, J., Gill, W. N. and Tobin, A. (1995) Modeling, Analysis and Kinetics of Transformations in Blackglas™ Preceramic Polymer Pyrolysis, in Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314715.ch24

Author Information

  1. 1

    Rensselaer Polytechnic Institute, Troy, NY

  2. 2

    Grumman R & D Center, Bethpage, NY.

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1995

ISBN Information

Print ISBN: 9780470375372

Online ISBN: 9780470314715

SEARCH

Keywords:

  • polysiloxane;
  • volatile;
  • refractory;
  • thermogravimetric;
  • decomposition

Summary

Blackglas™ composites are attractive materials that offer fabrication advantages in terms of lower cost and near net shape parts. To determine the effects of pyrolysis processing variables on response parameters and microstructure, relationships among curing cycles, heating rates, etc. and the kinetics of the transformations that govern the transition of the preceramic polysiloxane polymer into silicon carboxide glass were analyzed. Results for various heating rate programs were analyzed to obtain kinetic parameters including the order of the dependence of the reaction rate on the polymer concentration and its activation energy. TGA, RGA and NMR techniques were used to formulate a reaction rate expression for use in a reaction engineering model of the pyrolysis process which agrees well with the observed rate of evolution of volatile gases. Curing is shown to have a significant effect on the reaction rate and weight loss.