Accession Number : ADA185654

Title :   Preceramic Polymer Pyrolysis. I. Pyrolytic Properties of Polysilazanes.

Descriptive Note : Technical rept.,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Blum, Yigal ; Schwartz, Kenneth ; Laine, Richard M

PDF Url : ADA185654

Report Date : 07 Oct 1987

Pagination or Media Count : 46

Abstract : The physicochemical behavior of characterized polysilazanes has been examined during their pyroltic transformation into amorphous, silicon based, ceramics. Selected polysilazanes, bearing different substituents at silicon and nitrogen were synthesized by ruthenium catalyzed dehydrocoupling of Si-H bonds with N-H bonds. The relationships between the structure and chemical content of polymers and their pyrolyzed ceramic compositions and yields are discussed. The thermal reactivity during the pyrolysis is established by a set of hypothetical mechanisms that may occur during the heating process. The decomposition product patterns at different temperature levels and the compositions of the final ceramics suggest specific kinetically or thermodynamically controlled thermolysis pathways. Additional chemical reactivity has been observed when the amorphous ceramic products at 800 C are heated and crystallized at 1600 C. Keywords: Silicone; Nitrogen; Hydrogen; Chemical reactions; Inorganic polymers; Ceramic precursors; Pyrolysis; Thermolysis mechanism.

Descriptors :   *CERAMIC MATERIALS, *PYROLYSIS, *POLYSILANES, AMORPHOUS MATERIALS, BEHAVIOR, CHEMICAL REACTIONS, DECOMPOSITION, HEAT, HYDROGEN, INORGANIC POLYMERS, NITROGEN, PATTERNS, PHYSICOCHEMICAL PROPERTIES, POLYMERS, PRECURSORS, REACTIVITIES, RUTHENIUM, SILICON, SYNTHESIS, TEMPERATURE, THERMAL PROPERTIES, ORGANOMETALLIC COMPOUNDS, MOLECULAR STRUCTURE, SILICON NITRIDES, MASS SPECTROSCOPY, KNUDSEN GAGES, SUBSTITUTION REACTIONS

Subject Categories : Ceramics, Refractories and Glass
      Polymer Chemistry
      Industrial Chemistry and Chemical Processing

Distribution Statement : APPROVED FOR PUBLIC RELEASE