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Title: From precursors to non-oxide ceramics: Pyrolytic mechanisms studied by NMR

The pyrolysis of a poly ethylsilazane was studied using a CO{sub 2}-laser beam heated solid state MAS-NMR probe head. Chemical structures of the intermediate stages could be identified. The analogy of the pyrolysis evolution for the following two different methods could be shown: (A) in an inert gas furnace conventionally prepared and (B) laser irradiated in the NMR probe head under magic-angle spinning (MAS) conditions. Samples prepared by method A were studied by {sup 29}Si MAS-NMR and samples prepared by method B were studied with an appropriate cross polarization time by {sup 29}Si CP-MAS-NMR. Both experiments showed the same mechanisms for the pyrolysis as the polymer is transformed into a Si{sub 3}N{sub 4}/C ceramic.
Authors:
;  [1] ; ;  [2]
  1. Univ. of Stuttgart (Germany). Inst. for Nonmetallic Inorganic Materials
  2. Max-Planck-Inst. for Polymer Research, Mainz (Germany)
Publication Date:
OSTI Identifier:
470941
Report Number(s):
CONF-951155--
ISBN 1-55899-313-4; TRN: IM9722%%64
Resource Type:
Book
Resource Relation:
Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 27 Nov - 1 Dec 1995; Other Information: PBD: 1996; Related Information: Is Part Of Covalent ceramics III -- Science and technology of non-oxides; Hepp, A.F. [ed.] [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center]; Kumta, P.N. [ed.] [Carnegie Mellon Univ., Pittsburgh, PA (United States)]; Sullivan, J.J. [ed.] [MKS Instruments, Andover, MA (United States)]; Fischman, G.S. [ed.] [Food and Drug Administration, Rockville, MD (United States)]; Kaloyeros, A.E. [ed.] [Univ. of Albany, NY (United States)]; PB: 499 p.; Materials Research Society symposium proceedings, Volume 410
Publisher:
Materials Research Society, Pittsburgh, PA (United States)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SILICON NITRIDES; PYROLYSIS; MICROSTRUCTURE; COMPOSITE MATERIALS; GRAPHITE; ORGANOMETALLIC COMPOUNDS; AMORPHOUS STATE; LASER RADIATION; NUCLEAR MAGNETIC RESONANCE; EXPERIMENTAL DATA